Perinereis cultrifera (Grube, 1840)

Muir, Alexander I. & Bamber, Roger N., 2008, New polychaete (Annelida) records and a new species from Hong Kong: the families Polynoidae, Sigalionidae, Chrysopetalidae, Pilargiidae, Nereididae, Opheliidae, Ampharetidae and Terebellidae, Journal of Natural History 42 (9 - 12), pp. 797-814 : 808-809

Perinereis cultrifera (Grube, 1840)

Material

One specimen, Fan Tsang Chau (Conic Island) Cave, epifaunal sample 3.

This small, damaged specimen has about 53 chaetigers, but is probably not complete. It has a brown prostomium (with a trace of a white axial streak) and there is brown pigment at the base of the tentacles. The most anterior segments display five transverse brown stripes dorsally, two each side and one centrally. Posteriorly, the lateral stripes fade away while the central stripe increases in size, becoming a central patch, and this in turn reduces more posteriorly to a small transverse stripe: the most posterior segments are not patterned.

Paragnaths are present on both maxillary rings, but because of the small size of the worm are difficult to see on the first four groups: I5few; II5few; III 5several; IV5several; V 51; VI 51 small straight transverse bar; VII–VIII5about two zigzag rows of fine paragnaths.

The notopodial chaetae are homogomph spinigers. Neuropodia have homogomph spinigers and heterogomph falcigers with short blades.

Perinereis is a large genus (60 species according to Fauchald [1977]) which has not been fully revised, and there is no key to all the species. Huang (2001) lists 19 taxa from this genus which have been recorded from Chinese waters. Using the descriptions in Imajima (1972) and Wu et al. (1981, 1985) the nearest match from these 19 taxa appears to be Perinereis cultrifera var. floridana (Ehlers, 1868) . Perinereis cultrifera var. obfuscata Grube, 1878 is very similar, but Wu et al. (1981) show more paragnaths in areas I and II, while Fauvel (1953) states that it has shorter tentacular cirri than Perinereis cultrifera var. floridana . Wu et al. (1985, p. 207) referred to these as ‘‘ecological subspecies’’.

To further complicate matters, Wu et al. (1985), in discussing Perinereis nuntia (Savigny, 1818) and Perinereis cultrifera (Grube, 1840) , stated ‘‘The classification of infra-species of these 2 polytypic species, based only on the number of paragnaths, has caused the present confusion’’. This is illustrated by the fact that the specimen from the Conic Island cave does not key out as Perinereis cavifrons because that species has no paragnaths in area V of the proboscis while the present specimen has one. However, Wu et al. (1981, 1985) describe the colour pattern seen on our specimen for P. cavifrons but not for P. cultrifera . It may be questioned whether P. cavifrons is another ‘‘ecological subspecies’’ of P. cultrifera , or whether all the ‘‘ecological subspecies’’ of P. cultrifera ought to be raised to full species rank.

The species P. cultrifera has been reported from Hong Kong by Mak (1982) and Wang and Huang (1994); Hartmann-Schröder (1996) lists the distribution as the tropical and temperate zones of the oceans, including the North Sea. Perinereis cavifrons was reported by Wu et al. (1981, 1985) from rocky shores in Guangdong Province, with other records from India, Burma and Indonesia.