Three New Carnivorous sponge species (Demospongiae: Cladorhizidae) from the Seamounts of the Central Indian Ridge.

Deep-sea sponges are an imperative component of benthos. They accumulate the suspended organic matter by filtering large quantities of water and, with their intricate structures, provide the most suitable habitats for various associated organisms. We describe three new cadorhizid sponges from the Central Indian Ridge (CIR), Indian Ocean. The sponges are part of the benthic sledge collection conducted onboard the MGS Sagar in the CIR region. A detailed taxonomic description of two novel species, Asbestopluma (Asbestopluma) indiyansis sp. nov., and Asbestopluma (A.) bharatiyae sp. nov. are provided based on the morphological and molecular (mtCOI and 28S) markers. In addition, another new carnivorous species Chondrocladia sagari sp. nov. is described based on the morphological and mtCOI marker. The systematic and descriptions of new species are discussed based on the structural and phylogenetic analysis. Our study shows that the cladorhizid fauna of the seamounts from the CIR are unique and represent regionally endemic benthic habitats.

A new deep-sea sponge Fibulia occiensis sp. nov. (Poecilosclerida: Dendoricellidae) from the 25 South Oceanic Core Complex in the Central Indian Ocean Ridge.

We describe a new deep-sea sponge species, Fibulia occiensis sp. nov., from the Central Indian Ocean Ridge (CIOR) at Rodrigues Triple Junction (RTJ), of the family Dendoricellidae Hentschel, 1923. Two sponge specimens were collected between 19822079 m depth using a benthic sledge in the 25 South Oceanic Core Complex (OCC) region. The megabenthic fauna was collected to establish a baseline of environmental and benthic ecological data. This data will be handy in assessing the impact of sulfide mining in the near future. Fibulia occiensis sp. nov. is fragile and stalked, has a single type of oxea, and no sigma. The new species is different from the congeneric Fibulia species by its larger oxeas and the strongly curved isochelae.

A new report on the deep-sea sponge-associated Spongicoloides weijiaensis Xu, Zhou & Wang, 2017 (Decapoda: Spongicolidae) from the Southwest Indian Ocean Ridge.

The sponge-associated benthic shrimp Spongicoloides weijiaensis Xu, Zhou & Wang, 2017 is reported for the first time from the Southwest Indian Ridge (SWIR). A single female specimen of S.weijiaensis was associated with the hexactinellid sponge belonging to Dictyaulus sp. that was collected using a benthic sledge from the southwest Indian Ridge at a water depth of 2358 m. The spongicolid shrimp is reported using both classical taxonomic and molecular tools (cytochrome c oxidase subunit 1-COI). The S. weijiaensis specimen from the SWIR appears to represent a morphological variant that has pigmented eyes, telson with thirteen spines, and a broadly rounded setiferous posterior margin. This new report at a latitude of nearly 26° South on the seamount provides the first Mid Ocean Ridge sector record for stenopodidean shrimp known to date.

Molecular identification of deep-sea blind lobster Willemoesia forceps (Crustacea: Decapoda: Polychelidae) from the Central Indian Ridge.

The deep-sea blind lobster Willemoesia forceps A. Milne-Edwards, 1880 was collected at a water depth of 3433 m and is reported for the first time from the Central Indian Ridge (CIR). The species was identified based on morphological examination and supported by mitochondrial Cytochrome Oxidase Subunit I (mtCOI) gene. The phylogenetic analysis shows that W. leptodactyla is sister species of W. forceps. Our findings expand the distributional range of the specimen in the southern hemisphere.

Genetic variation of reef-building polychaete Sabellaria chandraae in the south-eastern Arabian Sea based on mitochondrial COI gene sequences.

The honeycomb worm Sabellaria chandraae is the most common reef-building polychaete in the intertidal area along the south-eastern Arabian Sea. We used the mitochondrial cytochrome c oxidase subunit I (mtCOI) gene to examine the levels of genetic variation the population. The samples were collected from seven intertidal areas along the south-eastern Arabian Sea. The hierarchical Analysis of Molecular Variance (AMOVA) and conventional population statistics (FST ) showed a low level of genetic differentiation (FST = 0.0864, p < .05), indicating no geographical patterning among seven populations. The present results were able to provide a reference for the single stock population along the south-eastern Arabian Sea.

18S rDNA sequencing data of benthic polychaetes from the Eastern Arabian Sea.

The limited DNA sequence data of the polychaetes species are available from the Eastern Arabian Sea. We have sequenced 18S rDNA gene from 54 polychaetes species and 37 species identified up to the species level. The DNA bar-coding data provides for molecular identification of benthic polychaetes that will provide imminent into drivers of species diversity in the Eastern Arabian Sea. The 18S rDNA sequence data set is made publicly available to enable critical or extended analyzes of DNA bar-coding.