Indian Waters Research Articles

Population structure analysis of mangrove mud crab Scylla serrata (Decapoda: Portunidae) from Indian coastal waters

Scylla serrata (Forskal, 1775) is an important crab resource for aquaculture and coastal fisheries in India. Study on population differentiation and population history of this economically important crab species is very much essential for conservation and management. Wild S. serrata samples were collected from 18 different locations in India including Andaman coastal waters. Population structure and demographic history of S. serrata was evaluated using 425bp of cytochrome b and 562bp of 16S rRNA genes. Only nine and three haplotypes were obtained by the analysis of cytochrome b and 16S rRNA gene respectively. Low level of haplotype diversity, nucleotide diversity, non significant F ST values for16S rRNA gene (F ST = 0.0133) and negative non significant F ST values for cytochrome b gene (F ST = −0.0063) were confirming the lack of population structure in Indian coastal waters. The maximum likelihood tree of cytochrome b gene showed that there were only 2 clusters and one cluster had only one representative (Hap8). The haplotypes of 16S rRNA gene were also clustered in to two groups with haplotype 1 (Hap1) as a separate group in maximum likelihood tree. The present study clearly figure out the S. serrata populations in Indian waters can be considered as a single stock during conservation and management programme.

Odin ex Black watch: Environmental shipbreaking frustrated by Indian courts. Black Watch Cruise Ltd. v. Cruise Vessel Odin ex Name Black Watch

Shipowners are facing increased pressure from changing laws and green investors to scrap and recycle their ships in yards with higher environmental and labor standards, rather than on the beaches of India and Bangladesh. Recently, English shipowner Fred Olsen sold a 50-year old cruise ship to a Turkish company with a clause stipulating it be recycled at a shipyard approved under the European and UK Ship Recycling Regulations. The Turkish company did not comply and sold the ship for scrapping in India. Fred Olsen sued the Turkish company in the United Kingdom and petitioned Indian courts to arrest the vessel in Indian waters. The ship was briefly arrested but then sent to the beach for breaking. Fred Olsen is now only able to seek monetary damages, as their environmentally sound intentions, along the effectiveness of any European ship recycling regime, faced a severe setback.

First report of free-living, solitary zoanthid from Andaman and Nicobar Islands

Studies on zoantharians (Cnidaria: Anthozoa: Zoantharia) from Indian waters are exceptionally sparse. Most studies were carried out on the colonial inter-tidal species whereas exploration from shallow coastal waters is yet to be carried out thoroughly. The present study reports the first record of one of the four species of free-living and solitary genus Sphenopus Steenstrup, 1856; Sphenopus marsupialis (Gmelin, 1791) from Andaman and Nicobar Islands. The specimens were collected from the sandy bottom of Point Island at depths of 25 to 38 m. Detailed morphological features along with distributional ranges are reported here.

Morphological and molecular systematics of swimming crabs (Decapoda: Brachyura: Portunidae) from India collected on-board the FORV Sagar Sampada (cruise no. 378, 385 and 392), with notes on biogeography of the Indian portunid fauna.

Morphological and molecular characters of swimming crabs (Family Portunidae Rafinesque-Schmaltz, 1815) collected during one cruise each of the Fishery Oceanographic Research Vessel Sagar Sampada in the northeastern Arabian Sea (97–110 m depth), southwestern Bay of Bengal (56 m), and southeastern Bay of Bengal (56 m) and western Andaman Sea (53 m) were studied. They are referred to 17 species representing 4 subfamilies, 8 genera and 2 subgenera. Cycloachelous levigatus Koch, 2021, Monomia rubromarginata (Lanchester, 1900), Thalamita malaccensis Gordon, 1938 are first records from Indian waters. The study also reveals variations in the pleonal and genital morphology of Monomia argentata (A Milne Edwards, 1861) form B (sensu Stephenson and Rees, 1967a). Mitochondrial Cytochrome oxidase subunit I and 16S rRNA gene sequences of 14 and 16 species, respectively revealed a monophyletic subfamily Lupocyclinae Alcock, 1899, and polyphyletic subfamilies Portuninae Rafinesque, 1815 and Thalamitinae Paulson, 1875. Analysis of the biogeographic distribution patterns of Indian portunids revealed a total of 104 species representing 22 genera, thereby suggesting mixed diversity in different ecological regions. The highest number of 72 species and 2 subspecies were recorded from the West and South Indian Shelf Province followed by Andaman Province (69 species), Bay of Bengal Province (54 species) and Central Indian Ocean Islands Province (26 species). Among the individual marine ecoregions, Andaman and Nicobar Islands recorded the highest number of species (69 species), followed by South India (57), Eastern India (50), Western India (47), Northern Bay of Bengal (32) and Maldives (26).

