Some aspects of the biology of the deep-water crab, Chaceon affinis (Milne-Edwards and Bouvier, 1894) off the Azores

During 1997, quarterly exploratory cruises of the RN "Archipelago" were car ried out in order to study the deep water crab Chareon affinis [Res. Camp. Sci. Monaco Fasc. VII (1894) 1]. South of Pico island (Azores) and at the M enez Gwen hydrothermal vent area (SW of the Azores, within the Azorean Econ omic Exclusive Zone). The crabs were caught with bottom traps according to a specified survey design. Different areas between 300 and 1200 m depth wer e surveyed. Information from previous collections was also compiled and ana lysed. A total of 1153 crabs (726 males and 427 females) were caught at dep ths ranging from 600 to 1100 m on rocky and/or muddy bottoms. Size ranged f rom 39 to 177 mm carapace length (CL), the males being larger than females. Males were relatively more abundant at depths < 800 m and females relative ly more abundant at depths > 800 m. The greatest abundance occurred at dept hs from 700 to 800 m. Ovigerous females. which were consistently > 70 mm CL , were found only from October to March. An annual reproductive cycle is su ggested. Size at first maturity for the females, was estimated to be within the size range of 83-97 mm CL. Other ecological and biological information such as distribution, morphometric aspects related to reproduction, occurr ence of parasites and epibionts, are discussed, as well as by-catch species . (C) 2001 Elsevier Science B.V. All rights reserved.