Sk. Istiaque Ahmed
Department of Fisheries Management, Faculty of Fisheries, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh; Faculty of Fisheries, Chittagong Veterinary
and Animal Sciences University, Khulshi, Chittagong- 4225, Bangladesh.
Mirja Kaizer Ahmmed
Faculty of Fisheries, Chittagong Veterinary
and Animal Sciences University, Khulshi, Chittagong- 4225, Bangladesh
Subrata Kumar Ghosh
Faculty of Fisheries, Chittagong Veterinary
and Animal Sciences University, Khulshi, Chittagong- 4225, Bangladesh
Md. Moudud Islam
Faculty of Fisheries, Chittagong Veterinary
and Animal Sciences University, Khulshi, Chittagong- 4225, Bangladesh
Md. Shahjahan
Department of Fisheries Management, Faculty of Fisheries, Bangladesh Agricultural
University, Mymensingh-2202, Bangladesh
Sumithion, Intestine, Zebra fish, Histology, Pesticide
Faculty of Fisheries, Bangladesh Agricultural University (BAU), Mymensingh, Bangladesh.
Animal Health and Management
Fish, Herbicide
Proper and absolute analysis of impacts of pesticides and their contamination under field conditions is extremely difficult, but the need for field tests in this aspect can be reduced to a greater extent by the implementation of controlled laboratory tests. That is why, the present study was carried out from January to April, 2014 at the wet laboratory of the Faculty of Fisheries, Bangladesh Agricultural University (BAU), Mymensingh, Bangladesh. The Zebrafishes ( Danio rerio ) with a length of 4±1 cm and weight of 0.9±0.2g, were selected on the basis of the health condition from different ponds adjacent to academic building of Fisheries Faculty, BAU. The selected fishes were acclimatized in aquaria at 22 ± 0.5°C under a controlled natural photo-regimen (14/10 h, light/dark) condition for a period of 21 days before the experiments. During acclimatization process, the fish were fed twice a day with commercial grower feed (CP Bangladesh Co., Ltd.). According to the standard method, a static acute toxicity bioassay was performed to determine the 24, 48, 72, and 96 h lethal concentration values (LC50) of sumithion for Zebra fish. Seven different concentrations (4, 5, 6, 7, 8, 9, and 10 ppm) of sumithion with three replicates were used in the test series. Control units with three replicates were also prepared. Exceeding aeration was app lied to the aquarium for 2 h in order to obtain a homogeneous concentration of the toxic compound, and then 10 fish were transferred into each aquarium. Mortality was assessed at 24, 48, 72, and 96 h after the start and dead fishes were removed immediately. Several behavioral changes, such as reduced activity, equilibrium imbalance, abnormal swimming and motion inactivity of the fishes were observed during the exposure period. Twelve aquaria (36 inch × 10 inch × 12 inches) were collected, cleaned, washed and sun-dried properly prior to set in the wet laboratory. The experiment was conducted with three treatments (T1 : 0.5 ppm, T2 : 1.0 ppm, T3 : 2.0 ppm) and a control (T0 : 0ppm), each having three replications. Ten fish were stocked in each aquarium containing 20L of tap water. Fish were sacrificed after the desired exposure of sumithion (7 days) to observe the effects on intestine. The fish sample was collected and fixed in 10% formalin for the use of histological analysis. The application of pesticide at desired concentration was reapplied at every 24 h with a regular exchange of water. The feeding frequency was 2 times per day (9.00am and 9.00pm) at a rate of 70% of their body weight throughout the experimental period. Before introducing feed for the next feeding, previous uneaten feeds and feces in aquarium were removed by siphoning using a plastic pipe. During the experimental period , the water quality parameters s uch as temperature with a thermometer, pH with a pH meter, dissolved oxygen with a DO meter and total alkalinity with hachkit were recorded. For histological analysis of intestine, three fish species were selected from each treatment. Then cephalic and caudal portion of the selected fishes were cut off and the intestinal section was preserved at 10% formalin. The preserved samples were taken out from vials and put into casset tes separately. Then dehydration process was carried out manually followed by clearing, infiltration, embedding, sectioning, staining and mounting. Finally, intestinal sections were observed under microscope and photographs were taken at 10x magnification. Values were expressed as means ± standard deviation (SD). Data were analyzed by one-way analysis of variance (ANOVA) followed by Tukey’s post hoc test to assess statistically significant differences among the control and different treated values. Statistical significance was set at P < 0.05. Statistic alanalyses were performed using PASW Statistics 18.0 software.
Res. Agric. Livest. Fish. Vol. 2, No. 3, December 2015: 499-506, ISSN : P-2409-0603
Journal