First Record of Stripe-faced Calamiana Eugnathogobius Mindora (Herre, 1945) in India, and Distribution Range Extension of Banded Mullet goby Hemigobius hoevenii (Bleeker, 1851) and Acentrogobius viganensis (Steindachner, 1893) (Gobiiformes: Gobiidae) Collected from Pazhaverkaadu Lagoon and Ennore Estuary, South India

The present work reports the occurrence of stripe-faced calamiana Eugnathogobius mindora (n = 2) for the first time in Indian waters and distribution range extension of Hemigobius hoevenii (n = 1) and Acentrogobius viganensis (n = 1) which co-occurs with E. mindora along the east coast of India. The specimens were collected from the Pazhaverkaadu lagoon and Ennore estuary, South India. E. Mindora can be readily distinguished from its closest congeners in having five prominent brown stripes in cheek and suborbital, elongations in first three dorsal spines, 33–36 lateral scales and a larger anterior nape scale. The present finding adds one more species to the Indian fish fauna by reporting the first species of the genus Eugnathogobius from Indian coastal waters. Description, meristic and morphometric characters provided for the three gobiid fish species in this study will aid to solve the ambiguity in their identities as these species have spatial synonyms in the tropical marine waters.

Cetaceans and cetacean research in India

The diversity of cetacean species in Indian waters is high, with 25 species recorded so far. Records of cetaceans from India during the last 200 years have provided insights into their spatiotemporal distribution, behaviour, feeding, reproduction, fishery interaction and pollution. The cetacean fauna is dominated by pantropical species, with a relatively high abundance of spinner dolphins, which is similar to other areas studied within the northern Indian Ocean. Historical records were analysed to propose an inventory of cetaceans. Cetacean diversity was highest in the Gulf of Mannar on the southeast coast of India, which with 14 species recorded from a small area can be considered a ‘hot spot’ for further research. Fishery interactions, domestic consumption, pollution and lack of quality information to inform management are the main threats for successful survival of cetaceans. The status of information regarding cetaceans in India could be classified based on this study as: six species with adequate data; five species where data is restricted to a few geographic locations; four species for which data collection is being initiated; five species with sparse data; and six species which are difficult to observe.

The taxonomy of Indian gorgonians: an assessment of the descriptive records of gorgonians (Anthozoa: Octocorallia: Alcyonacea) recorded as occurring in the territorial waters of India, along with neighbouring regions and the Andaman and Nicobar Islands, and the highlighting of perceived unethical practice

The descriptive taxonomic records of a total of 226 gorgonian species (Octocorallia: Alcyonacea) from Indian seas and neighbouring areas were surveyed and critically reviewed with the main aim of providing a more reliable checklist. The published accounts comprise: species originally described from within the region: subsequent descriptive records of the taxa originally described from within the region; and subsequent descriptive records of species originally described from outside of the region. The reviews include an attempt to assess the validity of all subsequent descriptive records, although in numerous cases the species have been assessed as unrecognisable from their type descriptions. Numerous new binomial combinations, some tentative, have been proposed. The assessment of the validity of a species record is expressed as an "Opinion" with supporting justification. Of the 226 species, there are 111 that were originally described from locations outside of Indian waters and have subsequently been described and recorded as occurring in the region. Of these, there are 9 species where we were unable to decide if the records are valid or not, 94 were assessed as invalid, 5 as possibly valid and 3 were considered valid. The survey highlights four major problems regarding the reliability of some more recently published taxonomic records for the region: the use of 'predatory journals'; plagiarism; the use of manipulated imagery in more than one description; and taxonomic decision apparently based on expediency.

