Research Article |
Corresponding author: Junn Kitt Foon ( jkfoon.research@gmail.com ) Academic editor: Eike Neubert
© 2017 Junn Kitt Foon, Thor-Seng Liew.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Foon JK, Liew T-S (2017) A review of the land snail genus Alycaeus (Gastropoda, Alycaeidae) in Peninsular Malaysia. ZooKeys 692: 1-81. https://doi.org/10.3897/zookeys.692.14706
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A total of 11 species and 1 subspecies of Alycaeus were recognised in Peninsular Malaysia prior to this study. However, these taxonomic descriptions of Alycaeus taxa were based on limited numbers of examined materials, where a whole spectrum of morphological variations were not accounted for and diagnoses were often provided without sufficient comparison between congeners from across the peninsula. We reviewed Peninsular Malaysian Alycaeus through the examination of 5137 specimens in 522 collection lots from all major museum collections and literature sources. Based on these examined materials, we utilised a more comprehensive revised set of 39 shell and operculum characters, as well as living animal colour to describe all Alycaeus species in this paper. We also noted their habitat and ecology, as well as updated the distribution of each species. Of the 12 previously described taxa, 10 are reconfirmed as present on Peninsular Malaysia (Alycaeus balingensis, Alycaeus carinata, Alycaeus conformis, Alycaeus gibbosulus, Alycaeus kapayanensis, Alycaeus kelantanensis, Alycaeus liratulus, Alycaeus perakensis perakensis, Alycaeus perakensis altispirus and Alycaeus thieroti) and 2 are confirmed as absent from the peninsula (Alycaeus jagori and Alycaeus pyramidalis). A new record of Alycaeus robeleni is reported for Peninsular Malaysia. One species, Chamalycaeus jousseaumei is confirmed as present on the peninsula and is reassigned to Alycaeus. The subspecies Alycaeus perakensis altispirus Möllendorff, 1902, is elevated to species. Examined Peninsular Malaysian materials that do not fit previously recognised species are described as new species. A total of 11 new species are proposed (Alycaeus selangoriensis sp. n., Alycaeus costacrassa sp. n., Alycaeus ikanensis sp. n., Alycaeus alticola sp. n., Alycaeus charasensis sp. n., Alycaeus kurauensis sp. n., Alycaeus regalis sp. n., Alycaeus virgogravida sp. n., Alycaeus senyumensis sp. n., Alycaeus expansus sp. n., Alycaeus clementsi sp. n.). Overall, 23 species of Alycaeus are now recognised in Peninsular Malaysia.
land snail, shell morphology, operculum, Alycaeinae, limestone karsts, Southeast Asia
The family Alycaeidae Blanford, 1864, is a distinct group of operculated land snails defined by their globular, conical or discoid shell, whorl constriction prior to the aperture and a conspicuous tube at the suture (‘breathing tube’) which runs from the constriction to whorls prior to the constriction (
In Peninsular Malaysia, 11 species and 1 subspecies of Alycaeus were recognised prior to this study (
Most past studies of Alycaeus in Peninsular Malaysia are either single species descriptions or checklists. There are only two studies that focused on the anatomy and radula of Alycaeus (
In view of this, we reviewed all Alycaeus species in Peninsular Malaysia using a revised set of 39 shell and operculum characters, as well as living animal colour. We consulted major museum collections in Europe, the United States of America, Singapore and Malaysia that house Alycaeus materials from Peninsular Malaysia, including types. A large collection of recently sampled Alycaeus from across Peninsular Malaysia housed in the BORNEENSIS collection, Universiti Malaysia Sabah, were also studied.
Based on this review, we reconfirmed the presence of 10 previously recognised species on the peninsula (A. balingensis, A. carinata, A. conformis, A. gibbosulus, A. kapayanensis, A. kelantanensis, A. liratulus, A. perakensis perakensis, A. perakensis altispirus and A. thieroti) while 2 species are confirmed as absent on the peninsula (A. jagori and A. pyramidalis). For Alycaeus jagori, records of the species in Perak, Peninsular Malaysia were reported without further elaboration by some workers (
Finally, we proposed and described 11 new species based on examined Alycaeus materials from Peninsular Malaysia that do not fit into previously recognised species: Alycaeus selangoriensis sp. n., Alycaeus costacrassa sp. n., Alycaeus ikanensis sp. n., Alycaeus alticola sp. n., Alycaeus charasensis sp. n., Alycaeus kurauensis sp. n., Alycaeus regalis sp. n., Alycaeus virgogravida sp. n., Alycaeus senyumensis sp. n., Alycaeus expansus sp. n., Alycaeus clementsi sp. n. Overall, 23 species of Alycaeus are now recognised in Peninsular Malaysia.
This study focuses solely on Peninsular Malaysia, with emphasis on limestone karsts where the majority of study materials were obtained. Peninsular Malaysia is situated at the lower end of the Malay Peninsula, which is also politically divided into Thailand and Myanmar in the north. Peninsular Malaysia is at the centre of the Tropical East Asian region and hence shares similar fauna with South and East Asia (
For literature review, the term “Alycaeus” was used to obtain publications from the Zoological Record, Google Scholar and Biodiversity Heritage Library (on 15 March 2016 and 30 May 2017). All publications mentioning Alycaeus species from Peninsular Malaysia were studied and reviewed.
The management of data for examined materials follows
The locality for each collection lot was identified and linked to its current name whenever possible. For limestone karst localities, we followed the standard format of code and name (e.g. PRK 18 Gunung Lanno) used in the limestone hill register by
In addition to the previously collected museum materials, a systematic sampling of Alycaeus at 80 localities across Peninsular Malaysia was conducted in 2016 (for full list of localities, see Suppl. material
BOR/MOL BORNEENSIS Malacology Collection, Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia.
HW Private collection of Jens and Christa Hemmen, Wiesbaden, Germany.
To date, most of the Alycaeus species in Peninsular Malaysia have been described and diagnosed using inconsistent, subjective, and descriptive conchological and opercular characters with little or no comparison with other congeners. No more than 7 characters were used in previous studies including (1) breathing tube shape and size, (2) aperture and peristome shape, (3) constriction shape, (4) whorl shape, (5) radial and spiral sculpture, (6) operculum characters and (7) shell shape (
Framework for species description based on 39 shell and operculum features, as well as living animal colour. Number codes are ascribed to each character and linked to illustrations in Figure
Morphological section | Character | Descriptions and measurements |
---|---|---|
1. Protoconch | 1.1 Sculpture seen at 5.0 × magnification | Smooth or grooved. |
2. Shell shape and size | 2.1 Shell shape | Conical (pyramidal), flat or globose. |
2.2 Shell height | Measured from apex to base of ultimate whorl parallel to coiling axis (in millimetres to the nearest 0.01 mm). | |
2.3 Shell width | Measured at outermost edges of shell including aperture, perpendicular to coiling axis (in millimetres to the nearest 0.01 mm). | |
3. Spire | 3.1 Spire height | Measured from apex to base of penultimate whorl at suture (in millimetres to the nearest 0.01 mm) (after |
3.2 Spire width | Measured at outermost edges of penultimate whorl perpendicular to coiling axis (in millimetres to the nearest 0.01 mm) (after |
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3.3 Number of whorls | Maximum number of whorls posterior of protoconch (after |
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3.4 Spire shape | Oblong conical (width > height) (after |
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3.5 Whorl periphery | Strongly keeled or rounded. | |
3.6 Umbilicus | Open or partially closed (i.e. partially blocked by penultimate whorl and/or peristome extension at columella). | |
4. Whorl constriction | 4.1 Position in whorl | Approximate position based on number of whorls posterior of protoconch. Non-integers are represented as fractions of 8 (⅛ to ⅞) for easier understanding (modified from |
5. Breathing tube | 5.1 Length | Length from posterior end to anterior end (in millimetres to the nearest 0.01 mm). |
6. Aperture and peristome | 6.1 Aperture shape | Circular. |
6.2 Aperture margin | Margins moderately expanded or very expanded. | |
6.3 Aperture height | Measured at outermost edges of aperture from the palatal to the basal side (in millimetres to the nearest 0.01 mm). Measurement made with aperture tilted parallel to the observer (after |
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6.4 Aperture width | Measured at outermost edges of aperture from columella to palatal side (in millimetres to the nearest 0.01 mm). Measurement made perpendicular to coiling axis. | |
6.5 Peristome types | Single, double or triple. | |
6.6 Peristome thickness | Thickened or not thickened. | |
6.7 Peristome shape | Notched or winged at suture. Upper palatal section sometimes folded posteriorly. | |
6.8 Peristome spacing | No interspace (inner peristome impressed flatly on outer peristome), narrow interspace (inner peristome slightly protruded posteriorly beyond outer peristome), wide interspace (inner peristome protruded posteriorly far from outer peristome, creating a new section of whorl) (after |
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6. Aperture and peristome | 6.9 Peristome orientation | Degrees of obliquity with respect to the coiling axis of the spire. |
7. Spiral lines | 7.1 Spiral line seen at 10.0 × magnification | Distinct (protruded from shell surface), indistinct (less protruded from shell surface) or absent. |
7.2 When present, spiral lines’ spacing | Spacing between lines regular or irregular. Number of spiral lines per 1 millimetre. | |
8. Radial ribs running anterior of breathing tube | 8.1 Radial ribs seen at 4.0 × magnification | Pronounced (i.e. protruded from shell surface), indistinct (i.e. less protruded from shell surface), or absent (i.e. replaced with radial growth lines). |
8.2 When present, radial ribs’ spacing | Evenly or unevenly spaced. Number of radial ribs per 1 milimetre. | |
9. Radial ribs running perpendicular to breathing tube | 9.1 Radial ribs seen at 4.0 × magnification | Pronounced (i.e. protruded from shell surface), indistinct (i.e. less protruded from shell surface), or absent (i.e. replaced with radial growth lines). Thick or not thick. |
9.2 When present, radial ribs’ spacing | Evenly or unevenly spaced. Number of radial ribs per 1 milimetre. | |
10. Radial ribs running posterior of breathing tube | 10.1 Radial ribs seen at 4.0 × magnification | Pronounced (i.e. protruded from shell surface), indistinct (i.e. less protruded from shell surface), or absent (i.e. replaced with radial growth lines). Thick or not thick. |
10.2 When present, radial ribs’ spacing | Evenly or unevenly spaced. Number of radial ribs per 1 milimetre. | |
11. Operculum | 11.1 Concavity | Concave (exterior cave-in) or flat. |
11.2 Shape | Rounded or conical. | |
11.3 Exterior composition | Proteinaceous or calcareous layered. | |
11.4 Exterior sculpture | Smooth, finely granulated, flaky, short calcareous spikes, cup-like projection at nucleus, scaffold-like calcareous deposits or appressed radially spiral lamellae. | |
11.5 Interior composition | Proteinaceous or calcareous layered. | |
11.6 Interior sculpture | Smooth, multilamellar impression, mamillate. | |
12. Shell colour | 12.1 Shell colour | White, pinkish-white, pink, yellow, orange, red, brownish-red. brown, purple. |
13. Living animal | 13.1 Body colour | Cream-white, yellow, cream-yellow, light brown, brown, maroon, greenish-black, light grey, grey. |
13.2 Head colour | Orange, pink, pinkish-brown, brown, maroon, greenish-black, grey, dark grey. | |
13.3 Tentacles colour | Uni-coloured (yellow, red, brown, reddish-brown, light grey, dark grey, black), or bi-coloured (green with brown tips, cream-white with pink tips, yellow with red tips). |
To assist with visualising the descriptions, we provided photographs of five standard shell views (apertural, lateral, apical, umbilical and dorsal/oblique dorsal), three close-up shell views (breathing tube, apical whorls, radial rib and spiral line sculpture) and four standard operculum views (exterior, interior, side and oblique exterior) for each species. More than one specimen is illustrated for each species to represent the intraspecific variability if required. A synoptic plate of shells at apertural view representing the 23 Alycaeus taxa in Peninsular Malaysia (Figure
We measured up to 28 shells representing the whole spectrum of variation in shell height, shell width, spire height, spire width, aperture height and aperture width for each species to gauge intraspecific variation of shell dimensions against interspecific variation (Table
Overall, we employed the morphological species concept in this study as our comprehensive 39 characters assessment on a large sample size enables us to understand intraspecific variation of shell dimensions against interspecific variation. In addition to this, we also follow previous studies in recognising the major role of limestone hill isolation and biogeography in vicariance and speciation of karst restricted taxa especially land snails in Peninsular Malaysia (
The description of shell and operculum characters partially follows the terminology established by
Distribution of 8 Alycaeus species in Peninsular Malaysia based on materials examined. Alycaeus altispirus is not included in the maps because no specific locality was given for the materials examined (see Discussion section under the species). Note the red areas are limestone karsts (derived from
Alycaeus Baird, 1850: 27–28.
