Gut microbiota of crabs from the Vellar estuary, southeast coast of India

Abstract

Animals in the aquatic environment carry a particular bacterial flora that is a reflection of their environment. In the present study the level of total heterotrophic bacterial (THB) populations observed in the gut of crabs simply reflected the THB in the water and sediment of the environments from which the crabs were collected. Crabs were collected from the different areas, i.e. neritic, mangrove and oyster zones, of the Vellar estuarine environment of the southeast coast of India. THB populations were high in the water and sediment in the mangrove and neritic zones. Among the three stations, less bacterial populations were observed in the water, sediment and the gut of the crabs in the oyster zones due to the constant disturbance of wave action from the estuarine mouth region. Bacteria belonging to the genera Pseudomonas and Vibrio were found to be higher in all the three different stations. In the mangrove region, Bacillus was the dominant genus in sediment samples. Key words: Gut microbiota, crabs, neritic zone, oyster zone, mangrove zone