Flowering and fruiting of Tape Seagrass Enhalus acoroides (L.f.) Royle from the Andaman Islands: observations from inflorescence buds to dehiscent fruits

Seagrass phenophases are crucial in understanding their reproductive biology but are seldom documented. We studied flowering and fruiting phenophases of Enhalus acoroides from a mixed-species intertidal seagrass meadow in Ritchie’s archipelago, Andaman Islands, India. The estimated mean densities of pistillate and staminate flowers were 16.0 ± 12.0/ m2 and 12.7 ± 7.3/ m2, respectively. We observed the bloom of free-floating male flowers (961.7 ± 360.4/ m2) during the spring low tides (at mean sea surface temperature ~30°C). Seagrass cover, shoot density, and canopy height of E. acoroides, along with flowering densities, showed a zonal variation within the sampled meadow. We report the first-time observations of several phenophases of E. acoroides, such as female inflorescence buds, male inflorescence, a bloom of released male flowers, pollination, and fertilized flowers from the Indian waters. We also report the prevailing threats to seagrass meadows, such as meadow scarring done by boat anchorage in the Andaman Islands.

Ghost fishing capacity of lost experimental gillnets: a preliminary study from Indian waters.

Abandoned, lost, or otherwise discarded fishing gear contributes considerably to global marine debris. These lost gears, mostly made of non-biodegradable synthetic materials, persist in the marine environment for longer periods of time and pose a great threat to marine life by entangling and killing target fishes and other non-target species such as turtles, birds, and mammals, a phenomenon known as ghost fishing. Other environmental impacts include physical impacts on aquatic habitats, transfer of microplastics into food web, and interference with fishing. Information regarding the catching efficiency and catch rates of lost nets in Indian waters is lacking. Ghost fishing capacity of simulated lost gillnets is being reported for the first time in India. This study investigates the ghost fishing capacity of lost gillnets through an experimental approach at Aroor, Vembanad lake, Kerala, India. Simulation studies using purposefully abandoned shrimp gillnets (32mm mesh size) were conducted to understand the fishing capacity of lost gillnets during two seasons (monsoon and post-monsoon) as separate experiments. The gillnets maintained their catching efficiency until the 15th day during the first experiment and up to the 50th day in the second experiment. Catches showed an exponential reduction over time in both experiments. A total of 251 specimens comprising of 27 species were caught from both sets of experimental nets, and the state of catch in the nets showed different decaying stages from the second day itself along with fresh stages. As the days progressed, particulate matter and detritus began to accumulate on the experimental nets, increasing net visibility and reducing their catching efficiency. The results of the study on ghost fishing capability will contribute to the development of strategies for reducing the effects of lost nets on the aquatic ecosystem and for suggesting improved management strategies.

The curious case of Phyllidia ocellata and the first molecular data of three phyllidiid species from India (Gastropoda, Heterobranchia, Phyllidiidae)

ABSTRACT The current study presents the first molecular data of three species of the family Phyllidiidae, Phyllidia ocellata, Phyllidia alyta and Phyllidiella rosans, from Indian waters. The P. ocellata molecular sequences closely match those available from the Pacific Ocean, whereas P. alyta and P. rosans form independent clades, confirming their identifications as distinct species. Phyllidia ocellata, frequently found in the Indo-Pacific tropical coral reefs, is renowned for its wide range of colours and external forms. Numerous variations have been found and are being examined at the molecular level, and the subject of this study is another variation that, until dissection and molecular analysis, was thought to be a colour form of Phyllidia multituberculata. Although India has a long history of heterobranch research, no phyllidiid species from Indian waters have ever been the subject of molecular research.

Reef-associated palaemonid shrimp fauna of Lakshadweep islands: special focus on Cuapetes Clark, 1919 (Decapoda; Caridea) with a description of new species and phylogenetic notes

ABSTRACT The reef-associated palaemonid shrimp fauna of Indian waters, especially in island ecosystems, is one of the least studied. During explorations at Lakshadweep Islands, Cuapetes elegans (Paulson 1875), C. grandis (Stimpson 1857) and a new species, Cuapetes purushothamani sp. nov., were recorded and illustrated based on the specimens collected from dead coral and rocky shore regions of eastern lagoon of Agatti Island (0.5–1.0 m), Lakshadweep, India. The new species shows close relation with C. elegans, possessing distinctive characteristics as indicated: rostrum extends as far as antennal scale, arrangement of ventral teeth below the wide edentulous dorsal part of rostrum, long dorsal spines of telson, a fewer number of segments in antennal flagellum, fingers of first chelated leg slightly longer than palm, chela of second cheliped longer than combined length of merus and carpus with inflated palm. In addition, the partial sequences of mitochondrial genes cytochrome c oxidase I (COI), 16S and nuclear Histone 3 (H3) gene were generated and compared with other available species of Cuapetes. The phylogenetic analyses strongly supported our new discovery, Cuapetes purushothamani sp. nov., which possesses a close relationship with C. elegans by having high interspecific genetic divergences (COI: 19.2–19.9%; 16S: 12–12.8%; H3: 3.1–3.9%). http://zoobank.org/urn:lsid:zoobank.org:pub:1B5C9228-9D9F-430E-BF11-C6DC7510DF1B