Protoconch. Smooth. In some species, second whorl grooved.
Shell shape and size. Conical (pyramidal), flat or globose. Shell height: 3.03–10.91 mm. Shell width: 3.36–15.04 mm.
Spire. Spire height: 0.93–3.21 mm. Spire width: 1.40–4.00 mm. Number of whorls: up to 3–5 ½. Spire shape always oblong conical. Whorl periphery strongly keeled or rounded. Always umbilicated. Umbilicus open or partially closed.
Whorl constriction. Position of constriction about 2 ¼–5 ¼ whorls posterior of protoconch.
Breathing tube. Always present, varies in length: 0.29–6.52 mm.
Aperture and peristome. Aperture always circular. Apertural margin moderately expanded or very expanded. Aperture height: 1.59–7.30 mm. Aperture width: 1.60–6.59 mm. Peristome single, double or triple. Peristome thickened or not thickened. Peristome notched or winged at suture. Interspace between peristome none, narrow or wide. Peristome orientation varies 4°–55° oblique to the coiling axis.
Spiral lines. Absent or present. When present, distinction varies (distinct or indistinct), spacing always regular to irregular. Number of spiral lines: 11–60 lines per 1 mm.
Radial ribs running anterior of breathing tube. Pronounced, indistinct or absent. Even or unevenly spaced. 6–21 radial ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Pronounced, indistinct or absent. Radial ribs sometimes are thicker and whiter compared to radial ribs anterior of breathing tube. Even or unevenly spaced. 6–29 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Pronounced, indistinct or absent. Usually unevenly spaced. 2–25 ribs per 1 mm.
Operculum. Concave or flat. Rounded or conical. Exterior usually calcareous layered of variable thickness. Exterior texture varies (smooth, finely granulated, flaky, short calcareous spikes, cup-like projection at nucleus, scaffold-like calcareous deposits or appressed radially spiral lamellae). Interior usually proteinaceous layered. Interior sculpture smooth, with multilamellar impression or mamillated.
Shell colour. Varies between and within species (white, pinkish-white, pink, yellow, orange, red, brownish-red. brown, purple). Apical whorls either in white or non-white colours, always fading to white in subsequent whorls.
Living animal. Body colour variable but lighter than head and tentacle (cream-white, yellow, cream-yellow, light brown, brown, maroon, greenish-black, light grey, grey). Head colour variable (orange, pink, pinkish-brown, brown, maroon, greenish-black, grey, dark grey). Tentacle either uni-coloured (yellow, red, brown, reddish-brown, light grey, dark grey, black), or bi-coloured (green with brown tips, cream-white with pink tips, yellow with red tips). Head and tentacle often darker coloured relative to the body.
Three distinct habitats: rock (crevices, rock walls, solution holes, moss and lichen covered rocks), vegetation (low shrubs, tree trunks) or forest floor (rotten logs, leaf litter). Usually in moist areas but ocassionally found in drier areas. Always in forested habitats.
The genus Alycaeus Baird, 1850, is separated into three subgenera – Alycaeus Baird, 1850, Pincerna Preston, 1907, and Stomacosmethis Bollinger, 1918 (
PHG 77 Bukit Mengapur, Pahang (3°44'42"N, 102°50'16"E).
Holotype. PHG 77 Bukit Mengapur, Pahang: BOR/MOL 12977. Paratypes. PHG 77 Bukit Mengapur, Pahang: BOR/MOL 6888/1, BOR/MOL 8398/26.
PHG 77 Bukit Mengapur, Pahang: BOR/MOL 8397(11).
Latin for “dweller at heights”. Named after the species’ apparent ecological preference for habitats at higher and drier parts of limestone hills.
Protoconch. Smooth.
Shell shape. Conical. Shell height: 5.08–6.04 mm. Shell width: 5.04–5.87 mm.
Spire. Spire height: 1.64–2.23 mm. Spire width: 2.32–2.71 mm. Number of whorls: up to 5. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 4 ¾ whorls posterior of protoconch.
Breathing tube. Length: 0.42–0.58 mm.
Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 2.40–2.70 mm. Aperture width: 2.32–2.72 mm. Peristome double, not thickened, slightly notched at suture. Peristome orientation 35–38° oblique with respect to the coiling axis.
Spiral lines. Indistinct, regularly spaced. Approximately 22–44 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 10–14 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, white and thicker than those anterior of breathing tube, evenly spaced. Approximately 9–15 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs absent immediately posterior of constriction, becoming pronounced and regularly spaced at the middle until prior to aperture. Approximately 7–15 ribs per 1 mm.
Operculum. Concave, rounded. Exterior covered with very thin calcareous layer, with indistinct appressed multilamellae. Interior covered with proteinaceous coating, smooth, with indistinct appressed multilamellae and indistinct mamilla.
Shell colour. Whorls yellow, fading to white posterior of constriction. Peristome white.
Living animal. Body cream-white with fine brown blotches. Head brown. Tentacles brown.
Lives on rock surfaces covered with powdery lichen at higher and drier areas of the limestone hills, often at open places exposed to ambient sunlight. They never appear on wet and mossy sections of limestone rocks and are rarely seen in lower parts of limestone hills that are shaded by forest cover.
Restricted to Bukit Mengapur, Pahang.
Alycaeus alticola sp. n. varies in the degree of ultimate whorl expansion within population but has a consistently more expanded and globose whorl compared to A. costacrassa sp. n., A. selangoriensis sp. n. and A. kapayanensis. Alycaeus alticola sp. n. shares similar shell shape with Alycaeus charasensis sp. n. but differs in the presence of pronounced radial ribs and spiral lines, as well as less expanded ultimate whorl.
A. alticola sp. n. is among the larger yellow, conical shelled Alycaeus in Peninsular Malaysia.
Photographs of 18 living Alycaeus species. A–B Alycaeus balingensis Tomlin, 1948, BOR/MOL 8356 C Alycaeus liratulus (Preston, 1907), BOR/MOL 8334 D Alycaeus thieroti Morgan, 1885b, BOR/MOL 6835 E Alycaeus conformis Fulton, 1902, BOR/MOL 6809 F Alycaeus gibbosulus Stoliczka, 1872, BOR/MOL 6850 G Alycaeus gibbosulus Stoliczka, 1872, BOR/MOL 8526 H Alycaeus jousseaumei Morgan, 1885a, BOR/MOL 8341 I Alycaeus jousseaumei Morgan, 1885a, BOR/MOL 8336 J Alycaeus alticola sp. n., BOR/MOL 8398 K Alycaeus charasensis sp. n., BOR/MOL 8399 L Alycaeus clementsi sp. n., BOR/MOL 8364 M Alycaeus costacrassa sp. n., BOR/MOL 6811 N Alycaeus expansus sp. n., BOR/MOL 6367 O Alycaeus kapayanensis Morgan, 1885b, BOR/MOL 13005 P Alycaeus kelantanensis Sykes, 1902, BOR/MOL 8325 Q Alycaeus kelantanensis Sykes, 1902, BOR/MOL 6200 R Alycaeus kurauensis sp. n., BOR/MOL 6851 S Alycaeus perakensis Crosse, 1879a, BOR/MOL 6852 T Alycaeus regalis sp. n., BOR/MOL 6881 U Alycaeus selangoriensis sp. n., BOR/MOL 6371 V–W Alycaeus senyumensis sp. n., BOR/MOL 6249. All photographs by Junn Kitt Foon.
Alycaeus
perakensis
altispirus
Möllendorff, 1902: 144–145;
Alycaeus (Alycaeus) perakensis altispirus
:
Kelantan.
