2 research outputs found
Energy allocation and metabolic scope in early turbot, Scophthalmus maximus, larvae
9 páginas, 4 tablas, 2 figurasEarly stages of marine fish larvae are characterized
by fast growth while having a limited aerobic
scope and an immature digestive system. In order to
understand this apparent paradox, the study of energy
allocation is a major necessity. Components of the
energy budget of turbot (Scophthalmus maximus) larvae
were determined during initial development (days
4–12) and the complete energy allocation budget is
presented. It was observed that food absorption efficiency
increased from 32 to 51% during the studied
period, and so did the energy available for growth and
metabolic purposes. The relative amount of energy for
maintenance decreased from 71 to 36% of energy
channelled to metabolism. Gross growth efficiency increased
from 20 to 26% of ingested energy, and net
growth efficiency decreased from 66 to 52% of assimilated
energy. Reduction of net growth efficiency is the
reflex of a higher metabolic rate in older larvae, due to
increased costs of activity and growth. Evidence, indicating
that metabolic scope of early turbot larva is unable to accommodate simultaneously high levels of
growth and activity was found. Alternative strategies to
accommodate the costs of growth and activity exist in
turbot larvae, and may result in a trade-off between
fast growth and viability. As larvae grow, the various
physiological processes described get more efficient,
and the metabolic scope increases.This study was financially supported by the
Comisio´n Interministerial de Ciencia y Tecnologı´a (CICYT,
Spain) under Project AGF 185/92. Isabel Cunha was supported
by a doctoral fellowship from FCT–Program Praxis XXI–BD/
3489/94.Peer reviewe