Smilosicyopus leprurus (Teleostei: Gobiidae) is a Fin-eater

Ying-Tzu Lu, Min-Yun Liu, You He, and Te-Yu Liao (2016) Smilosicyopus leprurus is a small goby distributed in the Ishigaki Island and Taiwan. Hobbyists found S. leprurus attacked on the caudal fin of fishes kept together. In this study we investigate whether this fin-eating behavior occurs in the field and whether S. leprurus can be considered a fin-eater. Behavior observation in a tank showed S. leprurus snapped off a piece of fins and swallowed. Among S. leprurus preserved immediately after capture, a fin fragment and a few scales were recovered in the gut of a specimen and DNA barcoding shows the fin fragment belonging to Sicyopterus japonicas. The fin-eating behavior of S. leprurus occurs in captivity and in the wild. In addition, the 3D renderings of oral jaws of S. leprurus were provided. Oral teeth are numerous and arranged in close proximity to each other all together like a bladed dentition, which may provide the capability to shear the fin of its prey. The present study shows S. leprurus a fin-eater despite not feeding exclusively on fins.