Research Article |
Corresponding author: Xinzheng Li ( lixzh@qdio.an.cn ) Academic editor: Christopher Glasby
© 2016 Yueyun Wang, Xinzheng Li.
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:
Wang Y, Li X (2016) A new Maldane species and a new Maldaninae genus and species (Maldanidae, Annelida) from coastal waters of China. ZooKeys 603: 1-16. https://doi.org/10.3897/zookeys.603.9125
|
Paramaldane, new genus, with type species Paramaldane glandicincta sp. n., and Maldane adunca sp. n. (Maldanidae, Polychaeta) are described based on material from the coast of south China. The new genus Paramaldane is similar to Maldane Grube, 1860 and Sabaco Kinberg, 1867, but it clearly differs from all genera within the subfamily Maldaninae by a unique combination of characters: the cephalic plate is almost circular with low, entire and smooth cephalic rim, nuchal grooves small and crescentic, lacking a collar on chaetiger 1, short companion notochaetae, a collar-like glandular band on the anterior part of the sixth chaetiger, and a well-developed anal valve. Paramaldane glandicincta sp. n. is characterised by having a glandular band on the anterior part of the sixth chaetiger, an almost circular cephalic plate, an entire and smooth cephalic rim, and small crescentic nuchal grooves. Maldane adunca sp. n. is characterised by a low cephalic rim, nuchal grooves with a strongly curved anterior part and isolated from the cephalic rim. Finally, a taxonomic key to genera of Maldaninae and a comparative table to species of Maldane are provided.
New species, new genus, Maldane , Paramaldane , Polychaeta , South China Sea, taxonomy
The Maldanidae, also known as bamboo worms, is a tubicolous and common family found in hard or soft substrates from the intertidal region to the deep sea (
Arwidsson (1906) split Maldanidae into subfamilies after the major and complete revision of the family, leaving Maldane and Asychis in the nominotypical subfamily as the Maldaninae. The subfamily Maldaninae is recognised by the presence of cephalic and anal plates, and having the anus dorsal to the plate (
During a sorting of the Maldanine specimens deposited in the Marine Biological
The specimens were collected from the South China Sea from 1959 to 1962. They have been stored in 70% ethanol. Specimens were examined under Zeiss Stemi 2000-C stereomicroscopes, and compound microscopes. Drawings were prepared with the aid of ‘AxioCam MRc 5’digital camera fitting on the stereomicroscopes. Line drawings are completed in the Adobe Photoshop CS6 using a graphics tablet. Notochaetae and neurochaetae were extracted carefully and observed under optical and scanning electron microscopes (SEM). All specimens are deposited in the Marine Biological
Morphological comparison of species of Maldane. Unless otherwise indicated, character information is from
Characters | M. adunca sp. n. | M. arctica Detinova, 1985 | M. californiensis Green, 1991 | M. capensis (Day, 1961) | M. cristata Treadwell, 1923 | M. cuculligera Ehlers, 1887 |
---|---|---|---|---|---|---|
Type locality | Southwest of Macao | Arctic | Southern California | South Africa | California | Gulf of Mexico |
Collar on chaetiger 1 | No | No | Yes, limited ventral side | No | No | Yes, limited ventral side |
Pigmentation | absent | ? | ? | Head of living worm flecked with brown | Anterior segments with dark brown pigment | Nuchal groove with brown pigment spot? |
Shape of nuchal grooves | Strongly curved anteriorly, J-shaped | Short, slightly curved | Slightly curved | J-shaped | Short and divergent anteriorly | slightly curved |
Posterior cephalic rim | Low | Pocket-like | Pocket-like | Pocket-like | Pocket-like | Pocket-like |
Dorsal glandular band on chaetiger 5 | Absent | ? | Absent | Absent | Sixth chaetiger with an anterior dorsal flange* | Dorsal glandular band |
Prostomial palpode | Bluntly rounded | Spade-like | Rounded to semi-triangular | Broadly spatulate | Hemispherical | Bluntly rounded |
Border of anal plate | Laterally notched | Laterally notched | Laterally notched | Laterally notched | Laterally notched | Laterally notched |
Ventral part of anal rim | Smooth to slightly crenulate | Smooth | Slightly crenulate | Crenulated | Slightly crenate | Smooth to slightly crenulate |
Characters | M. decorata Grube, 1877** | M. glabra Knox & Cameron, 1971 | M. glebifex Grube, 1860 | M. gorgonensis Monro, 1933 | M. malmgreni McIntosh, 1885*** | M. marsupialis Grube, 1878 |
