Wallaconchis sinanui, designated here.

Combination of Wallace, for Alfred Russel Wallace, one of the first naturalists to widely study the fauna of the Indo-Malay Archipelago, and Onchis, one of the names used to refer to onchidiid slugs. The core of the geographic distribution of this genus in Indonesia (Bali, Lombok, Sulawesi, and eastern Indonesia) corresponds to a region sometimes referred to as Wallacea, also after A. R. Wallace, which makes it especially fitting here.

Masculine, gender of Onchis.

Body not flattened. Dorsal gills absent. Dorsal eyes present on notum, mostly in groups of three or four eyes. Central dorsal papilla bearing eyes present and retractable, but usually not raised above the dorsal surface. Eyes at the tip of short ocular tentacles. Male opening below the right ocular tentacle. Oral lobes typically grey or dark brown. Pneumostome median. Foot wide. Visceral cavity pigmented (in black), which varies in intensity between individuals. Intestinal loops of type I. Rectal gland absent. Accessory penial gland absent. Penial morphology highly diverse, from short and straight to long and coiled. Penial hooks absent or present.

Every available genus name was carefully evaluated when searching for a name for this genus, which included examination of the type specimens of the type species of all existing genera, as well as the analysis of all the original descriptions. Nine existing species names are transferred to Wallaconchis, five of which are valid, one of which is a synonym, and three of which are nomina dubia. Historically, these five valid species names have been placed in three different genera: Onchidium Buchannan, 1800, Paraoncidium Labbé, 1934, and Scaphis Labbé, 1934. However, all five species were originally described in Onchidium (sometimes with the unjustified emendation Oncidium), traditionally used by default for many unrelated onchidiids (Dayrat 2009): Onchidium ater Lesson, 1830; Onchidium graniferum Semper, 1880; Oncidium nangkauriense Plate, 1893; Oncidium buetschlii Stantschinsky, 1907; and Oncidium gracile Stantschinsky, 1907. The one species name which is a synonym, Oncidium keiense Hoffmann, 1926, and the three species names which are nomina dubia (Onchidium ovale Semper, 1880; Oncidium simrothi Plate, 1893; Oncidium fungiforme Stantschinsky, 1907), were also originally created in the genus Onchidium. From this point forward, the unjustified emendation Oncidium is not repeated throughout the paper and is systematically replaced by the correct spelling Onchidium. The genus Onchidium actually refers to a different taxon including only three species and characterized by features (e.g., large dorsal conical papillae, rectal gland, accessory penial gland) that are absent in the species described here (see Dayrat et al. 2016). Hoffmann (1926) decided not to create a new genus for Onchidium keiense, despite the distinctive morphology of the copulatory parts: “The peculiarity of the penis could almost suggest the idea that we are dealing here with a whole new genus. In the genus Onchidium, however, there are already species which differ quite considerably from each other, so that I have no reason to create a new genus for my species.” (1926: 24, translated from German).

Hoffmann (1928) briefly mentioned the morphological similarity of six Onchidium species (Onchidium papuanum Semper, 1880, Onchidium palaense Semper, 1880, Onchidium ovale, O. buetschlii, O. nangkauriense, and Onchidium chameleon Brazier, 1886) which all lack an accessory penial gland, and five of which also lack a rectal gland: “The following six species are quite close to one another, and there are usually very few characteristic features which can be used for differentiation.” (1928: 81) Hoffmann (1928) also mentioned that some of those six names would likely become synonyms as new material became available, but none of these names has been proposed as synonymous. Three of these names are transferred to Wallaconchis here (O. ovale, O. buetschlii, and O. nangkauriense). Onchidium chameleon belongs to the genus Onchidina Semper, 1882 (Dayrat and Goulding 2017). Onchidium palaense and O. papuanum are poorly known because their type material is lost. However, Semper’s description of the position of the male aperture as “between the two very small eye tentacles” in O. palaense (1882: 276) and “exactly in the center line between the tentacles and mouth” in O. papuanum (1882: 277) indicates that they belong to another genus. A few years later, Labbé (1934) created the genus name Paraoncidium for eleven Onchidium species with no accessory penial gland, including the six aforementioned species considered morphologically similar by Hoffmann (1928). However, P. chameleon, the type species of Paraoncidium, belongs to the genus Onchidina and Paraoncidium is a junior synonym of Onchidina (Dayrat and Goulding 2017). The genus Onchidina, which so far is monotypic, differs greatly from Wallaconchis (e.g., dorsal eyes absent, male aperture on right lateral side of right ocular tentacle, rectal gland present).

Finally, a new combination was proposed by Labbé (1934) for Onchidium ater as Scaphis atra. However, Scaphis Starobogatov, 1976 is a synonym of Peronia Fleming, 1822 which refers to a different group of onchidiids characterized by dorsal gills, which are lacking in all the species described here.

Overall, none of the three genus names historically used in binomials for the species described here (Onchidium, Paraoncidium, Scaphis) could apply to our new genus.

(Fig. 6). Wallaconchis species are distributed from the Andaman Islands (India) in the Bay of Bengal to Vanuatu in the western Pacific. Nine out of ten species are sympatric over at least part of their distribution. Eight out of ten species are found widely within the Coral Triangle. Two species are known from only one station each, which suggests that they are endemic to a small region and specialized to a particular habitat. All species are found in tropical waters.

Figure 6. 

Geographic distribution of Wallaconchis species. The colors used for each species are the same as those used in phylogenetic trees (Figs 1–5), but note that for W. ater, W. graniferum, and W. melanesiensis, both units #1 and #2 are included within the distribution of the species and that only the color of unit #1 is being used. Black dots show sites sampled by the authors, and grey dots (in Papua New Guinea and the Pacific) show localities where samples were borrowed from a museum collection.

(Table 3). Wallaconchis slugs are found in various intertidal habitats. Two new species (W. comendadori and W. melanesiensis) live predominantly in the rocky intertidal, with large rocks covered in thin layers of algae, which may or may not be adjacent to mangrove trees. Two species (W. nangkauriense and W. ater) are commonly found in coral rubble habitats, where Avicennia trees often grow. Three species (W. buetschlii, W. uncinus, and W. sinanui) are found on firm mud (i.e., mud which is not deep and not saturated in water). Two species (W. gracile and W. buetschlii) are found on sandy mud, two species (W. achleitneri and W. buetschlii) on coarse sand, and one species (W. graniferum) on fine sand. Many Wallaconchis species can be found together on diverse substrates at stations with various habitats. For instance, at our station 198, on the southern coast of Bohol, Philippines, six species were present without any other onchidiids on just a few square meters of fine sand mixed with coral rubble and muddy sand.

A unique combination of characters can be used to determine whether a specimen is part of a Wallaconchis species: no dorsal gills, intestinal loops of type I, no rectal gland, and no accessory penial gland. This combination is not found in any other genus and these anatomical features can be easily and quickly observed through dissection. It is more challenging to identify Wallaconchis slugs using external characters, but it is not impossible. Wallaconchis slugs exhibit the highest degree of color variation in the Onchidiidae. In some species, the dorsal notum can be red, yellow, green, orange, brown, grey, black, etc., when most onchidiids are usually just brown, marbled with light to dark brown. Such bright dorsal colors are also found in Peronia, but Peronia is easily distinguished from Wallaconchis (the dorsal notum of Peronia bears gills that are absent in Wallaconchis). However, the three Wallaconchis species which are found on mud inside and around mangroves only occasionally exhibit patches of bright colors, and thus, can be easily mistaken for other genera found in mangroves. The male opening can also help identify Wallaconchis slugs at the generic level. In other genera, the male opening may be to the left of the right ocular tentacle (e.g., Melayonchis, Onchidium), or to the right of the right tentacle (e.g., Peronina, Onchidina), while in Wallaconchis it is directly below the right ocular tentacle (Dayrat et al. 2016, 2017, Goulding et al. in press). Another character which may be observed in Wallaconchis by naturalists in the field, although difficult to appreciate, is that live animals produce a sticky mucus from the ventral surface, which is most noticeable with large animals. Other onchidiids also produce some mucus, but that mucus is usually wet, while the mucus of Wallaconchis can be likened to drying glue.

Indonesia, Ambon, Lateri, 03°38.26'S, 128°14.72'E, st 128, mudflat next to small creek in mangrove preserve.

Holotype, 9/5 mm [2737], designated here (UMIZ 00058).

Indonesia, Ambon, Lateri, 03°38.26'S, 128°14.72'E, 6 specimens 11/6 mm [5844], 10/4 mm [2738], 9/6 mm [5845], 9/4 mm [2746], 9/4 mm [2740], and 7/5 mm [5846], st 128, mudflat next to small creek in mangrove preserve (UMIZ 00059).

Indonesia: Ambon (type locality).

(Fig. 7A–C, Table 3). Wallaconchis sinanui was found in a low intertidal mudflat, by a mangrove. The mud was firm, mixed with small pieces of broken shells, and threads of microalgae. The area in which W. sinanui was found was only about 200 square meters, but the density of slugs was extremely high (dozens of slugs per square meter). This species may need this highly specific substrate because it was not found at any other locality in Ambon or in the nearby island of Seram (Indonesia).

Figure 7. 

Habitats and live specimens, Wallaconchis sinanui, Indonesia, Ambon, Lateri. A Type locality, mudflat adjacent to a shallow river through a mangrove (st 128) B Close up of mud with a few individuals of W. sinanui (same locality as A) C Wider view of the mud with many individuals of W. sinanui (same locality as A) D Dorsal view, 9 mm long [2746] (UMIZ 00059) E Holotype, dorsal view, 9 mm long [2737] (UMIZ 00058) F Dorsal view, 9 mm long [2740] (UMIZ 00059).

