Effects of different temperatures on growth and gonad development related indexes of the ridgetail white shrimp, Exopalaemon carinicauda

Abstract

To explore the optimal growth and reproduction temperature of Exopalaemon carinicauda, this study tested five temperature gradients (16℃, 20℃, 24℃, 28℃, 32℃) to determine the effects of different temperatures on the growth, digestive enzyme activity, ovarian development performance, ovarian nutrient concentration, vitellogenin, and sex hormone levels of E. carinicauda. The results showed that (1) Between 20℃ and 32℃, the survival rate gradually decreased with the increase of temperature. As the temperature increases, the final body weight and specific growth rate first increase and then decrease (P<0.05), with the fastest growth at 28℃; (2) The lipase activity first increases and then decreases with the increase of temperature (P<0.05), reaching a maximum value of 1.22 ± 0.09 U/gprot at 28℃. The trypsin activity increased with the increase of temperature and reached a maximum value of 1695.45 ± 163.42 U/gprot at 32℃; (3) the gonadosomatic index and ovarian maturation rate increased with increasing temperature; the concentrations of total protein, total cholesterol, and triglycerides generally increased with temperature; the vitellogenin showed a trend of first increasing, then decreasing, and then increasing with the increase of temperature (P<0.05); and (4) at temperatures of 24℃ and 28℃, the concentrations of gonadotropin-releasing hormone were relatively high and close. The highest estradiol concentration was 26.62 ± 1.49 ng/L at temperatures of 28℃. These findings indicate that 28℃ is a suitable temperature for promoting the maturation of the parent shrimp of E. carinicauda and may be recommended for a commercialized culture of this species.