Free access article

Issue Aquat. Living Resour. Volume 11, Number 2, March 1998 Page(s) 111 - 118 DOI 10.1016/S0990-7440(98)80067-3

Aquat. Living Resour. 11 (1998) 111-118
DOI: 10.1016/S0990-7440(98)80067-3

Ovarian development and cycles in cultured Siberian sturgeon, Acipenser baeri

Patrick Williot and Rémy Brun

Cemagref, Ressources aquatiques continentales, 50 avenue de Verdun 33612 Cestas cedex France

(Received 14 May 1997; accepted 12 January 1998. Available online 11 November 1999.)

Abstract
Sturgeon lack external sexual dimorphism and have longer-than-annual ovarian cycles. Using gonadal biopsy of marked fish, we identified sex and monitored ovarian development in one cohort of cultured Siberian sturgeon over the age interval 8.5-12.5 year. Sex ratio in the population did not differ from 1:1 (268 females and 286 males). Each November, the females were separated into two groups: one with ovarian follicle diameter >= 2.8 mm (Group 2, spawnable) and another with smaller follicles in previtellogenic or vitellogenic growth (Group 1). During the 5 year period of observations, 11.2 % of the initial 268 females were lost. The oocytes of Group 2 exhibited migratory germinal vesicle but its position in animal hemisphere was not peripheral in November. The annual changes in proportions of Group 2 females, from 34.6 to 63.3 %, reflected ovarian cycles of different duration. Majority of 196 females, matured two or more times during a period of study, exhibited biennial ovarian cycle or recurring cycles of 1 and 2 years in the same individual. Annual and triennial cycles were also observed. Some abnormalities in oocyte pigmentation are described.

Key words: Acipenser baeri / broodstock management / ovarian development / ovarian cycle


© Elsevier, IRD, Inra, Ifremer, Cemagref, CNRS 1998

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