Wallaconchis sinanui is dedicated to Dominggus Ledrick Sinanu, the guard of the protected mangrove forest in Lateri who advocated for its conservation. This mangrove forest is one of the few left in Ambon, and the only locality where this species was found.

(Table 5). Externally, Wallaconchis sinanui has been observed with a unique dorsal color pattern. However, samples from additional populations are needed to determine if this dorsal coloration is diagnostic of the species or varies between populations. Additionally, W. sinanui is much smaller than most other Wallaconchis species, with the exception of W. achleitneri (which is endemic to Queensland). Internally, the combination of a smooth, short, and narrow penis, a free oviduct (not attached to the body wall by fibers), and a spherical spermatheca distinguishes W. sinanui from other Wallaconchis species.

(Fig. 7D–F). Live animals are usually not covered with mud and the color patterns on their dorsum are mostly visible. The head is small and remains covered by the dorsal notum as the animal crawls. The body is not flattened, although some animals appear flattened when crawling. The dorsal notum is oval, and not hard. Its surface, covered with small papillae of variable sizes and colors, is granular and not smooth.

The dorsal notum is mostly brown, usually with two additional dark stripes or a longitudinal dark band. The ocular tentacles are light brown. The hyponotum and the foot are brownish-grey.

(Fig. 8A–C). Dorsal gills are absent. Dorsal papillae with so-called ‘dorsal eyes’ are present, with typically three or four eyes per papilla (Fig. 8A). There usually are four or five papillae with dorsal eyes, even though their exact number is difficult to determine because they can be retracted within the notum. The papillae with dorsal eyes are located on the center of the notum. There is a retractable papilla with eyes in the center of the dorsal notum, which is not raised above the other papillae. The foot is wide relative to the hyponotum (between 1/2 and 3/4 of the total width), while in relaxed individuals the foot may even be as wide as the animal. The pneumostome is median (i.e., in line with the anus) and close to the edge of the pedal sole (Fig. 8C). Its position on the hyponotum relative to the notum margin and the edge of the pedal sole varies among individuals between the middle and closer to the notum margin. The anus is posterior, median, and very close to the lateral wall of pedal sole (Fig. 8C). On the right side (to the left in ventral view), a peripodial groove is present at the junction between the pedal sole and the hyponotum, running longitudinally from the buccal area to the posterior end, and ending with the female opening. The female opening is posterior, located approximately 0.5 – 1 mm from the anus depending on the size of the animal (farther from the anus in larger animals). The male aperture (opening of the penis) is anterior, located below the right ocular tentacle (Fig. 8B). The position of the male aperture varies little between individuals.

Figure 8. 

External morphology and digestive system, Wallaconchis sinanui, Indonesia, Ambon (A–C) holotype [2737] (UMIZ 00058) (D–F) [2738] (UMIZ 00059). A Dorsal notum B Anterior region, ventral view C Posterior region, ventral view D Digestive system, dorsal view E Digestive system, dorsal view (digestive gland removed) F Digestive system, ventral view (digestive gland removed). Abbreviations: a anus ddg dorsal digestive gland f foot fo female opening hn hyponotum i intestine mo male opening oddg opening of the dorsal lobe of the digestive gland oldg opening of the lateral lobe of the digestive gland opdg opening of the posterior lobe of the digestive gland ol oral lobe ot ocular tentacle pn pneumostome pdg posterior lobe of the digestive gland ppg peripodial groove st1 first stomach chamber st2 second stomach chamber st3 third stomach chamber st4 fourth stomach chamber. Scale bars: 2 mm (A, B, C); 1 mm (D, E, F).

Marginal glands (found in Onchidella Gray, 1850) are absent. The visceral cavity is not divided: the heart is not separated from the visceral organs by a thick, muscular membrane (as in Hoffmannola Strand, 1932). The heart is enclosed in the pericardium, in the posterior half of the right side of the visceral cavity. The large, anterior, ventricle becomes a large aorta that branches into smaller vessels delivering blood to the visceral organs. The auricle, significantly smaller than the ventricle, is posterior. The pericardium communicates through a small hole with the right portion of the renal-pulmonary complex. The kidney is intricately attached to the pulmonary cavity and is slightly asymmetrical (the right part being slightly larger than the left part).

(Figs 8D–F, 9, Table 4). There are no jaws. The left and right salivary glands on either side of the esophagus are heavily branched, joining the buccal mass dorsally. The radula is located between two large postero-lateral muscular masses. Each radular row contains a rachidian tooth and two half rows of lateral teeth. Examples of radular formulae are presented in Table 4. The half rows of lateral teeth form an angle of approximately 45° with the rachidian axis. The rachidian teeth are tricuspid: the median cusp is always present (Fig. 9A); the two lateral cusps, on the lateral sides of the base of the rachidian tooth, are small and inconspicuous (Fig. 9A). The lateral aspect of the base of the rachidian teeth is straight. The length of the main cusp of the rachidian teeth is approximately 15 µm, significantly smaller than that of the lateral teeth. The lateral teeth are unicuspid with a flattened and curved hook (Fig. 9B). The length of the hook of the lateral teeth gradually increases from 25 to 35 µm, along the half row from the inner teeth to the outer teeth, excluding the innermost lateral tooth and several outermost lateral teeth (Fig. 9D, F) which are significantly smaller. The inner and outer lateral aspects of the hook of the lateral teeth are straight (i.e., not wavy and not forming any protuberance). Along a half row, the lateral teeth transition in shape from the inner region, in which the lateral teeth are wide (Fig. 9C), to the outer region, in which the lateral teeth are narrow and closely packed (Fig. 9D, F). The wide lateral teeth of the inner third to half of each half row bear a spine on the lateral expansion of the base, while the narrow lateral teeth in the outer region of each half row lack a basal lateral spine (Fig. 9E, F). In most cases, the basal lateral spine cannot be observed because it is hidden below the hook of the next, outer lateral tooth.

Figure 9. 

Radula, Wallaconchis sinanui, Indonesia, Ambon [5845] (UMIZ 00059). A Rachidian and innermost lateral teeth B Rachidian and innermost lateral teethC Transition between inner lateral teeth and outer lateral teeth D Outermost lateral teeth E Right lateral teeth with basal lateral spine F Outermost lateral teeth. Abbreviations: rt rachidian tooth mc median cusp lc lateral cusp 1llt first left lateral tooth 1rlt first right lateral tooth 2llt second left lateral tooth 2rlt second right lateral tooth bls basal lateral spine (of lateral tooth) nls no lateral spine hlt hook of lateral tooth ollt outermost left lateral tooth. Scale bars: 10 μm (A); 20 μm (B, D, E); 40 μm (C), 10 μm (F).

The esophagus is narrow and straight; its internal folds cannot be seen externally. The esophagus enters the stomach anteriorly. The stomach is located on the left dorsal side of the visceral mass. In dorsal view, only a portion of its posterior aspect can be seen because it is partly covered by the lobes of the digestive gland. The dorsal lobe is mainly on the right, the left, lateral lobe is mainly ventral, and the posterior lobe covers the posterior aspect of the stomach. The stomach is a U-shaped sac divided into four chambers (Fig. 8E, F). The first chamber, just distal to the esophagus, is delimited by a thin layer of tissue, and receives the ducts of the dorsal and left lateral lobes of the digestive gland. The second chamber is delimited by a thick, muscular layer of tissue, and receives the duct of the posterior lobe of the digestive gland. In the third chamber of the stomach are thick ridges which extend towards the middle of the chamber. The fourth chamber is externally similar to the third chamber but is characterized by much lower and thinner internal ridges. The intestine is long and narrow, with loops of type I (Fig. 8D–F). No rectal gland is present.

(Fig. 10). The circum-esophageal nerve ring is post-pharyngeal and pre-esophageal. The cerebral commissure between the two cerebral ganglia is short but its length varies among individuals. Pleural and pedal ganglia are also all distinct. The visceral commissure is short but distinctly present and the visceral ganglion is approximately median. Cerebro-pleural and pleuro-pedal connectives are very short and pleural and cerebral ganglia touch each other. Nerves from the cerebral ganglia innervate the buccal area and the ocular tentacles, and, on the right side, the penial complex. Nerves from the pedal ganglia innervate the foot. Nerves from the pleural ganglia innervate the lateral and dorsal regions of the mantle. Nerves from the visceral ganglia innervate the visceral organs.

Figure 10. 

Nervous system, Wallaconchis sinanui, holotype, Indonesia, Ambon [2737] (UMIZ 00058) scale bar 0.5 mm. Abbreviations: lcg left cerebral ganglion lpg left pedal ganglion lplg left pleural ganglion rcg right cerebral ganglion rpg right pedal ganglion rplg right pleural ganglion vg visceral ganglion.

(Fig. 11A). Sexual maturity is correlated with animal length. Mature individuals have large, fully-developed, female and male parts. Immature individuals may have small, inconspicuous, or simply no female organs, and rudimentary male parts.

The hermaphroditic gland is a single mass. A hermaphroditic duct conveys the eggs and the autosperm from the hermaphroditic gland to the fertilization chamber, which connects to a large, elongate, usually bent receptaculum seminis (caecum). The shape and size of the receptaculum seminis vary between individuals. The female gland mass contains various glands (mucus and albumen) of which the exact connections remain uncertain. The spermoviduct (for the autosperm, the exosperm, and the eggs) is embedded within the female gland mass, at least proximally. Distally, the spermoviduct branches into the deferent duct (which conveys the autosperm to the anterior region, running through the body wall) and the oviduct. The latter conveys the eggs up to the female opening and the exosperm. The oviduct is short (approximately the same length as the free deferent duct) and almost as narrow as the deferent duct. The spherical spermatheca connects to the narrow distal portion of the oviduct through a short duct.

Figure 11. 

