DETERMINATION OF OPTIMAL THERMAL CONDITIONS FOR GROWTH OF CLAM (VENERUPIS-PULLASTRA) SEED

Citation
M. Albentosa et al., DETERMINATION OF OPTIMAL THERMAL CONDITIONS FOR GROWTH OF CLAM (VENERUPIS-PULLASTRA) SEED, Aquaculture, 126(3-4), 1994, pp. 315-328
Citations number
53
Categorie Soggetti
Fisheries,"Marine & Freshwater Biology
Journal title
ISSN journal
00448486
Volume
126
Issue
3-4
Year of publication
1994
Pages
315 - 328
Database
ISI
SICI code
0044-8486(1994)126:3-4<315:DOOTCF>2.0.ZU;2-E
Abstract
The energy budget of Venerupis pullastra clam seed (3 mm) fed the micr oalga, Isochrysis galbana T-ISO, was calculated after acclimation at 1 0, 15, 20 and 25 degrees C. Physiological measurements included ingest ion rate, absorption efficiency, oxygen consumption and ammonia excret ion. The effect of temperature on these rates was described. Ingestion rate was directly related to temperature up to a maximum at 20 degree s C. Further temperature increase caused a slight decrease in ingestio n. Absorption efficiency was not significantly influenced by the tempe rature, although maximum mean values were also found at 20 degrees C. Both respiration and ammonia excretion rates were directly related to temperature over the whole experimental range, reaching their maxima a t 25 degrees C. For all the physiological rates measured the higher sl opes in the rate/temperature lines occurred in the medium range of tem peratures (15-20 degrees C). The scope for growth (SFG) was positive a t all temperatures and maximum at 20 degrees C, chiefly as a consequen ce of the enhanced ingestion rate which offset the concomitant elevati on in metabolic rates. Both gross and net growth efficiencies are also expected to be maximum at 20 degrees C, which is, therefore, the ther mal optimum for this species under the experimental conditions applied in our study. An acclimation strategy for this low-shore species with in the range of thermal variation in its natural environment (10-20 de grees C), maximizing SFG at high temperatures by enhancing ingestion r ate, despite increased metabolic costs, is proposed.