Reversed sex-change in the protogynous reef fish Labroides dimidiatus
Reversed sex-change in the protogynous reef fish Labroides dimidiatus
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DOI：
10.1046/j.1439-0310.2002.00791.x
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发表时间：
2002-05-01
期刊：
影响因子：
1.7
通讯作者：
Sakai, Y
中科院分区：
文献类型：
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作者：
Kuwamura, T;Tanaka, N;Sakai, Y
雌雄同体，或雌性到雄性的性别变化，是已知的许多珊瑚鱼，包括濑鱼（家庭Labridae），其中大型男性垄断交配。当一个一夫多妻的群体中占统治地位的雄性消失时，最大的雌性可能会在几周内改变性别。大约30年前，这种对性别变化的社会控制首次在清洁工濑鱼Labroides dimidiatus的后宫中被记录。探讨社会地位的改变是否会导致L.为了进行反向性别改变，我们进行了实验：（i）将单个雄性释放到其配偶已在野外被移除的单个雄性附近;以及（ii）将两个配偶保持在水箱中。较小的雄性在成为从属时变回雌性：它们在水族箱中完成性腺变性并产卵需要53-77 d（n = 3）。雌雄配对进行产卵行为，较小的男性在女性角色已经5-58天前完成性腺性别转换。这是首次报道的先雌先熟的濑鱼的性别逆转。此外，我们进行了另一个实验，保持一对男性和一个较大的女性在一个坦克（n = 1）。我们发现了两性的性别变化，这在任何鱼类中都没有报道过。因此，L.在失去配偶后，无论其地位如何变化，都严格地由社会地位决定。
Protogynous hermaphroditism, or female-to-male sex change, is known for many reef fishes including wrasses (family Labridae) in which large males monopolize mating. When the dominant male disappears from a polygynous group, the largest female may change sex within a few weeks. Such social control of sex change was first documented in harems of the cleaner wrasse Labroides dimidiatus almost 30 yr ago. To examine whether change of social status would induce males of L. dimidiatus to perform reversed sex-change, we conducted experiments: (i) releasing single males near lone males whose mates have been removed in the field: and (ii) keeping two mates in a tank. Smaller males changed back to females when they became subordinate: it took 53-77 d (n = 3) for them to complete gonadal sex change and release eggs in the aquarium. The male-male pairs performed spawning behavior, with the smaller male in the female role already 5-58 d before completion of gonadal sex change. This is the first report of reversed sex-change among protogynous wrasses. Moreover, we conducted another experiment, keeping a pair of a male and a larger female in a tank (n = 1). We found sex change by both mates, which has not been reported from any fishes. Thus, the sex of L. dimidiatus is strictly determined by social status whenever it changes after mate loss.