Reproductive system, Wallaconchis sinanui, holotype, Indonesia, Ambon [2737] (UMIZ 00058). A Hermaphroditic (female), posterior parts, scale bar 0.8 mm B Anterior, male copulatory parts, scale bar 2 mm. Abbreviations: dd deferent duct fgm female gland mass hd hermaphroditic duct hg hermaphroditic gland ov oviduct ps penial sheath rm retractor muscle rs receptaculum seminis sp spermatheca v vestibule.

(Figs 11B, 12). The male anterior organs include the penial complex (penis, vestibule, deferent duct, and retractor muscle). There is no penial accessory gland. The penis (from 55 to 70 µm long) is narrow and smooth with no hooks (Fig. 12). The vestibule is much wider than the narrow penial sheath (Fig. 11B). The distal end of the penis is within the base of the vestibule. The beginning of the retractor muscle for the penis marks the separation between the deferent duct (proximal) and the penial sheath (distal). The deferent duct is approximately the same width as the penis proximally but becomes larger distally. The deferent duct is convoluted but short. The retractor muscle is approximately the same length as the penial sheath, and inserts posteriorly, on the body wall, near the rectum.

Figure 12. 

Penis, Wallaconchis sinanui, Indonesia, Ambon. A Penis evaginated outside the male opening, scale bar 200 μm [5846] (UMIZ 00059) B Penis removed from vestibule, scale bar 20 μm [5844] (UMIZ 00059).

Indonesia, Ambon, Lateri, 03°38.26'S, 128°14.72'E, st 128, mudflat next to small creek in the low intertidal of mangrove preserve.

Holotype, 22/17 mm [2751], designated here (UMIZ 00004).

Indonesia, North Sulawesi, Wori, 01°36.06'N, 124°51.73'E, 4 specimens 22/11 mm [2256], 22/16 mm [2250], 18/7 mm [2268], 17/7 mm [2261], st 90, old Avicennia, Sonneratia, Rhizophora mangrove forest with, rocks and dead logs (UMIZ 00005); Ambon, Lateri, 03°38.26'S, 128°14.72'E, 1 specimen 30/21 mm [2752], st 128, mudflat next to small creek and mangrove (UMIZ 00006); Ambon, Lateri, 03°38.24'S, 128°14.78'E, 1 specimen 28/17 mm [2843], st 131, muddy Rhizophora mangrove (UMIZ 00007); Bali, Pemuteran, Labuhan Lalang Harbor, 08°08.61'S, 114°32.33'E, 1 specimen 15/13 mm [3138], st 157, coral rubble, rocks and a few Avicennia (UMIZ 00008); North Maluku, Ternate, Bastiong, 00°46.41'N, 127°22.76'E, 1 specimen (24/11 mm [5056]), st 203, muddy rocks near a mangrove (UMIZ 00009); Halmahera, Sofifi, 00°45.47'N, 127°35.90'E, 2 specimens 25/16 mm [5070] and 22/16 mm [5029], st 205, Sonneratia mangrove (UMIZ 00010); Halmahera, Akelamo, 01°01.33'N, 127°39.09'E, 2 specimens 40/25 mm [5079] and 35/30 mm [5080], st 207, sandy-muddy beach at margin of mangrove (UMIZ 00011); Timor, Oesapa, Kupang City, 10°08.73'S, 123°38.10'E, 1 specimen 29/18 mm [5900], st 250, open Sonneratia mangrove (UMIZ 00071).

Indonesia: Ambon (type locality), Bali, Halmahera, northern Sulawesi, and Timor.

(Fig. 13, Table 3). Wallaconchis uncinus predominantly lives on firm mud, in and around mangroves. It can also sometimes be found on rocks inside or adjacent to muddy mangroves. It lives in the low to mid-intertidal zone (i.e., not in higher and dry areas only submerged at the highest tides) but is not found on water-saturated mud (unlike onchidiid species in other genera). Wallaconchis uncinus frequently co-occurs with W. buetschlii. It was also found in the same microhabitat as W. sinanui but in much lower abundance (one individual of W. uncinus was found on a patch of mudflat amongst dozens of individuals of W. sinanui).

Figure 13. 

Habitats, Wallaconchis uncinus, Indonesia. A, B Sulawesi, Wori, tall mangrove forest of Sonneratia and some Avicennia with a rocky area and dead logs (st 90) C Ambon, Lateri, muddy mangrove with Rhizophora and Avicennia (st 131) D Type locality, Ambon, Lateri, mudflat adjacent to a shallow river through a mangrove (st 128) E Halmahera, Sofifi, mangrove with Sonneratia trees, dense roots and hard mud (st 205) F Ternate, Bastiong, muddy rocks nearby a mangrove patch (st 203).

From the Latin adjective uncinus meaning “hooked”, to refer to the distinctive hooks that the penis bears.

(Table 5). Wallaconchis uncinus cannot be distinguished from other Wallaconchis species based on external features. Red individuals occur in at least three other species (i.e., W. nangkauriense, W. buetschlii, and W. ater). Individuals of W. uncinus with orange and yellow bands could be confused with W. gracile or W. buetschlii, and these color patterns also occasionally occur in onchidiid species of other genera (personal observation). Brown individuals of W. uncinus cannot be distinguished from brown individuals of other Wallaconchis species. Internally, the flattened hooks (both the curved hooks and the rounded hooks) can be used for identification because they are not present in any other known onchidiid species.

(Fig. 14). The dorsal color is variable but is often completely brown or brown mottled with dark orange or bright yellow. Occasionally, specimens are entirely red or black. The color of the hyponotum ranges from light grey to cream and orange in color. The color of the foot is yellow-grey or light grey. The brownish-orange ocular tentacles are short and extend for only a few mm beyond the margin of the notum when the animal crawls undisturbed.

Figure 14. 

Live specimens, Wallaconchis uncinus, Indonesia. A Dorsal view, 25 mm long [5070], Halmahera (UMIZ 00010) B Holotype, dorsal view, 22 mm long [2751], Ambon (UMIZ 00004) C Dorsal view, 30 mm long [2752], Ambon (UMIZ 00006) D Dorsal view, 28 mm long [2843], Ambon (UMIZ 00008) E Dorsal view, 15 mm long [3138], Bali (UMIZ 00005) F Dorsal view, 25 mm long [5080], Halmahera (UMIZ 00011) G Ventral view, same as F H Ventral view, same as B.

(Fig. 15A–C). There usually are between six and 12 papillae with dorsal eyes (even though their exact number is difficult to determine because they can be retracted within the notum). Exceptionally, 23 papillae were observed in one preserved specimen from Halmahera (Fig. 15C). The female opening is posterior, located 3 – 5 millimeters from the anus (Fig. 15B) depending on the size of the animal (farther from the anus in larger animals). The male aperture is located below the right ocular tentacle (Fig. 15A)

Figure 15. 

External morphology and digestive system, Wallaconchis uncinus, Indonesia. A Anterior region, ventral view, Sulawesi, scale bar 2 mm [2268] (UMIZ 00005) B Posterior region, ventral view, Sulawesi, scale bar 2 mm [2268] (UMIZ 00005) C Dorsal notum (papillae with dorsal eyes), Halmahera, scale bar 2.6 mm [5056] (UMIZ 00009) D Digestive system, dorsal view, Sulawesi, scale bar 1 mm [2268] (UMIZ 00005). Abbreviations: a anus ddg dorsal lobe of digestive gland f foot fo female opening hn hyponotum i intestine mo male opening ol oral lobe ot ocular tentacle pdg posterior lobe of the digestive gland pn pneumostome ppg peripodial groove st2 stomach chamber 2.

(Figs 15D, 16, Table 4). Examples of radular formulae are presented in Table 4. The length of the main cusp of the rachidian teeth is approximately 20 µm, significantly smaller than that of the lateral teeth. The length of the hook of the lateral teeth gradually increases from 40 to 55 µm, excluding the innermost lateral tooth and several outermost lateral teeth, which are significantly smaller. The intestinal loops are of type I (Fig. 15D).

Figure 16. 

Radula, Wallaconchis uncinus, Indonesia. A Rachidian and innermost lateral teeth, Bali, scale bar 10 μm [3138] (UMIZ 00008) B Rachidian and innermost lateral teeth, Halmahera, scale bar 20 μm [5079] (UMIZ 00011) C Transition from inner to outer lateral teeth, scale bar 20 μm, same as B D Outer lateral teeth, scale bar 40 μm, same as B E Outermost lateral teeth, scale bar 20 μm, same as B F Outermost lateral teeth, Ambon, scale bar 20 μm [2843] (UMIZ 00007). Abbreviations: bls basal lateral spine (of lateral tooth) nls no lateral spine.

(Fig. 17A). The middle portion of the oviduct is much wider than the proximal and distal ends (Fig. 17A). The spherical spermatheca connects to the narrow distal portion of the oviduct through a short duct.

Figure 17. 

Reproductive system, Wallaconchis uncinus, Indonesia. A Hermaphroditic (female), posterior parts, Sulawesi, scale bar 2 mm [2268] (UMIZ 00005) B Anterior, male copulatory parts, Halmahera, scale bar 3 mm [5079] (UMIZ 00011) C Anterior, male copulatory parts, Bali, scale bar 1 mm [3138] (UMIZ 00008) D Penis (fully evaginated), Halmahera, scale bar 0.5 mm [5079] (UMIZ 00011). Abbreviations: dd deferent duct fgm female gland mass hd hermaphroditic duct hg hermaphroditic gland ov oviduct ps penial sheath rm retractor muscle rs receptaculum seminis sp spermatheca v vestibule.

(Figs 17B–D, 18). The penial sheath is long: the length varies between 1/2 of the length of the visceral cavity to nearly the full length of the cavity. The vestibule is approximately 3 mm in length (in mature specimens). The vestibule is wider than the penial sheath and appears cylindrical or spherical depending on the orientation of the penis inside (Fig. 17B). Inside the vestibule, the penis can form multiple circular loops (Fig. 17D), a single loop, or simply be U-shaped. In mature specimens, the penis bears many large flattened hooks of two types: rounded hooks which lay flat on the surface of the penis and curved hooks which project perpendicularly from the surface of the penis (see hook labels, Fig. 18B–D). In the distal region of the penis there may also be immature hooks which are not fully developed (Fig. 18A); these small hooks may also be seen in immature specimens, or they may be absent. The developed hooks differ between regions of the penis: in the distal region, the rounded hooks are spread around the penis; in the middle region, the rounded hooks form a single row (Fig. 18A–B), some of these hooks being adjacent to a row of curved hooks; and, in the proximal region, rounded hooks are generally absent, but the curved hooks may be present. The deferent duct is highly convoluted with many loops (Fig. 17B) (though the deferent duct is significantly less convoluted in immature specimens, see Fig. 17C). The retractor muscle inserts posteriorly, on the body wall, near the rectum.

Figure 18. 

Penis, Wallaconchis uncinus, Indonesia. A Two most distal loops of fully evaginated penis (the loop on the right is proximal to the loop on the left), Halmahera, scale bar 0.5 mm [5079] (UMIZ 00011) B Two most distal loops of (nearly fully evaginated) penis (the loop on the right is proximal to the loop on the left), Ambon, scale bar 300 μm [2843] (UMIZ 00007) C Proximal region of penis, detail view of curved hooks, Sulawesi, scale bar 100 μm [2268] (UMIZ 00005) D Distal region of penis which is not fully evaginated, scale bar 300 μm, same as C. Abbreviations: ch curved hooks ih immature hooks rh rounded hooks.

Australien: Queensland [Queensland, Australia]. Stantschinsky indicated that the syntypes were collected from the state of Queensland by Professor Simroth, but no detailed information about the locality is available in either the original description or the jar of the type material. Fresh material was collected from the type locality (see below, additional material).

Lectotype, 19/17 mm, designated here (SMF 333595/2). The lectotype was dissected prior to the present study and its posterior end is missing. A lectotype is designated here because its remaining anterior, male parts can be used for species identification. The two other syntypes (30/22 mm and 30/29 mm) become paralectotypes (SMF 333595/2). Both paralectotypes were dissected prior to the present study and their male parts are missing. According to the original description, there were four syntypes, so one syntype has been lost or destroyed.

Indonesia, North Sulawesi, Wori, 01°36.06'N, 124°51.73'E, 2 specimens 31/14 mm [2120] and 27/14 mm [2122], st 84, old Sonneratia and Avicennia mangrove (UMIZ 00021); North Sulawesi, Bahoi, 01°43.36'N, 125°01.23'E, 1 specimen 22/18 mm [2189], st 85, sand and small rocks outside a mangrove (UMIZ 00022); North Sulawesi, Wori, 01°36.06'N, 124°51.73'E, 1 specimen 23/14 mm [2249], st 90, old mangrove forest with Avicennia, Sonneratia, and Rhizophora, with rocks (UMIZ 00024); North Sulawesi, Mantehage Island, 01°41.88'N, 124°46.74'E, 1 specimen 32/22 mm [2310], st 91, rocks behind a mangrove of Sonneratia and Rhizophora (UMIZ 00025); Ambon, Haruku Island, 03°36.52'S, 128°25.07'E, 1 specimen 46/21 mm [2722], st 127, rocky Sonneratia mangrove with coral rubble (UMIZ 00026); Ambon, Wai, 03°34.65'S, 128°19.53'E, 1 specimen 31/16 mm [2853], st 132, narrow band of old Avicennia trees on sandy mud, old logs on ground (UMIZ 00027); Seram, 02°58.24'S, 128°07.07'E, 1 specimen 21/17 mm [2872], st 135, mud next to a mangrove (UMIZ 00028); Maluku, Kei Islands, Tual City, Fiditan, 05°35.96'S, 132°45.11'E, 2 specimens 30/16 mm [2928] and 30/15 mm [2933], st 144, rocks behind muddy mangrove of Rhizophora (UMIZ 00029); Lombok, Don Don, 08°54.54'S, 116°21.50'E, 2 specimens 43/23 mm [2982] and 43/23 mm [2989] st 149, old, Avicennia forest with coral rubble (UMIZ 00030); Bali, Gilimanuk, 08°10.16'S, 114°26.65'E, 1 specimen 24/15 mm [3123], st 156, sandy mudflat outside Rhizophora and Avicennia mangrove (UMIZ 00032); Bali, Pemuteran, Labuhan Lalang Harbor, 08°08.61'S, 114°32.33'E, 1 specimen 27/17 mm [3128], st 157, coral rubble, rocks and mud with a few Avicennia (UMIZ 00033); North Maluku, Ternate, Bastiong, 00°46.41'N, 127°22.76'E, 1 specimen 32/19 mm [5016], st 203, muddy rocks near a mangrove (UMIZ 00034); Halmahera, Sofifi, 00°45.47'N, 127°35.90'E, 1 specimen 37/20 mm [5067], st 205, Sonneratia mangrove (UMIZ 00035); Timor, Oesapa, 10°08.73'S, 123°38.10'E, 1 specimen 44/26 mm [5898], st 250, sandy area with Sonneratia and Avicennia (UMIZ 00072). Australia, Queensland, Cairns, Yule Point, 16°34.23'S, 145°30.58'E, 2 specimens 43/23 mm [2554] and 16/10 mm [2555], st 100, sand flat outside mangrove with dense Rhizophora (st100, MTQ). Philippines, Mindanao, [no information on the collecting date], 1 specimen 28/20 mm, paralectotype of W. gracile, [no information on the collector] (ZMB 103082b); Luzon, Batangas, Lian, 13°59.76'N, 120°37.43'E, 1 specimen 52/34 mm [3159], st 181, sandy, open Avicennia forest (PNM 041209); Bohol, Guindulman, 09°44.06'N, 124°27.63'E, 1 specimen 31/25 mm [3631], st 197, rocks, coral rubble, and sand near a few Avicennia trees (PNM 041210); Bohol, Loay, 09°36.23'N, 123°59.72'E, 1 specimen 35/20 mm [3637], st 198, mostly sand, and a few Avicennia (PNM 041211); Bohol, Maribojoc, 09°44.28'N, 123°49.39'E, 2 specimens 36/17 mm [3409] and 18/13 mm [3410], st 202, coral rubble with sand and algae, near Sonneratia (PNM 041212).

Australia: Queensland (type locality). Indonesia: Ambon, Bali, Halmahera, Kei Islands, Lombok, Seram, Sulawesi, and Timor. Philippines: Bohol and Luzon. All records, except the type locality, are new.

(Fig. 19, Table 3). Wallaconchis buetschlii is found on firm mud or coarse sand in mangroves (i.e., mud which is not saturated in water) along with Wallaconchis uncinus. It also lives on fine, sandy mud along with W. gracile.

Figure 19. 

Habitats, Wallaconchis buetschlii. A Indonesia, Sulawesi, Wori, tall mangrove forest of Sonneratia and some Avicennia with a rocky area and dead logs (st 84) B Australia, Queensland, Yule Point, sandy area with a few Rhizophora and Avicennia trees (st 100) C Indonesia, Ambon, Wai, narrow band of old Avicennia trees on sandy mud, with old logs on ground (st 132) D Indonesia, Lombok, Don Don, old Avicennia forest, with coral rubble (st 149) E Indonesia, Sulawesi, Mantehage Island, rocks behind a mangrove of Sonneratia and Rhizophora (st 91) F Indonesia, Bali, Gilimanuk, sandy mudflat outside Rhizophora and Avicennia mangrove (st 156).

(Table 5). The slugs that are part of Wallaconchis buetschlii are the largest of the genus (the largest live animal measured 60 mm). However, species cannot reliably be distinguished based on individual length. Red individuals cannot be distinguished from several species (usually W. nangkauriense and W. ater), and grey or brown individuals cannot be distinguished from other species. Dorsal papillae with yellow tips can be prominent in W. buetschlii, but also can be visible in other Wallaconchis species (particularly in W. melanesiensis). In addition, the dorsal papillae with yellow tips found on the notum of W. buetschlii are nearly identical to those on the notum of several species in other genera. The color of the hyponotum is helpful to distinguish W. buetschlii (grey or yellow-grey hyponotum) from species in other genera (orange hyponotum) that live in the same habitat but is not fully reliable and should only be used with caution (i.e., the orange hyponotum in other onchidiids is occasionally a dull orange-grey similar to the yellow-grey hyponotum of W. buetschlii). As a result, W. buetschlii cannot be reliably distinguished externally from other onchidiid species.

Internally, the penis is diagnostic of W. buetschlii: it is not protected by a penial sheath or a vestibule and bears internal longitudinal ridges. The oviduct attached to the posterior wall of the visceral cavity is peculiar but it also occurs in W. gracile. However, the penis of W. gracile is protected by a penial sheath and extends into the vestibule.

(Fig. 20). The dorsal coloration is variable. It is usually brown or grey, but occasionally brown with red or yellow patches, or even completely red. In some individuals, many small yellow dots are present on the dorsal notum. The color of the ocular tentacles also varies, and may be yellow-orange, brown, or reddish brown. The hyponotum color can be grey, light grey, or yellow-grey. The foot is also grey or yellow-grey. Crawling slugs tend to be elongated, but they contract when disturbed.

Figure 20. 

