Pectinariidae, de Quatrefages, 1866

Zhang, Jinghuai, Hutchings, Pat & Qiu, Jian-Wen, 2022, Pectinariidae (Annelida, Polychaeta) from the coastal waters of China, with description of new species and new records, Zootaxa 5151 (1), pp. 1-74 : 8

Species of Pectinariidae from Chinese waters

Genus Amphictene Savigny, 1822

Type species. Amphictene auricoma ( Müller, 1776) subsequent designation by Hartman (1959)

Type locality. Denmark

Diagnosis. Cephalic veil free from operculum, with numerous long cirri on rim. Dorsal and lateral margins of semicircular operculum with numerous triangular lappets or cirri. Comb-like branchiae present on segments 3–4. Notopodia other than those of segment 1 which bear paleae, on segments 5–19, 20 or 21 (15–17 pairs), with two types of capillary notochaetae. Neuropodia, 12–13 pairs, with transverse row of uncini, on segments 8–19 or 20. More than one longitudinal row of major teeth on uncinus. Scaphe flattened dorsally, with anal flap and distinctly separate from posterior segments.

Remarks. The genus Amphictene can be easily distinguished by numerous triangular lappets or cirri on dorsal and lateral margins of semicircular operculum, but operculum of other genera of Pectinariidae have smooth margins. Six species were recorded from Chinese waters, but only four species of Amphictene were collected from the southern Yellow Sea and the northern South China Sea in this Study ( Table 2 & Fig. 1 ). The genus Amphictene is not supported by the result of phylogenetic tree based on the multigenes ( Fig. 41 ). The type species Amphictene auricoma ( Müller, 1776) is not nested in the clade with the other two species A. alata and A. jianqingi n. sp. from Chinese waters. The specimens of Amphictene auricoma have capillary notochaetae on segments 5–21 and neurochaetae (uncini) on segments 8–20, but A. alata and A. jianqingi n. sp. have notochaetae on segments 5–20 and neurochaetae (uncini) on segments 8–20. The other three species Amphictene catharinensis ( Grube, 1870) (type locality: Desterro, Brazil), Amphictene guatemalensis ( Nilsson, 1928) (type locality: West coast of Central America, Guatemala) and Amphictene helenae García-Garza & de Leon-Gonzalez, 2014 (type locality: Gulf of Mexico) have capillary notochaetae on segments 5–19, neurochaetae on segments 8–19 which differ from A. auricoma . The distribution of notochaetae on segments as an important generic character needs to be further explored, as well as more molecular data being obtained for other species of Amphictene . Currently, there is not enough data to split the genus, although we suggest this may be confirmed by additional studies.

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Figures

FIGURE 1. Map illustrating the distribution of species of Amphictene in the coastal waters of China

FIGURE 41. Bayesian phylogenetic tree of the family Pectinariidae based on multigene sequences (COI, 16S rDNA, 18S rDNA, 28S rDNA and H3), including 13 species of pectinariids and two outgroups (one of the family Trichobranchidae, another of the family Arenicolidae). Numbers above nodes are posterior probabilities.