Histology of the developing
digestive system and the effect of food deprivation in larval green sturgeon
(Acipenser medirostris)
E. Gisbert, S.I. Doroshov-2003
Aquatic Living Resources, 16(2) : 77-89
Abstract:
The histological development of the digestive tract
in hatchery-reared green sturgeon (Acipenser medirostris) larvae and
the effects of food deprivation on the digestive system organization were
studied from hatching until 31 days post-hatching (dph). At hatching, the
larval digestive system consisted of two rudiments: a large endodermal yolk
sac and a primordial hind-gut. During the endogenous feeding phase, the wall
of the yolk sac differentiated into the stomach (glandular and non-glandular
regions) and the anterior and intermediate intestine, while the hind-gut
primordium differentiated into the spiral valve and rectum. At the onset of
exogenous feeding (15 dph at 16°C), the organization and cytoarchitecture
of the digestive system in green sturgeon larvae was generally similar to
those of juveniles and adults. Larvae deprived of food exhibited a
progressive deterioration, with subtle pathological changes observed after
5-d starvation: shrinkage of digestive epithelia, tissue degeneration, and
necrosis were observed at 10–15 d of starvation (30 dph). No changes were
observed in the mucous secretion of different regions of the digestive tract
of food-deprived larvae. The histological analysis of the larval digestive
system may be used to evaluate the nutritional condition of larval green
sturgeon in their nursery habitats in spawning rivers, which are affected by
dams and flow diversions.
(Laboratori d'Aqüicultura, Departament de Biologia Animal, Facultat de
Biología, Universitat de Barcelona, Av. Diagonal, 645, 08028, Barcelona, Spain, e-mail: enric.gisbert@ifremer.fr)