Zooplankton abundance in Amini and Kadmat islands of Lakshadweep

Studies on zooplankters collected from the lagoons of Amini and Kadmat islands of Lakshadweep Archipelago were carried out based on a survey conducted during January - February, 2014. The displacement volume ofzooplankton in Amini and Kadmat were 58.35 and 15ml per 100 m3 respectively. The density was also higher in Amini than in Kadmat which is estimated as 64480 and 47726 numbers per 100 m3 respectively. A total of twentyone groups of zooplankters viz., copepods,ostracods, chaetognaths, Lucifer sp., medusae, doliolids,mysids, tintinnids, euphausiids, appendicularians,siphonophores, cladocera, amphipods, isopods,polychaete larvae, prawn larvae, crab larvae, squilla larvae, molluscan larvae, fish eggs and fish larvae were recorded from these two ecosystems. Groupwise studies indicated the dominance of copepods in Amini forming 40% while in Kadmat, the maximum was contributed by crab larvae (50%). The dominance of crab larvae in Kadmat was due to a swarm of zoea stage of crab at station 2 in the western side of the island.Among the copepods, calanoid copepods contributed the maximum with 71% in Amini and 81% in Kadmat.Followed by the dominance of copepods in Amini,ostracods (33%) and crab larvae (14%) formed major components. In Kadmat, copepods formed the second dominant group which contributed 20% followed by prawn larvae (11%), ostracods (6%) and the share by other groups were less than 5%. Comparative studies on the occurrence of different groups of zooplankters in these two island ecosystems showed that copepods and ostracods were very much higher in Amini than in Kadmat while, crab larvae contributed more in Kadmat which was due to the swarming of zoea stage of crab. Both qualitative and quantitative abundance of zooplankters in these two ecosystems are presentedand discussed