A photographic survey of a population of the stalked crinoid Diplocrinus (Annacrinus) wyvillethomsoni (Echinodermata) from the bathyal slope of the Bay of Biscay

摘要: Abstract During the 1973 cruise of BIOGAS deep-sea program, a series 83 frames showing high population density isocrinid stalked crinoid Diplocrinus ( Annacrinus ) wyvillethomsoni was obtained from depth 1246 m on bathyal slope Bay Biscay. The spatial distribution D. appears to be highly aggregated. Mean is 0.61 −2 with confidence limits determined as 0.53 and 0.69 , ranging up 8 or 10 specimens sea floor pebbles rocks. forms parabolic filtration fan its arms strongly recurved into current. distal group cirri grips sharp upper edges This active mode anchorage contrasts passive in other genera isocrinids such Cenocrinus . current velocities 15 25 cm s −1 irregular aspect rocky substrate are likely affect rheophilic suspension feeder. can produce crinoidal carbonate sand sedimentation rate 15.9 20.7 100,000 y. With same higher growth rate, stouter Saracrinus superbus could punctual 2 more 10,000 result compared possible similar rates for mesozoic paleozoic limestones.