Reversão sexual de rã-touro (Rana catesbeiana) com hormônio masculinizante misturado à ração de girinos
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Data
2001-06-01
Autores
Agostinho, Claudio Angelo [UNESP]
Grassiotto, Irani Quagio [UNESP]
Wechsler, Francisco Stefano [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Zootecnia
Resumo
Este trabalho consistiu em testar a eficiência de um hormônio masculinizante (17beta-hidróxi-17-metil-andróxi-4-en-3-ona) na reversão sexual de girinos de rã-touro (Rana catesbeiana). Foram usados 352 girinos com dois a três meses de idade, nos estádios 30 a 36, para testar quatro níveis de hormônio na ração (0, 30, 60 e 90 mig/g) por 45 dias. Após a metamorfose, 167 imagos foram sacrificados e 185 imagos foram criados até a idade de quatro meses e, então, sacrificados. As análises macroscópicas das gônadas e das características sexuais secundárias confirmaram a masculinização nos tratamentos com hormônio. Muitos ovócitos foram observados nos testículos dos imagos revertidos (ovotestis); entretanto, quatro meses após a metamorfose, os ovotestis ocorreram esporadicamente. Concluiu-se que, após a metamorfose, iniciou-se um processo de reabsorção dos ovócitos nos imagos revertidos, culminando com a quase total reabsorção dos ovócitos no quarto mês de idade.
This work consisted in testing the efficiency of a masculinizing hormone (17beta-hydroxy-17-methyl-androxy-4-en-3-one) in the sex reversal of bullfrog tadpoles. Three hundred and fifty two tadpoles with two or three months old, from the stages 30 to 36, were used to test four levels of hormone in the ration (0, 30, 60 and 90 mug/g), for 45 days. After metamorphosis, 167 juveniles were sacrificed and 185 were reared until the fourth month of age and sacrificed thereafter. Macroscopic analysis of the gonads and secondary traits confirmed the masculinization in the treatments with hormone. Many oocytes were observed in the testes of the masculinized juveniles; however, four months after metamorphosis the ovotestes were sporadic. It was concluded that, after metamorphosis, oocyte reabsorption started in reversed juveniles, culminating in almost total reabsorption at the fourth months.
This work consisted in testing the efficiency of a masculinizing hormone (17beta-hydroxy-17-methyl-androxy-4-en-3-one) in the sex reversal of bullfrog tadpoles. Three hundred and fifty two tadpoles with two or three months old, from the stages 30 to 36, were used to test four levels of hormone in the ration (0, 30, 60 and 90 mug/g), for 45 days. After metamorphosis, 167 juveniles were sacrificed and 185 were reared until the fourth month of age and sacrificed thereafter. Macroscopic analysis of the gonads and secondary traits confirmed the masculinization in the treatments with hormone. Many oocytes were observed in the testes of the masculinized juveniles; however, four months after metamorphosis the ovotestes were sporadic. It was concluded that, after metamorphosis, oocyte reabsorption started in reversed juveniles, culminating in almost total reabsorption at the fourth months.
Descrição
Palavras-chave
17beta-hidróxi-17-metil-andróxi-4-en-3-ona, girinos, Rana catesbeiana, Rana catesbeiana, 17beta-hydroxy-17-methyl androxy-4-en-3-one, tadpoles
Como citar
Revista Brasileira de Zootecnia. Sociedade Brasileira de Zootecnia, v. 30, n. 3, p. 911-915, 2001.