Type locality | Congo | Port Phillip Bay, Australia | French | Gorgona Island, Colombia | Strait of Gibraltar | Philippines |
Collar on chaetiger 1 | No | Ventrally; inconspicuous | No | No | No | No |
Pigmentation | ? | ? | No pigmentation | ? | ? | 2 eye spots on peristomium |
Shape of nuchal grooves | ? | Faintly J-shaped | Short and arched | Boldly curved | ? | Slightly curved |
Posterior cephalic rim | ? | Pocket-like | Pocket-like | Pocket-like | Low | Pocket-like |
Dorsal glandular band on chaetiger 5 | ? | Absent | Absent | ? | Absent | |
Prostomial palpode | ? | Prow-like | Spade-like | Bluntly rounded | ? | Spade-like |
Border of anal plate | ? | Laterally notched | Laterally notched | Complete, no notches | ? | Complete, no notches |
Ventral part of anal rim | ? | Smooth | Crenulated | Smooth | ? | Smooth |
Characters | M. meridionalis (Chamberlin, 1919) | M. monilata Fauchald, 1972 | M. philippinensis Treadwell, 1931 | M. pigmentata (Imajima & Shiraki, 1982) | M. sarsi Malmgren, 1865 | M. theodori Augener, 1926 |
Type locality | Between Galapagos Islands and Peru | Middle America Trench | Darvel Bay | Kashima Sea | Sweden | Queen Charlotte Sound, New Zealand |
Collar on chaetiger 1 | No | Yes | No | No | No | Yes |
Pigmentation | Living worm with dark pigment areas on anterior body | Without distinct color patterns | ? | Anterior body with brown spots | Anterior end with black-brown pigmentation, but smaller individuals may be missing | ? |
Shape of nuchal grooves | Short, curved | Short, curved | Short, curved | Short, curved in a semicircle | Short, slightly curved | J-shaped |
Posterior cephalic rim | ? | Pocket-like | Pocket-like | Low | Pocket-like | Pocket-like |
Dorsal glandular band on chaetiger 5 | Absent | Absent | ? | Absent | Crescentic glandular band, but not always present | ? |
Prostomial palpode | Narrow and pointed | Broudly rounded | Spade-like | Broudly rounded | Spade-like | Broadly spatulate |
Border of anal plate | ? | Laterally notched | Laterally notched | Laterally notched | Laterally notched | Laterally notched |
Ventral part of anal rim | ? | Crenulated | Smooth | Smooth | Smooth to slightly crenulated | Crenulated |
Paramaldane glandicincta sp. n.
Body with19 chaetigers. Cephalic plate circular. Prostomial palpode bluntly rounded, and confluent with cephalic rim. Cephalic rim low and entire with slight incisions. Cephalic keel short. First chaetiger without collar. Chaetiger 6 with a collar-like glandular band. Neurochaetae beginning to present on the second chaetiger. Notochaetae spirally fringed with short companion chaetae. Two preanal achaetigerous segment. Anus dorsal, with anal valve. Anal plate well-developed, but no anal cirri; with two lateral deep incisions on anal rim.
The generic name is a combination of the prefix para- (meaning resembing) and the generic name Maldane. The new genus is related to Maldane in morphology. Gender: feminine.
The new genus Paramaldane is superficially similar to Maldane Grube, 1860 and Sabaco Kinberg, 1867. The anal plate and notochaetae type of Paramaldane are closer to Maldane. The shape of prostomial palpode and nuchal grooves are closer to Sabaco. However, the new genus can be easily distinguished by the characters of the cephalic plate, which are considered to be of generic importance (
Holotype:
China, south of Hainan Island, 17°30'N, 110°00'E, 28 January 1959.
Complete specimen with 19 chaetigers and two preanal achaetigerous segments. Cephalic plate rounded. Cephalic rim with two lateral creases, margin of the rim almost smooth. Anterior chaetigers biannulate. Sixth chaetiger with thick, collar-like glandular band. Rim of anal plate with deep lateral notches,ventral margin of anal rim crenulate, dorsal margin smooth.
Holotype complete, 43 mm long, and 2.0 mm wide at the third chaetiger. Paratype of
Paramaldane glandicincta sp. n. A ventral side of anterior body B dorsal view of cephalic plate C lateral view of cephalic plate D ventral view of pygidium, arrows show preanal achaetigerous segments and anal valve E frontal view of anal plate F lateral view of glandular band on sixth chaetiger, showing collar-like glandular band G lateral view of neurochaeta from chaetiger 5 H spirally-fringed notochaeta from chaetiger 10 I geniculate companion chaeta from chaetiger 10 J capillary companion chaeta from chaetiger 10. Scale bars: A–F = 0.5 mm, G = 10 μm, H = 50 μm, I–J = 200 μm.
Paramaldane glandicincta sp. n. A–G holotype of
Cephalic plate obliquely truncated, edge almost circular (Fig.
