Abstract

We examined sexual dimorphism and parental care in the chocolate gourami (Sphaerichthys osphromenoides) by visual observations, video recording of spawning, and histological analysis of the gonads of individuals in which spawning and mouthbrooding was previously observed. S. osphromenoides is considered a rare exception among labyrinth fishes (Osphronemidae family) because of the presumed maternal parental care, which is not found in other species of this family. According to our observations of 32 spawning events, parental care in this species was always performed by the male. Our visual observations were confirmed by video and histological analysis. This suggests that the sex in this species has probably been misidentified so far. We argue that the putative “females” (previously defined by external features) were in fact males, and that there are probably no exceptions to male parental care in osphronemid fishes.

中文翻译：

---

巧克力吻口鱼 Sphaerichthys osphromenoides (Osphronemidae) 的父系口中育雏

摘要

我们通过目视观察、产卵录像以及对先前观察到产卵和口育的个体的性腺进行组织学分析，研究了巧克力吻口鱼（Sphaerichthys osphromenoides ）的性二态性和亲本护理。S. osphromenoides被认为是迷宫鱼（Osphronemidae 科）中的一个罕见的例外，因为假定有母性亲代照顾，这在该科的其他物种中是不存在的。根据我们对 32 次产卵事件的观察，该物种的亲代照顾始终由雄性承担。我们的视觉观察结果通过视频和组织学分析得到了证实。这表明迄今为止该物种的性别可能被错误识别。我们认为，假定的“雌性”（之前由外部特征定义）实际上是雄性，并且对于雄性鱼的父母照顾可能没有例外。