Kottarathil Rajendran Abhilash

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.

Physical and biogeochemical observations from an autonomous profiling Argo float in the Bay of Bengal show significant changes in upper ocean structure during the passage of tropical cyclone (TC) Hudhud (7–14 October 2014). TC Hudhud mixed water from a depth of about 50 m into the surface layers through a combination of upwelling and turbulent mixing. Mixing was extended into the depth of nutricline, the oxycline, and the subsurface‐chlorophyll‐maximum and thus had a strong impact on the biogeochemistry of the upper ocean. Before the storm, the near‐surface layer was nutrient depleted and was thus oligotrophic with the chlorophyll‐a concentration of less than 0.15 mg/m³. Storm mixing initially increased the chlorophyll by 1.4 mg/m³, increased the surface nitrate concentration to about 6.6 μM/kg, and decreased the subsurface dissolved oxygen (30–35 m) to 31% of saturation (140 μM). These conditions were favorable for phytoplankton growth resulting in an estimated increase in primary productivity averaging 1.5 g C·m⁻²·day⁻¹ over 15 days. During this bloom, chlorophyll‐a increased by 3.6 mg/m³, and dissolved oxygen increased from 111% to 123% of saturation. Similar observations during TC Vardah (6–12 December 2016) showed much less mixing. Our analysis suggests that relatively small (high) translation speed and the presence of cold (warm) core eddy leads to strong (weak) oceanic response during TC Hudhud (TC Vardah). Thus, although cyclones can cause strong biogeochemical responses in the Bay of Bengal, the strength of response depends on the properties of the storm and the prevailing upper ocean structure such as the presence of mesoscale eddies.

We compile an up-to-date checklist of 26 species of marine snakes known from the Indian coastlines. We furnish information on the original orthography, authorship, date of publication, current binominal representation, synonymy and chresonymy lists for each recognized taxon. In addition, we provide details of name-bearing types, repository and type locality (both original and subsequent restrictions where applicable) of the prevailing nomen for all recognized species. We summarise the history of research on Indian marine snakes from Linnaeus to the present day, including taxonomic and regional treatises, and highlight the taxonomic flux. We also provide a revised key for this group to facilitate easier identification and support effective conservation.

Species checklists enlist the species available within the defined geographical region and thus serve as essential input for developing conservation and management strategies. The fields of conservation biology and ecology confront the challenge of inflated biodiversity, attributed to non-recognition of taxonomic inconsistencies such as synonyms, alternate representation, emendations etc. Critical review of the checklists and distributional records of Phylum Echinodermata from Indian waters and subsequent validation of species names with World Register of Marine Species (WoRMS) database, revealed that the current literature included 236 incorrect entries comprising of 162 synonyms, 15 emendations, 5 nomina dubia, 1 nomen nudum, 40 species under alternate representation, 9 species with author misnomer, 1 subspecies and 1 unaccepted. The 226 species found to be mixed with valid names and a revised checklist was prepared. The revised and updated checklist holds 741 species of echinoderms comprising of 182 asteroids (24.56%), 70 crinoids (9.45%), 138 echinoids (18.62%), 179 holothuroids (24.16%) and 172 ophiuroids (23.21%), placed under 28 orders and 107 families. This paper discusses the cause for taxonomic inflation and argues that such taxonomic inconsistencies alter our interpretations of a species including its inaccurate distribution and, could possibly impede the country’s conservation and management efforts.