Lectotype. Kelantan:
Protoconch. Smooth.
Shell shape. Conical. Shell height: 6.40 mm. Shell width: 6.30 mm.
Spire. Spire height: 2.37 mm. Spire width: 2.68 mm. Number of whorls: up to 5 ½. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 5 ¼ whorls posterior of protoconch.
Breathing tube. Length: 0.77 mm.
Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 2.87 mm. Aperture width: 3.36 mm. Peristome double, not thickened, notched at suture, upper palatal section folded posteriorly into a wing-like structure. Peristome orientation 36° oblique with respect to the coiling axis.
Spiral lines. Absent.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 8 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, white and thicker than those anterior of breathing tube, evenly spaced. Approximately 16 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs absent immediately posterior of constriction, becoming pronounced and evenly spaced from the middle section until prior to aperture. Approximately 10 ribs per 1 mm.
Operculum. Unknown.
Shell colour. Whorls yellow. Peristome white.
Living animal. Unknown.
Unknown.
Unknown. Appears to be restricted to Kelantan.
Alycaeus altispirus is most similar to Alycaeus regalis sp. n. in having a large shell (shell height: 6.40–7.18 mm, shell width: 5.86–6.87 mm) and tall spire (spire height: 2.32–2.90 mm) but differs in the ultimate whorl being more keeled-like, upper palatal section folded posteriorly into a wing-like structure and peristome orientated oblique to the coiling axis. Unlike Alycaeus perakensis, Alycaeus altispirus is smaller (smaller by about 0.23 mm in shell height, 0.25 mm in shell width) and has a much less expanded ultimate whorl.
To date, this species is only known from the four type specimens collected by John Waterstradt (
Alycaeus
balingensis
Tomlin, 1948: 224–226, plate 11, figure, 3;
KDH 01 Bukit Baling, Kedah (5°40'50"N, 100°54'25"E).
Syntype. Bukit Baling, Kedah:
KDH 01 Bukit Baling, Kedah: BOR/MOL 6524/1, BOR/MOL 6853/1, BOR/MOL 8356/13, BOR/MOL 8357/27,
Protoconch. Smooth.
Globose. Shell height: 4.75–5.87 mm. Shell width: 5.11–6.00 mm.
Spire. Spire height: 1.23–2.16 mm. Spire width: 2.09–2.54 mm. Number of whorls: up to 4 ⅛. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 3 ¾ whorls posterior of protoconch.
Breathing tube. Length: 0.70–0.82 mm.
Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 2.60–3.13 mm. Aperture width: 2.69–3.22 mm. Peristome double, not thickened, slightly notched at suture. No interspace. Peristome orientation 4–8° oblique with respect to the coiling axis.
Spiral lines. Absent.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 9–16 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, evenly spaced. Approximately 7–10 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs initially indistinct and dense, but increasingly becomes pronounced and evenly-spaced towards the aperture. Approximately 2–4 ribs per 1 mm.
Operculum. Concave, rounded. Exterior covered by calcareous layer, with short calcareous spikes. Interior covered by proteinaceous layer, smooth.
Shell colour. Red, yellow or white at apical whorls. All colours fade to white towards ultimate whorl.
Living animal. Body greenish-black. Head greenish-black. Tentacle green with brown tips.
Lives in crevices on wet limestone boulders and shrubs close to the ground. In forested areas of limestone hills.
Distribution. Restricted to northern Perak (mykarst-171) and northeastern Kedah (Bukit Baling and Gunung Pulai).
Alycaeus balingensis shares similar shell shape (globose whorls) with Alycaeus liratulus and Alycaeus thieroti but differs in having whorls with denser and more pronounced radial ribs, absence of spiral lines, operculum exterior with short spikes and greenish-black body.
Alycaeus balingensis is listed as Critically Endangered in the IUCN Red List as it was known only from the actively quarried Bukit Baling at the time of assessment (
Alycaeus balingensis Tomlin, 1948. A–E Shell of syntype,
Alycaeus
carinata
Maassen, 2006: 137–138, figures 10–13;
PHG 74 Bukit Sagu, Pahang (3°58'54"N, 103°08'39"E).
Holotype. PHG 74 Bukit Sagu, Pahang:
Protoconch. Smooth.
Shell shape. Almost flat, conical. Shell height: 2.2–3.0 mm. Shell width: 4.0–4.6 mm. Shell measurements derived from
Spire. Spire height: 3.0 mm. Spire width: 4.5 mm. Number of whorls: up to 4. Spire shape: oblong conical. Whorl periphery strongly keeled except posterior of the constriction, where it becomes rounded. Umbilicus open.
Whorl constriction. At about 3 ¾ whorls posterior of protoconch.
Breathing tube. Length: 0.3 mm.
Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 2.2 mm. Aperture width: 2.0 mm. Peristome double, not thickened, winged at suture. Interspace narrow. Peristome orientation is 30–55° oblique with respect to the coiling axis.
Spiral lines. Indistinct. Regularly spaced. Approximately 25 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs indistinct to absent, only unevenly spaced radial growth lines present.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, evenly spaced. Approximately 13 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs indistinct to absent, only unevenly spaced radial growth lines present.
Operculum. Concave, rounded. Exterior and interior composition and sculpture not examined.
Shell colour. Whorls yellow to brown. Peristome white.
Living animal. Unknown.
Lives on limestone walls in a large, collapsed cave (
Restricted to Bukit Sagu and Bukit Tenggek, Pahang.
Alycaeus carinata is distinguished from all other Peninsular Malaysian Alycaeus species by its strongly keeled periphery, relatively low spire, very expanded ultimate whorls and very oblique peristome orientation with respect to the coiling axis (
Interestingly, no A. carinata was found during the 1950s University of Malaya, Singapore expedition to the type locality although congeners Alycaeus charasensis sp. n. and Alycaeus expansus sp. n. were obtained (
PHG 73 Bukit Charas, Pahang (3°54'35"N, 103°08'48"E).
Holotype. PHG 73 Bukit Charas, Pahang: BOR/MOL 12981. Paratypes. PHG 75 Bukit Tenggek, Pahang: BOR/MOL 264/2. PHG 73 Bukit Charas, Pahang: BOR/MOL 267/3, BOR/MOL 6891/1.
PHG 73 Bukit Charas, Pahang: BOR/MOL 8399/14, BOR/MOL 8401/26, BOR/MOL 8402/166, BOR/MOL 12982/120,
Subspecific epithet named after the type locality, Bukit Charas.
Protoconch. Smooth.
Shell shape. Conical. Shell height: 5.09–5.82 mm. Shell width: 5.23–6.62 mm.
Spire. Spire height: 1.57–2.11 mm. Spire width: 2.38–2.77 mm. Number of whorls: up to 5. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 4 ⅞ whorls posterior of protoconch.
Breathing tube. Length: 0.46–0.57 mm.
Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 2.58–2.90 mm. Aperture width: 2.47–2.84 mm. Peristome double, not thickened, slightly notched at suture. Peristome orientation 34–43° oblique with respect to the coiling axis.
Spiral lines. Indistinct, regularly spaced. Approximately 16–60 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs indistinct, unevenly spaced. They are sometimes absent and are replaced by evenly spaced radial growth lines.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, white and thick, evenly spaced. Approximately 8–15 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs absent immediately posterior of constriction, becoming pronounced and evenly spaced at the middle until prior to aperture. Approximately 7–19 ribs per 1 mm.
Operculum. Concave, rounded. Exterior covered with thin calcareous layer, with indistinct appressed multilamellae. Interior covered with proteinaceous coating, smooth, with indistinct appressed multilamellae.
Shell colour. Whorls yellow, fading to white posterior of constriction. Peristome white.
Living animal. Body cream-white with fine brown blotches. Head brown. Tentacles brown.
Lives on rock surfaces covered with powdery lichen at higher and drier areas of the limestone hills, often at open places exposed to ambient sunlight. They never appear on wet and mossy sections of limestone rocks and are not found in lower parts of limestone hills that are shaded by forest cover.
Restricted to Bukit Charas and Bukit Tenggek, eastern Pahang.
Alycaeus charasensis sp. n. shares similar variability in shell shape with Alycaeus alticola sp. n. but consistently differs in having a larger shell, wider ultimate whorl, widely spaced spiral lines and uneven, widely spaced radial growth lines in place of radial ribs. Alycaeus charasensis sp. n. is distinguished from other tall spired, conical yellow shelled Alycaeus in Peninsular Malaysia by its lack of distinct radial ribs.
A. charasensis sp. n. is among the larger yellow, conical shelled Alycaeus in Peninsular Malaysia.
Alycaeus
perakensis
:
Gua Kelam, PRS 64 Wang Ulu, Perlis (6°38'41"N, 100°12'09"E).
Holotype. Gua Kelam, PRS 64 Wang Ulu, Perlis: BOR/MOL 12970. Paratypes. Gua Kelam, PRS 64 Wang Ulu, Perlis: BOR/MOL 276/3, BOR/MOL 6865/1, BOR/MOL 8371/2. Bukit Ayer, PRS 64 Wang Ulu, Perlis: BOR/MOL 8365/2. Hill 9 km along the road from Kangar to Kaki Bukit, Perlis: BOR/MOL 270/1. KDH 10 Bukit Kodiang, Kedah: BOR/MOL 12969/1, BOR/MOL 8377/62. KDH 04 Gunung Keriang, Kedah: BOR/MOL 8407/7, BOR/MOL 12968/1. Limestone hill north of Sungai Ewa, Pulau Langkawi, Kedah: BOR/MOL 265/3.
Gua Kelam, PRS 64 Wang Ulu, Perlis: BOR/MOL 6194/4, BOR/MOL 6867/1, BOR/MOL 8370/11, BOR/MOL 8373/3,
Named after Gopalasamy Reuben Clements, in recognition of his contribution to the study of land snail biogeography on Peninsular Malaysian karsts.
Protoconch. Smooth.
Shell shape. Conical. Shell height: 5.65–6.98 mm. Shell width: 5.71–7.32 mm.
Spire. Spire height: 1.87–2.62 mm. Spire width: 2.39–3.32 mm. Number of whorls: up to 5 ⅛. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 4 ¾whorls posterior of protoconch.
