Effects of rearing temperature on growth, metabolism and thermal tolerance of juvenile sea cucumber, A postichopus japonicus Selenka: critical thermal maximum ( CTmax) and hsps gene expression.

Effects of different rearing temperatures (16, 21 and 26°C) on growth, metabolic performance and thermal tolerance of juvenile sea cucumber A postichopus japonicus (initial body weight 7.72 ± 0.96 g, mean ± SD) were investigated in this study. During the 40-day experiment, growth, metabolic performance, food intake and energy budget at different reared temperatures were determined. Sea cucumbers rearing at 16°C obtained better growth (final body weight 11.96 ± 0.35 g) than those reared at 21 (10.33 ± 0.41 g) and 26°C (8.31 ± 0.19 g) ( P < 0.05), and more energy was allocated for growth at 16°C (162.73 ±11.85 J g−1 d−1) than those at 21(79.61 ± 6.76 J g−1 d−1) and 26°C (27.07 ± 4.30 J g−1 d−1) ( P < 0.05). Critical thermal maxima ( CTmax) values of juvenile sea cucumbers reared at 16, 21 and 26°C were 33.1, 34.1 and 36.6°C, respectively, and the upregulation of hsps in sea cucumbers reared at 26°C was higher than those acclimated at lower temperatures (16 and 21°C), indicating that temperature acclimation could change the thermal tolerance of the sea cucumber, and CTmax and hsps were sensitive indicators of the sea cucumber's thermal tolerance. [ABSTRACT FROM AUTHOR]