A case of hermaphroditism in Tortonese’s stingray, Dasyatis tortonesei (Elasmobranchii: Rajiformes: Dasyatidae) from the lagoon of Bizerte, Tunisia

Abstract

A normal hermaphrodite Tortonese’s stingray, Dasyatis tortonesei Capapé, 1975, captured in the brackish Lagoon of Bizerte (north-eastern Tunisia) is described in this note. It was a large specimen measuring 685 mm total length, 350 mm disk width, and 2190 g of the total body mass. The specimen externally presented medial cuspidate tooth rows on both jaws, and two claspers were present, that were rigid and calcified although shorter than those observed in normal specimens. The dissection of the abdominal cavity revealed on each side, an ovary normally developed that contained yolked oocytes, a complete genital tract and an uterus less developed than in normal adult. Conversely the testes were rudimentary, both Leydig’s glands were developed and a complete, slightly convoluted, male duct existed on the left side only. In all, 13 cases of normal (4) and abnormal (9) hermaphroditism, including the Tunisian D. tortonesei, have been found in batoid species, to date, confirming that the phenomenon is very rare among these chondrichthyan fishes.

Keywords

• Dasyatis tortonesei
• normal hermaphrodite
• Lagoon