Live specimens, Wallaconchis buetschlii. A Dorsal view, 46 mm long [2722], Indonesia, Ambon (UMIZ 00026) B Dorsal view, 31 mm long [2853], Indonesia, Ambon (UMIZ 00027) C Dorsal view, 23 mm long [2249], Indonesia, Sulawesi (UMIZ 00024) D Dorsal view, 30 mm long [2928], Indonesia, Kei Islands (UMIZ 00029) E Dorsal view, 52 mm long [3159], Philippines, Luzon (PNM 041209) F Dorsal view, 36 mm long, [3409], Philippines, Bohol (PNM 041212) G Ventral view, 44 mm long [5898], Indonesia, Timor (UMIZ 00072) H Ventral view, same as F I Ventral view, 43 mm long [2982], Indonesia, Lombok (UMIZ 00030).

There are many papillae on the dorsal surface, which are usually bright yellow in color, or occasionally brown. Between six and 14 papillae bear eyes, with three or four eyes per papilla. There is a large, retractable papilla with eyes in the center of the dorsal notum, and it is often raised several millimeters above the dorsal surface.

(Fig. 21, Table 4). Examples of radular formulae are presented in Table 4. The length of the rachidian teeth is approximately 20 µm, significantly smaller than that of the lateral teeth. The length of the hook of the lateral teeth gradually increases, from 40 to 75 µm, from the inner to the outer teeth, excluding the innermost and outermost lateral teeth which are significantly smaller. The intestinal loops are of type I.

Figure 21. 

Radula, Wallaconchis buetschlii (A–D) Indonesia, Sulawesi [2120] (UMIZ 00021) (E) Australia, Queensland [2554] (MTQ st100) (F) Australia, Queensland [2555] (MTQ st100). A Rachidian and innermost lateral teeth, scale bar 10 μm B Rachidian and innermost lateral teeth, scale bar 40 μm C Inner lateral teeth, scale bar 30 μm D Outermost lateral teeth, scale bar 20 μm E Outermost lateral teeth, scale bar 10 μm F Transition between inner lateral teeth and outer lateral teeth, with the basal lateral spine revealed on the underside of the inner lateral teeth at the bottom, scale bar 30 μm.

(Fig. 22A). The distal region of the oviduct forms a loop, approximately 1/2 to 3/4 of a circle, attached by fibers of tissue to the inner wall of the visceral cavity (Fig. 22A). The oviduct is narrow and approximately of the same width as the deferent duct. The spermatheca is apple-shaped and joins the middle part of the oviduct through a short duct.

Figure 22. 

Reproductive system, Wallaconchis buetschlii. A Hermaphroditic (female), posterior parts, Indonesia, Sulawesi, scale bar 2 mm [2120] (UMIZ 00021) B Anterior, male copulatory parts, Australia, Queensland, scale bar 1 mm [2555] (MTQ st100) C Anterior, male copulatory parts, Indonesia, Kei, scale bar 1 mm [2933] (UMIZ 00029). Abbreviations: dd deferent duct fgm female gland mass hd hermaphroditic duct hg hermaphroditic gland of oviduct fibers attaching to the inner wall of the visceral cavity ov oviduct ps penial sheath rm retractor muscle rs receptaculum seminis sp spermatheca.

(Figs 22B, C, 23). The anterior, male copulatory apparatus exclusively consists of the deferent duct, the penis, and the retractor muscle of the penis. The penis, distal to the deferent duct, is a long and smooth tube, which can evaginate like a glove. It is not protected by a distinct penial sheath and, strictly speaking, there is no vestibule either. The penis is narrow proximally, widens gradually, with three longitudinal, internal ridges distally (one ridge shown in Fig. 23). In small individuals, the penis is narrow for its entire length. The relative length of the penis compared to that of the retractor muscle varies greatly, from both being of similar length to the penis being five times longer than the retractor muscle. The retractor muscle inserts near the rectum at the posterior end of the visceral cavity. In mature specimens, the deferent duct is thicker than the penis and convoluted distally (Fig. 22C). In immature individuals, the deferent duct is thinner, and less convoluted (Fig. 22B).

Figure 23. 

Penis, Wallaconchis buetschlii, Indonesia. A Longitudinal ridge on the internal surface of the penis, Kei Islands, scale bar 60 μm [2933] (UMIZ 00029) B Close-up of a groove between two longitudinal ridges showing smooth internal surface (no hooks), Sulawesi, scale bar 20 μm [2120] (UMIZ 00021).

Stantschinsky’s Onchidium buetschlii refers to a Wallaconchis species because of the unique combination of characters of the lectotype (intestine of type I, no penial accessory gland, no rectal gland). Stantschinsky’s original description of the penis (confirmed by our examination of the lectotype) matches exactly the penial anatomy of the species described here. The unique attachment of the oviduct to the posterior body wall was not described by Stantschinsky but is clearly present in the lectotype as well. Because the male parts of the two paralectotypes of W. buetschlii are missing, it cannot be confirmed that they are part of W. buetschlii. The anatomy of the posterior (female) reproductive parts of the paralectotypes matches that of the lectotype (with an oviduct attached to posterior body wall), indicating that they could be part of either W. buetschlii or W. gracile.

The two syntypes used by Stantschinsky to describe Onchidium gracile are part of two distinct species; therefore, one specimen is designated as the lectotype (see Wallaconchis gracile). The paralectotype of O. gracile is part of W. buetschlii. Both species share the unique attachment of the oviduct to the posterior body wall and are anatomically extremely similar. However, the penis (of the lectotype) of W. gracile is within a penial sheath, while the penis (of the lectotype) of W. buetschlii lacks a penial sheath. The penis of the paralectotype of W. gracile matches perfectly that of (the lectotype of) W. buetschlii. The written description of O. gracile (Stantschinsky 1907: 380–383) is confusing because it likely is a mix of both W. buetschlii (paralectotype) and W. gracile (lectotype). However, Stantschinsky’s (1907: pl. 13, fig. 34) illustration of O. gracile matches the copulatory apparatus of the paralectotype and is thus an illustration of W. buetschlii.

Hoffmann (1928) commented that O. buetschlii is similar to Onchidium palaense, but he did not list any new material for either species, and he does not seem to have examined the type material (he does not mention that he examined it). Semper’s description of the position of the male opening in O. palaense as “between the two very small tentacles, almost in the middle between these” (1880: 276) differs from all Wallaconchis species and indicates that O. palaense does not belong to Wallaconchis. The application of the name O. palaense will be discussed in the revision of another onchidiid genus.

Labbé (1934) identified two specimens from New Guinea as Paraoncidium buetschlii, but he also indicated they might be part of O. palaense, both of which were originally described with no rectal gland. The lack of rectal gland combined with traits described by Labbé (intestinal loops of type I, no accessory penial gland) indicate that the specimens he examined are part of a Wallaconchis species. However, Labbé’s brief description does not provide enough information to determine whether the specimens he examined are part of W. buetschlii or another Wallaconchis species without penial hooks. The fact that Labbé did not see any dorsal eyes was most likely due to preservation because dorsal eyes are present in all known Wallaconchis species. Finally, Bretnall (1919) summarized Stantschinsky’s original description of W. buetschlii but did not examine any new material.

Mindanao, Philippines. No fresh material was collected from the type locality. However, fresh material was collected from Bohol (Philippines), just north of Mindanao, and from Halmahera (Indonesia), just south of Mindanao.

Lectotype, 25/20 mm, designated here (ZMB 103082a). The lectotype was opened previously but all internal organs remain. The other syntype (28/20 mm), which becomes a paralectotype (ZMB 103082b) was dissected by Stantschinsky, but all of the internal organs remain. The paralectotype of W. gracile is part of W. buetschlii, which is not an issue because it is no longer a name-bearing type (see the remarks on both W. gracile and W. buetschlii).

Indonesia, North Sulawesi, Wori, 01°36.06'N, 124°51.73'E, 4 specimens 20/13 mm [2280], 19/15 mm [2252], 9/5 mm [2276], and 8/5 mm [2277], st 90, old Avicennia, Sonneratia, and Rhizophora mangrove with rocks (UMIZ 00055); Bali, Gilimanuk, 08°10.26'S, 114°26.61'E, 3 specimens 22/22 mm [#1], 19/9 mm [3107] and 17/10 mm [3106], st 155, muddy-sandy beach near a mangrove (UMIZ 00056); North Maluku, Ternate, 00°45.18'N, 127°20.17'E, 2 specimens 15/10 mm [5158] and 15/9 mm [5159], st 220, sandy beach behind a rock wall (UMIZ 00057); Timor, Oesapa, 10°08.69'S, 123°38.21'E, 1 specimen 27/18 mm [5932], st 254, mangrove with fine sand (UMIZ 00074). Philippines, Bohol, Loay, 09°36.23'N, 123°59.72'E, 1 specimen 10/5 mm [3633], st 198, mostly sand, and a few Avicennia (PNM 041230); Bohol, Loon, 09°49.91'N, 123°48.33'E, 3 specimens 25/10 mm [3653], 25/10 mm [3652] and 21/11 mm [3648], st 201, fine sand in front of Rhizophora forest (PNM 041231).

Indonesia: Bali, Halmahera, Sulawesi, and Timor. Philippines: Bohol and Mindanao (type locality). All records are new except for the type locality.

(Fig. 24, Table 3). Wallaconchis gracile is found on muddy sand at the margin of mangroves, by the sea (just a few meters away from it). This type of muddy sand is not as saturated with water as a mudflat, nor as firm as a sandy beach. The slugs are sensitive to changes in the pressure on the muddy sand and usually dig in when approached. Wallaconchis gracile is specific to its habitat, and slugs are found only where patches of muddy sand are found.

Figure 24. 

