Regulatory aspects of the brood capacity of Crepidula fecunda, Gallardo 1979 (Gastropoda: Calyptraeidae)

Incubation is thought to increase embryonic survival in numerous groups of marine invertebrates. This paper considers whether the production of gametes and physical space involved in capsular incubation limits brooding capacity in Crepidula fecunda, a marine gastropod from the coast of Chile. C. fecunda females spawned only mature eggs, leaving immature eggs within the gonad. Average oocyte area was significantly different (P < 0.05) between nonincubating females, those at terminal incubation (with advanced veligers), and those containing a pinnotherid crab, compared to females in early stages of incubation. Over the period of brooding. the area occupied by the capsules increased, and the area of the foot of the incubating female was gradually reduced. C. fecunda females that hosted a pinnotherid crab in the incubation space did not lay eggs during the 12-month study period. Addition of a pinnotherid to the incubation area completely inhibited oviposition. Addition of a crab-sized piece of parafilm inhibited the process in more than 80% of females, while none of the females from which the pinnotherid was eliminated failed to deposit egg capsules within the 5-week study period. This suggests that any material filling the brood space inhibits deposition of egg capsules. (C) 2001 Published by Elsevier Science B.V.