Hatching time
and post-hatch growth in Russian sturgeon Acipenser gueldenstaedtii
C. Nathanailides, M. Tsoumani, A. Papazogloy, I. Paschos-2002
Journal of
Applied Ichthyology, 18(4-6): 651-654
Abstract:
Embryos which were the progeny of a single
pair of Russian sturgeon (Acipenser gueldenstaedtii) were incubated
in zoug jars at 16°C ± 0.1. Larvae (TL = 2.0 ± 0.03 cm)
were divided according to hatching time into three groups (early-, mid- and
late-hatching). At hatching, there was no difference in size among the three
groups. During the on-growing phase, particularly after the conversion from
moist paste diet to dry diet, a significant proportion of small individuals
was present; it was not possible to continue feeding all the fish with the
same size dry feed pellets. Hence, according to standard aquaculture
practises, fish were divided into fast growing (FGG) and slow growing groups
(SGG). The FGG exhibited increased specific weight growth rate (SWGR = 3.36-3.6%)
compared to the SGG (SWGR = 2.47-2.80%), but there was no
influence in hatching time either on the growth rate, overall mortality
(8.1-11.5%), the proportion of small fish in each group, condition factor,
or the number of lateral and dorsal scute series.
(Department of Aquaculture and Fisheries
TEI of EPIRUS, Igoumenitsa, GR 46100, Greece. E-mail of I. Paschos: paschosi@otenet.gr)