Gut microbiome to keep a crab healthy

Previously relatively unstudied the microbiome and how it is derived within S. paramamosain’s open circulatory system can be important for aquaculture and further reaching human health. 

Zhang et al. (2019) extracted DNA from 12, in isolation kept, crab gills, midgut, hepatopancreas and haemolymph, to sequence and identify the bacterial community present. Significant differences between male and females were found in most areas with greatest abundance found in the midgut. SourceTracker analysis showed that the microbiome of the haemolymph was derived from the midgut and hepatopancreas. 

Confirming the hypothesis that the microorganisms in the haemolymph are derived from the gut due to the crabs open circulatory system. 

Overall, a variety of different microorganisms were found, some pathogenic and of potential risk to consumers. Healthy crabs are able to maintain and regulate their community well. Some stimulate immune molecules giving the microbiome a role within the crab immune system. Rapid proliferation of haemolymph biota may therefore lead to host disease. 

The paper makes promises on further reach without proper conclusion, resulting in a speculative discussion not always backed by results. As an explorative study this paper provides a baseline for further research, that could answer the wider significance on human health.

Zhang, X., Zhang, M., Zheng, H., Ye, H., Zhang, X., Li, S. (2019) Source of hemolymph microbiota and their roles in the immune system of mud crab. Development and Comparative Immunology, Vol. 102

Accessible through: https://doi.org/10.1016/j.dci.2019.103470