Research Article |
Corresponding author: Jian-Wen Qiu ( qiujw@hkbu.edu.hk ) Academic editor: Christopher Glasby
© 2015 Jinghuai Zhang, Yanjie Zhang, Jian-Wen Qiu.
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:
Zhang J, Zhang Y, Qiu J-W (2015) A new species of Amphictene (Annelida, Pectinariidae) from the northern South China Sea. ZooKeys 545: 27-36. https://doi.org/10.3897/zookeys.545.6454
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Pectinariids are a family of polychaetes commonly found in shallow coastal waters around the world, but their diversity is poorly known along the coasts of Asia. Here we describe Amphictene alata sp. n. (Pectinariidae), based on 15 specimens collected from the coastal waters of Guangdong in the northern South China Sea. This new species can be distinguished from all other 13 described species and one described subspecies of Amphictene by having a pair of dorsolateral lobes on segment 3, a pair of large lateral lobes on segment 21, and more scaphal hooks (26 to 37 pairs).
polychaete, taxonomy, systematics, Guangdong
Pectinariids, commonly called ice cream cone worms, are morphologically unique polychaetes with a cone-shaped tube which they build from sand grains, and a set of golden opercular paleae which they use for digging into soft sediment (
Amphictene can be distinguished from other genera of Pectinariidae by having a cirrate dorsal opercular rim. Currently this genus has 13 recognized species and one recognized subspecies (
Specimens were collected during benthic ecology surveys conducted in Daya Bay and Honghai Bay of the northern South China Sea (Table
Major morphological characters and collection information for the type specimens of Amphictene alata sp. n.
Catalogue number | Body length (mm) | Anterior body width (mm) | Number of cirri on cephalic veil | Pairs of paleae | Pairs of scaphal hooks | Number of lappets on opercular rim | Collection date (yyyy/mm/dd) |
Location | Water depth (m) | |
---|---|---|---|---|---|---|---|---|---|---|
N(°) | E(°) | |||||||||
Holotype | ||||||||||
MBM283388 | 27.9 | 4.6 | 15 | 9 | 26 | 22 | 2013/12/24 | 22.52333 | 115.09167 | 22.5 |
Paratype | ||||||||||
SCSMBC006677 | 29.4 | 5.3 | 11 | 10 | 26 | 24 | 2013/5/20 | 22.5880 | 114.5886 | 14.5 |
SCSMBC006678 | 36.1 | 3.9 | 13 | 8 | 29 | 22 | 2013/5/20 | 22.5880 | 114.5886 | 14.5 |
SCSMBC006679 | 34.5 | 4.7 | 13 | 8 | 37 | 24 | 2013/5/20 | 22.57611 | 114.68444 | 14.5 |
SCSMBC006680 | 38.8 | 5.8 | 15 | 9 | 39 | 24 | 2013/10/25 | 22.5880 | 114.6786 | 15.0 |
AMW.48292 | 33.0 | 4.0 | 14 | 10 | 32 | 21 | 2013/9/27 | 22.5914 | 114.5539 | 12.0 |
MBM283389 | 50.7 | 6.7 | 13 | 11 | 35 | 22 | 2013/9/27 | 22.55940 | 114.61190 | 20.0 |
MBM283390 | 48.8 | 6.9 | n.r. | 9 | 36 | 22 | 2013/9/27 | 22.5594 | 114.6119 | 20.0 |
MBM283391 | 30.8 | 4.0 | 13 | 9 | 34 | 20 | 2013/10/24 | 22.5914 | 114.5539 | 13.0 |
MBM283392 | 26.3 | 5.0 | n.r. | 9 | 33 | n.r. | 2013/8/28 | 22.55942 | 114.61192 | 16.0 |
SCSMBC006681 | 14.0 | 2.2 | 13 | 11 | n.r. | 20 | 2014/1/23 | 22.5914 | 114.5539 | 12.0 |
SCSMBC006682 | 10.2 | 2.4 | n.r. | 11 | n.r. | 20 | 2014/8/21 | 22.6247 | 114.6719 | 13.0 |
AMW.48293 | 25.0 | 4.0 | 16 | 10 | 26 | 25 | 2014/8/21 | 22.6083 | 114.7288 | 12.0 |
AMW.48294 | 16.0 | 2.8 | 16 | 9 | 25 | 22 | 2014/8/19 | 22.54550 | 114.87067 | 6.0 |
SCSMBC006683 | 45.2 | 5.8 | 16 | 10 | 32 | 22 | 2015/3/20 | 22.5930 | 114.5532 | 10.0 |
The following abbreviations are used in figure legends: op, opercular palea; or, opercular rim; cv, cephalic veil; pp, peristomial palp; tc, tentacular cirrus; br, branchia; dll, dorsal lateral lobes (segment 3); c1, chaetiger 1 (segment 5); c4, chaetiger 4 (segment 8); c10, chaetiger 10 (segment 14); sc, scaphe; sh, scaphal hooks; al, anal lobe; s21, segment 21.
