Effect of temperature on growth of the threatened annual fish Austrolebias nigrofasciatus Costa & Cheffe 2001

Biota Neotropica

Matheus Vieira Volcan²  Alinca Peres Da Fonseca²  Mário Roberto Chim Figueiredo²  Luís André Sampaio¹  Ricardo Berteaux Robaldo² 

[1] ,Universidade Federal do Rio Grande Instituto de Oceanografia Programa de Pós-graduação em AquiculturaRio Grande RS ,Brasil

关键词: annual fish;    laboratory conditions;    Cyprinodontiformes;    Rivulidae;    peixe anual;    condições de laboratório;    Cyprinodontiformes;    Rivulidae;   

DOI  :  10.1590/S1676-06032012000400007

来源: SciELO

【 摘 要 】

This study evaluated the effect of temperature on growth of Austrolebias nigrofasciatus, an endemic and threatened annual killifish species of the Patos-Mirim lagoon system in Southern Brazil. In order to verify the effect of temperature on initial growth of A. nigrofasciatus, eggs stored in the laboratory were hatched and juveniles reared for eight weeks at 16 and 22 ºC. The standard length of newly hatched fishes was 4.67 ± 0.25 mm and after eight weeks they reached 23.68 ± 3.73 and 22.68 ± 5.36 mm, respectively at 16 and 22 ºC. However, initial growth of fish reared at 22 ºC was faster and they reached sexual dimorphism at an earlier age compared to those reared at 16 ºC. Final length of females reared at 22 ºC was 23.00 ± 2.83 mm, they were significantly larger than those reared at 16 ºC (17.91 ± 2.47 mm). Males were significantly larger than the females at 16 ºC, but there was no difference for growth between sexes of fish reared at 22 ºC. The sex ratios were 1:0.6 and 1:1.1 (M:F) at 16 ºC and 22 ºC, respectively, suggesting temperature determination of phenotypic sex. Considering the results, it appears that juveniles to be developed in captivity should be kept at 22 ºC during the first six weeks of life, thus ensuring a higher growth rate until puberty.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License