| | C. Ciências Biológicas - 7. Fisiologia - 5. Fisiologia | | | INVESTIGATION OF ACUTE TOXICITY OF CYPERMETHRIN ON JUNDIÁ RHAMDIA QUELEN | | | Adriana Borges 1 (autor) Pós-graduanda / adriana.borges@ufrgs.br | | Guillermo Federico Wassermann 1 (orientador) Pesquisador / gwass@ufrgs.br | | Daiane Follmann Jurinitz 1 (colaborador) Aluna de Iniciação Científica / daiavet@zipmail.com.br | | Daniele Rodrigues Siqueira 1 (colaborador) Aluna de Iniciação Científica / dsiqueira@cpovo.net | | Fernanda do Amaral 1 (colaborador) Aluna de Iniciação Científica / fevet@bol.com.br | | Rebeca Zanini 1 (colaborador) Aluna de Iniciação Científica / kerubin@terra.com.br |
| | 1. Departamento de Fisiologia, ICBS, UFRGS |
| | INTRODUÇÃO:
Pyrethroids have been used extensively for more than two decades, as possible alternatives of some organophosphate, carbamate or organochlorine insecticides due to low toxicity to mammals, their efficacy and relatively faster biodegradability (Khan, 1983; Dörücü and Girgin, 2001). Synthetic analogs of the pyrethrins, extracts from the ornamental Chrysanthemum cineraiaefolium, have been widely used in field pest control, as household pesticides, and as veterinary and human pediculicides, and are among the most potent insecticides known. Pesticides are used extensively in agriculture and their residues often reach aquatic ecosystems. The acute toxicity of cypermethrin is different for each fish species and nothing was studied for jundiá until now. This study was conducted to determine the acute toxicity of cypermethrin, a synthetic pyrethroid pesticide, to the jundiá. | | METODOLOGIA:
Mature jundiá (mean of body mass: 419.9±8.7) were obtained from Rolante, RS, and brought to the laboratory within 2 h in plastic bags. The animals were kept in tanks of 500L, density of 5 g/L with dechlorinated water. Quality control of water was realized in the day of application of the pesticide. Groups (n≥10) of experimental animals were selected at random and placed into tank. Treatments consisting in the exposition of fishes to eight differents concentrations(µg/l) (0:control; 0.08; 0.1; 0.12; 0.16; 0.2; 0.24; 0.36) of cypermethrin. Four-day acute toxicity test was performed to determine the LC50 of cypermethrin. The fishes were observed at 24, 48, 72 and 96h after the start of the tests. Behavioral changes were also analysed. | | RESULTADOS:
Phisico-chemical parameters of the tank water were as follows: temperature 22.70C; pH 7.2; dissolved oxygen 7.0 ppm; total ammonia 0.8 ppm (measured daily); alkalinity 79.7 ppm and hardness 85.3 ppm (measured twice weekly). Probit analysis showed that the 48h LC50 value (95% confidence limits) to jundiá was 0.254 µg/l (0.214-0.304) of cypermethrin. Percentage of dead fishes in 48h with each dose was: 0.08: 0%; 0.1: 10%; 0.12: 14%; 0.16: 26.8%; 0.2: 40%; 0.24: 52.9%; 0.36: 67.8%. In the course of cypermethrin poisoning in jundiá, the following clinical symptoms were observed: movement in circles, keeping the gills in open position for prolonged periods, occasional loss of equilibrium, changes of body coloration, alteration from dark ash for light ash, swelling abdomen, hanging vertically in the water, genital protuberance, swimning at the water surface, presence of little lesions, prolonged and motionless laying down on the tank botton, backbone defects such as bending, enlargement of the eyes, in higher doses fishes sudden swimning motion in a spiral fashion and fell to the tanks botton in an uncontrolled manner. | | CONCLUSÕES:
The behavioral changes after treatment with cypermethrin are similar to the ones observed for in other fish species. On the contrary, the acute toxicity of cypermethrin in jundiá is different compared to other fishes, as compiled for Baser et al. 2003. | | | Instituição de fomento: CNPq, FAPERGS, PROPESQ-UFRGS | | | | | Palavras-chave: fish; cypermethrin; toxicity. |
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Anais da 56ª Reunião Anual da SBPC - Cuiabá, MT - Julho/2004 |