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Marine Biology

, Volume 137, Issue 1, pp 39–45 | Cite as

Timing of metamorphosis and larval segregation of the Atlantic eels Anguilla rostrata and A. anguilla, as revealed by otolith microstructure and microchemistry

  • T. Arai
  • T. Otake
  • K. Tsukamoto

Abstract

Otolith microstructure and microchemistry were examined in juveniles of American (Anguilla rostrata) and European (A. anguilla) eels. Otolith increment width markedly increased from age 132 to 191 d (156 ± 18.9 d; mean ± SD) in A. rostrata and 163 to 235 d (198 ± 27.4 d; mean ± SD) in A. anguilla, both of which were coincident with drastic decreases in otolith Sr:Ca ratios, suggesting that metamorphosis from leptocephalus to glass eel began at those ages in each species. The duration of metamorphosis was estimated to be 18 to 52 d from otolith microstructure, for both species studied. Ages at recruitment were 171 to 252 d (206 ± 22.3 d; mean ± SD) in A. rostrata and 220 to 281 d (249 ± 22.6 d; mean ± SD) in A. anguilla. In these two species, positive linear relationships were found in ages between the beginning of metamorphosis and recruitment, suggesting that early metamorphosing larvae recruited at younger ages. Duration of the leptocephalus stage to recruitment in A. anguilla was about 40 d longer than that in A. rostrata. The geographical segregation between the two species in the Atlantic Ocean seems to be involved in the differences in the duration of the leptocephalus stage (age at metamorphosis).

Keywords

Microstructure Linear Relationship Atlantic Ocean Drastic Decrease Positive Linear Relationship 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • T. Arai
    • 1
  • T. Otake
    • 2
  • K. Tsukamoto
    • 1
  1. 1.Ocean Research Institute, The University of Tokyo, Minamidai, Nakano, Tokyo 164-8639, Japan e-mail: arait@ori.u-tokyo.ac.jp Tel.: +81-3-53516520; Fax: +81-3-53516514JP
  2. 2.Faculty of Bioresources, Mie University, Kamihama, Tsu 514-8507, JapanJP

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