Larval growth and development of the smooth clam Callista chione (Mollusca: Bivalvia) under laboratory conditions

This study describes the first data on larval development and growth of the smooth clam Callista chione under two different temperature regimes (19 and 23 degrees C). The mean diameter of the oocytes was 89.5 +/- 0.7 mu m. After seven days, the mean length of D-shaped larvae was 132.9 +/- 7.8 mu m at 19 degrees C and 148.38 +/- 12.74 mu m at 23 degrees C. Metamorphosis took place between days 32 and 39. Differences in length associated with different culture temperatures were statistically significant on days 11, 13, and 20. At 23 degrees C, larvae reached a length of 175.15 mu m within 11 days, whilst during the same period they reached 137.88 mu m at 19 degrees C (a difference in growth of 39%); however, survival rate was higher at 19 degrees C (8%) than at 23 degrees C (2%).