Indian Council of Agricultural Research
CENTRAL MARINE FISHERIES RESEARCH INSTITUTE

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Morphological Deformities in Neotrygon kuhlii from Gulf of Mannar, Bay of Bengal, India

Morphological deformities in blue-spotted maskray, Neotrygon kuhlii (Muller & Henle, 1841) were observed from the regular fishery of the Gulf of Mannar, Southeast coast of India. The deformities were mostly noticed in the head (pectorals not fused) and the vertebral column (scoliotic/lordotic/kyphotic curve). The detailed observations on various deformities have been briefly described in the present investigation.


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First Record of Stanaland’s Sole (Solea stanalandi, Randall & McCarthy) from Indian waters

A single specimen of the Stanaland’s sole, Solea stanalandi was caught by a commercial trawl from Gujarat coast and landed in Mangrol fish landing centre on 23rd January, 2017. The species is presently considered as one of the data deficient species by the International Union for Conservation of Nature (IUCN) due to the dearth of crucial information on the ecology, distribution and population characteristics of the species. Hitherto, the species was believed to be endemic in Persian Gulf alone. This is the first report of its occurrence from Indian waters, describing the extension of its geographical distribution within the Indian water. The fish was examined for its morphometrics and meristic characters and described. The new report of S. stanalandi in Indian fisheries could provide a novel avenue for generating vital baseline information to understand the ecological significance of the species in the region.


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Evaluation of gross protein and lipid requirements in formulated feed for honey gourami, Trichogaster chuna

Gross protein and fat requirements in formulated feeds designed for the honey gourami, Trichogaster chuna (initial weight 1.34–1.38?g), were investigated. Feeds containing 30%, 40%, and 50% protein and 6% and 9% lipid at each protein level were tested. Protein and energy sources used were from fishmeal, shrimp meal, clam meal, soy flour, and wheat flour. An equal mixture of crude sardine oil and groundnut oil was used as the source of lipids. Comparison of the whole gourami amino acid profiles before and after the dietary treatments indicated a relative decline in all amino acids except methionine and lysine. Fatty acid profiles of whole individuals after dietary treatment showed a substantial increase in monounsaturated fatty acids relative to the initial fatty acid profiles. No significant differences were observed in fish growth between dietary treatments (p?>?.05). Feeds containing 30% protein and 6% lipid were found to be adequate for normal growth, while feeds with 40% protein and 6% lipid were seen to help accelerate growth and reproduction. In this study, protein and lipid levels required for regular maintenance, sexual maturation, and spawning of aquarium?reared gourami were established.


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Genetic variability of a small captive population of the Cobia through pedigree analyses

The genealogical information of a small captive population of the Cobia fish was evaluated to assess the genetic variability and the status of inbreeding through pedigree analyses. Pedigree data (n=238) for 6 years (2010-2016) were analyzed and offspring born from 2015 to 2016 were considered as reference population to compute the population genetic parameters based on the gene origin probabilities using the program ENDOG (version 4.8). Molecular marker based FAP (Family Assignment Program, version 3.6) was used for parentage assignment. The pedigree completeness was 68% for the parent, 29% for the grandparents and 7% for the greatgrandparents generations with a mean equivalent to complete generations of 2.66. Mean generation interval, computed from four pathways, was 2.38 years. Considering the reference population into account the coefficients of average inbreeding and average relatedness were computed as 9.6% and 9.9%, respectively. The mean values of individual increase in inbreeding (rate of inbreeding) were 6.5% and 2.5% for the reference population and for the whole pedigree, respectively. Realized effective population size was computed from the individual increase in inbreeding and from the individual increase in coancestry as 7.7 and 10.6, respectively. The effective numbers of founders (fe), ancestors (fa), founder genomes (fg) and non-founder genomes (nfe) for the reference population were computed as 6, 6, 3.8 and 11.1, respectively. About 85% of total genetic variation was explained by 7 most influential ancestors, with a maximum individual contribution of 33.5%. Though the genetic bottleneck, as expressed by the fe/fa ratio as 1.0, was not evident, the loss of genetic variability caused by genetic drift was evident by fg/fe ratio which was 0.64 for the reference population. The analysis revealed the evidences on loss of genetic diversity with a very critical effective population size. Recommendations were made to improve the genetic variability in the herd. The present study signifies the importance of maintaining the pedigree and can help in carrying out similar studies on captive-bred fish species where small populations are inevitable.


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Population structure of Spanish mackerel Scomberomorus commerson in the Northern Indian Ocean

Narrow barred Spanish mackerel, Scomberomorus commerson (Lacepede, 1800) is one of the economically important marine fish species in the Northern Indian Ocean. Genetic stock structuring is reported in S. commerson from Arabian Peninsula, Indo-West Pacific, Northern Australian, Southeast Asia and Northern Australia. The present study utilized microsatellite markers to elucidate the population structure of S. commerson (Lacepede, 1800) in the Arabian Sea and Bay of Bengal. A total of 12 polymorphic microsatellite loci were amplified in 250 samples collected from five different geographic locations. Low FST values (0.0023–0.027), AMOVA, PCoA and the Bayesian analysis of genetic structure indicated unit stock of the species in Indian waters. Bottleneck analysis using Wilcoxon signed rank tests and Mode shift test indicated lack of recent bottleneck events across populations of S. commerson. The findings of the present study could be used in managing the commercially important species, S. commerson as a unit stock in Arabian Sea and Bay of Bengal of Northern Indian Ocean and reinforces the need for regional cooperation on fisheries management.


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First report of bioactive sterols from the muricid gastropod Chicoreus ramosus

Two unusual ?5 sterols with unprecedented skeletons were isolated from the organic extract of muricid gastropod Chicoreus ramosus collected off the Gulf of Mannar Coast. This is the first report of isolation of bioactive sterols endowed with anti-inflammatory potentials from this species. The compounds were characterized as (5Z)- 24a-homo-cholesta-5,24a1(24a2) dien-3?-ol (1) and 27(25?23)-abeo-(5Z)-3?-hydroxy-24-isopropyl cholesteno- 26,23-lactone (2) by the interpretation of a series of spectroscopic techniques involving two-dimensional nuclear magnetic resonance and mass spectral data. The compound 1 is unusual in that it has an ethylene attachment stemming from the additional methylene group at the 24a position of the steroid side chain, whereas compound 2 has a unique side chain bearing a ?-valerolactone ring. The ?5 sterol bearing ethylene group (1) displayed comparatively better antidiabetic activity as characterized by inhibitory effects towards ?-amylase and ?-glucosidase enzymes (IC50 1.97mM and 1.78 mM, respectively), whereas the cholestenolactone analogue (2) manifested higher anti-inflammatory activity (IC50 1.42 mM) as determined by in vitro 5-lipoxygenase inhibitory potential. Structure-activity correlation study showed that the biological activities of the studied sterols were directly related to their electronic properties. The homosterol (1) exhibiting improved antidiabetic properties showed higher lipophilic character coupled with lesser steric restrictions.


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