Marine Flora and Fauna of Hong Kong and Southern China IV

Peracarid crustaceans from Cape d'Aguilar and Hong Kong, I. Mysidacea and Isopoda: Anthuridea

The Marine Flora and Fauna ofHong Kong and Southern China IV (ed. B. Morton). Proceedings of the Eighth International Marine Biological Workshop: The Marine Flora and Fauna of Hong Kong and Southern China, Hong Kong, 2-20 April 1995. Hong Kong: Hong Kong University Press, 1997. PERACARID CRUSTACEANS FROM CAPE D'AGUILAR AND HONG KONG, I. MYSIDACEA, ANDISOPODA:ANTHURIDEA R. N. Bamber Fawley Aquatic Research Laboratories Ltd., Marine and Freshwater Biology Unit, Fawley, Southampton, Hampshire S045 ITW, U.K. ABSTRACT Incidental records of mysid and anthurid isopod crustaceans collected in April 1995 from the Cape d'Aguilar Reserve, Hong Kong, are reported, together with a description of a new species of anthurid isopod of the genus Amakusanthura collected from the Tolo Channel, Hong Kong, in 1986, for which both male and female specimens were available. INTRODUCTION The present paper is the first in a series on the peracarid crustaceans recorded at Cape d'Aguilar, Hong Kong, during April 1995. The peracarid fauna of Hong Kong is as yet poorly known, although Moore (1990) has reported on amphipods and Ma (1990) and Markham (1992) have described isopods of the Oniscidea and Bopyridae, respectively. This paper reports on the single mysid and opportunistically collected anthurid isopod species collected in 1995. Morton and Harper (1995) describe the general features of the Cape d' Aguilar Marine Reserve, including its marine ecology, geology and topography. In addition, while examining material from Hong Kong New Territories (principally the Tolo Channel region) collected by A.S.Y. Mackie and others in 1986 (Mackie et al. 1993; held at the National Museum of Wales, Cardiff) a further anthurid isopod, an Amakusanthura species new to science, was collected and is described below. MYSIDACEA Despite much searching of littoral pools in 1995, no mysids were observed freeswimming . Of numerous faunal samples collected from the benthos, algae, fouled nets, 78 R. N. BAMBER epifauna and fine mesh plankton samples, only one contained mysids - a diver-collected sediment sample from Telegraph Bay, to the west of the Cape d'Aguilar Reserve Area. In this sample there were three specimens of a single species. The material has been lodged at the museum of the Swire Institute of Marine Science (SWIMS). Anisomysis Hansen, 1910 Anisomysis (Paranisomysis) ijimai Nakazawa, 1910. Anisomysis ijimai Nakazawa, 1910,252-253, Pl.VIII, figs 5, 14,27,33. Ii, 1964,551. Anisomysis ijimai estafricana Bacescu, 1973(b), 321-323, fig.3. Fig. 1. Anisomysis (Paranisomysis) ijimae, Cape d'Aguilar specimen: A, Mandibular palp; B, telson. Scale line =0.2 mm. PERACARID CRUSTACEANS FROM HONG KONG 79 Material: 3~ (l brooding; 1 freshly moulted); Site 7: black muddy sand, 5 m depth, Telegraph Bay, Cape d'Aguilar, 12 April 1995 (SWIMS No. 00 SWIMS-CRU-95-008) The subgenus Paranisomysis Bacescu (1973a) was erected for those species of Anisomysis with a constricted telson and with flagellate tubercles on the mandibular palp. The genus is of bottom-associated species, mostly confined to warm coastal waters in the Indo-West Pacific (twelve species are recorded from waters around Japan and China). Anisomysis (Paranisomysis) ijimai is a species characteristic of the subgenus, originally recorded from Japan, with 7 flagellate tubercles on the mandibular palp (Fig. 1A), the rostrum not acuminate, and the telson with a constriction, the distal lobe not truncate (Fig. 1B). In comparison with the type the antennal scale of this material is slightly longer (in proportion to its breadth); the ratio of widest distal width to the constriction width of telson is 1.69, falling between that of the nominate subspecies (2.03) and that of Bacescu's (l973b) A. (P.) ijimae estafricana (l.49). ISOPODA ANTHURIDEA While isopods were not actively collected during April 1995, a specimen of Paranthura from a fouling community was retained. Information on the anthurid isopods of the northwest Pacific off China generally relies on the Japanese records of Nunomura (e.g. 1975; 1977). The Paranthuridae were comprehensively reviewed by Poore (1980), who also pointed out that the species of the Anthuridea are generally of a restricted geographical range. PARANTHURIDAE Paranthura Bate and Westwood, 1868 Paranthura kobensis Nunomura, 1975 P. kobensis Nunomura 1975, 25-27, figs 8-9. Poore, 1980, 63. Material: 1~, from community fouling a discarded monofilament fishing net, depth between 0 and 14 m (the seabed), northwest of Kau Pei Chau, Cape d'Aguilar, 13 April 1995 (SWIMS). This species was originally recorded littorally from Hyogo, Japan, as two females. Nunomura...