The Effect of Salinity Stress on Enzyme Activities, Histology, and Transcriptome of Silver Carp (Hypophthalmichthys molitrix)

Abstract

A 56-day study was performed to examine the effect of freshwater (FW) and brackish water (BW 6‰ salinity) on the antioxidant ability, Na+/K+-ATPase (NKA) activities, histology, and transcriptome of the gill and kidney tissue in juvenile silver carp (Hypophthalmichthys molitrix). The results show that when juvenile silver carp were exposed to 6‰ salinity, the activities of superoxide dismutase (SOD) and catalase (CAT) were shown to be substantially increased (p < 0.05), while glutathione peroxidase (GSH-PX) activities in gill were not significantly affected (p < 0.05). In kidney tissue, SOD, CAT, and GSH-PX, enzyme activities peaked at 24, 8, and 4 h, respectively, but were not significantly different compared with the control group (p < 0.05). In addition, significant effects of salinity were observed for the NKA level in both the gills and kidney tissues (p < 0.05). The gill filaments of juvenile silver carp under the BW group all underwent adverse changes within 72 h, such as cracks and ruptures in the main part of the gill filaments, bending of the gill lamellae and enlargement of the gaps, and an increase in the number of mucus and chloride-secreting cells. Transcriptome sequencing showed 171 and 261 genes in the gill and kidney tissues of juvenile silver carp compared to the BW group, respectively. Based on their gene ontology annotations, transcripts were sorted into four functional gene groups, each of which may play a role in salt tolerance. Systems involved in these processes include metabolism, signal transduction, immunoinflammatory response, and ion transport. The above findings indicate that the regulation processes in juvenile silver carp under brackish water conditions are complex and multifaceted. These processes and mechanisms shed light on the regulatory mechanism of silver carp osmolarity and provide a theoretical foundation for future research into silver carp growth in brackish water aquaculture area.

Effects of Low-Salinity Environments on Growth, Antioxidant Response, and Intestinal Microorganisms of the Largemouth Bass (Micropterus salmoides)

“…At the same time, there was no difference between GSH-Px levels in the high salinity group S3 and the GSH-Px levels of the freshwater group. These results are similar to those of studies on turbot (Scophthalmus maximus) [22], where CAT and GSH-Px work together to degrade hydrogen peroxide in high-salinity environments. In low-salinity environments where fish do not experience significant oxidative stress, GSH-PX does not rise to the same level as in freshwater groups.…”

Effects of Saline-Alkaline Stress on Metabolome, Biochemical Parameters, and Histopathology in the Kidney of Crucian Carp (Carassius auratus)

“…However, the excessive accumulation of ROS occurs when ROS production exceeds the capacity of the antioxidant system or when the ROS detoxifying system is compromised, which causes severe damage to the structure and function of the cell membrane leading eventually to cell death [ 21 , 29 ]. Numerous previous studies have demonstrated that saline-alkaline exposure leads to the excessive accumulation of ROS and causes oxidative stress in aquatic animals [ 30 ]. Antioxidant enzymes are important components of the fish’s antioxidant system, and the SOD–CAT–GSH-Px cascade serves as the first line of defense against ROS [ 31 ].…”

Adaptasi Salinitas Mampu Meningkatkan Pertumbuhan dan Kelulushidupan Benih Nila Sultana (Oreochromis niloticus) : (Kelas : Osteichtyes; Famili : Cichlidae)

“…Ikan air tawar yang dipindahkan ke dalam media bersalinitas tinggi akan cenderung memasukkan garam-garam ke dalam tubuhnya. Ikan air tawar yang diadaptasikan ke media air bersalinitas lebih tinggi dari tubuhnya memperlihatkan perubahan konsentrasi garam tubuh secara berangsur-angsur akibat kontrol permeabilitas oleh hormon dan sistem saraf otomatis terhadap lingkungan baru dan pengaruh langsung sel-sel tubuhnya (Hayuningtyas et al, 2016;Jiang et al, 2022;dan Sitio et al, 2017). Kondisi salinitas awal yang tinggi dengan peningkatannya yang tinggi pula mengakibatkan benih ikan nila salin tidak mengalami pertumbuhan, bahkan cenderung mengalami penurunan laju pertumbuhan harian.…”