Effects of long-term starvation on health indices, gut microbiota and innate immune response of fresh water crayfish, marron (Cherax cainii, Austin 2002)

Present study aimed to investigate the physiological and molecular response of 28-days starved marron (Cherax cainii), an economically important freshwater crayfish species. Thirty two marron were randomly distributed into two distinct groups in quadruplicated tanks with a density of 4 marron per tank. The feeding- group of marron was fed the marron basal diet on every day while the starved- group was deprived of feed for four weeks. The results showed a significant (P <.05) reduction in protein, energy and fat contents in the tail muscle of marron due to starvation. The microbiome data showed significant modulation of bacterial abundance at both genus and species level in post-starved marron where core microbiota was replaced by Vibrio. The predicted KEGG metabolic pathway based on 16S rRNA data showed a notable shifting of biosynthesis capability towards nutrients stress response activity in starved marron. Significant impact of starvation on the relative expression level of immune genes was observed in starved marron where pro and anti-inflammatory cytokine genes were significantly down-regulated in fourth weeks. This study provides an insights into the immune response and health of marron exposed to starvation under farming conditions.