Breathing tube. Length: 0.59–0.90 mm.
Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 2.95–3.88 mm. Aperture width: 2.83–3.49 mm. Peristome double, thickened, notched at suture. Peristome orientation 25–45° oblique with respect to the coiling axis.
Spiral lines. Distinct. Regularly spaced. Approximately 11–34 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 9–16 lines per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, white and thicker than those anterior of breathing tube, evenly spaced. Approximately 11–16 radial ribs per 1 mm
Radial ribs running posterior of breathing tube. Radial ribs pronounced, unevenly spaced immediately posterior of constriction, becoming pronounced and evenly spaced from the middle section until prior to aperture. Approximately 11–16 ribs per 1 mm.
Operculum. Concave, rounded. Exterior covered with thin calcareous layer, surface finely granulated with a scattered arrangement of calcareous blunt spikes. Interior covered with proteinaceous coating, smooth, mamillated.
Shell colour. Yellow at the first 4 whorls. Fades to white towards aperture.
Living animal. Body cream-white. Head pink. Tentacles cream-white, tips pink.
Lives on wet limestone rock walls and crevices. In shady forests on limestone hills.
In Perlis, retricted to limestone hills of the Nakawan Range. In Kedah, restricted to limestone hills of the Langkawi archipelago, Kodiang and Gunung Keriang.
Alycaeus clementsi sp. n. is similar to A. kelantanensis in its shell colouration. Despite shell size of A. clementsi sp. n. being variable within populations across its range, A. clementsi sp. n. is distinguished from A. kelantanensis by its consistently large shell (larger by about 2.13 mm in shell height, 2.32 mm in shell width), thick expanded peristome, spiky operculum exterior as well as the animal colouration.
Historically, Alycaeus clementsi sp. n. shells from Kaki Bukit, Perlis were misidentified as A. perakensis in
Alycaeus
conformis
Fulton, 1902: 68–69;
Alycaeus
confirmis
[sic]:
Alycaeus
coniformis
[sic]:
Perak.
Syntypes. Perak:
KTN 01 Gunung Reng, Kelantan: BOR/MOL 6836/2. KTN 66 Batu Tongkat, Kelantan:
Protoconch. Smooth at first whorl, becomes grooved in the second whorl. Grooves arranged parallel to each other and tilted anteriorly at 45° to the coiling axis.
Shell shape. Conical. Shell height: 8.77–10.19 mm. Shell width: 7.16–8.19 mm.
Spire. Spire height: 2.37–3.21 mm. Spire width: 3.24–3.66 mm. Number of whorls: up to 4 ⅜. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 4 ¼ whorls posterior of protoconch.
Breathing tube. Length: 4.70–5.76 mm.
Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 4.11–5.14 mm. Aperture width: 4.27–4.93 mm. Peristome double, thickened, slightly notched at suture. Interspace narrow. Peristome orientation 10–16° oblique with respect to the coiling axis.
Spiral lines. Indistinct, regularly spaced. Approximately 11–59 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 10–17 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs more pronounced and thicker than those anterior of breathing tube, evenly spaced. Approximately 9–13 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Ribs absent. Only radial growth lines.
Operculum. Concave, conical. Exterior covered by thick calcareous layer. Exterior has radially spiral lamellae of 6 revolutions. Interior covered by proteinaceous layer, mamillated.
Shell colour. First 3 whorls usually red or pink. All colours fade to white towards ultimate whorl.
Living animal. Body grey. Head grey. Tentacles dark grey to black.
Lives under large rotten logs and on leaf litter. In wet, shady forests in both limestone and non-limestone areas.
Distribution. Localised in Perak but widespread in Kelantan, Pahang, Selangor and Johor. Elsewhere, in Phuket, southern Thailand (
Differential diagnosis Alycaeus conformis is most similar to Alycaeus gibbosulus in shell shape but differs in having a less expanded penultimate whorl, finer radial ribs anterior of breathing tube, shorter constriction whorl, shorter breathing tube, less oblique peristome and multilamellated operculum exterior. The animal body is dark grey in A. conformis compared to brown in A. gibbosulus.
Alycaeus conformis Fulton, 1902. A–D Shell of syntype,
Alycaeus
perakensis
var.
minor
nomen nudum,
Mykarst-065 Batu Balong, Pahang (3°42'41"N, 101°51'25"E).
Holotype. Mykarst-065 Batu Balong, Pahang: BOR/MOL 12995. Paratypes. Mykarst-065 Batu Balong, Pahang: BOR/MOL 8320/2, BOR/MOL 6811/4, BOR/MOL 8319/6.
KTN 06 Gua Ikan, Kelantan: BOR/MOL 6631/1. KTN 148 unnamed hill, Kelantan: BOR/MOL 12993/1. KTN 95 Gua Panjang, Kelantan: BOR/MOL 12994/12. PHG 15 Gua Bama, Pahang: BOR/MOL 243/1, BOR/MOL 6235/4, BOR/MOL 6818/2, BOR/MOL 8323/2, BOR/MOL 8324/6. Mykarst-169 Gua Gajah, Pahang: BOR/MOL 6250/5, BOR/MOL 12992/1. PHG 03 Gunung Jebak Puyuh, Pahang: BOR/MOL 6628/3, BOR/MOL 6882/1. PHG 05 Bukit Cintamanis, Pahang: BOR/MOL 6634/2, BOR/MOL 6892/2. PHG 01 Kota Gelanggi, Pahang: BOR/MOL 6635/1,
In Latin – costa crassa, meaning thick ribbed. Named after the species’ diagnostic widely spaced, pronounced radial ribbing of the whorls.
Protoconch. Smooth.
Shell shape. Conical. Shell height: 3.47–6.37 mm. Shell width: 3.42–6.12 mm.
Spire. Spire height: 1.06–2.43 mm. Spire width: 1.53–2.79 mm. Number of whorls: up to 5 ¼. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 5 whorls posterior of protoconch.
Breathing tube. Length: 0.30–0.67 mm.
Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 1.79–2.89 mm. Aperture width: 1.62–2.84 mm. Peristome double, not thickened, winged at suture. Peristome orientation 26–39° oblique with respect to the coiling axis.
Spiral lines. Distinct. Regularly spaced. Approximately 19–52 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 9–18 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, evenly spaced. Approximately 11–17 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs pronounced and ueneven immediately posterior of constriction, becoming pronounced and evenly spaced towards the aperture. Approximately 10–21 ribs per 1 mm.
Operculum. Concave, rounded. Exterior covered with thick but flaky calcareous layer, surface finely granulated. Interior proteinaceous layered, smooth, with indistinct mamilla.
Shell colour. Whorls yellow, fading to white posterior of constriction. Peristome white.
Living animal. Body cream-white. Head pinkish brown. Tentacles reddish-brown.
Lives on wet limestone walls covered with mosses. Occassionally found in crevices, on lower parts of tree trunks. In shady forests on limestone hills.
Widespread from southern Kelantan to central Pahang.
Alycaeus costacrassa sp. n. most resembles A. selangoriensis sp. n. in its thick operculum, pronounced radial ribbing and spiral lines but has a narrower ultimate whorl and a more circular peristome without posterior folding at the upper palatal section. Alycaeus costacrassa sp. n. also resembles A. kapayanensis in shell shape but differs in its consistently more pronounced radial ribs as well as operculum with thicker calcareous exterior.
Shells of A. costacrassa sp. n. are consistent in their diagnostic characters but vary considerably in shell size and whorl convexity across its range. Populations in Gua Sai and Gua Bama have the smallest shells (Shell height: 3.47–4.46 mm, Shell width: 3.42–4.27 mm, Figure
PHG 74 Bukit Sagu, Pahang (3°58'54"N, 103°08'39"E).
Holotype. PHG 74 Bukit Sagu, Pahang: BOR/MOL 12983. Paratypes. PHG 74 Bukit Sagu, Pahang: BOR/MOL 269/2, BOR/MOL 6358/4. PHG 75 Bukit Tenggek, Pahang: BOR/MOL 273/2.
PHG 72 Bukit Panching, Pahang: BOR/MOL 247/1,
Latin, meaning expanded. In reference to the very expanded peristome and globose whorls.
Protoconch. Smooth.
Shell shape. Conical. Shell height: 4.11–5.88 mm. Shell width: 3.87–5.96 mm.
Spire. Spire height: 1.33–1.85 mm. Spire width: 1.88–2.57 mm. Number of whorls: up to 4 ½. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 4 ¼ whorls posterior of protoconch.
Breathing tube. Length: 0.44–0.62 mm.
Aperture and peristome. Aperture very expanded, ocassionally forming wing-like extensions at columellar and upper palatal sections. Wing-like extension at columellar section of the aperture is angular. Aperture height: 1.81–3.44 mm. Aperture width: 1.78–3.13 mm. Peristome double, not thickened, notched at suture. Peristome orientation 27–32° oblique with respect to the coiling axis.
Spiral lines. Indistinct. Regularly spaced. Approximately 18–40 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs indistinct, evenly spaced. Approximately 6–15 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced and thicker than those anterior of breathing tube, evenly spaced. Approximately 11–17 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs indistinct, unevenly spaced to absent.
Operculum. Concave, conical. Exterior covered with thick calcareous layer, surface finely granulated. Interior covered with proteinaceous coating, smooth, mamillated.
Shell colour. Whorls yellow. Peristome white.
Living animal. Body cream-white. Head pink. Tentacles cream-white, tips pink.
Lives on wet rock surfaces and crevices covered with mosses at higher areas and wang of limestone hills. In shaded forests.
Restricted to the Kuantan Hills of eastern Pahang (comprises of Bukit Tenggek, Bukit Sagu, Bukit Charas and Bukit Panching).
Alycaeus expansus sp. n. is distinguished from all other Peninsular Malaysian Alycaeus by its very obtuse ultimate whorl, very expanded peristome with wing-like extensions at columellar and upper palatal sections, thick operculum and animal colouration.
Prior to this study, shells of A. expansus sp. n. from Bukit Charas and Bukit Panching were labelled as A. kelantanensis (BOR/MOL and
Alycaeus
gibbosulus
Stoliczka, 1872: 268–269, plate 10, figure 14;
Alycaeus chaperi Morgan, 1885a: 70.
