Morphological and Molecular Characterization of Two New Species of Ceratomyxa Thélohan, 1892 (Cnidaria: Myxosporea) from the Marine Ornamental Fish Zanclus cornutus (Linnaeus, 1758) off Lakshadweep Islands, Arabian Sea.

PURPOSE: The present study provides the complete morphological and molecular description of two new species of myxosporeans, Ceratomyxa zancli n. sp. and Ceratomyxa cornuti n. sp. infecting the gallbladder of Zanclus cornutus from the Lakshadweep Islands, Arabian Sea. METHODS: Zanclus cornutus were screened for the presence of myxosporeans, and the recovered myxospores were morphologically characterized using Nomarski Differential Interference Contrast (DIC) optics. The sequences of SSU rDNA were employed for molecular and phylogenetic studies. RESULTS: Both the parasites exhibited a prevalence of 21% each. C. zancli n. sp. is characterized by broadly cresentic myxospores with convex anterior and slightly concave to straight posterior margins and rounded ends. Spore valves two, unequal, measured 9.6 ± 0.7 µm × 25.2 ± 1.3 µm. Polar capsules two, unequal, spherical, measured 4 ± 0.6 µm × 3.5 ± 0.6 µm. Polar filament exceptionally long and arranged irregularly. Myxospores of C. cornuti n. sp. are elongated with convex anterior and slightly concave to straight posterior margins. Spore valves two, unequal, measured 7.00 ± 0.4 µm × 26.56 ± 1.8 µm. Polar capsules spherical, unequal, measured 3.52 ± 0.2 × 3.36 ± 0.35. Molecular analysis of C. zancli n. sp. (ON818297) and C. cornuti n. sp. (ON818298) resulted in 1469 and 1491 bp long SSU rDNA sequences, respectively. Molecularly C. zancli n. sp. is close to C. diplodae and C. barnesi with 91.39% similarity, while C. cornuti n. sp. appears closer to C. robertsthomsoni with 97.46% similarity. In phylogenetic analyses, C. zancli n. sp. branched separately within the Ceratomyxa clade while C. cornuti n. sp. clustered with C. robertsthomsoni and C. thalassomae. CONCLUSION: Based on the differences in morphological, morphometric, molecular, and phylogenetic characteristics, as well as differences in the host and geographic location, the above two species of myxosporeans are considered novel. The study forms the first report of a species of Ceratomyxa from Z. cornutus.

Autochthonous nutrient recycling driven by soil microbiota could be sustaining high coconut productivity in Lakshadweep Islands sans external fertilizer application.

The soils of Lakshadweep Islands are formed as a result of the fragmentation of coral limestone, that is carbonate-rich, with neutral pH, but poor in plant nutrients. Coconut palm (Cocos nucifera L.) is the main crop cultivated, supporting the life and livelihood of the islanders. No external fertilizer application or major plant protection measures are adopted for their cultivation as the Islands were declared to go organic decades back. Yet, Lakshadweep has one of the highest productivity of coconut compared with other coconut growing areas in India. Therefore, a question arises: how is such a high coconut productivity sustained? We try to answer by estimating in three main islands (i) the nutrients added to the soil via the litter generated by coconut palms and (ii) the role of soil microbiota, including arbuscular mycorrhizae, for the high productivity. Our results indicated that, besides adding a substantial quantum of organic carbon, twice the needed amount of nitrogen, extra 20% phosphorus to the already P-rich soils, 43-45% of potassium required by palms could be easily met by the total coconut biomass residues returned to the soil. Principal Component Analysis showed that soil organic carbon %, potassium, and organic carbon added via the palm litter and AM spore load scored >± 0.95 in PC1, whereas, available K in the soil, bacteria, actinomycetes, phosphate solubilizers and fluorescent pseudomonads scored above >± 0.95 in PC2. Based on our analysis, we suggest that the autochthonous nutrients added via the coconut biomass residues, recycled by the soil microbial communities, could be one of the main reasons for sustaining a high productivity of the coconut palms in Lakshadweep Islands, in the absence of any external fertilizer application, mimicking a semi-closed-loop forest ecosystem.

A checklist of marine sponges (Porifera) of peninsula India.

An inventory of sponges from the shallow subtidal reefs of the west and east coasts of southern India is presented. The specimens offered in this paper were based on in-situ collections unlike the previous records of dry and net-entangled collections. A total of 101 species belonging to 12 orders, 22 families, 5 subfamilies and 44 genera from 4 subclasses of Class Demospongiae and one species from Class Calcarea are recorded. We recorded 18 new records to India, six new species combinations, 37 potential new records, and 40 species for the first time from the southwest coast.

Assessment of litter in the remote beaches of Lakshadweep Islands, Arabian Sea.

The objective of this study was to obtain baseline data on litter from three beaches of the Lakshadweep Islands (Kadmat, Suheli Par, and Minicoy). At each site, three transects of 20 × 20 m of the foreshore and intertidal zone were sampled during low tide. All macro litter (size >2.5 cm to <1 m) within each transect were collected and counted. A total of 1231 litter items belonging to 22 categories were recorded. The highest average abundance (193 ± 97 items/400 m2) of marine litter was found in Kadmat, followed by Suheli Par (154 ± 31items/400 m2) and Minicoy (63 ± 49 items/400 m2) islands. The Clean Coast Index (CCI) suggests that Minicoy Island has a clean beach (CCI 3.15) while Suheli Par (CCI 8) and Kadmat (CCI 10) were moderate. The primary contributing sources of litter on the beaches were fishing (45%) and public (34%). Better management practices are required to control litter sources.

