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Abstract:
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The family Cyprinidae is the largest of freshwater fishes and, with the possible
exception of Gobiidae, the largest family of vertebrates.Various members of this family are important as food
fish, as aquarium fish, and in biological research. In this study, a fish species from this family exclusively found in the west flowing rivers originating from the Western Ghat region — Gonoproktopterus curmuca — was
taken for population genetic analysis.There was an urgent need for restoration ecology by the development of apt management strategies to exploit resources judiciously. One
of the strategies thus developed for the scientific management of these resources was to identify the natural units of the fishery resources under exploitation
(Altukov, 1981). These natural units of a species can otherwise be called as stocks. A stock can be defined as a panmictic population of related individuals within a single species that is genetically distinct
from other such populations.It is believed that a
species may undergo micro evolutionary process and differentiate into
genetically distinct sub-populations or stocks in course of time, if reproductively
and geographically isolated.In recent times, there has been a wide spread degradation of natural aquatic environment due to anthropogenic activities and
this has resulted in the decline and even extinction of some fish species. In such situations, evaluation of the genetic diversity of fish resources assumes important to
conservation.The species selected for the study, was short-listed as one of the candidates for stock-specific, propagation assisted rehabilitation and
management programme in rivers where it is naturally distributed. In connection
with this, captive breeding and milt cryopreservation techniques of the species have been developed by the National Bureau of Fish Genetic Resources, Lucknow. However, for a scientific stock-specific rehabilitation
programme, information on the stock structure and basic genetic profile of the
species are essential and that is not available in case of G. curmuca. So the present work was taken up to identify molecular genetic markers like allozymes, microsatellites and RAPDs and, to use these markers to discriminate the distinct populations of
the species, if any, in areas of its natural distribution. The genetic markers were found to be powerful tools to analyze the population genetic
structure of the red-tailed barb and demonstrated clear cut genetic differentiation between pairs of populations examined. Geographic isolation by land distance is likely to be the factor that contributed to the restricted gene flow between the river systems. So the present study emphasizes the need for stock-wise, propagation
assisted-rehabilitation of the natural populations of red-tailed barb,
Gonoprokfopterus curmuca. |