Amphitrite auricoma Müller, 1776
15 type specimens, all collected from the silt-clay bottom of Daya Bay and Honghai Bay, Guangdong Province, China at 6 to 22.5 m depth (Table
The specific name alata is derived from ala, a Latin word for wing. It refers to the pair of wing-shaped dorsal lateral lobes on segment 3, a distinctive feature for this species.
Cephalic veil completely free from operculum forming dorsal semi-circle around numerous peristomial palps. Rim of cephalic veil with 11 to 16 long cirri. Dorsal operculum raised with 20–25 marginal cirri. Comb-like branchiae present on segments 3 and 4. A pair of dorsal lateral lobes present on segment 3. Chaetigers 1 to 3 (segments 5 to 7) with notopodia and notochaetae only. Chaetigers 4 to 16 (segments 8 to 16) biramous with notopodia, neuropodia, notochaetae and neurochaetae. Notochaetae winged capillaries. Neurochaetal uncini with major teeth arranged in two to three rows. Segment 21 with a pair of large lateral lobes but without chaetae. Scaphe distinctly separated from abdomen, with 26–37 pairs of short hooks with a slightly curved tip.
Preserved specimens pale cream to grey in colour. Body length of intact specimens including scaphe 16.0 to 50.7 mm, and greatest width at cephalic region 2.2 to 6.9 mm (Table
Amphictene alata sp. n., drawn from holotype MBM283388. A ventral view of anterior end B lateral view of anterior end C dorsal view of posterior end D ventral view of notochaeta 1 E ventral view of notochaeta, chaetiger 2 F dorsal view of notochaeta, chaetiger 2 G lateral view of neurochaeta uncinus. Scale bars: 1 mm (A–C); 50 μm (D–F); 5 μm (G). Abbreviations for morphological characters have been defined in Material and methods.
Amphictene alata sp. n. paratypes W.48293. A tube, broken in the middle B dorsal view of the whole worm C ventral view of the whole worm D dorsal view of anterior end E ventral view of anterior end F lateral view of anterior end G lateral view of posterior end. Scale bars: 1 cm (A); 5 mm (B, C); 2 mm (D, E); 1 mm (F, G). Abbreviations for morphological characters have been defined in Material and methods.
Amphictene alata sp. n. Scanning electron micrographs of paratype SCSMBC006683. A dorsal view of anterior end B ventral view of anterior end C lateral view of anterior end D left dorsal lateral lobe on segment 3 E some examples of the scaphal hooks F, H, I ventral view of notochaetae from chaetiger 2 G dorsal view of notochaetae from chaetiger 2 J ventral view of notochaetae from chaetiger 4 K, L and M ventral neurochaetae from chaetiger 4, 6 and 13, respectively N and O dorsal neurochaetae from chaetiger 5 and 16, respectively P dorsolateral view of scaphe Q ventral view of scaphe. Scale bars: 2 mm (A–C); 500 μm (D); 100 μm (E, J); 200 μm (F, G); 20 μm (H, I); 5 μm (K–M, O); 10 μm (N); 1 mm (P, Q). Abbreviations for morphological characters have been defined in Material and methods.
Tentacular cirri subulate, annulate, tapering to apex (Figs
Segment 3 with a large midventral lobe (Figs
Segment 4 with a small midventral lobe (Figs
Segments 5 to 7 (chaetigers 1 to 3) with notopodia and notochaetae only (Figs
Segment 21 achaetous, with a pair of large lobes covering much of the lateral sides of the body (Figs
Scaphe formed by fusion of 5 posterior segments, distinctly separated from abdomen (Fig.
Tube yellowish, conical, straight, composed of sand grains and shell fragments held together by cement (Fig.
A number of morphological characters exhibit variations (Table
Currently only known from Daya Bay and Honghai Bay, Guangdong in the northern South China Sea.
Amphictene alata sp. n. can be distinguished from other currently recognized species in the genus by several features. First, it has a pair of dorsolateral lobes with crenulated margins on segment 3. None of the other species has dorsolateral lobes. Second, segment 21of A. alata sp. n. has a pair of large lateral lobes but has no chaetae. Among the reported species of Amphictene, A. japonica is also achaetous in segment 21, but it does not have large lateral lobes. Third, A. alata sp. n. has more scaphal hooks (26-37 pairs) than other species of Amphictene (4 to 25 pairs). Forth, the scaphal morphology of A. alata sp. n. is unique among Amphictene spp. in having 2 pairs of lateral lappets, four small triangular terminal lappets, and an oval anal plate with a smooth margin.
According to the generic diagnosis of
This study was supported by the National Natural Science Foundation of China (Grant No. 41406179 to J. Zhang) and the Environment and Conservation Fund, Hong Kong (Grant No. 2014-64 to J.W.Qiu). We thank Pat Hutchings and Chris Glasby for helpful comments on the manuscript.