Symbiotic partner specificity and dependency of two gobies (Apocryptodon punctatus and Acentrogobius sp. A) and four alpheid shrimps inhabiting the temperate estuary of southern Japan

We collected two gobies, Apocryptodon punctatus and Acentrogobius sp. A, and four alpheid shrimps from an estuary in southern Japan, to identify the symbiotic shrimps with gobies and to understand their partner specificity and dependency. Analysis based on generalized linear models identified two specific partners for each goby. A. punctatus frequently coexisted with partners and showed similar habitats, suggesting that this goby might be an obligate mutualist. Acentrogobius sp. A had lower rates of coexistence and appeared in habitats different from one of its partners, suggesting that this goby might be a facultative mutualist.