The Shallow-Water Crinoid Fauna of Lakshadweep Atolls, North-Western Indian Ocean

A biodiversity survey carried out from 2016 to 2018 by the Department of Science and Technology in the Lakshadweep Atolls, India, recorded six species of shallow-water feather stars new to the archipelago (Comanthus wahlbergii, Comaster schlegelii, Himerometra robustipinna, Dichrometra palmata, Stephanometra indica, and Phanogenia typica). Himerometra sol A.H. Clark, 1912, previously known only from the Maldive Islands, is synonymized under Himerometra robustipinna (Carpenter, 1881). This study brings the total number of shallow-water crinoids recorded from Lakshadweep to ten species. Of the four species collected previously from the archipelago, only Comatella nigra was found in this survey. Of those not collected, Comatella stelligera and Oligometra serripinna are widespread in the Indo-western Pacific region, whereas Heterometra compta is known only from Lakshadweep, and its validity remains uncertain. The known shallow-water crinoid fauna of the archipelago is substantially less diverse than that of the adjacent and environmentally similar Maldive Islands, emphasizing the need for additional research in this island group, in particular, to determine whether the differences are actual or not, and whether they are based on natural conditions versus anthropogenic impacts

Benthic polychaetes off Edward VIII Plateau in the continental shelf of East Antarctica

921-925Samples of marine benthos were collected from three stations (200-300 m depth) off the Edward VIII Plateau (Enderby Land, East Antarctica) during the Third Indian Expedition to the Southern Ocean (2009). Dominant taxonomic groups collected were the polychaetes (165 individuals), nematodes (71) and crustaceans (83), along with echinoderms (19), bivalve molluscs (18), mast pycnogonids (4) and bryozoans. Among the polychaetes, 53 species could be identified. Syllids were represented by the most number of individuals (18.5%), followed by the paraonids (13.1%), spionids (12.5%) and cirratulids (11.9%). Most abundant species collected were Brania sp. (Syllidae) and Laonice weddellia (Spionidae). The polychaete species represented in the samples are listed

New records of brittle stars (Echinodermata: Ophiuroidea) from the Lakshadweep atolls, northern Indian Ocean, with notes on Indophioderma ganapatii Sastry Marimuthu & Rajan, 2019

Parameswaran, Usha V., Nowshad, B. Mohammed, Dixit, Sudhanshu, Manjebrayakath, Hashim, Idreesbabu, K.K., Saravanane, N. (2020): New records of brittle stars (Echinodermata: Ophiuroidea) from the Lakshadweep atolls, northern Indian Ocean, with notes on Indophioderma ganapatii Sastry Marimuthu & Rajan, 2019. Zootaxa 4809 (3): 560-570, DOI: https://doi.org/10.11646/zootaxa.4809.3.

Evaluation of changes in benthic standing stock and polychaete community structure along the south eastern Arabian Sea shelf during the monsoon trawl-ban

The south eastern Arabian Sea is characterized by moderate coastal upwelling, high biological production and subsurface oxygen depletion during the southwest monsoon(June–September). Concurrently,a seasonal closure to trawling activities(15th June–31st July)is implemented here,as a sustainable ecosystem management practise. The effects of monsoon driven environmental changes and consequences of trawling cessation on macrofauna were assessed, based on surveys at 12 sites(30–200m)preceding and during different phases of the southwest monsoon. Macrofaunal density and biomass increased considerably towards the mid and late monsoon along the inner shelf(30–50 m)where trawling is in- tense, while no temporal changes were observed along the outer shelf(100–200m).Density increased four-folds at the 30m contour and three-folds at 50m, while biomass nearly doubled at both depths,reflecting a marked increase in density of polychaetes(61–87% of macrofauna). The disproportionate increase in faunal density and biomass along the inner shelf(30–50 m) was due to abundance of juvenile polychaetes and dominance of small-sized opportunists towards late monsoon(August–September).A concurrent hike in nominal species count of polychaetes was also observed in the study area. The increase in polychaete standing stock and high density of planktonic larvaed uring onset and peak monsoon, coupled with occurrence of juveniles as well as gamete-bearing adults in sediments,indicates that the southwest monsoon is a peak breeding season for the dominant polychaetes in the region. The trawl-ban during this period facilitates the recoupment of benthos by maximising spawning success and larval settlement, thereby enhancing overall ecosystem integrity