Comparative study of resident mysids: community structure, abundance and small scale distributions of Mesopodopsis orientalis was undertaken in coastal, estuarine and saltpan waters. The study was carried out monthly basis, once in Waxing period and once in Waning period at Coastal, estuarine and Saltpan waters during May 2016 to December 2017. Monthly collection found with wide fluctuating water parameters viz., temperature, pH and salinity. Mesopodopsis orientalis breed throughout the year but there is a seasonal variation in the intensity of breeding. The mean body length of females with “eyed embryos” and with “eyeless embryos” is related to those of the females with “eggs”. In coastal waters, estuarine waters and salt pan waters, number of male and female ratio was noticed as 1: 20.69, 1: 0.44 and 1: 0.83 respectively. Whereas, male: female length ratio in coastal waters, estuarine waters and salt pan waters was observed 1: 1, 1: 1.02 and 1: 1.05 respectively. In terms of mysid population density, a greater abundance of mysids occurred in the coastal waters and estuarine waters (35.59% and 35.67%) compared to the Saltpan waters (28.72%). As a result of its abundance, this mysid is regarded as one of the most important species of the shallow water crustacean community.
