Aseasonal and short life cycles of the protandrous hermaphrodite blue threadfin (Eleutheronema tetradactylum) in a near-equatorial tropical region
Aseasonal and short life cycles of the protandrous hermaphrodite blue threadfin (Eleutheronema tetradactylum) in a near-equatorial tropical region
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近赤道热带地区早熟雌雄同体蓝线鳍鱼（Eleutheronema tetradactylum）的非季节性和短生命周期
DOI：
10.1071/mf22240
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发表时间：
2023
影响因子：
1.8
通讯作者：
Yamaguchi Y
中科院分区：
文献类型：
--
作者：
Ogino Y;Kongasa W;Furumitsu K;Kume G;Yamaguchi Y
背景四指毛藻在印度-西太平洋地区的整个分布中都被开发利用。目的调查泰国南部四指鱼的年龄、生长、性别变化和繁殖情况。方法对449尾鱼的体长、耳石和性腺数据进行分析。相反，除了体型较大的个体外，每天的增量是可以区分的。在69-341天的年龄范围内，生长呈线性，1年时全长为430 mm(最大长度的69%)。最年轻的成熟雄鱼为137天龄。此外，半数个体由雄变雌体的长度为376 mm，相当于282天。性腺指数表明没有特定的产卵季节，孵化日期的计算表明全年都有孵化。结论与高纬度地区的种群相比，生活在近赤道地区的四指石斑鱼具有种群更替快的特点，这表明了一种重要的沿海鱼类的生活史变化，包括近赤道生境的季节性丧失。这些信息对物种保护很重要。
Context Eleutheronema tetradactylum is exploited throughout its distribution in the Indo–West Pacific region. However, there is a lack of data on its life cycle in near-equatorial regions and the northern hemisphere.Aim To investigate the age, growth, sex change and reproduction of Eleutheronema tetradactylum in southern Thailand.Methods Analysis of length, otolith and gonad data of 449 fish.Key results Contrary to findings from regions at higher latitudes, otoliths did not show seasonal increment formation. Instead, with the exception of large individuals, daily increments were distinguishable. Within the age range of 69–341days, growth was linear, with results indicating a total length of 430mm (69% of maximum length) at 1year. The youngest mature male was 137days old. Moreover, the length at which half the individuals changed from male to female was 376mm, corresponding to 282days. The gonadosomatic index indicated no specific spawning season, and the hatch-date calculations indicated year-round hatching.Conclusions Eleutheronema tetradactylum inhabiting near-equatorial regions is characterised by rapid population turnover compared with populations of higher latitudes.Implications Our findings indicated life-history variability, including seasonality loss in near-equatorial habitats, of an important coastal fish. This information is important for species conservation.