Distribution and early life-history characteristics of anguillid leptocephali in the western South Pacific
Mari Kuroki A D , Jun Aoyama A , Michael J. Miller A , Shun Watanabe A , Akira Shinoda A , Donald J. Jellyman B , Eric Feunteun C and Katsumi Tsukamoto AA Ocean Research Institute, The University of Tokyo, 1-15-1 Minamidai, Nakano, Tokyo 164-8639, Japan.
B National Institute of Water and Atmospheric Research, PO Box 8602, Christchurch 8440, New Zealand.
C Biologie des Organismes Marins et Ecosystèmes (BOME UMR CNRS 5178), Muséum National d’Histoire Naturelle, Laboratoire Maritime et Musée de la Mer de Dinard, 17 Av. Georges V, 35801 Dinard, France.
D Corresponding author. Email: mari@ori.u-tokyo.ac.jp
Marine and Freshwater Research 59(12) 1035-1047 https://doi.org/10.1071/MF08041
Submitted: 21 February 2008 Accepted: 31 August 2008 Published: 18 December 2008
Abstract
Freshwater eels are important fisheries species in parts of the western South Pacific, but little is known about their oceanic early life history or spawning areas. The age, growth, morphology and geographic distribution of five species of genetically identified anguillid leptocephali collected in 1995, 2000 and 2005 were compared. The sizes and ages of the leptocephali collected, Anguilla australis (n = 18), Anguilla marmorata (n = 15), Anguilla reinhardtii (n = 12), Anguilla megastoma (n = 2) and Anguilla obscura (n = 1), ranged from 19.0 to 50.9 mm and from 25 to 155 days, respectively. Leptocephali were mostly collected in the South Equatorial Current region. The total myomere ranges overlapped among species, but anodorsal myomere numbers clearly divided shortfinned and longfinned eels. The myomere ranges of the leptocephali were similar to the reported ranges of the numbers of vertebrae in adults. Larval growth rates suggested that the temperate species A. australis had slightly slower growth than the tropical species A. reinhardtii. The present study suggests that both temperate and tropical anguillid eels use the South Equatorial Current region for spawning and larval development, although some species might have different early life parameters and migration routes to their recruitment areas.
Additional keywords: freshwater eel, larval migration, otolith microstructure.
Acknowledgements
We thank the captain, crew and technicians of the R/V Hakuho Maru for their help during these three cruises. We also thank N. Mochioka, T. Otake, G. Minagawa and T. Ma for assistance in the measurement and identification of leptocephali and all the other scientific members of these cruises for their assistance in the collection and sorting of the plankton. All sampling for leptocephali was conducted with permission kindly provided by each country whose territorial waters we entered. We appreciate the comments and suggestions of three anonymous reviewers that helped to improve the final manuscript. The study was partly supported by grants from the Ministry of Education, Science and Culture of Japan (Grant-in-aid Nos. 08456094, 10460081, 08041139 and 11691177), ‘Research for the Future’ Program No. JSPS-RFTF, 97 L00901 from the Japan Society for the Promotion of Science, the Research Foundation from Touwa Shokuhin Shinkoukai, and the Eel Research Foundation from Nobori-kai. M. K. was supported by grants from Research Fellowships of the Japan Society for the Promotion of Science for Young Scientists.
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