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reduction of HDL-cholesterol fraction was not A total of 45 ponds used for fish polyculture were
significant (p>0.05). investigated in three zones of Bangladesh to
identify the differences among the zones in
562 KHAN, M.H. & HUSSAIN, M.G. respect to aquaecology, culture practices, fish
(Freshwater Station, Bangladesh Fisheries productivity and health management. Four
Research Institute, Mymensingh). Identification of hundred and fifty fish from three zones were
causes of Thai pangas mortality in ponds and their clinically examined by naked eye and
control strategies. Bang. J. Fish. Res., 2005, 9(1), histopathology. Out of total number of fish
55-56. examined, 45 fish from Dhaka zones were
examined for parasites and bacteria in addition to
Mass mortality of Thai pangas (Pangasius histopathology. Faded and haemorrhagic gill,
hypophthalmus) is reported to be a big threat to skin, fin, scale loss and lesions were observed
monoculture of the species in Bangladesh. during fish examination. Aeromonas spp.
Twenty affected and twenty control Thai Pseudomonas spp. and Streptococcus spp. were
pangas ponds were investigated around isolated respectively from 56%, 46% and 39%
Mymensingh district in order to identify the affected fish. Among the five water quality
causes of pangas mortality. Sixty affected and parameters analyzed, the highest average hardness
sixty unaffected fish samples were examined and alkalinity respectively were recorded in
and compared to find the fish-level variables Rajshahi (156 ppm and 142 ppm) followed by
associated with the disease. A range of Dhaka (146 ppm and 132 ppm) and Chittagong
haemorrhagic signs on snout, skin and fins (81 ppm and 90 ppm). The highest average pH
were recorded during examination with naked was recorded in Mymensingh (7.52) followed by
eyes. Aeromonas spp. and Edwardsiella spp. Rajshahi (7.13) and Chittagong (7.05). Water
were isolated from 87% and 80% of the holding capacity of soil in Rajshahi zone was poor
affected fish, respectively. Even 4% of the compared to other zones and farmers were found
seemingly healthy fish carried Aeromonas spp. to be reluctant to fish farming.
on their skin. Among the four water quality
parameters monitored, remarkably higher total 564 KHAN, M.M.R.; BARUA, S. & ALAM,
ammonia (1.5 ppm) was found in water of the M.S. (Dept. of Fisheries Biology and Genetics,
affected ponds compared to that of the Bangladesh Agricultural University, Mymensingh).
unaffected ones (0.4 ppm). High ammonia in Allozyme and morphological variation in four
affected water caused by excessive organic hatchery stocks of Thai pangas, Pangasius
decomposition and poor pond management hypophthalmus in Mymensingh, Bangladesh.
might have reduced the immunity of fish, Bang. J. Fish. Res., 2005, 9(1), 9-10.
which predisposed them for bacterial invasion Genetic and morphological characters of four
hatchery population (Shambhuganj, Brahmaputra,
and consequent disease outbreak. Anudan and Bhai-Bhai) of Thai pangas, Pangasius
563 KHAN, M.H.; SULTANA, S.; UDDIN, hypophthalmus in Mymensingh region of
K.M.A. & ZAHER, M. (Freshwater Station, Bangladesh was studied using morphological
Bangladesh Fisheries Research Institute, characters and allozyme markers from 29
Mymensingh). Study on regional differences in November 2001 to 29 November 2002. A total of
soil-water characteristics and their relevance to 14 morphometric and 6 meristic characters were
aquaculture productivity and fish disease. Bang. J. verified, among which 3 morphometric (BDA,
PELFL and HW) and 2 meristic characters (AFR,
Fish. Res., 2005, 9(1), 57-58. CFR) of Anudan hatchery population were found
to be significantly higher (p>0.001) than those of
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