| Abstrakt: |
The scallop Nodipecten subnodosus is the largest pectinid species targeted in Mexico for hatchery seed production. Thus, effects of larval density (LD = 5, 10 and 15 ml−1) and food concentration (FC = 15,000; 30,000; 45,000 and 60 cells ml−1) were assessed on survival (S) and growth. Clearance (CR) and ingestion rates (IR) were also studied. Lowest S was observed at 15,000 cells ml−1 (19%–22%), while S > 50% prevailed at ≥30,000 cells ml−1. Both LD and FC significantly affected gross growth rate (GGR), with maximal values (7.3 µm d−1) observed at 5 larvae ml−1. Mean GGR of 6.1 to 6.9 µm d−1 was recorded at 10–15 larvae ml−1 and 45,000 to 60,000 cells ml−1. Maximal CR (13.8–23 ml larva−1 h−1) was recorded at 15 cells ml−1. Ingestion rates increased as FC increased, reaching asymptotic values (9.7–11.5 cells larva−1 min−1) at 45,000 and 60,000 cells ml−1. Allometric IR—Shell height exponents increased (b = 1.1 to 1.9) as FC increased. The combined results suggest that N. subnodosus larvae may be reared at stocking densities from 5 to 15 larva ml−1 and reach maximal GGR if fed 45,000 to 60,000 cells ml−1. [ABSTRACT FROM AUTHOR] |
