Larval biology and mariculture of the angelwing clam, Cyrtopleura costata

Abstract

The deep-burrowing angelwing clam, Cyrtopleura costata (Family Pholadidae), occurs in shallow water from Massachusetts, USA, to Brazil and has been a commerically harvested food product in Cuba and Puerto Rico. This study examines its potential for commerical aquaculture development. The combined effects of salinity and temperature on survival and shell growth to metamorphosis of angelwing larvae were studied using a 5 × 5 factorial design; salinities ranged from 15 to 35‰ S, in 5‰ S intervals, and temperatures ranged from 15 to 35°C in 5°C intervals. Greatest larval shell growth occurred at 30°C and 20‰ S over the first 8 days and at 30°C and 25‰ S over the entire 16-day larval period. Substantial survival (at least 70% of maximal) occurred at all temperature-salinity combinations below 30°C and 35‰ S over the first 8 days; and at 15, 20 and 25°C combined with all salinities, as well as at 30°C combined with 20‰ S and 25‰ S over 16 days. Larvae were competent to metamorphose at 12 days (at optimal temperature-salinity) at a mean shell length of 317 μm. Exposure to a 10 −3 M solution of epinephrine for 1 h induced more than 95% metamorphosis in competent angelwing larvae. Juvenile angelwing shell length incrased at a mean rate of 0.190 mm/day over the first 60 days of post-larval life. Field-planted angelwings reached market size (5–7 cm) in 5–6 months.