| dc.description | In this world, 100 million people entirely depend on fish and fisheries for food and
nutrition, income and livelihoods. Due to enormous growth of aquaculture, the world per
capita fish supply increased up to 20kg (FAO, 2016). Within the production cyprinidae
family plays significant role due to worldwide diversification and culture performances.
Cyprinids are highly important as food fish; they are fished and farmed across Eurasia.
Without the fast-flowing rivers majority in the land lock countries, cyprinidae is main
species used for consumption due to covering the largest part of the fish biodiversity
(Eschmeyer and Fong, 2015) and also used for drying and salting. Besides this to use as
food fishes, in many areas including Bangladesh, cyprinidae fishes used as recreational
fishing for centuries deliberately stocked in ponds and lakes (Kottelat, 2013). Several
species of cyprinids have been introduced outside of their native habitat to provide food,
sport or biological control for some pest species (Steven et al. 2005).Other than food
fishes, there are significant number of popular aquarium cyprinids that include danionins,
rasborines, and true barbs. Larger species are bred by the thousands in outdoor ponds,
particularly in Southeast Asia and trade in these aquarium fishes is of considerable
commercial importance. The small rasborines and danionines are perhaps only rivalled
by characids and poecilid livebearers in their popularity for community aquaria (Riehl
and Baensch, 1996).One particular species of these small and undemanding danionines is
the zebra fish (Danio rerio). It has become the standard model species for studying
developmental genetics of vertebrates, in particular fish (Helfman et al. 1997).
Bangladesh is one of the richest countries of the world in respect of her vast and diverse
inland water bodies in the form of rivers, flood plain, canals beels, haors, ponds, ox-bow
lakes and coastal area. Fish and fisheries have been the integral part of the people of
Bangladesh and play major role in employment generation providing nutritional security
foreign exchange earnings and other aspect of the economy (DOF, 2016). | en_US |
| dc.description.abstract | Amblypharyngodon mola, locally known as “Mola” and Labeo bata, as “Bata” are fish of
small indigenous species (SIS), belonging to subfamily Danioninae and Cyprininae,
family Cyprinidae. Now a days both fishes are being considered as high aquaculture
potential in Bangladesh. Hence, attempt was taken to reveal the evolutionary relationship
of both species by using partial sequences of mitochondrial gene Cytochrome b (Cyt b).
Sequences were amplified through PCR and submitted to the NCBI Genbank database
after determined the final consensus size through multiple sequence alignment. The
nucleotide sequences of related fishes were also retrieved from the NCBI genebank
databases. The analyses were performed using computer software packages MEGA
(Version 6.01). The length of consensus Cyt b were 357, 364 and 356 bp in A. mola, L.
bata and A. testudineus respectively. The Transition/Transversion bias (R) was 0.91,
where the rate of transitional substitution from A to G, T to C, C to T, G to A were 5.49,
24.93, 29.19 and 7.82 respectively. The rate of transversional substitution from A to T, A
to C, T to A, T to G, C to A, C to G, G to T, G to C were 4.37, 4.37, 4.77,4.77, 3.07 and
3.07 respectively. The highest sequence divergence was found in between A. mola and a
marine species Opsarius keta (10.003), and the lowest in between L. bata and a
freshwater fishes of Australia Melanotaenia duboulayi (3.516). In Maximum likelihood
method, studied taxa were grouped into three clades; clade 1consisted of Danio rerio, M.
splendida, O. keta, Barilius bendelisis and L. carbasu; clade 2 formed by including O.
bakeri, C. mrigala and L. gonius; clade 3 with M.dubolulayi, where A. mola did not
form sister with any taxa. In Neighbour joining tree, three clades were also formed with
similar cluster formation. Three clades were also observed in Maximum parsimony (MP)
method. Interestingly in MP method A. mola formed clade 1 with B. bendelisis and L.
bata. Same as previous two method D. rerio and O. keta formed sister group here. The
time tree based on maximum likelihood method showed that there were the least times of
divergence in between C. mrigala and L. gonius. There was the highest times of
divergence (4.89 MYA) in between D. rerio and outgroup taxa A. testiduneus. The study
concluded that A. mola and L. bata showed considerable variation in Cyt b gene
sequences. A detailed phylogenetic and evolutionary analyses of entire fishes of the
famiy Cyprinidae including more genes such as Cytochrome C Oxidase subunit-I, and
nuclear genes are highly required to conserve the gene pools of these fishes | en_US |
