Indian Council of Agricultural Research
CENTRAL MARINE FISHERIES RESEARCH INSTITUTE

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Population genetic structure of oceanic whitetip shark, Carcharhinus longimanus, along Indian coast

Sharks are undergoing population declines worldwide and it is imperative to devise conservation and management strategies to prevent their extinction. Oceanic whitetip sharks are large pelagic sharks distributed circumglobally and recent IUCN assessments classified them as “critically endangered.” Considering their vulnerability, we investigated the intraspecific diversity and genetic stock structure of oceanic whitetip shark, Carcharhinus longimanus, along the Indian coast using mitochondrial control region sequences so that viable management guidelines can be formulated in the Indian Ocean region. Population genetic analyses revealed a lack of significant genetic differentiation along the Indian coast indicating substantial gene flow and connectivity among populations. Comparisons of data of the present study with that of Atlantic Ocean regions indicated significant connectivity and gene flow between Indian and East Atlantic regions and a lack of connectivity between Indian and West Atlantic Ocean regions. Oceanic whitetip sharks have substantial capacity for oceanic migration resulting in the mixing of gene pools. Despite these capabilities, overfishing is one of the major drivers of population decline worldwide, resulting in severe fragmentation of populations. Based on the results of the present study, this species can be managed as a single stock along the Indian coast. Further co-management measures along with countries bordering East Atlantic coast can also be devised. Management should consider a complete or seasonal ban of the fishery in addition to restrictions in gear types.


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High-value compounds from molluscs of marine and estuarine ecosystems as prospective functional food ingredients

Extensive biodiversity and availability of marine and estuarine molluscs, along with their their wide-range of utilities as food and nutraceutical resources developed keen attention of the food technologists and dieticians, particularly during the recent years. The current review comprehensively summarized the nutritional qualities, functional food attributes, and bioactive properties of these organisms. Among the phylum mollusca, Cephalopoda, Bivalvia, and Gastropoda were mostly reported for their nutraceutical applications and bioactive properties. The online search tools, like Scifinder/Science Direct/PubMed/Google Scholar/MarinLit database and marine natural product reports (1984–2019) were used to comprehend the information about the molluscs. More than 1334 secondary metabolites were reported from marine molluscs between the periods from 1984 to 2019. Among various classes of specialized metabolites, terpenes were occupied by 55% in gastropods, whereas sterols occupied 41% in bivalves. The marketed nutraceuticals, such as CadalminTM green mussel extract (Perna viridis) and Lyprinol® (Perna canaliculus) were endowed with potential anti-inflammatory activities, and were used against arthritis. Molluscan-derived therapeutics, for example, ziconotide was used as an analgesic, and elisidepsin was used in the treatment of cancer. Greater numbers of granted patents (30%) during 2016–2019 recognized the increasing importance of bioactive compounds from molluscs. Consumption of molluscs as daily diets could be helpful in the enhancement of immunity, and reduce the risk of several ailments. The present review comprehended the high value compounds and functional food ingredients from marine and estuarine molluscs.

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First report of anti-inflammatory chromenyl derivatives from spineless cuttlefish Sepiella inermis

The spineless cuttlefish Sepiella inermis encompasses a major share in the marine fisheries sector, and represents as a culinary delicacy in many cultures. Bioactivity-guided fractionation of methanol:ethyl acetate (MeOH:EtOAc, 1:1) extract of the edible parts of the species ensued in identification of two hexahydro chromenyl analogues namely, methyl 7-ethyl-hexahydro-8a-methyl-2H-chromene-4-carboxylate (1) and methyl 1-acetoxy-hexahydro-3-methyl-3-propyl-1H-isochromene-4-carboxylate (2). The isolated metabolites were checked for their radical scavenging and anti-inflammatory potentials by selective in vitro models. The isochromenyl derivative exhibited potential 2,2-diphenyl-1-picryl-hydrazil and 2,2?-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (IC50?<?0.45?mg mL?1) radical-scavenging capacities along with pro-inflammatory cyclooxygenase-2 (COX-2) (IC50 0.75?mg mL?1) and 5-lipoxygenase (5-LOX) (IC50 0.77?mg mL?1) inhibitory activities. The titled compounds displayed the selectivity indices (IC50 anti-COX-1/IC50 anti-COX-2) greater than 1.25, in comparison with synthetic anti-inflammatory drug ibuprofen (0.44), which attributed to their greater selectivity towards inducible pro-inflammatory enzyme COX-2.


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Impact evaluation of marine fisheries interventions among Tribal Fisher Commune of Car Nicobar Island

Fisheries and tourism are two important sectors that provide livelihood and employment in the tropical Islands. Andaman and Nicobar group of Islands is a biodiversity hotspot in the Bay of Bengal inhabited by settler population along with indigenous tribal communities. The Nicobar tribal community is one among occupying the Nicobar group of Islands in the majority and are quite socialized tribal communities of the Islands. Agriculture, animal husbandry and fisheries are the major sectors that contribute to the livelihood and nutritional security of the Nicobar tribes. Traditional fishing activities have been a part of their culture over the years however, tribal youths were reluctant in taking up fishing as a profession considering the changing scenario and alternative employment options. To reinstate fisheries as a profession and to improve their livelihood and employment opportunities, interventions were carried out in Car Nicobar Island. The interventions were mainly aimed towards increasing fish catches, to expand their fishing grounds and to sensitize safe fishing and navigation practices. Fishing inputs such as modern fishing boats, GPS and outboard engines were provided as inputs to tribal fishers based on the outcome of an expert consultation meeting. Structured questionnaires were prepared to analyze the impact of the interventions. The results indicated that the interventions led to a significant improvement (p <0.001) in the expansion of their fishing grounds (3.47 ± 0.2 km), reduced time spent to reach the fishing grounds (2.3 ± 0.25 hour) and increased catch per unit effort (7.93 ± 1.23 kg/boat). This study shows that the targeted interventions coupled with awareness and sensitization programmes could make fishing activities profitable, attractive and can motivate the unemployed youths to opt for fishing as a profession.


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Influence of certain environmental parameters on mass production of rotifers

Larviculture of many finfishes and crustaceans in aquaculture depends mainly on the live feed and its unavailability in sufficient quantity is hampering its expansion and culture progress all around the world. The most suitable feed for marine finfish larvae is the commonly available zooplankton species such as rotifer, copepods and Artemia nauplii. Among all, the live feed that has been demonstrated more successfully as the first feed for most of the marine finfish species is rotifer. Optimum conditions are required for better growth, reproduction and increased productivity of rotifers. The major factors that influence the population size of rotifer are temperature and salinity. Hence, the impact of environmental parameters with special focus on the salinity and temperature on the increase in biomass and smaller rotifer production is of utmost importance in the present scenario.


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Rare observation of scar-bearing cuttlebone in a wild-caught Sepia pharaonis from Arabian Sea

A rare observation of the severely fractured cum healing cuttlebone of wild-caught Sepia pharaonis is reported and discussed here. The observation showed that cuttlebone of one specimen was severely affected by scars. Scars were interpreted as oval-shaped teeth marks on the dorsal side having a diameter of 23 mm. Several other teeth marks (3-4 numbers) were also observed at the anterodorsal region. Fracture was completely healed at the dorsal side while fracture (19 mm length) was notable in posteroventral region. Inverted ‘V’shaped blackline was also observed on the posteroventral region. However, scar-bearing cuttlebones was more or less symmetrical with respect to the sagittal plane.


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