The timing of puberty in cultured female yellowtail flounder, Limanda ferruginea (Storer): Oogenesis and sex steroid production in vivo and in vitro

• Published in: Aquaculture 2008-07, Vol.279 (1), p.188-196
• Main Authors: Manning, Anthony J., Burton, Margaret P.M., Crim, Laurence W.
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal aquaculture; Animal productions; Animal reproduction; Animal, plant and microbial ecology; Aquaculture; Biological and medical sciences; blood plasma; Endocrinology; estradiol; fish culture; Flounder; Fundamental and applied biological sciences. Psychology; General aspects; Hormones; Limanda ferruginea; Marine; Oogenesis; ovaries; phenotypic plasticity; Pleuronectidae; Pleuronectiformes; Puberty; Reproduction; Sea water ecosystems; Sexual maturation; sexual maturity; Studies; Synecology; testosterone; vitellogenesis; Yellowtail flounder
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/j.aquaculture.2008.03.059

This study examines puberty in female yellowtail flounder, correlating macroscopic, histological and endocrine parameters at the gonadal level. Short-term ovarian tissue incubations were used to study estradiol-17β production in relation to oogenic stage. Examining 2 year classes of young flounder demonstrated that cultured females retain phenotypic plasticity in reproductive age with pubertal onset occurring in one-year, two-year and three-year-olds. Immature ovaries were steroidogenic and capable of responding to gonadotropic stimulation. Endocrine puberty in females was detected by a peak in estradiol-17β production during the cortical alveolar oocyte stage prior to any ovarian evidence of vitellogenesis. Puberty, once initiated, proceeded to ovulation within 8 to 12 months; vitellogenic oocyte development followed the group synchronous pattern. Estradiol-17β was clearly the dominant of the two measured plasma hormones during pubertal onset and throughout vitellogenesis. Plasma testosterone was consistently detectable at low levels by mid-to late-vitellogenesis. Ovaries showed the highest sensitivity to gonadotropic stimulation in vitro during late-vitellogenesis. Variable plasma levels in both estradiol-17β and testosterone occurred in preovulatory and ovulating females during the captive spawning period. Together the results show that yellowtail flounder can mature at a young age and small size when culture conditions permit. In addition, the early sensitivity to gonadotropin by the immature ovaries may be an important physiological determinant for the timing of puberty in this species.