Venom glands in scatophagid fish

Abstract

Venom glands have been demonstrated in scatophagid fishes for the first time. Six specimens of Scatophagus argus, from 62 mm to 296 mm in standard length, possessed a pair of venom glands accommodated in paired antero-lateral grooves in each fin spine. The venom glands of the larger specimens were shorter than those of the smaller fishes. In Selenotoca multifasciata specimens up to 98 mm in standard length possessed venom glands but glands were lacking in specimens greater than approximately 140 mm in standard length. In both species scales extended relatively further distally along the fin spines in larger specimens than in smaller specimens. The glands of both species were aggregations of large gland cells in the thickened epidermis of the integumentary sheath which filled the spine grooves. The glands were not encapsulated in connective tissue sheaths. Elongate supporting cells occurred among the venom gland cells some of which possessed unusual rod-like bodies in their cytoplasm.