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Updated: Sep 7, 2025

Handling and Treatment of Male European Eels Anguilla anguilla for Hormonal Maturation and Sperm Cryopreservation
Published on: January 28, 2018
Morphological and gonadal histological characteristics of the silver-phase male Indo-Pacific eel Anguilla marmorata
Seishi Hagihara1, Ryoshiro Wakiya1, Tatsuhiko Maeda1
1Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, Japan.
Abstract:
Eight silver-phase male Indo-Pacific eels (giant mottled eels) Anguilla marmorata were collected from three small rivers on subtropical Amami-Oshima Island, Japan, and their morphological and gonadal-histological characteristics were examined. The total length, body mass and age of the silver eels were 543.8 ± 49.3 (496-659) mm, 376.0 ± 116.0 (282-660) g and 14.6 ± 2.3 (11-19) years old, respectively. The silvering-related characteristics (eye index, pectoral-fin index, gut-somatic index) and reproductive characteristics (gonadosomatic index, histological stage) of the silver eels were significantly advanced compared to those of yellow eels, which is similar to other anguillid species.