Alycaeus (Orthalycaeus) gibbosulus
:
Alycaeus
gibbosulos
[sic]:
Dioryx
pyramidalis
:
Alycaeus (Alycaeus) gibbosulus
:
Penang Island.
Syntypes. Penang Island: 12 shells deposited at the Indian Museum, Kolkata (
Botanic Garden, Penang Island: BOR/MOL 8525/1, BOR/MOL 8526/12. KDH 01 Bukit Baling, Kedah: BOR/MOL 6855/1, BOR/MOL 8358/1, BOR/MOL 8359/23, BOR/MOL 12996/1,
Protoconch. Smooth at first whorl, becomes grooved in the second whorl. Grooves arranged parallel to each other and tilted anteriorly at 45° to the coiling axis.
Shell shape. Conical. Shell height: 9.20–10.15 mm. Shell width: 8.46–9.75 mm.
Spire. Spire height: 2.32–3.07 mm. Spire width: 3.32–3.67 mm. Number of whorls: up to 4 ⅛. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 4 whorls posterior of protoconch.
Breathing tube. Length: 5.28–6.52 mm.
Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 4.11–5.14 mm. Aperture width: 4.27–4.93 mm. Peristome double, thickened, slightly notched at suture. Interspace narrow to wide. Peristome orientation 18–24° oblique with respect to the coiling axis.
Spiral lines. Indistinct, regularly spaced. Approximately 20–44 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 14–21 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs more pronounced and thicker than those anterior of breathing tube, evenly spaced. Approximately 8–14 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Ribs absent. Only radial growth lines.
Operculum. Concave, conical. Exterior covered by thick calcareous layer. Exterior has scaffold-like calcareous deposits overlaid on radially spiral lamellae. Interior covered by proteinaceous layer, mamillated.
Shell colour. First 3 whorls usually red, purple or pink. All colours fade to white towards ultimate whorl.
Living animal. Body brown. Head brown. Tentacles light to dark grey.
Lives under large rotten logs or on leaf litter. In wet, shady forests in both limestone and non-limestone areas.
Widespread from Perlis to Perak on the west coast and in parts of Kelantan and Terengganu on the east coast but not found in Selangor, Pahang and the southern states of Peninsular Malaysia. Elsewhere, in Trang, southern Thailand (as Dioryx pyramidalis (Benson, 1856), in
Alycaeus gibbosulus is most similar to A. conformis in shell shape but differs in having a more expanded penultimate whorl, coarser sculpture, more oblique peristome, longer constriction whorl, longer breathing tube (longer by 0.66 mm), ultimate whorl that is very obtused prior to constriction and scaffold-like calcareous deposits at the operculum exterior. The animal body is brown in A. gibbosulus compared to grey in A. conformis.
The syntypes of A. gibbosulus is housed in the Indian Museum, Kolkata, India (
This species is closely related to A. conformis and has historically been confused with it. Studies that reported A. gibbosulus in various localities are as follows: Penang (
Alycaeus gibbosulus has been reported to exist sympatrically with A. conformis in Gunung Rapat, Perak (
Alycaeus
perakensis
var.
minor
nomen nudum,
KTN 06 Gua Ikan, Kelantan (5°21'14"N, 102°01'33"E).
Holotype. KTN 06 Gua Ikan, Kelantan: BOR/MOL 12972. Paratypes. KTN 06 Gua Ikan, Kelantan: BOR/MOL 6834/23.
KTN 06 Gua Ikan, Kelantan: BOR/MOL 6193/2, BOR/MOL 6632/17.
Named after the type locality, Gua Ikan.
Protoconch. Smooth.
Shell shape. Conical. Shell height: 4.02–4.58 mm. Shell width: 3.58–4.16 mm.
Spire. Spire height: 1.42–1.78 mm. Spire width: 1.83–2.03 mm. Number of whorls: up to 4 ½. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 4 ¼ whorls posterior of protoconch.
Breathing tube. Length: 0.35–0.42 mm.
Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 1.59–1.87 mm. Aperture width: 1.60–1.96 mm. Peristome double, not thickened, notched at suture. Peristome orientation 16–27° oblique with respect to the coiling axis.
Spiral lines. Distinct. Regularly spaced. Approximately 22–30 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 9–19 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, white and thicker than those anterior of breathing tube, evenly spaced. Approximately 13–18 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs absent immediately posterior of constriction, becoming pronounced and unevenly spaced towards the aperture.
Operculum. Concave, rounded. Exterior covered with very thin and indistinct calcareous layer, surface finely granulated, with very indistinct appressed multilamellae. Interior proteinaceous layered, smooth, very indistinct appressed multilamellae.
Shell colour. Whorls yellow, fading to white posterior of constriction. Peristome white.
Living animal. Unknown.
Lives on limestone walls and boulders covered with mosses. In shady forests on limestone hills.
Restricted to Gua Ikan, central Kelantan.
Alycaeus ikanensis sp. n. is distinctive in being the smallest species among conical, yellow shelled Alycaeus species in Peninsular Malaysia. Alycaeus ikanensis sp. n. is distinguished from A. costacrassa sp. n. by its consistently much smaller shell (smaller by about 0.62 mm in shell height, 0.90 mm in shell width) and narrower ultimate whorl.
Limestone hills adjacent to the type locality Gua Ikan may also harbour populations of the species.
Alycaeus
jousseaumei
Morgan, 1885a: 70;
Alycaeus (Chamalycaeus) jousseaumi
[sic]: Kobelt and Möllendorff
Alycaeus (Chamalycaeus) jousseaumei
:
Chamalycaeus
jousseaumei
:
Mont Lano (= PRK 18 Gunung Lanno), Perak (4°31'31"N, 101°08'48"E).
Syntypes. Mont Lano (= PRK 18 Gunung Lanno), Perak:
PRK 01 Gunung Tempurung, Perak: BOR/MOL 6847/1, BOR/MOL 8346/3, BOR/MOL 11136/11, BOR/MOL 11211/37, BOR/MOL 11408/10. PRK 15 Gunung Keroh, Perak:
Protoconch. Smooth.
Shell shape. Flat. Shell height: 7.50–8.76 mm. Shell width: 12.42–15.03 mm.
Spire. Spire height: 1.77–2.27 mm. Spire width: 2.94–3.45 mm. Number of whorls: up to 3. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 2 ¾ whorls posterior of protoconch.
Breathing tube. Length: 5.44–5.97 mm.
Aperture and peristome. Aperture circular, very expanded. Aperture height: 4.88–7.30 mm. Aperture width: 4.92–6.59 mm. Peristome triple. The first (most anterior) peristome is moderately expanded but not thickened. The second (outer) peristome is very expanded but not thickened. The second peristome is impressed on the thickened third (inner), non-expanded peristome. Interspace between first and second peristome wide. Interspace between second and third peristome narrow. Peristome orientation is 44–55° oblique with respect to the coiling axis.
Spiral lines. Absent.
Radial ribs running anterior of breathing tube. Radial ribs indistinct, evenly spaced. Approximately 10–18 ribs in 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced and thick, evenly spaced. Approximately 8–15 ribs in 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 10–25 ribs per 1 mm.
Operculum. Flat, conical. Exterior calcareous, smooth but occasionally with calcareous deposits. Interior covered by proteinaceous layer, smooth.
Shell colour. First 3 whorls usually red, orange, purple or white. Ultimate whorl white. Whorl constriction generally white, occasionally red.
Living animal. Body light grey to light brown. Head pinkish-brown to dark grey. Tentacles brown.
Lives on limestone rock surfaces and crevices. In wet, shady forests on limestone hills.
Restricted to the karsts of Kinta Valley, Perak. Its known northern limit is at Gunung Tchehel and southern limit at Gunung Tempurung.
Alycaeus jousseaumei is distinguished from all other Alycaeus species in Peninsular Malaysia by its very low spire, very expanded, obtuse ultimate whorl and very expanded, double peristome with wide interspace.
Alycaeus jousseaumei is morphologically unique and unmistakable among Peninsular Malaysian Alycaeus. Alycaeus jousseaumei has been subjected to attempts of supraspecific reclassification.
Alycaeus jousseaumei Morgan, 1885a. A–E Shell of syntype,
Alycaeus
kapayanensis
Morgan, 1885b: 403, plate 8, figure 5;
Alycaeus (Orthalycaeus) kapayensis
[sic]:
Alycaeus (Orthalycaeus) kapayanensis
: Kobelt and Möllendorff
Alycaeus (Alycaeus) kapayanensis
:
Alycaeus
perakensis
var.
minor
nomen nudum,
Alycaeus
kapayanesis
[sic]:
Gunong Lano (= PRK 18 Gunung Lanno), Perak (4°31'31"N, 101°08'48"E).
Syntype. Perak, Gunong Lano (= PRK 18 Gunung Lanno), Perak:
PRK 01 Gunung Tempurung, Perak: BOR/MOL 11142/11, BOR/MOL 11229/1, BOR/MOL 11385/2, BOR/MOL 11414/3. PRK 23 Gunung Rapat, Perak: BOR/MOL 241/2, BOR/MOL 6845/1, BOR/MOL 8343/4, BOR/MOL 8344/2, BOR/MOL 10031/4, BOR/MOL 10230/10, BOR/MOL 10259/4, BOR/MOL 12985/1. PRK 27 Gunung Datok, Perak: BOR/MOL 10482/4, BOR/MOL 10502/3. PRK 29 Gunung Lang, Perak: BOR/MOL 244/1, BOR/MOL 13005/13. PRK 34 Gunung Tasek, Perak: BOR/MOL 6840/5, BOR/MOL 6905/1, BOR/MOL 8405/11, BOR/MOL 8406/20, BOR/MOL 10793/52, BOR/MOL 11028/29, BOR/MOL 11065/5. PRK 42 Gunung Bercham, Perak: BOR/MOL 10629/1. PRK 47 Gunung Kanthan South, Perak: BOR/MOL 9081/38, BOR/MOL 9161/12,
Protoconch. Smooth.
Shell shape. Conical. Shell height: 4.85–5.34 mm. Shell width: 4.44–5.09 mm.
