First Record of Bathyraja sp. (Chondrichthyes: Rajiformes: Arhynchobatidae) in the Northern Indian Ocean and Evidence of a Deep‐sea Skate Spawning Ground

ABSTRACT The conservation of cartilaginous fishes, particularly skates, has become increasingly urgent because of their high vulnerability to anthropogenic pressures such as overfishing and habitat degradation. The genus, Bathyraja (Rajiformes: Arhynchobatidae) Ishiyama 1958, comprises deep‐sea skate species predominantly distributed across the Pacific and Atlantic Oceans, yet with scarce reports in the Indian Ocean. Here, we report the first record of Bathyraja in the Ninetyeast Ridge (3.7° N, 90.4° E), northern Indian Ocean. During four dives of Jiaolong , a human‐occupied vehicle (HOV), we obtained in situ imagery of a live skate at 1896 m depth, counted 303 skate egg cases and collected one with an embryo. Genetic analysis of the embryo's COI gene and 13 mitochondrial protein‐coding genes (PCGs) consistently placed its lineage within Bathyraja , yet species‐level assignment was not possible due to deficiency of available data. The highest density was estimated along one 2.5‐km‐long diving track, at ca. 2 egg cases/100 m 2 , indicating that this region might serve as a significant spawning ground for the species. Our discovery extends the known distribution range of Bathyraja and highlights the conservation implication of this region.