An updated checklist of Stomiiformes from Indian waters with nine new records

Abstract Over the years as a part of many fishery surveys, considerable number of stomiiform fishes were collected by the Centre for Marine Living Resources and Ecology (CMLRE) Research Vessel ‘Sagar Sampada’. The collection came from throughout the Indian EEZ and some from the western Indian Ocean. However, a systematic identification of these fishes had never been carried out prior to this paper. Thirty-four species were identified and it was found that eight species were new records to India and one to peninsular India. Among the records, two species, Photonectes paxtoni Flynn and Klepadlo, 2012 and Photonectes barnetti Klepadlo, 2011, are collected from the Indian Ocean for the first time. The paper provides a detailed report on all the new records and a list of stomiiform species collected during these surveys. Differences in barbel morphology observed for many of the stomiids are discussed.

From the Ground Up: Community Solutions to India's Water Scarcity

India’s groundwater scarcity is a growing issue, especially in the context of its growing population and its agricultural sector’s reliance on the resource. Community based interventions can be an effective method for meaningful water management.

Seven new distributional records of cryptobenthic reef fishes in Lakshadweep, India

Abstract Investigations on the diversity of cryptobenthic reef fishes resulted in observation of seven new geographic records for Lakshadweep waters, India: halfbarred goby Amblygobius semicinctus, target shrimpgoby Cryptocentrus strigilliceps, thread shrimpgoby Ctenogobiops mitodes, eye-bar goby Gnatholepis anjerensis, Miki's dwarfgoby Eviota mikiae, Erythrops goby Bryaninops erythrops, and Enneapterygius sp. Ctenogobiops mitodes is a new record to Indian waters. The genera Cryptocentrus and Bryaninops are reported from Lakshadweep for the first time. The observations were conducted in the lagoon and reef slope of Kavaratti Island, one of the 12 atolls of the Lakshadweep archipelago, from January–March 2021. The cryptobenthic reef fishes were observed and recorded through underwater photography and videography.

Population dynamics of the geographically defined metapopulations of brown shrimp Metapenaeus monoceros (Fabricius, 1798) from Indian waters

Population dynamics of the brown shrimp Metapenaeus monoceros (Fabricius, 1798) was studied along the Indian coast using catch and effort data of trawlers from 8 States and 2 Union Territories for the period 2007-2015. Classical length-based stock assessment methods and spatial database of the shrimp catch were used to derive fishing ground related conclusions. Inclusion of spatial data revealed the possibility of existence of metapopulations of M. monoceros in the region. Maximum sustainable yield (MSY) cannot be a reasonable reference point for deciding the fishing pressure in M. monoceros. By analysing stock fluctuations noticed during the study period with varying spawning stock biomass combinations, retention of 40% spawning biomass seems to be a safe option for sustaining M. monoceros production from Indian waters. Based on this, the study recommends reduction of fishing pressure along north-west, south-west and northeast coast by 70, 60 and 70% respectively from the base level of effort in 2017. The study illustrates that the spatial data from fishing ground, can serve as an additional tool to derive management options. The study also emphasises the need for further investigations on the possibilities of metapopulations of M. monoceros which is widely distributed in all agro-climatic zones along the Indian coast. Keywords: Indian coast, Metapopulation, M. monoceros, Spatial study, Stock assessment

