Effects of hypoxia on immune responses and carbohydrate metabolism in the Chinese mitten crab, Eriocheir sinensis

Abstract

In aquaculture, hypoxia is an important stressor that can inhibit the healthy development of Chinese mitten crab, Eriocheir sinensis. The aim of this work was to research on how hypoxia (1 mg/L) followed by reoxygenation affects the immune response and carbohydrate metabolism in the Chinese mitten crab. The activities of immune‐related enzymes including lysozyme (LZM), acid phosphatase (ACP), alkaline phosphatase (AKP), superoxide dismutase (SOD) and phenoloxidase (PO) and concentration changes in haemolymph glucose, trehalose and hepatic glycogen were evaluated after 8 hr of hypoxia followed by 12 hr of reoxygenation. After 8 hr of hypoxia, the activities of LZM, PO, SOD and hepatic glycogen concentration significantly decreased to the minimum when compared to the control group, but the activities of ACP and AKP, and haemolymph glucose concentration significantly increased. After 12 hr of reoxygenation, the activities of LZM, ACP, AKP and SOD recovered to the normal level except SOD in plasma, while the PO, SOD in plasma and hepatic glycogen concentration were still significantly lower than the control level. No significant change was observed in trehalose concentration during hypoxia and reoxygenation periods. These results indicated that although the activities of ACP and AKP were likely increased to facilitate the hydrolysis of foreign matter, the overall strength of the immune response was decreased as LZM, PO and SOD activities were suppressed after exposure to hypoxic conditions. The energy stores of exposed crabs were reduced due to the expenditure of energy during exposure to hypoxic stress. In general, chronic hypoxia would impair the immunocompetence and increase the energy expenditure of Chinese mitten crab, further increased the risk of pathogen infection and feed coefficient, so the negative effects of hypoxia should not be ignored.

Role of hypoxia in the behaviour, physiology, immunity and response mechanisms of crustaceans: A review

“…sapidus 81 and Chinese mitten crab E . sinensis 82 have reported that hypoxia caused reductions in LZM and PO activities and attendant suppression of immune responses. Further, production and release of haemocytes into the haemolymph is known to be an innate immune response in crustaceans 83 .…”

Detection of immune‐related enzyme activity, gene expression and metabolomic profiling in Chinese mitten crab Eriocheir sinensis parasitized by Polyascus gregaria

“…The Chinese mitten crab is one of the most important aquaculture species in China because of its economic and ecological roles (Gao et al, 2018). It is produced in aquaculture yielding 750,000 tonnes per year, exceeding 7.5 billion USD value in 2017 (Bao et al, 2020).…”

“…The Chinese mitten crab is one of the most important aquaculture species in China because of its economic and ecological roles (Gao et al, 2018). It is produced in aquaculture yielding 750,000 tonnes per year, exceeding 7.5 billion USD value in 2017 (Bao et al, 2020). Due to the substantial economic benefits, the culture density of Chinese mitten crab in rearing ponds has gradually increased every year (Bao et al, 2020).…”

“…It is produced in aquaculture yielding 750,000 tonnes per year, exceeding 7.5 billion USD value in 2017 (Bao et al, 2020). Due to the substantial economic benefits, the culture density of Chinese mitten crab in rearing ponds has gradually increased every year (Bao et al, 2020). Increasing densities may also increase pathogen pressure and emergence of diseases in crab cultures, leading to massive losses (Ding et al, 2018; Li et al, 2011); however, increasing pathogen pressure may also occur under natural settings.…”

Effects of different stocking densities on the CO2 fluxes at water-air interface and the respiration metabolism in sea cucumber Apostichopus japonicus (Selenka)

“…Changes in the respiration metabolism of aquatic organisms would directly affect the water-air interface CO 2 fluxes. As known, some biotic and abiotic stresses are able to change the rates of respiratory metabolism of many aquatic vertebrates and invertebrates, such as osteichthyes (Liu et al, 2016), echinoderms (Bai et al, 2015;Kühnhold et al, 2017;Sin et al, 2019), crustaceans (Fernańdez-Cisnal et al, 2018;Bao et al, 2020;Ulaje et al, 2020) and molluscans (Haure et al, 2003;Romo et al, 2009). Oxygen consumption rate is generally worked as an important indicator to assess their respiratory and metabolic status.…”