Tolerance, Growth, and Physiological Responses of the Juvenile Razor Clam (Sinonovacula constricta) to Environmental Ca2+ and Mg2+ Concentrations

Abstract

To facilitate transplanting razor clam ( Sinonovacula constricta ) populations to inland saline-alkaline waters (ISWs), we evaluated the tolerance of juvenile S. constricta (JSC) to Ca 2+ and Mg 2+ concentrations, and determined the effects of these ions on JSC growth and physiological parameters. After 30 days stress, the tolerable ranges of JSC to Ca 2+ and Mg 2+ were determined to be 0.19 mmol⋅L -1 –19.46 mmol⋅L -1 and 0 mmol⋅L -1 –29.54 mmol⋅L -1 , respectively. The concentrations of Ca 2+ (less than 0.65 mmol⋅L -1 or more than 3.24 mmol⋅L -1 ) and Mg 2+ (less than 0.37 mmol⋅L -1 or more than 14.17 mmol⋅L -1 ) significantly inhibit JSC growth. Physiological enzyme activity no significant response when the concentrations range of Ca 2+ and Mg 2+ are 0.93 mmol⋅L -1 –6.49 mmol⋅L -1 and 0.37 mmol⋅L -1 –14.77 mmol⋅L -1 , respectively. For transplantation practice, these data indicate that only high concentrations of Ca 2+ (3.24–6.825 mmol⋅L -1 ) and Mg 2+ (14.77–33.69 mmol⋅L -1 ) in target inland saline-alkaline water had significantly impact on growth and physiological response. In addition, present study suggests that the increase in Ca 2+ and Mg 2+ ion concentrations caused by ocean acidification will not affect the survival, growth and physiology of S. constricta . Current research suggests that S. constricta can adapt to extreme changes in the marine environment (Ca 2+ and Mg 2+ ) and may be an excellent candidate for inland saline-alkaline water transplantation practice.

Dietary laminarin administration to enhance the immune responses, promote growing and strengthen physique inIctalurus punctatus

“…This shows that the ability of fish to digest protein has improved. AST is an important transaminase in organisms and plays an important role in protein metabolism and energy conversion (Lu, Lai & Du, 1989; Peng, Li, et al, 2019, Peng, Liu, et al, 2019; Zhao et al, 1995). When amino acid metabolism was increased, it will lead to an increase in AST.…”

“…In this study, the activity of LYZ in the results increases significantly with the increase of the proportion of larminarin added. SOD and CAT involve in cellular defences against uncontrolled oxidative processes and catalyse the dismutation of superoxide radical and hydrogen peroxide (Otto & Moon, 1996; Peng, Li, et al, 2019, Peng, Liu, et al, 2019). Some researchers have studied the effect of MDP on the antioxidant activity of aquatic animals: oral MDP‐based nutritional feeds have shown significant increase in SOD and CAT activities of L .…”

“…Superoxide dismutase (SOD) activity in liver was tested using SOD assay kit by WST‐1 method (Jiancheng Bioengineering Institute, Nanjing, China) (Peng, Li, et al, 2019, Peng, Liu, et al, 2019). The rate of the reduction of WST‐1 with O 2 − is linearly related to the xanthine oxidase activity, and this reduction is inhibited by SOD.…”

“…The aspartate aminotransferase (AST) activity in liver was tested using AST assay kit by UV‐malate dehydrogenase method (Jiancheng Bioengineering Institute, Nanjing, China) (Li et al, 2020; Peng, Li, et al, 2019, Peng, Liu, et al, 2019). The AST activity can be determined by monitoring the rate of decrease of the light absorption value at 340 nm.…”

The Chromosome-Level Genome Assembly and Comprehensive Transcriptomes of the Razor Clam (Sinonovacula constricta)

“…As living in the estuarine and intertidal region, the razor clam faces tremendous exposure to extreme environmental stresses such as drastic salinity fluctuation, highly variable temperature, high concentration of ammonia nitrogen and hydrogen sulfide (Morton, 1984). Unlike oysters, mussels and most clams with thick and sealed shells for protecting their soft bodies, the razor clam with two thin and unclosed shells has chosen a survival strategy of deep-burrowing lifestyle with high tolerance of a broad range of salinities (5-45 psu) (Morton, 1984;Peng et al, 2019). Therefore, it is an ideal model with which to investigate the adaptive mechanisms of a deep-burrowing lifestyle.…”