Evaluation of optimum temperature for the early larval growth of Japanese eel in captivity
Early larval growth of the Japanese eel Anguilla japonica reared at five different water temperatures (19, 21, 23, 25, and 27 °C) is described for the first month post-hatching, a critical period of time in the culture of these sensitive larvae. After 3 weeks of culture, larvae reared at 27 °C attained the greatest total length and body height of all temperature treatments. Larvae reared at higher temperatures developed rapidly due to active feeding, despite higher metabolic costs. At lower temperatures of 19–21 °C, sudden mortality 12–16 days post-hatching coincides with the transition of larvae from endogenous to exogenous feeding. A linear relationship between water temperature and otolith diameter for cultured eel larvae otoliths suggests that the mean ambient water temperature experienced by wild larvae during their first month after hatching is about 23 °C. This temperature corresponds to mean water temperatures likely experienced by larvae during diel vertical migrations in the North Equatorial Current. We propose rearing early stage Japanese eel larvae at variable temperatures throughout the light/dark cycle to enhance their survival and growth in captivity.
KeywordsFreshwater eel Growth Leptocephalus Mortality Otolith Seedling production Temperature
We are grateful to the members of the IRAGO Institute for their kind support during experimentation. This work was supported in part by KAKEN grants (nos. 26252030, 17H03859) from the Japan Society for the Promotion of Science and the Ministry of Education, Culture, Sports, Science and Technology of Japan.
- Chang S-L, Kou G-H, Liao IC (2004) Temperature adaptation of the Japanese eel (Anguilla japonica) in its early stages. Zool Stud 43:571–579Google Scholar
- Hjort J (1914) Fluctuations in the great fisheries of northern Europe viewed in the light of biological research. Rapp P-V Reun Cons Perm Int Explor Mer 20:1–228Google Scholar
- Ishikawa S, Suzuki K, Inagaki T, Watanabe S, Kimura Y, Okamura A, Otake T, Mochioka N, Suzuki Y, Hasumoto H, Oya M, Miller MJ, Lee TW, Fricke H, Tsukamoto K (2001) Spawning time and place of the Japanese eel, Anguilla japonica, in the North Equatorial Current of the western North Pacific Ocean. Fish Sci 67:1097–1103CrossRefGoogle Scholar
- Kurokawa T, Okamoto T, Gen K, Uji S, Murashita K, Unuma T, Nomura K, Matsubara H, Kim SK, Ohta H, Tanaka H (2008) Influence of water temperature on morphological deformities in cultured larvae of Japanese Eel, Anguilla japonica, at completion of yolk resorption. J World Aquacul Soc 39:726–735CrossRefGoogle Scholar
- Kuroki M, Fukuda N, Yamada Y, Okamura A, Tsukamoto K (2010) Morphological changes and otolith growth during metamorphosis of Japanese eel leptocephali in captivity. Coast Mar Sci 34:31–38Google Scholar
- Miller MJ, Tsukamoto K (2004) An introduction to leptocephali: biology and identification. Ocean Research Institute, The University of Tokyo, TokyoGoogle Scholar
- Miller MJ, Otake T, Aoyama J, Wouthuyzen S, Suharti S, Sugeha HY, Tsukamoto K (2012) Observations of gut contents of leptocephali in the North Equatorial Current and Tomini Bay, Indonesia. Coast Mar Sci 35:277–288Google Scholar
- Okamura A, Yamada Y, Horie N, Utoh T, Mikawa N, Tanaka S, Tsukamoto K (2007) Effects of water temperature on early development of Japanese eel Anguilla japonica. Fish Sci 73:1241–1248Google Scholar
- Shinoda A, Aoyama J, Miller MJ, Otake T, Mochioka N, Watanabe S, Minegishi Y, Kuroki M, Yoshinaga T, Yokouchi K, Fukuda N, Sudo R, Hagihara S, Zenimoto K, Suzuki Y, Oya M, Inagaki T, Kimura S, Fukui A, Lee TW, Tsukamoto K (2011) Evaluation of the larval distribution and migration of the Japanese eel in the western North Pacific. Rev Fish Biol Fisher 21:591–611CrossRefGoogle Scholar
- Tsukamoto K, Uchida K (1990) Early life history and oceanic migration of the eel, Anguilla japonica. La mer 28:188–198Google Scholar
- Tsukamoto K, Aoyama J, Miller MJ (2009a) The present status of the Japanese eel: resources and recent research. In: Casselman J, Cairns D (eds) Eels at the edge. Am Fish Soc Symp 58, Bethesda, Maryland, pp 21–35Google Scholar
- Tsukamoto K, Chow S, Otake T, Kurogi H, Mochioka N, Miller MJ, Aoyama J, Kimura S, Watanabe S, Yoshinaga T, Shinoda A, Kuroki M, Oya M, Watanabe T, Hata K, Ijiri S, Kazeto Y, Nomura K, Tanaka H (2011) Oceanic spawning ecology of freshwater eels in the western North Pacific. Nat Commun 2:179CrossRefGoogle Scholar