Spire. Spire height: 1.66–2.03 mm. Spire width: 2.11–2.39 mm. Number of whorls: up to 5. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 4 ⅝ whorls posterior of protoconch.
Breathing tube. Length: 0.29–0.51 mm.
Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 2.01–2.77 mm. Aperture width: 2.13–2.36 mm. Peristome single, not thickened, notched at suture. Peristome orientation 29–32° oblique with respect to the coiling axis.
Spiral lines. Distinct. Regularly spaced. Approximately 27–48 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 11–15 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, evenly spaced. Approximately 10–19 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs absent immediately posterior of constriction, becoming pronounced and evenly spaced at the middle until prior to aperture. Approximately 11–23 ribs per 1 mm.
Operculum. Concave, rounded. Exterior covered with very thin calcareous layer, with indistinct appressed multilamellae. Interior covered with proteinaceous coating, smooth indistinct appressed multilamellae.
Shell colour. Whorls yellow. Peristome white.
Living animal. Body yellow. Head orange. Tentacles red.
Lives on both dry, bare rock and wet limestone walls covered with mosses or tree roots. Although it inhabits forested areas, A. kapayanensis has also been found on revegetated limestone walls at former quarries.
Restricted to the karsts of Kinta Valley, Perak. Its known northern limit is at the Sungai Kerdah karst region, northeast of Sungai Siput Utara town and southern limit at Gunung Tempurung.
Alycaeus kapayanensis is similar to A. costacrassa sp. n. but differs consistently in having less pronounced spiral ribs and much thinner operculum. Alycaeus kapayanensis also resembles A. selangoriensis sp. n. but is consistently smaller shelled (smaller by about 0.96 mm in shell height, 1.6 mm in shell width), has less whorls, less expanded ultimate whorl and thinner operculum.
Historically, many Peninsular Malaysian Alycaeus with small, yellow and conical shells were lumped under A. kapayanensis out of convenience (
Alycaeus kapayanensis Morgan, 1885b. A–E Shell of syntype,
Alycaeus
kelantanense
Sykes, 1902: 60–62, Figure
Alycaeus
kelantanensis
:
Kelantan, Malay Peninsula.
Syntype. Kelantan:
KTN 01 Gunung Reng, Kelantan: BOR/MOL 6837/1. KTN 45 unnamed hill at Kampung Bayu, Kelantan: BOR/MOL 6236/6, BOR/MOL 12974/1. KTN 66 Batu Tongkat, Kelantan:
Protoconch. Smooth.
Shell shape. Conical. Shell height: 3.33–5.04 mm. Shell width: 3.36–5.04 mm.
Spire. Spire height: 1.08–1.76 mm. Spire width: 1.40–2.25 mm. Number of whorls: up to 4. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 3 ⅝ whorls posterior of protoconch.
Breathing tube. Length: 0.38–0.67 mm.
Aperture and peristome. Aperture circular, moderately expanded to very expanded. Aperture height: 1.82–2.73 mm. Aperture width: 1.69–2.46 mm. Peristome double, thickened, folded posteriorly into a wing-like upper palatal structure, notched at suture. Peristome orientation 26–34° oblique with respect to the coiling axis.
Spiral lines. Distinct. Regularly spaced. Approximately 15–28 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 12–18 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, white and thicker than those anterior of breathing tube, evenly spaced. Approximately 12–29 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs absent immediately posterior of constriction, becoming pronounced and evenly spaced at the middle, absent again towards the aperture. Approximately 11–20 ribs per 1 mm.
Operculum. Concave, rounded. Exterior covered with thin calcareous layer, with very indistinct appressed multilamellae. Interior covered with proteinaceous coating, smooth, with indistinct mamilla.
Shell colour. Whorls white throughout. First 3 whorls occasionally yellow.
Living animal. Body cream-white. Head pinkish. Tentacles yellow, with red tips.
Lives in rock crevices and limestone solution holes. In moist, shady forests. Occur on both limestone and non-limestone areas.
Widespread across southern Kelantan.
Alycaeus kelantanensis varies in shell size and whorl convexity but can nevertheless be distinguished from other similar sized Alycaeus by its rather angular and winged double peristome, pronounced and widely-spaced radial ribs and spiral lines, as well as the red-tipped yellow tentacles of its soft body. Alycaeus kelantanensis is similar to A. clementsi sp. n. in shell colour but differs in being consistently smaller shelled (smaller by about 2.13 mm in shell height, 2.32 mm in shell width), having smooth operculum exterior and a more angular double peristome.
The type specimen for A. kelantanensis was collected by John Waterstradt, likely from the Pulai Princess Cave hill (4°47'38"N, 101°56'31"E), south of Gua Musang, Kelantan (after
Alycaeus kelantanensis Sykes, 1902. A–E Shell of syntype,
PRK 59 Bukit Batu Kurau, Perak (4°55'45"N, 100°49'02"E).
Holotype. PRK 59 Bukit Batu Kurau, Perak: BOR/MOL 12967. Paratypes. PRK 59 Bukit Batu Kurau, Perak: BOR/MOL 6851/10, BOR/MOL 8408/2.
PRK 59 Bukit Batu Kurau, Perak: BOR/MOL 8353/22,
Named after the type locality, Batu Kurau.
Protoconch. Smooth.
Shell shape. Conical. Shell height: 5.04–5.56 mm. Shell width: 5.34–6.06 mm
Spire. Spire height: 1.08–2.06 mm. Spire width: 2.34–2.52 mm. Number of whorls: up to 4. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 3 ⅝ whorls posterior of protoconch.
Breathing tube. Length: 0.45–0.62 mm.
Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 2.51–2.84 mm. Aperture width: 2.34–2.65 mm. Peristome double, thickened, notched at suture. Peristome orientation 35–45° oblique with respect to the coiling axis.
Spiral lines. Distinct. Regularly spaced. Approximately 24–36 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 7–16 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced and thicker than those anterior of breathing tube, evenly spaced. Approximately 9–16 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs absent immediately posterior of constriction. At the middle section, becoming pronounced and evenly spaced from the middle section until prior to aperture. Approximately 10–15 ribs per 1 mm.
Operculum. Concave, rounded. Exterior covered with thick calcareous layer, smooth. Interior covered with proteinaceous coating, smooth, mamillated.
Shell colour. Whorls yellow. Peristome white.
Living animal. Body cream-yellow. Head orange. Tentacles red.
Lives on both dry and wet limestone walls. In shady forests and cliffs on limestone hills.
Restricted to Batu Kurau, Perak.
Alycaeus kurauensis sp. n. is similar to Alycaeus perakensis in conical shell shape and radial ribs spacing but differs in being consistently smaller (by about 1.33 mm in shell height, and by about 1.85 mm in shell width), has a less expanded ultimate whorl and peristome, a thick operculum with smooth exterior as well as body and tentacle colouration. Alycaeus kurauensis sp. n. is also similar to Alycaeus kapayanensis in size and colour but differs in having a wider ultimate whorl, thicker operculum with smooth exterior and more widely spaced radial ribs.
A nomen nudum “Alycaeus perakensis var. minor” was used for this subspecies in the
Alycaeus (Pincerna) liratula
Preston, 1907: 206;
Alycaeus (Alycaeus) liratulus
:
Alycaeus
liratulus
:
Pincerna
liratula
:
Kelantan.
Syntypes. Ke-lan-tan (=Kelantan):
Mykarst-186 Gua Madu, Kelantan: BOR/MOL 6826/2. KTN 136 Gua Musang, Kelantan:
Protoconch. Smooth.
Globose. Shell height: 5.62–6.70 mm. Shell width: 5.195–6.08 mm.
Spire. Spire height: 1.42–2.01 mm. Spire width: 2.30–2.83 mm. Number of whorls: up to 4 ⅛. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 3 ¾ whorls posterior of protoconch.
Breathing tube. Length: 1.13–1.25 mm.
Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 2.78–3.16 mm. Aperture width: 2.88–3.43 mm. Peristome double, thickened, slightly notched at suture. No interspace. Peristome orientation 9–20° oblique with respect to the coiling axis.
Spiral lines. Distinct. Regularly spaced. Approximately 11–14 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 6–7 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, evenly spaced. Approximately 9–12 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs absent immediately posterior of constriction, becoming distinct and unevenly spaced at the middle and then absent again prior to aperture.
Operculum. Concave, rounded. Exterior covered by calcareous layer. Exterior nucleus with calcareous, cup-like projection. Interior covered by proteinaceous layer, smooth, mamillated.
Shell colour. Off white, apical whorls occasionally pinkish white.
Living animal. Body maroon. Head maroon. Tentacles red or brown tipped.
Lives on shrubs close to the ground. In forested areas of limestone hills.
Restricted to central and southern Kelantan. Elsewhere, isolated records in northern Sumatra, Indonesia (
Alycaeus liratulus is most similar to Alycaeus thieroti in shell shape but differs in having a larger shell (larger by about 1 mm in shell height, 0.8 mm in shell width), wider-spaced radial ribs and spiral lines, longer breathing tube (longer by 0.65 mm) and flat operculum with cup-shaped calcareous extension at the nucleus exterior.
Confusion between A. liratulus and A. thieroti due to similarity in shell shape and poor original descriptions have led to many misidentifications in the past (see Discussion in Alycaeus thieroti). Isolated records of A. liratulus from northern Sumatra (
Supraspecific classification was attempted for A. liratulus by
Alycaeus liratulus (Preston, 1907). A–E Shell of syntype,
Alycaeus
perakensis
Crosse, 1879a: 206–208, plate 7, figure 7;
Alycaeus (Orthalycaeus) perakensis
:
Alycaeus (Alycaeus) perakensis
:
Alycaeus
perakensis
perakensis
:
Buket Pondong (= PRK 55 Gunung Pondok), Perak (4°46'57"N, 100°50'01"E).
Syntypes. Buket Pondong (= PRK 55 Gunung Pondok), Perak:
KDH 01 Bukit Baling, Kedah: BOR/MOL 6525/1, BOR/MOL 6854/5, BOR/MOL 8527/1, BOR/MOL 8528/2. KDH 02 Gunung Pulai, Kedah: BOR/MOL 6858/2. PRK 55 Gunung Pondok, Perak: BOR/MOL 272/1, BOR/MOL 6849/1, BOR/MOL 8349/29, BOR/MOL 8350/23, BOR/MOL 11479/46, BOR/MOL 11506/31, BOR/MOL 11539/50, BOR/MOL 11563/20,
Protoconch. Smooth.
