A new sisorid catfish of the genus Gagata Bleeker from India

CONTENTS Introduction .................. 207 Description................... 207 Sexual dimorphism................. 211 Relationships .................. 211 A key to the species of the allied genera, Gagata Bleeker etc....... 213 Acknowledgements................. 215 References................... 215 INTRODUCTION Recently four specimens of a species of the genus Gagata Bleeker, from North Koel River at Daltonganj (Chotanagpur, South Bihar), were collected by the author; three of these are females and one is a male. Fortunately, we discovered three more similar specimens, all males, among the unidentified lots in our old collections, bearing the locality label "Delhi", exact locality unknown, while a few more examples were procured from an area adjoining the first locality, River Ganga at Haldi-Chapra. By a thorough examination of this material, we could ascertain that they belong to a species yet unnamed. The material is, therefore, described here under the new name Gagata sexualis, nov. spec. DESCRIPTION Gagata sexualis nov. spec. (figs. 1-6) It is a small statured fish (the largest sexually mature specimen being 58 mm long) in which the dorsal profile rises gradually to the origin of the dorsal fin, after which it slopes down similarly to the base of the caudal. The ventral profile is more or less straight in males, while in females it is