Egg size and larval size among teleosts: implications to survival potential
A survey of the early life history characteristics of 135 teleost fishes from freshwater, marine, tropical, temperate and boreal habitats show the influence of egg size and larval size on survival potential. Marine species have smaller eggs and larvae than freshwater species at similar temperatures. Coldwater species tend to have larger eggs and larvae than warm water species. Egg diameters are positively correlated with larval lengths (Lh) and weights at hatching. The times from fertilization to onset of feeding (tf), to yolk and oil resorption (ty) and to irreversible starvation (ts), increase linearly with Lh and decrease exponentially with temperature. Both tf and ts are positive linear functions of ty. Thus, larger larvae with much yolk that lasts for a relatively longer period feed later and if not fed, will starve later than small larvae with little yolk. Larger larvae will thus have the advantage under conditions of limited or variable food supply. Moreover, large larvae tend to have large mouths and are thus capable of ingesting large high-calorie prey. They also tend to have higher swimming speeds and greater potential to encounter food and avoid predators. There is no definite relation between growth rates and Lh, but tropical species with small eggs and larvae tend to have high growth rates. Survival potential has implications in the recruitment to natural stocks and in seed production in hatcheries.
Size measurement and nutritional condition evaluation methods in sandfish (Holothuria scabra Jaeger) Watanabe, Satoshi; Zarate, Jacques M.; Sumbing, Joemel Gentelizo; Lebata-Ramos, Maria Junemie Hazel; Nievales, Marie Frances (Wiley, 2012)The aims of this study were to establish an accurate size measurement method and a nutritional condition evaluation method of Holothuria scabra (Jaeger). Although 0.5% KCl and 0.05% MgSO<sub>4</sub> did not induce anaesthesia, ...
Staples, Derek; Funge-Smith, Simon (Secretariat, Southeast Asian Fisheries Development Center, 2005)The use of the terms 'low value' and 'trash fish' varies across the Asia-Pacific region and can also change both seasonally and with location. This article defines low value/trash fish as 'Fish that have a low commercial ...
Evaluation of the salinity tolerance of Oreochromis mossambicus, O. niloticus and their F1 hybrids Villegas, Cesar T. (Elsevier, 1990)The salinity tolerance of freshwater-spawned and reared Oreochromis mossambicus, O. niloticus and their F<sub>1</sub> hybrids of various ages was studied. Several tests were conducted using three indices as practical ...