Seasonal abundance and distribution of ichthyoplankton diversity in the Coleroon estuarine complex, Southeast coast of India

The seasonal abundance and spatial distribution of ichthyoplankton in relation to environmental parameters were made from October 2011 to September 2012 in the estuarine and coastal waters of Coleroon. A total of 25,810 finfish eggs were collected in the Coleroon estuary belonging to 7 orders which include 24 families and 46 taxa. Majority of the eggs represents the order of Perciformes (13 family) followed by Culpeiformes (5 family), Mugiliformes, Anguliformes, Tetradontiformes, Atheriniformes, and Gonorhynchiformes (1 family form each order). In addition, a total of 11,320 finfish larvae also were collected belonging to 7 orders which include 24 families and 45 taxa, the majority of the group belongs to the order of Perciformes (15 family) followed by Culpeiformes (4 family), Mugiliformes, Anguliformes, Tetradontiformes, Atheriniformes, and Gonorhynchiformes (1 family form each order). In the present observation, both eggs and larvae of finfish were higher during postmonsoon whereas lesser number of eggs was recorded in summer and larvae in premonsoon season. The physico-chemical parameters viz., Surface water temperature, salinity, pH, dissolved oxygen, Biological oxygen demand and NH3 are also provided a relatively stable environment which was favorable for larval production and survival in the Coleroon estuarine region.