Chemmencheri Ramakrishnan Sreeraj

The discovery of three previously undocumented gobioid fish species in Kerala's mangrove ecosystems, namely Eugnathogobius mindora, Mugilogobius mertoni, and Mugilogobius rambaiae, marks a significant advancement in our understanding of the region's aquatic biodiversity. These findings highlight the importance of targeted sampling initiatives and underscore the need for continued exploration and conservation efforts to protect Kerala's fragile mangrove habitats. The adaptability of gobioid fish species from the genera Eugnathogobius and Mugilogobius to fluctuating salinity levels makes them particularly well-suited to thrive in the dynamic environments of shallow intertidal and subtidal estuaries, as well as mangrove ecosystems. Their presence is crucial in maintaining the ecological balance of coastal habitats in the Indo-Pacific region, including Kerala. The discovery of these gobioid fish species not only enhances the ecological richness of Kerala but also offers a significant understanding of the intricate relationships between these fish and their habitats. By enhancing the understanding of the range of gobioid fish species found in the mangroves of Kerala, more effective conservation and management approaches to safeguard these vital coastal ecosystems can be developed. Continuing study and conservation efforts are crucial for the preservation of Kerala’s mangrove ecosystems and the species diversity. By comprehending the enigmas of gobioid fish diversity and other fundamental facets of mangrove ecosystems, substantial advancements can be made in guaranteeing enduring sustainability for future generations.

Two new species of marine flatworms, Paraplanocera kalpeniensis sp. nov. and Pseudoceros bifascia sp. nov., are described. The specimens were collected from the Lakshadweep Islands (situated in the Arabian Sea) in India and belong to the suborders Acotylea and Cotylea, respectively. Pink coloration with a few irregular white blotches on the dorsum and a white rim surrounding violet and purple marginal bands distinguishes Paraplanocera kalpeniensis sp. nov. from other congeners. Pseudoceros bifascia sp. nov. is characterised by two coloured bands on the pseudotentacles; white background colour with a black pattern on the dorsum; a thin broken orange sub-marginal band followed by a thick white rim and a thin fluorescent coloured longitudinal stripe that runs from cerebral eyespots to the posterior end. This is the fifth description in the genus Paraplanocera from the Indian Ocean and second from the Indian waters. With the inclusion of two new species, the total number of polyclad species found in Indian waters is now seventy-three.

This communication presents the first distributional report of four gastropod species from West Bengal coast of India. These species include Littoraria intermedia (Philippi, 1846), Nerita semirugosa Récluz, 1841, Pila virens (Lamarck, 1822), and Tonna tessellata (Lamarck, 1816). These findings were made during a six-month investigation of malacofaunal diversity in the Sunderban Biosphere Reserve. This discovery underscores the need for more comprehensive surveys throughout the Sunderban region to gain a better understanding of the current diversity of malacofauna in the Indian Sunderban.

An updated systematic inventory of the fish faunal variety from the state of West Bengal, comprising 894 species represented by 36 orders and 152 families, has been produced following an extensive review of the literature. Diversity-wise, order Acanthuriformes, has 19 families and 120 species, is the top order of both freshwater and marine fishes. Cypriniformes, which has 7 families and 117 species, is the second most diverse order and the most diverse order in freshwater. Cyprinidae, makes up 6% of the entire fish population in West Bengal, is the family with the most diversity. Marine fishes showed the highest diversity in Gobiidae and Carangidae with 5.6% and 4.8% respectively. 221 species are fully freshwater species, whereas 297 species are marine. The rest of the species are associated with fresh water, brackish and marine habitats. According to the IUCN red list status, 8 species belong to the critically endangered category, 18 belong to the endangered category, 30 species belong to the vulnerable category and 37 species belong to the near threatened category. The conservation status of 239 fish species found in West Bengal has not yet been determined by IUCN. The present study is the first attempt to provide a comprehensive data of fish faunal diversity occurring from all the habitats present in West Bengal, which will ultimately help in the management of the prospects of fisheries resources from West Bengal as well as provide support for the effective conservational planning process.

Photographic evidence of some important coral diseases (black band disease, black disease/Terpios hoshinota, white syndrome, pink line syndrome, pink spots, invertebrate galls, skeletal growth anomalies, tissue loss), coral competing sponges, and coral–algal phase shifts (competitive overgrowth of the seaweed Caulerpa spp. over corals and competitive scleractinian interactions such as with Halimeda spp.) have been collected during field observations in a few atolls within the Lakshadweep archipelago, Arabian Sea. Further, earlier reports of similar diseases and other stressors within the Indian Exclusive Economic Zone (EEZ) and its contiguous international waters, including the reefs of the Maldives and Sri Lanka, are highlighted and their distributional ranges are shown.

Our study documents the outbreak of a coral-killing sponge Terpios hoshinota in the coral reefs of Lakshadweep archipelago and highlights that it has further extended its territory into the isolated atolls of Arabian Sea and maybe a growing threat to the existing coral reefs in the region.