The sexual and mating system of the shrimp Odontonia katoi (Palaemonidae, Pontoniinae), a symbiotic guest of the ascidian Polycarpa aurata in the Coral Triangle.

摘要: Theory predicts that monogamy is adaptive in symbiotic crustaceans inhabiting relatively small and morphologically simple hosts tropical environments where predation risk away from high. We tested this prediction the shrimp Odontonia katoi, which inhabits atrial chamber of ascidian Polycarpa aurata Coral Triangle. Preliminary observations O. katoi indicated males were smaller than females, suggestive sex change (protandry) some organisms. Thus, we first investigated sexual system to determine if was sequentially hermaphroditic. Morphological identification size frequency distributions population comprised that, on average, females. Gonad dissections demonstrated absence transitional individuals. a gonochoric species with reverse dimorphism. The distribution its host did not differ significantly random shrimps same individual as pairs found similar expected by chance alone. This contrast reported for other socially monogamous heterosexual conspecifics are individuals more frequently available information argues against katoi. Furthermore, high solitary females brooding embryos ratio skewed toward suggests might be roaming among search receptive Symbiotic can used model understand value mating systems marine invertebrates.