R. Beiras et al., INFLUENCE OF TEMPERATURE ON THE PHYSIOLOGY OF GROWTH IN RUDITAPES-DECUSSATUS (L) LARVAE, Journal of shellfish research, 13(1), 1994, pp. 77-83
Larvae of the butterfish clam Ruditapes decussatus obtained from a wil
d stock were reared at 10, 16, 22 and 28-degrees-C from D-larval stage
to metamorphosis. Growth in length and weight in addition to clearanc
e and ingestion rates were studied. Growth efficiencies were calculate
d for each temperature. Allometric equations relating feeding rates to
weight and length were obtained. Growth rate steadily increased with
increasing temperature during the experimental interval. Larval life c
ould be divided into an initial mixotrophic period (from D stage to 14
0-150 mum length) followed by an exotrophic period (from 140-150 mum l
ength to metamorphosis), according to their feeding activity. The clea
rance rate (CR) in fully active feeding (exotrophic) larvae was an iso
metric function of the ash free dry weight (AFDW), CR (ml . h-1) = 7.4
6 AFDW (mg). The effect of temperature on feeding rates was specially
noticeable during the first few days of culture. Low temperatures (10-
degrees-C) strongly inhibited feeding rates whereas high temperatures
(28-degrees-C) yielded the maximum feeding activity. Gross growth effi
ciency ranged between 33 and 78%, increasing with increased temperatur
e and decreasing with larval development.