Gene

Malondialdehyde

Ecology

Biology

Heat shock protein

Hemocyte

Fish <Actinopterygii>

Animal science

Fishery

Endocrinology

Biochemistry

Hypoxia (environmental)

Hemolymph

Immunology

Hsp70

Eriocheir

Organic chemistry

Superoxide dismutase

Immune system

Oxygen

Antigen

Oxidative stress

Antioxidant

Internal medicine

Melatonin

Aquaculture

Hemocyanin

Medicine

Chemistry

Crustacean

Decapoda

Chinese mitten crab

Oxygen is essential for crustaceans, and hypoxia will have a negative impact on the growth and development of crustaceans. The aim of this study was to evaluate the protective effects of melatonin (MT) on hemolymph immune parameters (Hemocyanin, Total haemocytes count (THC), Phenoloxidase (PO)), Antioxidant capacity, heat shock proteins (Hsp), mitochondrial number, cytochrome C (CytC) and Na+-K+ ATPase activities of Eriocheir sinensis under the hypoxia conditions (DO = 0.5 mg/L). The results showed that hypoxia stress significantly increased the hemocyanin content and PO activity (p < 0.05), and significantly reduced THC (p < 0.05). Contrary to the above results, the hemocyanin content and PO activity of E. sinensis fed with MT were significantly decreased under hypoxia (p < 0.05), but MT did not change the THC. Hypoxia significantly decreased the activity of Superoxide dismutase (SOD) and the relative expression of Hsp70,90 in E. sinensis, and significantly increased the content of Malondialdehyde (MDA), but MT did not significantly affect the above parameters. After feeding MT diet, the number of mitochondria in haemocytes of E. sinensis decreased significantly both in control and hypoxia group (p < 0.05). However, hypoxia stress did not change the number of mitochondria. Moreover, hypoxia stress significantly increased the activities of Cytochrome C enzyme-linked (CytC) and Na+ − K+ ATPase (p < 0.05). No obvious changes of Cyt-C and Na+-K+ ATPase were observed in MT hypoxia group compared with the hypoxia group. This study shows that hypoxia stress can cause immune damage of haemocytes of E. sinensis, reduce its antioxidant capacity, and cause changes to mitochondrial function of haemocytes. Feeding MT diet can improve the anti-hypoxia ability and protect the immune system on haemocytes of E. sinensis to a certain extent.

Effects of melatonin feed on the changes of hemolymph immune parameters, antioxidant capacity, and mitochondrial functions in Chinese mitten crab (Eriocheir sinensis) caused by acute hypoxia