Distribution and Abundance of Finfish Larvae in Coastal Waters off the Rekawa.

Abstract

Though, there are studies on distribution and abundance of commercially important finfish larvae over the globe, such accounts on ichthyoplankton fauna in coastal waters of Sri Lanka are relatively scarce and to our knowledge, no national or international article has been published hitherto. Present study investigated the distribution and abundance of finfish larvae in coastal waters of Sri Lanka with particular reference to the importance of Rekawa mangrove forest as a refugee for early life stages of fish. Surface plankton samples were collected monthly by larval net at five sampling sites along the axis from Rekawa lagoon mouth to southward.. A total of 932 finfish larvae were collected from the study area, with a mean abundance of 46.6 larvae per 100 m3. The larval fish assemblage comprised 24 species belongs to 12 families. Blenniidae was the most abundant family which contributed 80.4% of the total larval fish abundance which was followed by Gerridae (5.0%), Mullidae (4.6%), Carrangidae (2.6%) and Clupidae (2.2%). The gradient in Shannon Weiner diversity index suggests that Rekawa is an important spawning area for pelagic spawning non resident species. However, further studies are essential to provide the detailed accounts on the spawning season of the species commercially important to Sri Lanka.