Transition from endogenous to exogenous nutritional sources in larval Black Sea turbot Psetta maxima
-2001
Fisheries Science, 67(4): 571-578
Abstract
Early growth, yolk and oil globule absorption, early
morphological development and initial feeding were studied in the Black Sea
turbot Psetta maxima. Based on energy transition and morphological
development, the nutritional transition process from endogenous to exogenous
sources was divided into six phases: (i) primordial phase (from hatching to
approx. 30 h after hatching, HAH); (ii) organogenesis phase (to approx. 90
HAH); (iii) onset of feeding (to approx. 110 HAH); (iv) early feeding (to
approx. 190 HAH); (v) intensified feeding (to approx. 230 HAH); and (vi)
completion of oil globule absorption (to beyond 345 HAH). Based on
comparisons with early life stage features of other marine species, the
turbot larvae were shown to possess the following characteristics: (i) oil
globule remaining for a long period, resulting in an extended mixed feeding
period; and (ii) feeding rate extremely high in larvae immediately following
final absorption of the oil globule. These features in early turbot larvae
were regarded as advantageous for survival in a rearing condition, although
the coincidence of initial feeding with completion of yolk absorption
signaled a period of leveled-off growth rate.
(Laboratory of Ichthyology, Tokyo University of
Fisheries, Minato, Tokyo 108-8477, Japan, tel: 81-3-5463-0529. Fax: 81-3-5463-0527. Email: hirokun@tokyo-u-fish.ac.jp)