Shell shape. Conical. Shell height: 5.98–7.27 mm. Shell width: 6.48–8.62 mm.
Spire. Spire height: 1.83–2.64 mm. Spire width: 2.80–3.39 mm. Number of whorls: up to 4 ½. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 4 ¼ whorls posterior of protoconch.
Breathing tube. Length: 0.61–0.88 mm.
Aperture and peristome. Aperture circular, expanded. Aperture height: 3.06–4.32 mm. Aperture width: 2.86–4.10 mm. Peristome double, not thickened, notched at suture. Peristome orientation 43–49° oblique with respect to the coiling axis.
Spiral lines. Distinct. Regularly spaced. Approximately 17–35 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 8–14 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, white and thicker than those anterior of breathing tube, evenly spaced. Approximately 9–15 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs pronounced, widely and regularly spaced, approximately 9–16 ribs per 1 mm. Prior to aperture, radial ribs become absent.
Operculum. Concave, rounded. Exterior covered with thin calcareous layer, surface finely granulated with a scattered arrangement of calcareous spikes. Interior covered with proteinaceous coating, smooth.
Shell colour. Whorls yellow. Peristome white.
Living animal. Body cream-white. Head pink. Tentacles brown.
Lives on both dry and wet limestone walls. Some individuals have been spotted on tree trunks and fallen logs beside limestone cliffs. In shady forests on limestone hills.
Restricted to central and northern Perak as well as northeastern Kedah (Bukit Baling and Gunung Pulai). Elsewhere, in Yala, Thailand (
Alycaeus perakensis is most similar to Alycaeus roebeleni in conical shell shape but differs in being smaller (smaller by about 0.97 mm in shell height, 1.96 mm in shell width), aperture margins more circular and has a less expanded ultimate whorl. Alycaeus perakensis is distinguished from Alycaeus kapayanensis and Alycaeus kurauensis sp. n. by its much larger shell (larger by about 1.43 mm in shell height, 2.32 mm in shell width), more expanded penultimate whorl, operculum exterior with spikes and more oblique peristome. Shells of A. perakensis vary in the degree of expansion of the ultimate whorl.
Historically, the lack of access to type specimens and poor original diagnosis have led to the misidentification of A. selangoriensis sp. n., A. clementsi sp. n. and A. kapayanensis as A. perakensis (
Alycaeus perakensis Crosse, 1879a. A–E Shell of syntype,
Alycaeus
perakensis
altispirus
:
PHG 02 Gunung Senyum, Pahang (3°41'50"N, 102°26'04"E).
Holotype. PHG 02 Gunung Senyum, Pahang: BOR/MOL 12990. Paratypes. PHG 02 Gunung Senyum, Pahang: BOR/MOL 12991/11. PHG 03 Gunung Jebak Puyuh, Pahang: BOR/MOL 6629/14.
PHG 02 Gunung Senyum, Pahang: BOR/MOL 6232/3, BOR/MOL 6240/4, BOR/MOL 6881/1, BOR/MOL 8393/5,
Latin, meaning royal. In reference to the species’ tall spire and colour reminiscent of the yellow royal parasol which is part of the regalia of Southeast Asian kingdoms.
Protoconch. Smooth.
Shell shape. Conical. Shell height: 6.57–7.18 mm. Shell width: 5.86–6.87 mm.
Spire. Spire height: 2.32–2.90 mm. Spire width: 2.88–3.21 mm. Number of whorls: up to 5 ½. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 5 ¼ whorls posterior of protoconch.
Breathing tube. Length: 0.62–0.81 mm.
Aperture and peristome. Aperture circular, very expanded. Aperture height: 2.91–3.66 mm. Aperture width: 2.95–3.59 mm. Peristome double, sometimes thickened, slightly notched at suture. Peristome orientation 4–17° oblique with respect to the coiling axis.
Spiral lines. Regularly spaced. Approximately 20–36 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 7–15 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, white and thicker than those anterior of breathing tube, evenly spaced. Approximately 6–15 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs pronounced and uneven immediately posterior of constriction, becoming pronounced and evenly spaced from the middle section until prior to aperture. Approximately 8–16 ribs per 1 mm.
Operculum. Flat. Exterior with proteinaceous coating and indistinct appressed multilamellae. Interior with proteinaceous coating, smooth, mamillated. Operculum interior sometimes with a hard, ligament-like proteinaceous extension embedded within the columellar muscle of the animal when alive.
Shell colour. Whorls yellow. Peristome white.
Living animal. Body cream-white. Head pinkish-brown. Tentacle tips brown.
This species lives on dry rock surfaces covered with powdery lichens. They never appear on wet and mossy sections of limestone rocks.
Restricted to limestone karsts at central Pahang (Gunung Senyum and Gunung Jebak Puyuh) only.
Alycaeus regalis sp. n. is most similar to A. altispirus in shell size (shell height: 6.40–7.18 mm, shell width: 5.86–6.87 mm) and tall shell spire (spire height: 2.32–2.90 mm) but differs in the ultimate whorl periphery being rounder, upper palatal section lacking the posterior folding and peristome orientated parallel to the coiling axis.
Prior to this study, specimens of A. regalis sp. n. from Gunung Senyum were always labelled as Alycaeus perakensis altispirus (
Alycaeus
roebeleni
Möllendorff, 1894: 146–156;
Alycaeus (Alycaeus) roebelini
[sic]:
Alycaeus (Alycaeus) roebeleni
:
Samui Islands (= Koh Samui archipelago), Thailand.
Lectotype. Koh Samui, Thailand:
PRS 11 Bukit Tok Seri, Perlis: BOR/MOL 6863/1, BOR/MOL 8368/2. PRS 17 Gunung Chabang, Perlis: BOR/MOL 6230/1, BOR/MOL 6869/1, BOR/MOL 6873/6, BOR/MOL 8374/8. PRS 19 Bukit Chuping, Perlis: BOR/MOL 6859/1, BOR/MOL 8363/30, BOR/MOL 12980/1,
Protoconch. Smooth.
Shell shape. Conical. Shell height: 7.20–8.01 mm. Shell width: 8.94–10.08 mm.
Spire. Spire height: 2.17–2.74 mm. Spire width: 3.13–3.68 mm. Number of whorls: up to 4 ½. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 4 ¼ whorls posterior of protoconch.
Breathing tube. Length: 0.71–0.94 mm.
Aperture and peristome. Aperture circular, very expanded. Aperture height: 4.39–5.21 mm. Aperture width: 4.08–5.01 mm. Peristome single to double, not thickened. Peristome orientation 44–49° oblique with respect to the coiling axis.
Spiral lines. Indistinct. Regularly spaced. Approximately 23–37 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 8–9 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, evenly spaced. Approximately 7–10 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs pronounced, unevenly spaced immediately posterior of constriction.
Operculum. Concave, rounded. Exterior covered with thin calcareous layer, smooth. Interior covered with thick proteinaceous coating, smooth, mamillated.
Shell colour. Yellow at apical whorls. Either fades to white towards ultimate whorl or remain yellow throughout.
Living animal. Unknown.
Lives on limestone rock crevices covered by mosses. In shady forests on limestone hills.
Restricted to limestone hills of the Chuping geological formation in central Perlis. Elsewhere, in Koh Samui and Phatthalung, southern Thailand (
Alycaeus roebeleni is most similar to A. perakensis in shell shape but is larger (larger by about 0.97 mm in shell height, 1.96 mm in shell width), spire taller and wider (taller by about 0.22 mm in spire height, wider by about 0.31 mm in spire width), penultimate whorl wider as well as peristome more expanded (
This species was considered closely related to A. perakensis by
Alycaeus roebeleni Möllendorff, 1894. A–E Shell of syntype,
Alycaeus
perakensis
:
Alycaeus (Alycaeus) perakensis
:
Alycaeus
kapayanensis
:
Alycaeus
perakensis
var.
minor
nomen nudum,
SGR 01 Batu Caves, Selangor (3°14'17"N, 101°41'02"E).
Holotype. SGR 01 Batu Caves, Selangor: BOR/MOL 12988. Paratypes. SGR 01 Batu Caves, Selangor: BOR/MOL 6808/1, BOR/MOL 8314/9, BOR/MOL 12989/1. SGR 02 Bukit Takun, Selangor: BOR/MOL 6810/7, BOR/MOL 8318/2.
SGR 01 Batu Caves, Selangor: BOR/MOL 268/2, BOR/MOL 6371/>1, BOR/MOL 8315/24,
Named after Selangor, the state that the type locality of this species is part of.
Protoconch. Smooth.
Shell shape. Conical. Shell height: 5.07–5.44 mm. Shell width: 5.06–5.88 mm.
Spire. Spire height: 1.81–2.00 mm. Spire width: 2.35–2.50 mm. Number of whorls: up to 5 ¼. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 5 whorls posterior of protoconch.
Breathing tube. Length: 0.52–0.71 mm.
Aperture and peristome. Aperture circular, expanded. Aperture height: 2.68–2.37 mm. Aperture width: 2.33–2.61 mm. Peristome double, not thickened, upper palatal section folded posteriorly into a wing-like structure, notched at suture. Peristome orientation 35–40° oblique with respect to the coiling axis.
Spiral lines. Distinct. Regularly spaced. Approximately 20–33 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 7–20 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, white and thicker than those anterior of breathing tube, evenly spaced. Approximately 11–21 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs absent immediately posterior of constriction, becoming pronounced and evenly spaced at the middle until prior to aperture. Approximately 9–14 ribs per 1 mm.
Operculum. Concave, rounded. Exterior covered with thick but flaky calcareous layer, surface finely granulated. Interior proteinaceous layered, smooth, with indistinct mamilla.
Shell colour. Whorls yellow. Peristome white.
Living animal. Body cream-white. Head pinkish-brown. Tentacles reddish-brown.
Lives on wet limestone walls covered with mosses, in forested areas. It can also be found in areas with substantial human disturbance such as on the limestone walls of the temple at Batu Caves.
