Open AccessFactors Influencing Early Survival and Growth of Laboratory‐reared Pacific Bluefin Tuna, Thunnus orientalis , Larvae
Author(s) -
Tanaka Yosuke,
Kumon Kazunori,
Higuchi Kentaro,
Eba Takeshi,
Nishi Akefumi,
Nikaido Hideki,
Shiozawa Satoshi
Publication year - 2018
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/jwas.12453
Subject(s) - broodstock , biology , larva , hatching , zoology , aeration , fishery , thunnus , tuna , aquaculture , ecology , fish <actinopterygii>
The collection of fertilized eggs for mass culture of Pacific bluefin tuna (PBT) relies on the spontaneous spawning of broodstock in captivity, and the spawning season of the broodstock is generally from mid‐May to September. The diameter of fertilized eggs from the broodstock decreases during the spawning season. To investigate the influence of three potential factors, the egg diameter (larger or smaller), the rearing water temperature (25 or 28 C), and the aeration rate during the night (strong or weak), on early survival and on growth of PBT larvae, replicate trials were conducted to assess these three factors until 7 d after hatching (d.a.h.). At 7 d.a.h., survival rates of larvae reared with strong nighttime aeration were found by a three‐way ANOVA to be significantly higher than for larvae reared with weak aeration. Furthermore, growth rates of PBT larvae hatched from larger eggs were significantly faster than those from smaller eggs. However, a significant difference in the survival rate was not detected for the factors, egg diameter and rearing water temperature. The results indicate that rearing with strong nighttime aeration significantly improved the early survival of PBT larvae and the egg diameter (a proxy for egg quality) and influenced growth.