545 research outputs found
Random amplified polymorphic DNA (RAPD) fingerprinting resolves species ambiguity of domesticated clown fish (genus: Amphiprion, family: Pomacentridae) from India
Clown fishes of the genus Amphiprion are a valuable
resource from the point of view of the aquarium
trade. There are about 27 species distributed widely
in the Indo West Pacific region, extending from the
eastern Indian Ocean to the Indonesian and Philippine
archipelagos and from the coast of northwestern
Australia to the Ryukyu Islands of Japan (Allen
1980; Fautin & Allen 1992). Allen (1991) used morphological
similarities to designate six taxonomic
complexes of closely related species. Apart from colour
variation, tooth shape, scalation on the head
and body proportions are used to identify the species
of clown fish (Fautin & Allen1992).The occurrence of
multiple colour variants in most of the species, besides
variations in colour patterns between juveniles
and adults of the same species, makes unambiguous
identification in clown fishes difficult
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Application of DNA fingerprinting in genome analysis of fishes
DNA-level markers find several applications in fisheries research analysis and aquaculture. Species identification, evaluation of phylogeny, delineation of stock structure,
measuring levels of genetic variation in wild and
cultured stocks, conservation genetics, determination of breeding strategies, gene mapping, marker - assisted selected and assessment of genome manipulation techniques
are among various uses of DNA markers in studies of natural and cultured fish populations
Environmental DNA (eDNA) metabarcoding-based estimation of marine stocks
Information on species composition and biomass/abundance of exploited species in coastal
fisheries is vital in management of resources. One of the most important mandates of the
leading institution is judicious management of coastal and deep sea fishery resources.
Traditional methods of identifying species and estimating biomass/abundance have inherent
drawbacks which could be ameliorated by DNA marker based approach. Environmental DNA
(eDNA) can be obtained from the skin, mucous, gamates, faeces, blood and other cells that
are constantly being shed into the immediate environment by the organism. Analysis of
this eDNA can give us information on the organisms, their abundance and biomass. Recent
advances in next generation sequencing enable simultaneous sequencing of DNA from
whole communities known as metabarcoding. Studies carried out in aquaria, large lakes,
rivers and marine environment consistently suggest that eDNA metabarcoding outperforms
traditional survey methods in terms of non-invasive sampling, sensitivity and cost incurred
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Record landings of the catfish, Osteogeneious militaris (Linnaeus) at Rameswaram
Duringjanuary-April 1992, 368t of Catfishes
were landed (CPUE 52.2 kg) at Rameswaram fished
by Pair trawlers in the area 9┬░20' - 9┬░30'N latitude
and 79┬░ 20' -79┬░30'E longitude, west of Katchativeu,
which is a record catch. Osteogeniosus militaris
formed 62% (228t) of catfishes; such heavy landings
of this species have never been reported earlier from
this area
Population dynamics of big-eye croaker Pennahia macrophthalmus and blotched croaker Nibea maculata (Pisces/Perciformes/Sciaenidae) in the trawling grounds off Rameswaram island, east coast of India
In the region off Rameswaram (lat. 86 55'-9┬░ 20'N; long. 79"-79┬░ 40'E) sciaenids are exploited almost exclusively by trawlers, Of the 9 commonly occurring species of croakers. Pennahia macrophthalmus (Bleeker) in the Palk Bay and Nibea maculate (Schneider) in the Gulf of Mannar are the dominant one
Ornamental fish culture and trade: current status and prospects
Ornamental fishes are often called as
'living jewell; due to their colour, shape,
behaviour and origin. They are peaceful,
generally tiny available in attractive colours
and capable ofliving in confmed spaces. In
China aquarium fish keeping has been a
hobby from ancient times
Some observations on the biology of the blotched Croaker Nibea maculata (schneider, 1801) from Mandapam
Some aspects of the biology of NQ>ea maculata from Mandapam waters are studied. Regression coefficients
in the length-weight relationships of females and males of N. macutala show significant difference between
them and both significantly differ from the cubic value. The spawning season is from April to August
and the females appear to perform two spawning acts during this period. Relative condition factor is
apparently related to the reproductive cycle. Females and males attain first maturity at 185 and 167 mm,
respectively. Fecundity show wide fluctuations from 21,584 to 475,043 with high correlation to ovary
weight. Overall sex-ratio shows predominance of females
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