Restricted to Batu Caves and Bukit Takun, Selangor.
Alycaeus selangoriensis sp. n. is most similar to A. kapayanensis but differs in having a consistently larger shell (larger by about 0.96 mm in shell height, 1.6 mm in shell width), more expanded ultimate whorl and thicker operculum with calcareous exterior. The upper palatal section of the peristome in A. selangoriensis sp. n. is always folded posteriorly and downwards, creating a wing-like extension prior to the notch at the suture, a feature not present in the simple circular expanded peristome of A. kapayanensis. Alycaeus selangoriensis sp. n. resembles A. perakensis in having a moderately expanded ultimate whorl but differs in being smaller shelled (smaller by about 1.37 mm in shell height, 2.08 mm in shell width).
Historically, Alycaeus selangoriensis sp. n. shells have been assigned to superficially similar congeners A. perakensis and A. kapayanensis (
Alycaeus
kelantanensis
:
PHG 02 Gunung Senyum, Pahang (3°41'50"N, 102°26'04"E).
Holotype. PHG 02 Gunung Senyum, Pahang: BOR/MOL 12965. Paratypes. PHG 02 Gunung Senyum, Pahang: BOR/MOL 6880/2, BOR/MOL 12966/69. PHG 03 Gunung Jebak Puyuh, Pahang: BOR/MOL 8395/6, BOR/MOL 12964/2.
PHG 02 Gunung Senyum, Pahang: BOR/MOL 275/1, BOR/MOL 6195/6, BOR/MOL 6239/4, BOR/MOL 6249/11, BOR/MOL 8391/41, BOR/MOL 8392/29,
Named after the type locality, Gunung Senyum.
Protoconch. Smooth.
Shell shape. Conical. Shell height: 4.49–5.01 mm. Shell width: 3.96–4.41 mm.
Spire. Spire height: 1.47–1.94 mm. Spire width: 2.05–2.28 mm. Number of whorls: up to 5 ¼. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus partially closed.
Whorl constriction. At about 5 whorls posterior of protoconch.
Breathing tube. Length: 0.44–0.57 mm.
Aperture and peristome. Aperture circular, very expanded especially at columellar section. Aperture height: 2.17–2.36 mm. Aperture width: 2.02–2.20 mm. Peristome double, thickened, upper palatal section folded posteriorly into a wing-like structure, notched at suture. Peristome orientation 21–28° oblique with respect to the coiling axis.
Spiral lines. Indistinct. Regularly spaced. Approximately 14–24 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 8–15 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, white and thicker than those anterior of breathing tube, evenly spaced. Approximately 14–21 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs unevenly spaced, sometimes distinct but usually absent.
Operculum. Concave, conical. Exterior covered with thin calcareous layer, surface finely granulated. Interior covered with proteinaceous layer, smooth.
Shell colour. Whorls yellow or brownish-red. Peristome white.
Living animal. Body cream-white. Head pink. Tentacles yellow or red.
Lives on both wet, mossy limestone rock walls and boulders. In shady forests on limestone hills. Some living individuals were observed dangling on mucous threads under rock overhangs.
Restricted to limestone karsts at central Pahang (Gunung Senyum and Gunung Jebak Puyuh) only.
Alycaeus senyumensis sp. n. is distinguished from other Alycaeus by its peristome that is distinctly expanded and angled at the columellar section and partially obscuring the umbilicus, narrow ultimate whorl, strong radial ribs, shallow suture and small shell. Alycaeus senyumensis sp. n. is differentiated from the sympatric A. regalis sp. n. and A. costacrassa sp. n. by its much smaller shell and expanded peristome angled at the columellar base.
Historically, Alycaeus senyumensis sp. n. specimens were labelled as A. kelantanensis (
Alycaeus
thieroti
Morgan, 1885b: 403-404, plate 10;
Alycaeus (Orthalycaeus) thieroti
:
Alycaeus (Alycaeus) thieroti
:
Alycaeus
liratulus
:
Pincerna
thieroti
:
PRK 18 Gunung Lanno, Perak (4°31'31"N, 101°08'48"E).
Syntype. Gunong Lano (= PRK 18 Gunung Lanno), Perak:
Endau-Kluang, Johor: BOR/MOL 6466/1, BOR/MOL 6467/1. KTN 01 Gunung Reng, Kelantan: BOR/MOL 6835/1, BOR/MOL 8335/6. KTN 95 Gua Panjang, Kelantan: BOR/MOL 12962/5. Lojing, Kelantan: BOR/MOL 6528/2. PHG 01 Kota Gelanggi, Pahang: BOR/MOL 6886/2, BOR/MOL 6636/1. PHG 02 Gunung Senyum, Pahang: BOR/MOL 12961/4. PHG 03 Gunung Jebak Puyuh, Pahang: BOR/MOL 6885/3. PHG 05 Bukit Cintamanis, Pahang: BOR/MOL 6633/1. PHG 75 Bukit Tenggek, Pahang:
Protoconch. Smooth.
Globose. Shell height: 4.55–5.68 mm. Shell width: 4.36–5.34 mm.
Spire. Spire height: 1.06–1.58 mm. Spire width: 1.73–2.30 mm. Number of whorls: up to 4. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open or partially closed.
Whorl constriction. At about 3 ⅝ whorls posterior of protoconch.
Breathing tube. Length: 0.40–0.53 mm.
Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 2.28–2.76 mm. Aperture width: 2.42–2.98 mm. Peristome double, thickened, notched at suture. No interspace. Peristome orientation 15–18° oblique with respect to the coiling axis.
Spiral lines. Distinct. Regularly spaced. 20–37 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 8–15 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced, evenly spaced. Approximately 9–21 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Ranges from absent to indistinct, unevenly spaced.
Operculum. Almost flat. Exterior covered by calcareous layer. Exterior has calcareous ridges radiating outwards of the nucleus. Interior covered by proteinaceous layer, smooth.
Shell colour. Variable – red, yellow or white.
Living animal. Body cream-white or maroon. Head pink. Tentacles red or brown tipped.
Lives in crevices on wet limestone boulders and shrubs close to the ground. In thickly forested areas. Lives in both limestone and non-limestone areas.
Widespread in Perak, Selangor, Kelantan and Pahang.
Alycaeus thieroti is most similar to Alycaeus liratulus in shell shape but differs in having a smaller and more elongated shell (smaller by about 1 mm in shell height, 0.8 mm in shell width), narrowly-spaced radial ribs and spiral lines, shorter breathing tube (shorter by 0.65 mm) and flat operculum with calcareous ridges radiating out from the exterior nucleus.
Alycaeus thieroti Morgan, 1885b. A–E Shell of syntype,
Limestone hill at east side of Pulau Dayang Bunting, off Langkawi Island, Kedah (6°12'26"N, 99°47'04"E).
Holotype. Limestone hill at east side of Pulau Dayang Bunting, off Langkawi Island, Kedah: BOR/MOL 12978. Paratypes. Limestone hill at east side of Pulau Dayang Bunting, off Langkawi Island, Kedah: BOR/MOL 12979/1, BOR/MOL 6248/6.
Latin, meaning pregnant maiden. Named after the type locality, Pulau Dayang Bunting, meaning island of the pregnant maiden.
Protoconch. Smooth.
Shell shape. Conical. Shell height: 4.71–5.14 mm. Shell width: 4.44–4.97 mm.
Spire. Spire height: 1.68–1.77 mm. Spire width: 2.19–2.50 mm. Number of whorls: up to 4 ½. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.
Whorl constriction. At about 4 ¼ whorls posterior of protoconch.
Breathing tube. Length: 0.49–0.51 mm.
Aperture and peristome. Aperture circular, expanded. Aperture height: 2.10–2.36 mm. Aperture width: 2.10–2.29 mm. Peristome double, not thickened, notched at suture. Peristome orientation 29–33° oblique with respect to the coiling axis.
Spiral lines. Distinct. Regularly spaced. Approximately 18–34 lines per 1 mm.
Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 11–15 ribs per 1 mm.
Radial ribs running perpendicular to breathing tube. Radial ribs pronounced and thicker than those anterior of breathing tube, evenly spaced. Approximately 14–17 ribs per 1 mm.
Radial ribs running posterior of breathing tube. Radial ribs pronounced, unevenly spaced throughout.
Operculum. Concave, rounded. Exterior calcareous layer thick, smooth and polished. Exterior nucleus punctured through, with a cup-like projection. Four concentric ridges were distributed in the tunnel within the thick, cup-like projection. Interior calcareous, with dense concentric circles of multimellae, nucleus punctured through. Operculum edge teethed, etched with regularly spaced grooves.
Shell colour. Whorls yellow. Peristome white.
Living animal. Unknown.
Unknown.
Known only from the type locality Pulau Dayang Bunting, Langkawi archipelago.
Alycaeus virgogravida sp. n. is similar to A. kapayanensis in having a conical shell but is distinguished by its more expanded whorls, spacing of radial and spiral ribs, and notably, the thick, calcareous operculum with cup-shaped nucleus. Alycaeus virgogravida sp. n. is distinguished from the globose-shelled Alycaeus liratulus, the only other species in Peninsular Malaysia with cup-shaped operculum nucleus, by its conical shell.
Alycaeus virgogravida sp. n. is the only small, conical and yellow Alycaeus species in Peninsular Malaysia with cup-shaped operculum.
This study was conducted with permits from the Department of Wildlife and National Parks Peninsular Malaysia (JPHL&TN(lP):100-34t1.24 Jld 6(14)) and the Forestry Department of Peninsular Malaysia (JH/100 Jld. 14(9); PPN.PK 600/03/01Jld 9(62); AM-PM-202-16). We thank Páll-Gergely Barna, Gopalasamy Reuben Clements, Mohammad Effendi Marzuki and Siong Kiat Tan for help with processing museum (
List of names and coordinates of localities visited during fieldwork in 2016
Data type: Table in CSV file
Explanation note: A CSV file containing a list of name and coordinates of localities visited during fieldwork in 2016.
List of specimen measurements used for this study
Data type: Table in Microsoft Excel file
Explanation note: A Microsoft Excel file containing a list of specimens and their measurements used in this study.