Zygoparity and sex steroid hormone profiles in bluemouth Helicolenus dactylopterus

• Autor(a) principal: Sequeira, V.
• Data de Publicação: 2017
• Outros Autores: Couto, Elsa, Neves, A., Vieira, A. R., Paiva, R. B., Canario, A.V.M., Gordo, L. S.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.1/13141
• topic: Trout salmo-gairdneri; Reproductive-cycle; Oocyte growth; Fish; Fecundity; Sebastes; Spermatogenesis; Scorpaeniformes; Delaroche; Rockfish

Two hundred and seven individuals (103 females and 104 males) of bluemouth Helicolenus dactylopterus (Scorpaeniformes, Sebastidae), a commercially important deep-water species with an unusual reproductive strategy, from the eastern Atlantic Ocean ranging from 13<bold></bold>9 to 37<bold></bold>5 cm total length (L-T) were analysed from September 2011 to October 2012. The analysis included gonad maturity phases and blood-plasma levels of oestradiol-17 (E-2), 11-ketotestosterone (11-KT) and 17,20-dihydroxypregn-4-en-3-one (17,20-P). Results confirmed the existence of an annual reproductive cycle with asynchrony between females and males and a spawning season from January to May. A pronounced peak in 17,20-P in October for both sexes was associated with possible mating behaviour and recent copula. Levels of E-2 increased preceding the elevation of the gonado-somatic index during ovarian growth and were lower during regression and regeneration. The frequency distribution of oocyte-embryonic stages and variation of hormone levels suggest the existence of daily rhythms. Fertilization was detected between 2000-0000 and 0800-1200 h and spawning took place throughout the day peaking between 2000 and 0000 h. The cyclic pattern of sex steroids and ovarian recruitment provides a new insight into the reproductive strategy of this species.