Respiratory Metabolism and Antioxidant Response in Chinese Mitten Crab Eriocheir sinensis During Air Exposure and Subsequent Reimmersion

Abstract

Chinese mitten crab, Eriocheir sinensis , often suffers from severe air exposure stress during transportation and culture; high mortality occurs due to desiccation. In this study, the effects of air exposure stress (0, 2, 4, 8, and 16 h) and reimmersion (2, 6, 12 h) on respiratory metabolism and antioxidant responses in Chinese mitten crabs were studied under laboratory conditions. The results showed that air exposure and reimmersion had a significant impact on the oxygen consumption rate (OCR), ammonia excretion rate (AER), oxygen to nitrogen ratio (O:N), superoxide dismutase (SOD), catalase (CAT), succinate dehydrogenase (SDH), and lactate dehydrogenase (LDH). Significant interaction between air exposure and reimmersion was observed for OCR, AER, O:N, SOD, CAT, SDH, and LDH in Chinese mitten crab. During the air exposure stage, SOD, CAT, and LDH activities in the gills and hepatopancreas first increased and then decreased as air exposure time increased. All of these parameters were significantly higher in the 4-h air exposure group than those in the control group. All the parameters were significantly lower in the 16-h air exposure group than those in the control group, except LDH in the hepatopancreas. However, SDH activity gradually decreased with increased air exposure time, and all the air exposure groups were markedly lower than those in the control group in the gills. During the reimmersion stage, OCR, AER, and O:N restored to normal levels after 12-h reimmersion, except in the 16-h air exposure group, where OCR and O:N were significantly higher than those in the control group and AER was significantly lower than that in the control group. The LDH activity in all groups restored to normal levels after 12-h reimmersion. The SDH, SOD, and CAT activities of the 2- and 4-h air-exposed groups returned to normal levels after 12-h reimmersion; however, these three parameters were still significantly higher in the 16-h air-exposed group than in the control group in the gills and hepatopancreas. Overall, Chinese mitten crabs reduce aerobic respiration and increase anaerobic respiration capacity during desiccation. Under air exposure stress, Chinese mitten crabs change their energy utilization mode to meet their energy demands and adjust their respiratory metabolism and antioxidant enzymes activities to adapt to adverse environments.

Biomarkering metabolic activities of the tapeworm Khawia armeniaca (Cholodkovsky, 1915) in association to its fish host Barbus grypus (Hekle, 1843)

“…Thus, in hypoxic environment (like intestinal lumen), some mitochondrial bound enzymes such as SDH, mitochondrial ALT will have inhibited with simultaneous elevation of LDH. Such condition suggests a bias towards the anaerobic glycolytic pathway (41). The state that may explain a relatively higher LDH activity and lesser carbohydrate concentration and ALT activity in tissues of K. armeniaca tapeworm.…”

“…Akinrotim et al (40) revealed that the elevation of LDH activity under stress conditions (like endoparasites infestation) provides the oxaloacetate that is required for the gluconeogensis pathway to meet the additional supply of glucose for the production of energy under reduced phase of oxidative metabolism. Bao et al (41) clarified that Sub lethal concentration of copper chloride resulted in significant elevation of LDH activity in muscle and hepatopancreas tissues of the crab Sesarma quadratum. They concluded that the increase in LDH activity may reflect an increased dependence on anaerobic carbohydrate metabolism by the muscle, gills and hepatopancreatic tissues upon exposer to such a toxicant (copper chloride).…”

“…We hypothesize that the infected fish B. grypus has been stressed and exposed to protein, carbohydrate and lipids deficit in intestinal tissues upon the tapeworm infestation. Such stress factors added to hunger and other factors like tapeworm toxic exudates could change membranes permeability toward membrane bound enzymes like SDH and mitochondrial ALT (41,44). Furthermore, famishing conditions may lead to hypoglycemia and increased NADH/NAD+ ratio and thus increase dependent on gluconeogenesis to maintain blood glucose levels in the infected fish.…”

Histological, physiological, and transcriptomic responses of hepatopancreas to air exposure in asian freshwater clam Corbicula fluminea

“…LDH is also a vital metabolism-regulating enzyme of anaerobic respiration and can catalyze pyruvate to lactic acid ( Schurr and Payne, 2007 ). Previous studies have shown that the activities of LDH, HK, and PK can be altered by air exposure or hypoxia stress ( Bao et al, 2019 ; Mattioli et al, 2019 ; Ding et al, 2020 ). In the present study, we found that the activities of HK, PK, and LDH increased first and then decreased during air exposure.…”

“…Lots of evidence indicate that severe air exposure will cause several adverse effects on aquatic animals, such as oxidative stress injury, cell apoptosis, destruction of the histological structure, disruption of energy homeostasis, poor muscle quality, reduced growth, and even death ( Arlinghaus and Hallermann, 2007 ; Gu et al, 2017 ; Lu et al, 2021 ; Harianto et al, 2022 ). To cope with desiccation and hypoxia stress of air exposure, aquatic animals can mobilize multiple adaptive physiological and molecular mechanisms, including changing respiratory metabolic strategies, enhancing immune function, increasing antioxidant defense, and altering gene expression ( Romero et al, 2007 ; Bao et al, 2019 ). At present, there are many studies on the response of various aquatic animals, including shellfish, to air exposure.…”