Description of the first five larval stages of Plesionika narval (Fabrieius, 1787) (Crustacea, Decapoda, Pandalidae) obtained under laboratory conditions

摘要

The first five zoeal stages of Plesionika narval were obtained from 15 days of laboratory culture. All larval stages are described and illustrated in detail. Zoeal characters are compared with the previous described larvae of Plesionika acanthonotus and Plesionika edwardsii and with undetermined zoeas of Pandalidae from plankton samples. The pandalid shrimp, Plesionika narval (Fabrieius, 1787) is a benthic species inhabiting muddy, sandy, and rocky substrates on the continental shelf, being also found in submarine caves (González 1995). Although the species may occur at depths between 4 m and 910 m, it is most frequently found between 200 and 400 m (Crosnier & Forest 1973; Biscoito 1993; González et al. 1997; Fransen 2006). P. narval shows a widegeographical distribution at low latitudes. In the Indo-West Pacific it has been recorded from the Red Sea and Madagascar to French Polynesia. In the Mediterranean it spreads from the Alborán Sea, western Libya and southern Adriatic Sea, to continentalGreece and Marmaris Sea (Fransen 2006). In North-eastern Atlantic it has also been reported throughout the Southwestern Iberian Peninsula, the North-western African coast and in the archipelagos of Azores, Madeira, Salvajes, Canary Islands and Cape Verde, while in South Atlantic it has been identified at St. Helena Island (Udekem D'Acoz 1999). Plesionika narval is valuable as a commercial fishery resource and it is included in the FAO catalogue (Holthuis 1980). At present, this species is being targetedof an important artisanal fishery industry in the Canary Islands, Madeira and Azores.