Factors affecting secondary sex characteristics in the yellowtail tetra,Astyanax altiparanae

Autor(es)

Siqueira-Silva, Diogenes H. ^{[1, 2]} ; Bertolini, Rafaela M. ^[3] ; Levy-Pereira, Nycolas ^[4] ; Nascimento, Nivaldo F. ^[4] ; Senhorini, Jose A. ^[4] ; Piva, Lucas Henrique ^[4] ; Ferraz, Jose Bento S. ^[5] ; Yasui, George S. ^[4]

Afiliação do(s) autor(es)

^[1] Univ Fed Sul & Sudeste Para UNIFESSPA, Grp Estudos Reprod Peixes Amazon GERPA LaNec, Fac Biol, Inst Estudo Saide & Biol FACBIO IESB, Maraba, Para - Brazil

^[2] Postgrad Program Amazonian Anim Reprod ReproAmazo, Belem, Para - Brazil

^[3] Univ Estadual Paulista, UNESP, Programa Posgrad Ciencias Biol Zool, Botucatu, SP - Brazil

^[4] Ctr Nacl Pesquisa & Conservacao Biota Aquat Conti, Pirassununga, SP - Brazil

^[5] Univ Sao Paulo, Dept Med Vet, Fac Zootecnia & Engn Alimentos, Pirassununga, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: FISH PHYSIOLOGY AND BIOCHEMISTRY; v. 47, n. 3, p. 737-746, JUN 2021.
• Citações Web of Science: 0

Resumo

This study interrogated factors which affect the appearance of secondary sexual characteristics, namely, fin spinelets (rigid dimorphic structure empirically associated with male sexual maturity in characids), inAstyanax altiparanae.Many variables such as the season of the year and several biotic components, including organism length, sex, phase of maturation, and the presence of gonads, were investigated. These factors were then associated with the physiological development of fin spinelets. The development of this trait is related to reproductive strategies but demonstrates considerable population variability as it is found throughout the year in some species but only during specific periods in others. Seventy-five specimens obtained from spontaneous spawn of farmed fish were arbitrarily grouped into small-, medium-, and large-sized groups in both summer and winter. Gonadal histology was performed to confirm each animal's sex and phase of maturation. Diaphanization of the fish was performed to visualize, count, and measure the fin spinelets. Finally, gonadectomization of some males was utilized to investigate the gonadal effect on the presence of fin spinelets. The present results show that the presence of fin spinelets is a secondary sexual characteristic of males which occurs independently of the season and is always present in males longer than 48 mm. However, in the summer, male specimens presented more rays with fin spinelets than during the winter. Furthermore, since fin spinelets were observed on immature males as well as spawning capable males, their presence cannot be directly associated with sexual maturity in maleA. altiparanae,as previously supposed. Finally, gonadectomization resulted in an initial reduction in the length of fin spinelets. However, this trend was eventually normalized with time. (AU)

• Processo FAPESP: 11/11664-1 - Quimerismo em espécies nativas de peixes como ferramenta para a propagação mediada na aquicultura
• Beneficiário: George Shigueki Yasui
• Modalidade de apoio: Bolsas no Brasil - Jovens Pesquisadores
• Processo FAPESP: 10/17429-1 - Quimerismo em espécies nativas de peixes como ferramenta para a propagação mediada na aquicultura
• Beneficiário: George Shigueki Yasui
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores