Morphological study of epithelial tissue of tail spine in Cow-tail stingray (Pastinachus sephen) brown eagle ray (Aetobatus flagellum) and butterfly ray (Gymnura poecilura) in the Persian Gulf and Oman Sea

Ray fishes have spines on their whip-like tails. In this study, histological survey was undertaken to explore venom secretory cells in spines of the 3 species of ray fish in the Persian Gulf and Oman Sea. Separated spines were preserved in formalin to transfer them to the laboratory, and spines were dip in EDTA 4%, for decalcification and in the end part, histological study were done. Results showed that venom secretory cells occurred in cow-tail stingray (P. sephen) but no venom secretory cell was found in brown eagle ray (A. flagellum) and butterfly ray (G. poecilura) species. This suggest that layers covering spine is similar to common covering structure of fishe body.