Effects of heat-shock selection during pelagic stages on thermal sensitivity of juvenile sea cucumber, Apostichopus japonicus Selenka

Abstract

The effects of heat-shock during pelagic stages on growth and survival of juvenile sea cucumber Apostichopus japonicus were investigated to test the possibility to acquire high thermal tolerance individuals after the heat-shock selection. Larvae at the stages of blastula, gastrula, and auricularia were heat-shocked at selected temperatures (21.5, control; 26, 28, and 30°C) for 45 min and returned to 21.5°C for continuous rearing. There was a significant difference in thermal sensitivity among different developmental stages, and thermal tolerance of the larvae was correlated with the expression of heat shock protein 70 (Hsp70). Juveniles after the heat-shock selection at pelagic stages showed higher induced thermotolerance than those without heat-shock. Therefore, heat-shock application at early pelagic development stages is potentially a useful way to select highthermotolerance variety of the sea cucumbers.

Parental Effect of Long Acclimatization on Thermal Tolerance of Juvenile Sea Cucumber Apostichopus japonicus

“…But no significant difference in mortality was found in the culture of juveniles among the four groups. In Northern China, ~10% mortality was common for adult sea cucumbers cultured in aquaculture ponds, and this value can reach to 30%-40% due to the high temperature in summer [ 37 ]. In the present study, high mortality rates of adults in group 3 and group 4 might result from higher temperature and longer duration of acclimatization.…”

“…Juveniles whose parents experienced high temperature acclimatization had relatively high level of expression of genes encoding heat shock proteins ( hsp 70 and hsp 90) from June to July 2012. It is well known that heat shock proteins play important roles for protecting proteins as molecular chaperones [ 28 , 37 , 45 ]. The constitutive expression of hsp s in group 4 indicates that offspring whose parents experienced high temperature acclimatization has a “preparative defense” strategy.…”

The influence of genetics factor on key growth traits and quantitative genetic analysis of sea cucumber Apostichopus Japonicus (Selenka) heat-resistant and fast-growing strain

“…In recent years, the basic studies of domestic and foreign scholars on A. japonicus have mainly focused on the breeding ecology, molecular biology, ecological engineering, immunology, physiology, feed nutrition, pathology, etc. Slater et al 2011;Xia et al 2013;Sun et al 2010;Wang et al 2011;Yang et al 2012). However, there were rare reports in the past on the study of the A. japonicus selective culture through quantitative genetic analysis.…”