Effect of water temperature on the behavior of Neptunea cumingii and the histology, immune enzyme activity, and transcriptome of its gills and kidneys

The behavior of the marine snail Neptunea cumingii cultured at different temperatures (0, 4, 8, 12, 16 (control), 20, 24, and 28{degrees}C) and the histology, immune enzyme activity, and transcriptome of its gills and kidneys were studied using ecological and molecular methods. At 0{degrees}C, most of the snails shrank in size and did not eat during the first 6 h. At 28{degrees}C, snails also did not eat, death began to occur at 24 h. when the temperature was 8 {degrees}C and 12 {degrees}C, there was no significant difference in the mean feed intake of N. cumingii (P>0.05). And it was higher than the average conch intake under other temperature conditions. However, the histology of the gills and kidneys differed among test temperatures. At 0{degrees}C, the morphology of the gill pieces was difficult to judge. At 24{degrees}C, edema was present in the small gills, and at 28{degrees}C the small gills were severely deformed, the distance between the gill capillaries and the surrounding area was enlarged, and the gill tissue was severely damaged. Temperature increase or decrease from 16{degrees}C caused the columnar cells of the kidney to become shorter and more numerous. The total antioxidant capacity (T-AOC), catalase (CAT) and superoxide dismutase activities (SOD) of the gill and kidney differed significantly among the temperature conditions (p < 0.05). Transcriptome results showed that temperature change resulted in up-regulation of 2339 genes and down-regulation of 2058 genes in the gills, and in up-regulation of 2300 genes and down-regulation of 2060 genes in the kidneys of N. cumingii. Furthermore, the DEGs were subject to GO and KEGG enrichment analysis, and which showed that most of the DEGs in gill were involved in protein folding, defolding, translation, ribosome, and most of the DEGs in kidney were involved in DNA recombination, nuclear euchromatin, RNA-directed DNA polymerase activity. Finally, the results from this study show that N. cumingii prefers the temperature range was 8 to 16, temperature increase or decrease from that range, many aspects of N. cumingii biology could be significantly affected.