A description of late and transformation stages of larvae of the Diaphus ostenfeldi in the western periphery of the South Pacific Gyre

摘要

Postflexion and transformation stages of the Diaphus ostenfeldi in the southwestern Pacific Ocean are described for the first time. Identification to the species level was based on tracing characters from fully formed, large metamorphic specimens backward to smaller specimens. It was found that larval D. ostenfeldi >= 9.5 mm standard body length (SL) can be characterized by a unique character within the genus Diaphus, namely the presence of melanophores at the dorsal fin base and between branchiostegal rays. Metamorphosis in larvae of this species occurs at a much longer body length (similar to 20 mm SL) than in larvae of other species of this genus.