In order to explore the tolerance of Glyptosternon maculatum to extreme temperatures at different stages, this study performed acute hyperthermic stress on the fry and adult fish, determined semi-lethal time at each temperature, and measured the respiratory rate of adult fish under hyperthermia. The results showed that the semi-lethal time (LT₅₀) of fry G.maculatum shortened with the increase of temperature, and there was a significant difference in the LT₅₀ of the different temperature groups (P<0.05), among which LT₅₀ was 13.53 h at 28 ℃ and 71.20 h at 24 ℃. The respiratory rate of adult fish under high temperature stress increased significantly, and the semi-lethal time (LT₅₀) of adult fish at 24 ℃ was 15.6 h, which was much lower than that of fry at this temperature. The results showed that there were differences in heat tolerance at different growth stages, and attention should be paid to water temperature control during the breeding process. The short-term lethal temperature of fry was 28 ℃, and the short-term lethal temperature of adult fish was 24 ℃. The results of this study can provide basic data for healthy breeding and further study of high temperature tolerance mechanism of G.maculatum.

An enzyme-linked immunosorbent assay(ELISA)for detecting the residue of malachite green(MG)and its metabolite leucomalachite green(LMG)in aquatic seedlings was established in the present study.The pretreatment process was optimized by using acetonitrile as the extractant,ultrasonic extraction instead of vortex oscillation extraction,saturated n-hexane with pure water,and marking the centrifugal tube with red marker.The results showed that MG content had good linear in the range of 0.050 0~4.50 ng·mL^-1,which the correlation coefficients was R²=0.997 0,and the detection limit was 0.075 0 μg·kg^-1.The average recoveries ranged from 79.7%~104.5% at the spiked level of 0.075 0,0.150 and 0.750 μg·kg^-1 in the seedlings of Penaeus chinensis,Portunus trituberculatus,Stichopus japonicus and Paralichthys olivaceus.The relative standard deviations(RSD)was 3.3%~7.9%.The results showed that this method was accurate,rapid and cheap,which would be suitable for periodic spot check of MG & LMG residues in different aquatic seedlings substrate.