Hydroides operculata (Treadwell, 1929) was originally very briefly described from a single specimen as Eupomatus operculata, collected in the Gulf of Aden, Somalia. Later the species was reported from the Mediterranean as a potential Lessepsian migrant. The taxa Hydroides inornata Pillai (1960) from Sri Lanka, as well as H. basispinosa and H. gradata described by Straughan (1967) from Australia, were synonymised with H. operculata based only on their similar opercular morphology, making the latter species’ distribution to include South and East Africa, India, Pakistan, Sri Lanka, Hong Kong, tropical Australia, and the eastern Mediterranean. Here we examined the taxonomic status of H. operculata using standard molecular techniques to determine whether this species is a global invader, a complex of regionally distributed morphologically similar species, or a combination of both. The study revealed three well supported clades suggesting a natural phylogeographic pattern. Thus, we argue that the taxa H. inornata (India and Hong Kong) and H. basispinosa (Australia) should be re-instated to full species, but that the Australian H. gradata should be synonymised with H. basispinosa.

Tropical cyclones are extreme random meteorological events that can have profound implications to coastal biodiversities. Given that the frequency, intensity and duration of these events are poised to increase due to the global climate change, understanding the ecological impacts of such erratic occurrences becomes imperative to devise better management strategies. The eventful passage of the tropical cyclone, Phyan, along the northwestern coast of India in November 2009, coupled with the availability of historical data presented a rare opportunity to elucidate the consequences on the polychaete assemblages of the Malvan Marine Sanctuary and their subsequent recovery. This was achieved by comparison of the pre- and post-Phyan seasonal data from four different sites in and around the Sanctuary. MDS analyses and polychaete community parameters suggested conspicuous cyclone related effects on the polychaete community characteristics in the three outer stations off Malvan, whereas the relatively protected bay station remained more or less unscathed. Impacts, attributable to the cyclone apart from seasonal variations, included changes in polychaete composition, reductions in total polychaete density, species diversity, evenness and functional groups. Dominance of the opportunistic polychaete, Paraprionospiopatiens was all pervasive just after Phyan, resulting in poor diversity and evenness values. In the outer stations, diverse feeding modes present prior to the cyclone were replaced by microphagous feeders post the disturbance. However, the study also observed complete recovery as substantiated by the improvement inpolychaete density, diversity indices and re-instatement of multiple feeding guilds in affected areas. This resilience of the coastal waters off Malvan is attributed to its marine protected status, implying that reduced human interference aided rapid revival of damaged ecosystems.

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Effect of heated effluent released from the Tarapur Atomic Power Station, India were investigated by analyzing the level of antioxidant enzyme activities on Nerita oryzarum. Seasonal variation of antioxidant enzyme (LPO, CAT, SOD, GPx and GST) were determined at six location. CAT increases in the pre-monsoon season (range of 0.12 to 2.1 mM of H2O2 consume/min/mg of protein) and LPO activities also increasing trend (range of 0.4 to 2.3 nM of MDA/min/mg) during same pre-monsoon at NIII and SII respectively. Enzyme values encountered high during pre-monsoon, which indicating that increased in temperature is resulting in increased activities. In experimental condition also (300C, 350C, 400C and 250C as control), antioxidant enzyme activities were in increasing trend due to raises of water temperatures. Present study was prima facie work related to physiological response of N. oryzarum related to heated effluent released from atomic power station and useful as baseline information for future research work.