Ichthyological Research

, Volume 49, Issue 3, pp 267–269

Leptocephalus larvae of Pterothrissus gissu collected from the Kuroshio–Oyashio transition region of the western North Pacific, with comments on its metamorphosis

  • Youichi Tsukamoto

DOI: 10.1007/s102280200038

Cite this article as:
Tsukamoto, Y. Ichthyol Res (2002) 49: 267. doi:10.1007/s102280200038


Pterothrissusgissu is a rare albulid fish that is distributed in deep water off Japan. This fish is known to pass through a leptocephalus larval stage, but only metamorphosed (after reaching the fully grown stage) specimens have been available. In this study, the premetamorphosis (before fully grown stage) leptocephalus larva of P. gissu is first described from 45 specimens (117.2–194.5 mm SL) collected by a pelagic otter trawl in the Kuroshio–Oyashio transition region of the western North Pacific in May 1995. Premetamorphosis leptocephalus larvae are characterized by having poorly developed fin rays except for the caudal fin, a translucent body, branched melanophores beneath the eye, and punctuate melanophores on the dorsal edge of the gut from the throat to the anus. Previously fully grown leptocephali were estimated to reach about 130 mm SL based on the size distributions of metamorphosing specimens. However, the present specimens show that fully grown leptocephali of P. gissu exceed 180 mm SL.

Key words ElopiformPterothrissusLeptocephalus larvaeMetamorphosis

Copyright information

© The Ichthyological Society of Japan 2002

Authors and Affiliations

  • Youichi Tsukamoto
    • 1
  1. 1.National Research Institute of Fisheries and Environment of Inland Sea, 2-17-5 Maruishi, Ohno, Saeki, Hiroshima 739-0452, Japan (e-mail: ytsuka@nnf.affrc.go.jp)JP