First four chaetigers completely biannulate, each comprising an achaetigerous and chaetigerous annulus. First six chaetigers short, following chaetigers elongated. Epidermal glands developed well on chaetigers 1–6. Glands only present on parapodial tori of following segments.Thick glandular band resembling a collar located on anterior part of sixth chaetiger, covering rear of fifth chaetiger, divided into dorsal and ventral parts by two lateral slits (Figs
Neurochaetae beginning to present on second chaetiger, with many small teeth on main fang (Figs
Two preanal achaetigerous segments marked by parapodial rudiments (Figs
The specific name glandicincta is a combination of glans and cinctus (meaning "belt", feminine form cincta), refering to the characteristic glandular belt on the six chaetiger.
Paramaldane glandicincta sp. n. is characterised by a collar-like glandular band on the anterior margin of the sixth chaetiger.
Holotype:
Other material examined:
China, southwest of Macao, 21°00'N, 113°00'E, 21 April 1959 .
Maldane sarsi.
Cephalic plate obliquely truncated, elliptical. Cephalic rim low and divided into lateral and dorsal lobes by lateral incisions. Lateral cephalic rim confluent with prostomial palpode. Prostomial palpode bluntly rounded. Nuchal grooves deep and strongly curved outward anteriorly, J-shaped. Anal plate almost truncate and rounded. Rim of anal plate low, with deep lateral incisions.
Holotype about 65 mm in length, 1.5 mm in width. Largest specimen more than 70 mm in length, and 3.0 mm in width. Segments short on anterior and posterior body, longer on middle body (Figs
Maldane adunca sp. n. A–C paratype of
Body with 19 chaetigers, two preanal achaetigerous segments followed by a pygidium. Cephalic plate obliquely truncated, elliptical (Figs
First five chaetigers biannulate (Figs
Chaetae of Maldane adunca sp. n. A–B neurochaetae from the 2nd and 17th chaetigers C spinose part of notochaetae D notochaetae from 16th chaetiger E short limbate companion chaetae from 18th chaetiger F transitional part of geniculate companion chaetae G companion chaetae from 14th chaetiger. H–J, notochaetae drawn from optical microscope H spirally-fringed notochaetae I geniculate companion chaetae J bilimbate companion chaetae. BC, bilimbate companion chaeta. GC, geniculate companion chaeta. Scal bars: A–C = 60 μm, D–E = 0.5 mm, F–G = 50 μm, H–J = 0.5 mm.
Two short and rudimentary preanal achaetigerous segments (Figs
Body wall of small individuals thin but thick in large ones. Body of small individuals smooth, semitransparent and lacking epidermal glands. Large individuals with glandular pads on parapodial tori and ventral side of chaetigers 3–5.
The specific epithet is the Latin adjective adunca (feminine, meaning hooked) and refers to the strongly curved nuchal grooves.
Maldane adunca sp. n. is distinctive in the genus Maldane with its low cephalic rim and hook-like nuchal grooves. Maldane adunca sp. n. is close to Maldane sarsi Malmgren, 1865, a potential species-complex, which is thought to be a cosmopolitan species (
1 | First two chaetigers without neurochaetae | Bathyasychis Detinova, 1982 |
– | Only first chaetiger without neurochaetae | 2 |
2 | Chaetiger 6 without collar-like glandular band | 3 |
– | Chaetiger 6 with collae-like glandular band | Paramaldane gen. n. |
3 | Pygidium with anal valve | 4 |
– | Pygidium without anal valve | 5 |
4 | Nuchal grooves U-shaped; prostomial palpode mushroom-shaped | Chirimia Light, 1991 |
– | Nuchal grooves slightly curved to J-shaped; prostomial palpode spade-like | Maldane Grube, 1860 |
5 | First chaetiger without a collar | Asychis Kinberg, 1867 |
– | First chaetiger with a collar complete or limited to the ventral side | 6 |
6 | Nuchal grooves J- or U-shaped; prostomial palpode mushroom-shaped; cephalic rim with crenulations or digitiform cirri; first chaetiger with a collar usually ventrally limited, sometimes complete | Metasychis Light, 1991 |
– | Nuchal grooves small, crescentic; prostomial palpode spadelike or indistinct; cephalic rim smooth without crenulations or digitiform cirri; the first chaetiger with a complete collar | Sabaco Kinberg, 1867 |
This study was financially supported by the Ocean Public Welfare Scientific Research Project (No. 201505004-1 and 201105012). We are grateful to Dr. José Eriberto De Assis of Federal University of Pernambuco for his comments and providing us with many papers. We are grateful to Dr. Geoff Read for his comments and suggestions improving the manuscript. We thank Dr Chris Glasby for his assistance in language. Thanks to all the managers of the MBMCAS for their help with specimens sorting.