High-temperature and starvation tolerances of juvenile Japanese Spanish mackerel Scomberomorus niphonius

Abstract

Japanese Spanish mackerel Scomberomorus niphonius is a target species for stocking, but 18 their biological characteristics at the juvenile stage are not well understood. Here, we 19 investigated the high-temperature and starvation tolerances of hatchery-reared juveniles in 20 captivity. We used juveniles of approximately 40 mm standard length, which was the size of 21 the juveniles released into the field. The upper incipient lethal temperature (50% lethal water 22 temperature) was estimated to be 31.8 °C, which was higher than the maximum sea surface 23 temperature in the field (approximately 29 °C). The critical thermal maximum was 34.8 °C, 24 whereas it was 36.1 °C when juveniles were preliminarily acclimated to 31 °C for 24 h.