Habitats, Wallaconchis gracile, Indonesia. A–B Bali, Gilimanuk, muddy-sandy beach near a mangrove (st 155) C–D Ternate, sandy mudflat adjacent to a rocky beach (st 220) E–F Timor, sandy area of mangrove with ripples in the sand and near crab pellets (st254).

(Table 5). Wallaconchis gracile cannot be distinguished externally from other Wallaconchis species. Grey or brown individuals cannot be distinguished from any other Wallaconchis species. Even patches of color (i.e., red, yellow- orange, or brown-black) do not help distinguish it from similar species (W. uncinus, W. nangkauriense, W. buetschlii, W. ater, and W. comendadori).

Internally, the attachment of the oviduct to the body wall distinguishes W. gracile from the species with a similar penial anatomy (i.e., W. sinanui, W. comendadori, and W. melanesiensis), but is shared with W. buetschlii. The penial sheath enclosing the penis of W. gracile distinguishes it from W. buetschlii. Also, the retractor muscle is thicker in W. gracile than in W. buetschlii.

(Fig. 25). The dorsal color is usually brown, greyish brown, or dark brown, occasionally with an orange or yellow hue. The color may be homogenous or with brown patterns. Longitudinal stripes or a patch of color (red, yellow-orange, or brown-black) are sometimes present. The hyponotum is light yellow-orange. The foot is light grey.

Figure 25. 

Live specimens, Wallaconchis gracile. A Dorsal view, 19 mm long [3107], Indonesia, Bali (UMIZ 00056) B Dorsal view, 15 mm long [5158], Indonesia, Halmahera (UMIZ 00057) C Dorsal view, 21 mm long [3648], Philippines, Bohol (PNM 041231) D Dorsal view, 19 mm long [2252], Indonesia, Sulawesi (UMIZ 00055) E Dorsal view, 15 mm long [5159], Indonesia, Halmahera (UMIZ 00057) F Dorsal view, 27 mm long [5932], Indonesia, Timor (UMIZ 00074) G Dorsal view, 25 mm long [3652], Philippines, Bohol (PNM 041231) H Frontal view, same as F I Ventral view, 25 mm long [3653], Philippines, Bohol (PNM 041231) J Ventral view, same as F.

Between six and eight dorsal papillae bear eyes, with three or four per papilla. There is a retractable papilla with eyes in the center of the dorsal notum, which may be slightly raised above the dorsal surface.

(Fig. 26, Table 4). Examples of radular formulae are presented in Table 4. The length of the rachidian teeth is approximately 15 µm, significantly smaller than that of the lateral teeth. The length of the hook of the lateral teeth gradually increases (from 35 to 45 µm) from the inner teeth to the outer teeth, excluding the innermost and outermost lateral teeth which are significantly smaller. The intestinal loops are of type I.

Figure 26. 

Radula, Wallaconchis gracile, Indonesia, Bali (A–C) [3106] (UMIZ 00056) (D) [spm #1] (UMIZ 00056). A Rachidian and innermost lateral teeth, scale bar 6 μm B Rachidian and innermost lateral teeth, scale bar 20 μm C Transition between inner lateral teeth and outer lateral teeth, scale bar 30 μm D Left lateral teeth, scale bar 30 μm E Left lateral teeth, gradually increasing in length towards the left, scale bar 40 μm F Outermost lateral teeth, scale bar 20 μm.

(Fig. 27A). The distal region of the oviduct forms a loop (approximately 1/2 to 3/4 of a circle) attached by fibers of tissue to the inner wall of the visceral cavity. The oviduct is narrow and approximately of the same width as the deferent duct. The surface of the spermatheca is marked by several lobes. A short duct connects the spermatheca to the middle part of the oviduct.

Figure 27. 

Reproductive system, Wallaconchis gracile, Indonesia. A Hermaphroditic (female), posterior parts, Sulawesi, scale bar 2 mm [2280] (UMIZ 00055) B Anterior, male copulatory parts, Bali, scale bar 2 mm [3106] (UMIZ 00056). Abbreviations: dd deferent duct fgm female gland mass hd hermaphroditic duct hg hermaphroditic gland of oviduct fibers attaching to the inner wall of the visceral cavity ov oviduct ps penial sheath rm retractor muscle rs receptaculum seminis sp spermatheca.

(Figs 27B, 28). The distal end of the penis lies free within the proximal part of a long, narrow vestibule, and the proximal end of the penis is protected within the penial sheath. The length of the penis varies between individuals, and ranges from approximately 1 – 3 mm. The penis is elongated, narrow, and does not bear hooks (Fig. 28). The narrow penial sheath measures approximately 6 – 8 mm long. Proximally, the vestibule is slightly wider than the penial sheath and gradually widens distally (Fig. 27B). The short retractor muscle is approximately 1.5 – 4 mm long and inserts at the posterior end of the visceral cavity near the rectum. In mature specimens, the deferent duct is convoluted and thicker than the penis.

Figure 28. 

Penis, distal part free in the vestibule, Wallaconchis gracile, Indonesia, Bali, scale bar 40 μm [3106] (UMIZ 00056).

Onchidium gracile refers to a Wallaconchis species due to a unique combination of characters (intestinal loops of type I, no accessory penial gland, and no rectal gland). Stantschinsky’s original description was based on two syntypes which are actually part of two species, hence the necessity of designating a lectotype. The anatomy of one of the former syntypes is in agreement with the species described here, so it is designated as the lectotype to clarify the application of the name W. gracile. The other former syntype, now a paralectotype without a name-bearing function, is anatomically indistinguishable from W. buetschlii. This nomenclatural decision helps avoid having to create a new species name for the species described here. Wallaconchis gracile and W. buetschlii are similar anatomically (Table 4) and it is understandable that Stantschinsky confused them. Stantschinsky’s original description and illustration (pl. 13, fig. 34) of the male parts of W. gracile were based on the paralectotype, and therefore correspond to W. buetschlii.

Stantschinsky (1907: 381, our translation from German) described Onchidium gracile as “very similar in appearance to O. fungiforme” and bearing “much resemblance with regard to internal structure.” Stantschinsky distinguished O. gracile from O. fungiforme externally by the mantle sculpture and the coloration, and internally by the anatomy of the buccal mass and the radular teeth. However, in our experience, all those characters are not informative for distinguishing species in Wallaconchis (or in any other onchidiid genus for that matter). The holotype (24/19 mm), by monotypy, of O. fungiforme (SMF 333604/1), was previously dissected by Stantschinsky. Although the digestive system and the female reproductive system are still present, the penial complex is missing. Onchidium fungiforme needs to be transferred to Wallaconchis because the holotype shares its unique combination of aforementioned characters given above (see diagnostic features of the genus Wallaconchis, p. 22). However, the name W. fungiforme is regarded here as a nomen dubium because its exact application is unclear. The female reproductive parts of the holotype of W. fungiforme bear the distinctive attachment of the oviduct to the body wall only known in W. gracile and W. buetschlii. Of these two species, Stantschinsky’s (1907: 380) description of the penis as “two sharply delineated portions, of which the longer posterior part passes, as a very thin tube, into a gradual thickening” distinguishes it from W. buetschlii and is only consistent with W. gracile. However, a species matching the anatomy of W. fungiforme was not found during extensive sampling in Queensland (29 stations) nor in the MNHN collections from Papua New Guinea. Therefore, it cannot be evaluated whether the male parts of W. fungiforme differ from those of W. gracile or not. Given the large distance (more than 2,500 kilometers) between our samples from the Coral Triangle and the type locality of Queensland, it is unclear whether the names W. fungiforme and W. gracile could apply to a single widely distributed species, or if W. fungiforme is distinct and endemic to Australia. Moreover, it is unclear where the holotype of W. fungiforme was collected exactly since its type locality is simply stated as “Queensland”.

Hoffmann (1928: 82) regarded O. fungiforme as a synonym of Onchidium ovale. However, O. ovale is regarded here as a nomen dubium because its type locality is also unknown. The holotype (22/14 mm) of O. ovale (ZMB 39045) was dissected by Semper. Its internal organs remain, with the exception of the male parts. Onchidium ovale clearly refers to a Wallaconchis species because intestinal loops of type I and a male opening below the right eye tentacle can still be observed in the holotype, and because Semper clearly mentioned the lack of penial accessory gland. The fact that the male parts of the holotype are missing and that they were never illustrated by Semper is yet another reason to regard O. ovale as a nomen dubium.

Hoffmann (1928: 82) regarded O. gracile as a synonym of Onchidium palaense. However, the position of the male opening in Semper’s description of O. palaense (between the ocular tentacles) indicates that O. palaense does not refer to a Wallaconchis species (see remarks on W. buetschlii).

Nangkauri, eine Insel der Nicobaren [Nancowry, Nicobar Islands, Indian Ocean]. No fresh material was collected from the type locality (access to the Nicobar Islands is extremely restricted). However, fresh material was collected from the Andaman Islands, just north of the Nicobar Islands (see below, additional material).

Lectotype, 19/14 mm, designated here (ZMB 45659a). The lectotype was dissected prior to the present study but is well preserved, with all organs remaining except for the penis. The lectotype is designated because it still displays the diagnostic characters of the species (a retractor muscle inserted within the left side of the body wall). The paralectotype (22/15 mm) also was dissected prior to the present study (ZMB 45659b). A piece of the notum is missing, as well as the digestive glands, and a part of the female reproductive system.

