Monthly changes of hepatosomatic index (HSI), gonadosomatic index (GSI), and plasma testosterone (T) levels in the reproductive season of male golden rabbitfish (Siganus guttatus) in captivity were investigated by sampling the liver, testis, and blood. HSI and GSI were estimated as percentage of relative weight of liver and testis to total body weight, respectively. Plasma T levels were measured using enzyme immune assay (EIA). Fragments of the testis were embedded in paraffin, cut to 5 μm thickness, and stained with Harris' hematoxylin and eosin. The results included seasonal changes in HSI, GSI, T, and testicular stages. The plasma T levels were observed high at spermation stage and during February-March and May-June. The values of HSI were monthly fluctuations, but no significant differences between testicular stages were observed. The GSI values continuously exhibited a significant increase from December to April and maintained at high levels until June. GSI continuously increased from stage II (immature testis) to stage V (spawning testis). There was correlation between GSI and testicular stages. Histological sections showed that male golden rabbitfish are multiple spawners and spawning season starts from March to June. These results contribute to further understanding of reproductive biology in golden rabbitfish, which can be implicated for artificial propagation.

中文翻译：

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雄性金兔鱼（Siganus guttatus）的性腺成熟的三个指标的季节性变化：对人工繁殖的影响。

通过对肝脏，睾丸和血液进行采样，研究了圈养雄性金兔鱼（Siganus guttatus）繁殖季节的肝体指数（HSI），性腺激素指数（GSI）和血浆睾丸激素（T）的月变化。HSI和GSI分别以肝脏和睾丸相对重量占总重量的百分比估算。使用酶免疫测定法（EIA）测量血浆T水平。将睾丸的片段包埋在石蜡中，切成5μm的厚度，并用哈里斯苏木精和曙红染色。结果包括HSI，GSI，T和睾丸阶段的季节性变化。在精子期和二月至三月和五月至六月期间，血浆T水平较高。恒指的值是每月波动，但睾丸阶段之间没有观察到显着差异。从12月到4月，GSI值持续呈现显着增长，并一直保持高水平，直到6月。GSI从第二阶段（未成熟的睾丸）持续增长到第五阶段（产卵的睾丸）。GSI与睾丸分期之间存在相关性。组织学切片显示，雄性金兔鱼是多个产卵场，产卵季节从三月到六月开始。这些结果有助于进一步了解金兔鱼的生殖生物学，这可能与人工繁殖有关。组织学切片显示，雄性金兔鱼是多个产卵场，产卵季节从三月到六月开始。这些结果有助于进一步了解金兔鱼的生殖生物学，这可能与人工繁殖有关。组织学切片显示，雄性金兔鱼是多个产卵场，产卵季节从三月到六月开始。这些结果有助于进一步了解金兔鱼的生殖生物学，这可能与人工繁殖有关。