conclude that under generally favourable rearing conditions, egg size has no direct implications for larval survival of Siberian sturgeon. q 2000 Elsevier Science B.V. All rights reserved.
Keywords: Siberian sturgeon; Acipenser baeri; Larvae; Mortality; Growth; Egg size
1. Introduction
Sturgeon fingerling production is considered to be one of the most difficult phases of hatchery rearing. Egg size and development may affect their quality, ability to produce
viable larvae, and to some extent directly determine growth and survival of young fish Ž
. Heming and Buddington, 1988; Kjorsvik et al., 1990 . Under artificial conditions, once
larvae hatch from the egg and deplete their intraembryonic yolk sac reserves, their survival depend on multiple factors, such as the nutritional input, rearing system design
Ž .
and hatchery management Conte et al., 1988 . Early life stages of development are some of the most important phases of fish development, which include the replacement
Ž of embryonic adaptations and functions e.g., yolk sac nutrition and cutaneous respira-
. Ž
. tion
by definitive ones e.g., exogenous feeding and branchial respiration . Such
Ž adaptations alter the relationship of the developing fish with the environment Dettlaff et
. al., 1993 , and these changes can directly affect growth and survival of young speci-
mens. Mortality of acipenserids during embryonic and larval development is of considerable
Ž importance Buddington and Christofferson, 1985; Gisbert and Williot, 1997; Bardi et
. al., 1998 . As a result, substantial efforts were focused on the early life developmental
stages of this group of fishes in order to understand how to increase their survivorship and improve hatchery efficiency. While there are several studies on growth and survival
Ž of Siberian sturgeon larvae under different experimental conditions Evgrafova et al.,
1982; Semenkova, 1983; Dabrowski et al., 1985; Charlon and Bergot, 1991; Gisbert and .
Williot, 1997 , little information is available on larval mortality and whether larger egg and newly hatched larvae sizes provide any advantage for growth and survival of young
fish. This information would be useful to fish farmers for estimating fingerling produc- tion, to improve rearing techniques and for hatchery management and evaluation of the
Ž .
quality of fish produced Krasnodembskaya, 1993 . The objective of the study was to examine the relationships between egg and newly
hatched larvae sizes, growth and survival of young Siberian sturgeon.
2. Materials and methods