Compositional analysis of live fish import trade in India

The live fish import trade in India under the harmonised system (HS) code 0301 (HS-0301) increased exponentially in terms of import quantity and value during the period 2000-2019. India imported 1.32 t of live fish worth US $ 0.017 million in 2000, which increased to 653.27 t worth US $ 3.21 million in 2019. The import of both marine as well as freshwater ornamental fish was found to increase during the period 2013-2019. The major countries exporting marine and freshwater ornamental fish to India were Thailand, Indonesia, Malaysia, Singapore and Sri Lanka. The import of live trout and carp to India was found to be very less during the period 2000-2019. The majority of live fish import to India accounted in the subclass HS030199 since 2017, with 81.55, 91.86 and 74.03% of total live fish imported to India in 2017, 2018 and 2019, respectively. Bangladesh accounted 81.02, 87.84 and 83.11% of total import quantity and 0.74, 82.42 and 49.51% of total import value under the sub-head HS-030199 during 2017, 2018 and 2019, respectively. While import of live fish offers economic opportunities, it has the potential to bring biosecurity threats including fish pathogens to Indian waters. The economic trade-off is to be evaluated on a case to case basis supported with legal and institutional back-up. Enacting a comprehensive legal framework and creating quarantine facilities are critical in this direction. Keywords: Compositional analysis, HS-0301, Import, Ornamental fish, , Trade balance

Panmictic stock structure of milkfish (Chanos chanos, Forsskål 1775) from Indian waters determined using mtDNA marker

Panmictic stock structure of milkfish (Chanos chanos, Forsskål 1775) from Indian waters determined using mtDNA marker

Comparative Otolith Morphology and Morphometry of Cyprinid Fishes from Indian Waters

Comparative Otolith Morphology and Morphometry of Cyprinid Fishes from Indian Waters

Species-specific molecular signatures for the commercially important scombrids using mitochondrial gene analysis; a tool for fisheries management

The family Scombridae, comprising of commercially important marine fishes, which are widely distributed across tropical, subtropical, and temperate waters. Scombrids constitute an important fishery and are exploited across their range of distribution. Accurate identification of species is important for effective fisheries management and forensics purposes. In the present study, commercially important species of scombrids distributed in Indian waters were selected for molecular phylogeny and development of species-specific diagnostic keys using mitochondrial cytochrome c oxidase I (COI) gene. In addition to morphological identification, the species were identified using molecular-based identification approach and character-based identification system. Molecular phylogeny for 16 species of scombrids was ascertained using mitochondrial COI analyses. The character-based molecular diagnostic keys for 16 species of scombrids were developed in-silico from data set comprising 603 mtCOI sequences generated in the present study as well as collected from published resources. The study uncovered 39 unambiguous molecular keys, capable of distinguishing all reference taxa under study. The development of species-specific sequences and key diagnostic nucleotides for scombrid fish species will be helpful in effective forensic applications, enforcement of fisheries regulations, and for sustainable utilization of this commercially important group of species.

Performance Comparison of Optical Wireless Communication Using Gray Relational Analysis

In this study, Indian Optical Wireless Communication (IOWC) is examined as a short-range method for transferring data at high rates. It is rapidly gaining popularity as an effective method, with an optical transmitter at the IOWC terminal and a receiver included. For example, it can be used in tall buildings separated by several hundred meters, where light beams propagate through the atmosphere and convey information to the recipient. IOWC has several advantages over its competitors, most notably its quick setup, free-of-charge licensing, and lightweight, high-capacity communications. However, IOWC still faces many challenges, including improving communication efficiency in adverse weather conditions or during construction. In the field of underwater acoustic communication, great progress has been made, but IOWC is still better than traditional audio communication systems due to its significantly lower power consumption and ability to provide simple computational problems for short-range wireless links. IOWC has many potential applications, including in Indian coastal waters. The gray relational analysis (GRA) method is simple in calculations and optimizations, and research shows that it is easy to extend this proposed method for problems with more than two answers. To determine the material and life strategies in a one-dimensional array, a method provides multidimensional alternatives based on Taguchi using gray correlation analysis. The optimization design is done on a top cap with a thin wall section unique to TWBs structures. The gray relational analysis method can be used to describe the alternative and evaluation parameters in optical wireless communication. As far as the optical wireless communication APM-EDM process is concerned, alternatives include Lamina Atlas NT-42C1-0484, AOP LED Corp PU-5WAS, Kingbright AADI-9090QB11Gitek/3, LGLB-313E, Toshiba TL12B01 (T30), and Lumex SML-LX1610USBC. The evaluation parameters are wavelength (nm) and luminous flux (Im). From the final result, it is seen that AOP LED Corp PU-5WAS got the first rank, whereas Toshiba TL12B01 (T30) has the lowest rank