International Journal of Aquaculture, 2016, Vol.6, No.4, 1
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observed number of alleles, effective number of alleles, Nei’s genetic diversity and Shannon’s diversity index in
the Dooars region populations were 1.8657±0.3423, 1.5311±0.3486, 0.3082±0.1740 and 0.4589±0.2366
respectively (Table 2). Locus-specific Nei’s genetic diversity was found to be highest in OPB03-8, OPA16-12 and
OPA2-9 loci (Terai rivers) and that in OPA19-5, OPB12-3 loci (Dooars rivers) (Table 1 and Table 2).
The PhiPT values showed the degree of population differentiation. The highest level of differentiation was found
between TR-1 and TR-5 populations (0.719) in the the Terai region (Table 3) and between DR-3 and DR-7
populations (0.810) in the Dooars region (Table 4).
3 Discussion
RAPD technique has been widely used to ascertain the genetic architecture of different subdivided populations of
a species. Due to its cheap, inexpensive and rapid use, RAPD is the best alternative to other more sophisticated
molecular tools in population genetic analyses. The ornamental fish
Badis badis
has been considered to be a
vulnerable fish species in the Indian context, demanding proper conservation, management and stock
enhancement in the sub-Himalayan Terai and Dooars regions of West Bengal, India. We have previously studied
the genetic architecture of this species in detail in the Terai region through RAPD fingerprinting (Mukhopadhyay
and Bhattacharjee, 2015). In the present study we have ascertained locus specific genetic diversity analyses and
population differentiation of the Terai and Dooars region
Badis badis
populations. We have focused only the
locus specific diversity of this species in the Dooars region of West Bengal, India. The study has identified few
more diverse RAPD bands or loci which could be further used to study similar populations in the nearby regions
to study changes in diversity patterns. The detailed study of this species in the study region should be done to
analyze its genetic diversity in a robust way.
We have also carried out population differentiation study in these two regions to show how much genetic
differentiation has occurred in this species in the particular study area. We have found that a significant level of
population differentiation has occurred between some populations (Table 3 and Table 5). This differentiation
might have happened due to lower level of gene flow between these populations or lower level of intermixing
between these populations due to some allopatric or sympatric processes. The region is within a biodiversity
hotspot therefore, acquiring information regarding the population genetic structure of this species might be helpful
to the development of suitable conservation strategies and management practices.
4 Materials and Methods
4.1 Survey and sample collection
A total thirty
Badis badis
individuals were collected from six spots of the major streams of the Terai Region of
West Bengal, India (five samples from each spot) and geographic coordinates of the collection spots were
recorded. The collection spots were as follows: TR1=Mahananda Barrage, Fulbari, TR2=Mahananda-Panchanoi
River Junction, TR3=Balason River at Palpara, TR4=Panchanoi River, TR5=Mahananda River at Champasari and
TR6=Balason River at Tarabari (Figure 1). A total seventy fish samples of
Badis badis
were collected from seven
different spots of Dooars Region of West Bengal, India (ten samples from each spot) and geographic co-ordinates
were recorded. The collection spots were as follows: DR-1= Sevoke (Teesta River), DR-2=Ghish river,
DR-3=Gajoldoba (Teesta Barrage), DR-4=Chel river, DR-5= Neora river, DR-6=Dharla river and
DR-7=Jalpaiguri (Teesta river). The collection spots are depicted in Figure 1. Fishes were identified according to
Talwar and Jhingran (Talwar and Jhingran, 1991).
