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the other three hatchery populations. Brahmaputra while the mean proportion of heterozygous
hatchery population was also significantly higher loci was 13.33% per individual in Banchte
in two meristic characters (PCFR and CFR). For Shekha and Maola hatcheries. The UPGMA
allozyme electrophoresis nine enzyme markers dendrogram of Nei's (1972) genetic distances
were used viz.: Est-1*, G3pdh-2*, Gpi-1*, Gpi-2*, indicated a relationship between the genetic
Ldh-1*, Ldh-2*, Mdh-1*, Mdh-2* and Pgm* distance and geographical difference. High
where three loci (Est-1*, Gpi-2* and Pgm*) were genetic variability in stocks of Thai pangas
polymorphic (p>0.95) in Anudan and Brahmaputra was observed in the Banchte Shekha and
hatchery populations. The mean proportion of Maola hatcheries and less variability was
polymorphic loci per population was higher found in the other three hatcheries.
(33.3%) in Brahmaputra and Anudan hatchery
populations. Also the expected heterozygosity 566 KHAN, M.M.R.; YUNUS, A.T.M. &
levels were 0.149 and 0.177 in Brahmaputra and PARVEZ, I. (Dept. of Fisheries Biology and
Anudan hatchery populations, respectively. Based Genetics, Bangladesh Agricultural University,
on Nei's (1972) genetic distances, the UPGMA Mymensingh). Allozyme variation in four
dendrogram grouped the populations into two hatchery populations of Thai pangas,
clusters. The Brahmaputra and Anudan populations Pangasius hypophthalmus in Bogra,
are in one group; Shambhuganj, and Bhai-Bhai Bangladesh. Bang. J. Fish. Res., 2005, 9(1), 5-
populations are in the second group. High genetic 6.
variation in Thai pangas was observed in the
Brahmaputra and Anudan hatchery populations Genetic variation of four hatchery stocks of
and less variation in the other two hatchery Thai pangas, Pangasius hypophthalmus of
populations. Bogra region, Bangladesh was studied from
1 January 2002 to 31 December 2003.
565 KHAN, M.M.R.; NOOR, N.R.U. & Muscle samples were collected for allozyme
RAHMAN, S.M.Z. (Dept. of Fisheries analysis from four (Bhai-Bhai, Jahangir,
Biology and Genetics, Bangladesh Agricultural Belal and Bhai-Bon) different hatchery
University, Mymensingh). Use of allozyme populations. For allozyme electrophoresis,
markers to determine the genetic structure of eight enzymes were used and 11 loci viz.
hatchery population of Thai pangas, Pangasius Adh-1*, Est-1*, G3pdh-l*, Gpi-1*, Gpi-2*,
hypophthalmus of Jessore, Bangladesh. Bang. Idhp-1*, Ldh-l*, Ldh-2*, Mdh-1*, Mdh-2*
J. Fish. Res., 2005, 9(1), 7-8. and Pgm* were identified , of which three loci
(Est-1*, Gpi-2*, G3pdh-l and Pgm*) were
Genetic structure of hatchery population of polymorphic in all the four populations. The
Thai pangas (Pangasius hypophthalmus) of mean proportion of polymorphic loci per
Jessore region, Bangladesh has been population and the mean proportion of
investigated from 1 January 2004 to 31 heterozygous loci per individual was 36.36%
December 2004. Samples for this study were and 13.33, respectively for all the population
collected from five fish hatcheries viz. Asrom, studied. The highest variability measured by
Banchte Shekha, Chowdhury, Maola and the mean number of alleles per locus was
Rezaul Haque. The enzymes were encoded by 1.545 in Bhai-Bon hatchery population. Based
15 gene loci: Adh-1*, Est-l*, G3pdh-2*, Gpi- on Nei's (1972) genetic distance, the
1*, Gpi-2*. Idhp-1*, Idhp-2*, Ldh-l*, Ldh-2*, dendrogram (UPGMA) shows that four
Mdh-1*, Mdh-2*, Pgm*, Sdh-l*, Sdh-2*and populations have made two clusters by D-
Sod*. Among them four (Est-1*, G3pdh-2*, value (D=0.043). Bhai-Bhai and Jahangir
Gpi-2* and Pgm*) were found to be hatchery populations have made cluster-I, and
polymorphic in different populations but only Belal Uddin and Bhai-Bon hatchery
Gpi-2* was polymorphic in all the sampled populations formed cluster-II. Among the four
populations. The mean proportion of populations, Bhai-Bhai and Jahangir hatchery
polymorphic loci per population was the populations were differentiated from each
highest (26.7%) in Banchte Shekha hatchery other by
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