India, Andaman Islands, South Andaman, Burman Nala, 11°33.23'N, 92°44.00'E, 2 specimens 25/12 mm [1074] and 24/10 mm [1075], st 53, rocky shore with a patch of Rhizophora, sand and coral rubble, but no mud. (BNHS 50). Indonesia, Sumatra, Lampung, Penegahan, 05°40.40'S, 105°33.76'E, 4 specimens 42/25 mm, 28/15 mm [1787], 23/15 mm [1788], and 23/15 mm [1786], st 78, coral rubble on beach exposed to estuary (UMIZ 00012); North Sulawesi, Bahoi, 01°43.36'N, 125°01.23'E, 2 specimens 25/14 mm [2161] and 18/13 mm [2156], st 85, sand and small rocks outside a mangrove (UMIZ 00013); North Sulawesi, Tamperong, 01°41.51'N, 125°00.80'E, 1 specimen 20/13 mm [2192], st 87, rocks behind mangrove of small Rhizophora trees (UMIZ 00014); North Sulawesi, Wori, 01°36.06'N, 124°51.73'E, 1 specimen 30/20 mm [2257], st 90, old mangrove forest with Avicennia, Sonneratia, and Rhizophora, with rocks (UMIZ 00016); Ambon, Haruku Island, 03°36.52'S, 128°25.07'E, 1 specimen 22/14 mm [2731], st 127, rocky Sonneratia mangrove with coral rubble (UMIZ 00017); Lombok, Seriwe Bay, 08°54.55'S, 116°22.22'E, 1 specimen 39/28 mm [2972], st 148, rocks with Avicennia trees (UMIZ 00018); Bali, Pemuteran, Labuhan Lalang Harbor, 08°08.61'S, 114°32.33'E, 2 specimens 20/12 mm [3136] and 18/12 mm [3129], st 157, coral rubble, rocks and a few Avicennia (UMIZ 00020). Philippines, Luzon, Batangas, Lian, 13°59.76'N, 120°37.43'E, 1 specimen 28/17 mm [3162], st 181, sandy, open Avicennia forest (PNM 041204); Luzon, Batangas, Calatagan, 13°55.32'N, 120°37.26'E, 2 specimens 30/17 mm [3208] and 24/14 mm [3217], st 183, rocks in Avicennia and Rhizophora mangrove (PNM 041205); Bohol, Maribojoc, 09°44.02'N, 123°47.45'E, 3 specimens 32/20 mm [3269], 32/23 mm [3268], and 28/20 mm [3276], st 191, coral rubble with sand (PNM 041206); Bohol, Loay, 09°36.23'N, 123°59.72'E, 1 specimen 21/14 mm [5763], st 198, mostly sand, and a few Avicennia (PNM 041229); Bohol, Maribojoc, 09°44.02'N, 123°47.45'E, 2 specimens 28/16 mm [3396] and 18/12 mm [3401], st 200, coral rubble with sand at night (PNM 041207); Bohol, Maribojoc, 09°44.28'N, 123°49.39'E, 1 specimen 28/16 mm [3427], st 202, coral rubble with sand and algae, near Sonneratia (PNM 041208).

India: Nicobar Islands (type locality) and Andaman Islands. Indonesia: Ambon, Bali, Lombok, Sulawesi, and southeastern Sumatra. Philippines: Bohol and Luzon. All records are new except for the type locality.

(Fig. 29, Table 3). In the Andaman Islands, W. nangkauriense is found in rocky mangroves, on the roots of Rhizophora covered with algae (Fig. 29B). Throughout the rest of its range, W. nangkauriense is found predominantly on coral rubble or small stones, which may be mixed with mangrove trees (Fig. 29C, –D), adjacent to a mangrove (Fig. 29A) or a few isolated mangrove trees (Fig. 29E), or completely without mangrove trees (Fig. 29F). Wallaconchis nangkauriense frequently occurs with W. ater.

Figure 29. 

Habitats, Wallaconchis nangkauriense. A Indonesia, Sulawesi, sand, rocks, pieces of wood behind narrow coastal mangrove (st 85) B India, Andaman Islands, Burman Nala, slugs were on the stilt roots (st 53) C Indonesia, Ambon, Haruku Island, narrow mangrove of Sonneratia trees on rocky beach (st 127) D Close up (same locality as C) E Indonesia, Bali, Pemuteran, Labuhan Lalang Harbor, coral rubble, rocks and a few Avicennia (st 157) F Philippines, Bohol, Maribojoc, coral rubble of uplifted coral reef (st 191).

(Table 5). Wallaconchis nangkauriense cannot be distinguished from other Wallaconchis species based on external features. Brightly-colored individuals (e.g., red, yellow, and orange) cannot be distinguished from W. ater and W. graniferum. Grey or brown specimens cannot be distinguished from any other Wallaconchis species. Internally, however, the extremely long oviduct is a diagnostic feature of W. nangkauriense. The long retractor muscle of the penis inside the posterior body wall is also distinctive (although it is not present in all individuals).

(Fig. 30). In sandy habitats, sand grains may be stuck to the dorsal notum. The dorsal coloration is highly variable, often a mottling of two or three colors. The most common colors are grey, brown, black, and yellow; combinations of red, green and orange also occur. The colors of the hyponotum and foot are variable. The hyponotum is usually light grey or cream, occasionally dark grey or white. The foot is either cream, light grey or dark grey. The color of the ocular tentacles varies between yellow-orange, light brown and reddish brown.

Figure 30. 

Live specimens, Wallaconchis nangkauriense. A Dorsal view, 28 mm long [3162], Philippines, Luzon (PNM 041204) B Dorsal view, 23 mm long [1786], Indonesia, Sumatra (UMIZ 00012) C Dorsal view, 18 mm long [2156], Indonesia, Sulawesi (UMIZ 00013) D Dorsal view, 23 mm long [1788], Indonesia, Sumatra (UMIZ 00012) E Dorsal view, 34 mm long [3269], Philippines, Bohol (PNM 041206) F Dorsal view, 24 mm long [2161], Indonesia, Sulawesi (UMIZ 00013) G Dorsal view, 32 mm long [3268], Philippines, Bohol (PNM 041206) H Dorsal view, 28 mm long [1787], Indonesia, Sumatra (UMIZ 00012) I Dorsal view, 24 mm long [3217], Philippines, Luzon (PNM 041205) J Ventral view, same as G K Ventral view, 28 mm long [3427], Philippines, Bohol (PNM 041208) L Ventral view, 22 mm long [2731], Indonesia, Ambon (UMIZ 00017).

The number of dorsal papillae with eyes (three or four per papilla) is between five and 15, but, exceptionally, 25 papillae were observed in one specimen. There is a retractable papilla with eyes in the center of the dorsal notum, which may be slightly raised above the dorsal surface.

(Fig. 31, Table 4). Examples of radular formulae are presented in Table 4. The length of the rachidian teeth is approximately 20 µm, significantly smaller than that of the lateral teeth. The length of the hook of the lateral teeth gradually increases, from 40 to 65 µm, along the half row from the inner teeth to outer teeth (excluding the innermost and outermost lateral teeth, which are significantly smaller). The intestinal loops are of type I.

Figure 31. 

Radula, Wallaconchis nangkauriense, Indonesia, Bali [3129] (UMIZ 00020). A Rachidian and innermost lateral teeth, scale bar 20 μm B Innermost lateral teeth, scale bar 20 μm C Outer lateral teeth, scale bar 20 μm D Outermost lateral teeth, scale bar 20 μm.

(Fig. 32A). Posteriorly, the oviduct is extremely long, convoluted, and slightly narrow. The spermatheca is spherical and joins the distal region of the oviduct through a thin, short duct.

Figure 32. 

Reproductive system, Wallaconchis nangkauriense. A Hermaphroditic (female), posterior parts, Philippines, Bohol, scale bar 4 mm [3276] (PNM 041206) B Anterior, male copulatory parts, Indonesia, Sulawesi, scale bar 5 mm [2192] (UMIZ 00014) C Anterior, male copulatory parts (vestibule removed around the penis), Indonesia, Sumatra, scale bar 2 mm [1788] (UMIZ 00012). Abbreviations: bc body cavity bw lateral left body wall dd deferent duct fgm female gland mass hd hermaphroditic duct hg hermaphroditic gland ov oviduct p penis ps penial sheath rm retractor muscle rs receptaculum seminis sp spermatheca.

(Figs 32B, C, 33). The distal end of the penis lies free within a long, narrow vestibule, and its proximal end is protected within the penial sheath (in Fig. 32C, distal part of penial sheath removed). The length of the penis varies between individuals and geographic localities and ranges from approximately 9–22 mm. In specimens from the Philippines, the penis tends to be longer and frequently folds back upon itself within the vestibule. The penis is elongated, narrow, and smooth with no hooks (Fig. 33). The length of the penial sheath varies from a few millimeters (in small individuals) to longer than the body length. In addition, the proximal end of the penial sheath may be partially hidden within the left posterior body wall (Fig. 32B). The deferent duct is highly convoluted with many loops; however, in immature specimens, the deferent duct is significantly less convoluted. The retractor muscle enters the body wall at the posterior end of the visceral cavity near the rectum and lies (partially or completely) hidden inside the body wall. The insertion of the retractor muscle varies. In large specimens, the retractor muscle may extend anteriorly inside the left side of the body wall and insert up to half way up the body; in smaller specimens, it inserts within the posterior region of the left body wall. Exceptionally, in large specimens from southeastern Sumatra and the Andaman Islands, the retractor muscle inserts on the posterior wall of the visceral cavity, near the rectum, and not within the body wall. Finally, in small specimens from the Andaman Islands, the retractor muscle inserts on the body wall, near the heart, on the right side of the visceral cavity.

Figure 33. 

Penis, Wallaconchis nangkauriense, Philippines. A Luzon, scale bar 200 μm [3208] (PNM 041205) B Bohol, scale bar 200 μm [3268] (PNM 041206).

Onchidium nangkauriense belongs to Wallaconchis because it shares its unique combination of characters (intestinal loops of type I, no rectal gland, no dorsal gills, no penial accessory gland). Also, there is strong evidence that the name W. nangkauriense applies to the species being described here. Indeed, Plate (1893: pl. 12, fig. 84) illustrated an extremely long oviduct, a character which matches exactly the species described here and has not been found in any other onchidiid species, as well as a long retractor muscle entering the body wall at the posterior end of the body cavity and extending anteriorly inside the left side of body wall, a peculiar character only known in this onchidiid species.

