Danionella translucida, a new genus and species of cyprinid fish from Burma, one of the smallest living vertebrates

Abstract

Danionella translucida, a new genus and species of danioin cyprinid fishes, is described from Burma. Females are mature at 10–11 mm standard length, and the largest known specimen is only 12 mm. Ripe eggs are few in number and relatively large, 0.4–0.6 mm in diameter. Adults are scaleless and largely transparent, with a complex pattern of large melanophores on the ventral surface of the abdomen. Specializations observed in skeletal preparations include the ‘danioin notch’ in the medial surface of the mandibles; a large maxillo-mandibulary cartilage; a cartilage (epibranchial 5?) uniting the branchial arches 4 and 5; pharyngeal bones with a single row of 4 tricuspid teeth; and pectoral, pelvic, and caudal fins with fewer rays than reported or observed in any other members of the family Cyprinidae.