Periclimenella agattii sp. nov., a new Palaemonid shrimp (Crustacea, Decapoda, Palaemonidae) from Lakshadweep Islands, India.

The recent collection of Palaemonid shrimps from Agatti Island, Lakshadweep, Arabian Sea, have provided further additions to the Indian marine fauna. In the manuscript, a new species, Periclimenella agattii sp. nov. is described and illustrated. The new species is morphologically most similar to P. spinifera among other congeners, but it strongly differs from that species by having upper the antennular flagellum with 14-16 segments, short free ramus with 12-13 segments, lower antennal flagellum thin and bearing 35-37 segments; 4 minute lateral spines on basal segment of 3rd maxilliped; male palm:carpus ratio of second pereopod higher than in female, propodus of 3rd pereopod with 7-8 ventral spines and hepatic spine with groove. Genetic analysis using the mitochondrial COI and 16S rRNA genes sequences proved that, the new species is significantly distinct from the closed related species.

Prevalence of disease vectors in Lakshadweep Islands during post-monsoon season.

BACKGROUND & OBJECTIVES: : Increase of vector-borne diseases (VBDs) in India has posed a question on the situation in Lakshadweep Islands, where VBDs are reported from time-to-time. The present investigation was aimed to assess the faunastic situation of the prevailing vectors along with their breeding sites in different islands of the Lakshadweep. METHODS: : Extensive surveys were carried out from November 2017 to January 2018 (post-monsoon season) randomly in the nine inhabited islands of Lakshadweep for conducting faunastic studies on mosquitoes and to know the basic binomics like breeding and resting preference of mosquitoes. The study islands included, Kavaratti, Agatti, Chetlat, Bitra, Amini, Kadmath, Andrott, Kalpeni and Kiltan. Both immature and adult collections were carried out by standard/appropriate sampling techniques. The obtained data were calculated and analysed in terms of different entomological indices. RESULTS: : A total of 3356 mosquitoes were collected during the study period which comprised of 16 species from nine genera. Out of the 16 species, six belonged to mosquito vectors. The collection included malaria vector, Anopheles stephensi; Japanese encephalitis vector, Culex tritaeniorhynchus; Bancroftian filariasis vector, Cx. quinquefasciatus; Brugian filariasis vector, Mansonia uniformis; and dengue and chikungunya vectors, Stegomya albopicta and St. aegypti. Stegomya albopicta was the most predominant species observed constituting 54% of the catch, followed by Cx. quinquefasciatus, An. stephensi, Cx. tritaeniorhynchus, and St. aegypti constituting 10.5, 6, 3 and 1.2%, respectively. Apart from vector species many non-vectors such as Heizmannia chandi, An. subpictus, An. varuna, Cx. sitiens, Cx. minutissimus, Cx. rubithoracis, Fredwardsius vittatus, Lutzia fuscana, Malaya genurostris and Armigeres subalbatus were also present in the study area. In Kavaratti Island, the capital of Lakshadweep, a non-vector species of sandfly, Sergentomyia (Parrotomyia) babu was observed during the indoor resting collection. The major breeding sites which supported various mosquito species included, discarded plastic containers, tree holes, open sintex tanks (water storage tanks), unused wells, discarded tyres, discarded iron pots, unused and damaged boats, cement tanks, pleated plastic sheets, coral holes, pits and irrigation canals, discarded washing machines, and Colocasia plant leaf axils. Breteau index ranged between 65.3 and 110, CI ranged between 63.64 and 72.41; and HI ranged between 38.46 and 70 among the various islands. INTERPRETATION & CONCLUSION: : Entomological indices such as house index (HI), breteau index (BI) and pupal index (PI) were high in all the nine islands and exceeded the threshold levels specified by WHO, indicating high risk for dengue virus transmission in case of outbreaks. Occurrence of vector as well as non-vector species indicates that the global change in climate is causing notable changes in terms of breeding of vector and non-vector species in the islands. With the reported cases of VBDs and the presence of vectors species in Lakshadweep Islands, a stringent control measure needs to be implemented at the Lakshadweep Islands.

Epidemiological and entomological aspects of an outbreak of chikungunya in Lakshadweep Islands, India, during 2007.

Since 2006, the Indian state of Kerala has reported outbreaks of chikungunya (CHIK). During July-August 2007, an unusual increase in the incidence of fever was noticed in Kadmat, Amini and Kavaratti Islands in the Union Territory of Lakshwadeep, a group of Indian islands adjacent to the Kerala coast inthe Arabian Sea.The populations affected as per the primary health centre (PHC) records of three islands, viz. Kadmat,Amini and Kavaratti, was 85%, 1.4% and 0.15% respectively. Entomological surveys revealed very highlarval indices of Aedes albopictus only in the three surveyed islands. Aedes aegypti, the classical vectorof dengue, was not detected. The maximum breeding of Ae. albopictus was found in coconut shells(57%), tyres (9%), metal containers (9%) and plastic containers (8%). The breeding was also detected intree holes and rat-bitten coconuts on top of the trees. The House Index for Ae. albopictus rangedbetween 95.4% in Kavaratti to 79% in Amini. Kadmat island which was the worst affected, recording the maximum Container Index of 90%, compared with 40% in Amini island. The CHIK outbreak seemed to have been caused by importation of the virus from Kerala, because of heavy movement of the islanders to the mainland.