In the same publication, Plate also described Onchidium simrothi from the same type locality as O. nangkauriense (Nangkauri, Nicobar Islands, India). Onchidium simrothi is transferred here to Wallaconchis but is regarded as a nomen dubium because important characters are not mentioned in the original description and could not be observed in the type material. The two syntypes of O. simrothi are small (10/6 and 10/5 mm) and in very poor condition (they previously dried, and most of the organs are missing, with the exception of parts of the female reproductive system and of the digestive system). Plate does not indicate whether the rectal gland is present or absent, but the intestine of type I and the absence of an accessory penial gland indicate that the two syntypes of O. simrothi belong to a Wallaconchis species or a Platevindex species. However, the male opening of O. simrothi (below the right tentacle) and its central dorsal tubercle with multiple eyes are inconsistent with Platevindex. We therefore consider that O. simrothi belongs to Wallaconchis. Given that both W. simrothi and W. nangkauriense were described from the Nicobar Islands, that the Nicobar Islands are within the geographic range of only one Wallaconchis species (W. nangkauriense) and are very far from the limits of distribution of all other Wallaconchis species, it is most likely that both names are synonyms. According to Plate, the difference between O. simrothi and O. nangkauriense is the length of their penis (4 mm long and 55 mm, respectively). However, our observations show that the small specimens (< 20 mm long) of W. nangkauriense from the Andaman Islands (which are very close to the Nicobar Islands) have a smaller penis with a retractor muscle inserted halfway down the body, which could explain the shorter penis described by Plate in the tiny (10 mm long) syntypes of O. simrothi. However, strictly speaking, neither Plate’s original description of O. simrothi nor the dried remains of its type material can be used to apply this name to any species. Therefore, O. simrothi is transferred to Wallaconchis but is regarded as a nomen dubium.

Onchidium nangkauriense was transferred by Labbé (1934) to his genus Paraoncidium (because of the lack of penial accessory gland in O. nangkauriense), but he did not comment on the species itself. Labbé (1934) re-described O. simrothi based on new material from New Guinea, which is far from the type locality (Nangkauri, Nicobar Islands). However, Labbé’s specimens were not part of a Wallaconchis species (and thus could not be part of O. simrothi) because their median male opening is incompatible with Wallaconchis. Considering the lack of information about the reproductive anatomy in Plate’s original description of O. simrothi, Labbé likely applied O. simrothi arbitrarily to his specimens from New Guinea, based mostly on the preserved color and the width of the foot in relation to the hyponotum, aspects which do not suffice to distinguish species. Hoffmann (1928) included both O. nangkauriense and O. simrothi in his revision but did not examine any new material or add further comment.

(O. ater). Havre de Doréry (for Dorey), à la Nouvelle Guinée [Manokwari, West Papua, Indonesia]. No fresh material was collected from the type locality. However, fresh material was collected from Halmahera, approximately 700 kilometers from the type locality in West Papua (see below, additional material).

Type locality (O. keiense). Toeal (Kei-Inseln) [Kei Islands, Moluccan Islands, Indonesia]. Fresh specimens were collected from the type locality (see below, additional material).

Type material (O. ater). Two syntypes: 30/17 and 28/15 mm (MNHN 22950). Both syntypes were previously dissected and some internal organs are missing. The posterior (female) reproductive parts remain in the smaller syntype and only the oviduct remains in the larger syntype. The male (anterior) parts are missing in both syntypes. The digestive system is present in both syntypes, but the intestinal loops are not preserved.

Type material (O. keiense). Lectotype, 32/21 mm, designated here (ZMUC). Thirty paralectotypes (35/24 to 11/8 mm) are well preserved (ZMUC), although several specimens were dissected prior to the present study and the male parts were previously removed (ZMUC). The lectotype was dissected for this study and all organs left in vials inside the jar. The species name on the label is Onchidium mortenseni. However, the rest of the information on the label (specimens collected by Mortensen from Toeal and studied by Hoffmann) is identical to the information in Hoffmann’s original description of O. keiense (the collector is not mentioned in the species description, but the title of the paper indicates the species are described based on collections from Mortensen’s expedition). The only other onchidiid species described by Hoffmann from the Kei Islands was Onchidium verruculatum Cuvier, 1830, which Hoffmann recognized thanks to the presence of gills on the posterior notum (O. verruculatum actually belongs to the genus Peronia). Gills are not visible on any of the syntypes labeled O. mortenseni, which strongly suggests that those specimens are the type material of O. keiense and that Hoffmann changed his mind for the specific name (i.e., he replaced mortenseni by keiense).

Indonesia, North Sulawesi, Bahoi, 01°43.36'N, 125°01.23'E, 5 specimens 37/15 mm [2170], 30/15 mm [2145], 26/16 mm [2164], 25/14 mm [2157] and 25/11 mm [2177], st 85, sand and small rocks outside a mangrove (UMIZ 00049); North Sulawesi, Bahoi, 01°43.36'N, 125°01.23'E, 3 specimens 30/18 mm [2221], 29/16 mm [2220] and 26/17 mm [2228], st 88, sand and small rocks outside a mangrove (UMIZ 00050); North Sulawesi, Wori, 01°36.06'N, 124°51.73'E, 1 specimen 33/22 mm [2283], st 90, old Avicennia, Sonneratia, Rhizophora mangrove (UMIZ 00038); North Sulawesi, Mantehage Island, 01°41.88'N, 124°46.74'E, 1 specimen 25/16 mm [2330], st 91, rocks behind a Sonneratia and Rhizophora mangrove (UMIZ 00039); Ambon, Haruku Island, 03°36.52'S, 128°25.07'E, 1 specimen 9/8 mm [2727], st 127, rocky Sonneratia mangrove with coral rubble (UMIZ 00040); Maluku, Kei Islands, Tual City, Fiditan, 5°35.96'S, 132°45.11'E, 1 specimen 17/9 mm [2939], st 144, rocks behind muddy mangrove of Rhizophora trees (UMIZ 00041); Lombok, Seriwe Bay, 08°51.70'S, 116°32.87'E, 1 specimen 18/10 mm [2966], st 147, small beach of coral rubble and rocks by bay (UMIZ 00042); Lombok, Seriwe Bay, 08°54.55'S, 116°22.22'E, 2 specimens 43/20 mm [2970] and 35/24 mm [2974], st 148, rocks behind mangrove with Avicennia trees (UMIZ 00043); Lombok, Don Don, 08°54.54'S, 116°21.50'E, 2 specimens 35/19 mm [2986] and 25/13 mm [2978] st 149, old Avicennia forest with coral rubble (UMIZ 00051); Bali, Gilimanuk, 08°10.26'S, 114°26.61'E, 1 specimen 18/14 mm [3591], st 155, large rocks near a patch of Rhizophora (UMIZ 00052); Bali, Pemuteran, Labuhan Lalang Harbor, 08°08.61'S, 114°32.33'E, 3 specimens 22/12 mm [3137], 20/11 mm [3132], and 14/8 mm [3130], st 157, coral rubble, rocks and a few Avicennia (UMIZ 00053); North Maluku, Ternate, Bastiong, 00°46.41'N, 127°22.76'E, 1 specimen 38/17 mm [5057], st 203, muddy rocks near a mangrove (UMIZ 00046); Halmahera, Akelamo, 01°01.33'N, 127°39.09'E, 1 specimen 35/20 mm [5078], st 207, sandy-muddy beach at margin of mangrove (UMIZ 00047); Halmahera, Foli, 01°14.66'N, 128°10.61'E, 1 specimen 28/16 mm [5121], st 217, rocky shore near a beach (UMIZ 00048); Halmahera, Foli, 01°14.66'N, 128°10.61'E, 1 specimen 25/10 mm [5125], st 217, rocky shore near a beach (UMIZ 00054). Philippines, Luzon, Batangas, Calatagan, 13°55.32'N, 120°37.26'E, 3 specimens 30/16 mm [3215], 29/16 mm [3212] and 26/12 mm [3210], st 183, rocks in Avicennia and Rhizophora mangrove (PNM 041221); Bohol, Maribojoc, 09°44.02'N, E 123°47.45'E, 6 specimens 36/20 mm [3266], 34/21 mm [3271], 33/18 mm [3265], 33/22 mm [3272], 32/20 mm [3277], and 30/17 mm [3270], st 191, uplifted coral rubble with sand (PNM 041222); Bohol, Mabini, 09°51.59'N, 124°34.16'E, 2 specimens 21/12 mm [3373] and 14/8 mm [3370], st 196, open Avicennia and Sonneratia mangrove with sand, and coral rubble (PNM 041223); Bohol, Guindulman, 09°44.06'N, 124°27.63'E, 2 specimens 38/15 mm [3624] and 22/13 mm [3629], st 197, rocks and coral rubble near a few Avicennia trees (PNM 041216); Bohol, Loay, 09°36.23'N, 123°59.73'E, 1 specimen 33/19 mm [3634], st 198, mostly sand, and a few Avicennia (PNM 041217); Bohol, Maribojoc, 09°44.02'N, 123°47.45'E, 2 specimens 29/16 mm [3393] and 19/12 mm [3404], st 200, coral rubble with sand, at night (PNM 041218); Bohol, Maribojoc, 09°44.28'N, 123°49.39'E, 4 specimens 37/17 mm [3420], 33/23 mm [3406], 26/16 mm [3405] and 21/11 mm [3408], st 202, uplifted coral rubble with sand and algae, near Sonneratia trees (PNM 041224).