INVESTIGADORES
CAZENAVE Jimena
congresos y reuniones científicas
Título:
Haematological characterization and response to sublethal hypoxia in a neotropical fish, Corydoras paleatus (Pisces, Callichthyidae)
Autor/es:
CAZENAVE, J., WUNDERLIN, D.A., BISTONI, M.A.
Lugar:
Buenos Aires
Reunión:
Congreso; VI Congreso SETAC Latinoamérica.; 2003
Institución organizadora:
SETAC
Resumen:
We report both a field and laboratory study establishing normal ranges of haematological indices in healthy Corydoras paleatus as well as changes occurring in specimens living under conditions of physiological stress caused by hypoxia. Haematological parameters studied include: erythrocyte counts (Er), haematocrit (Ht), haemoglobin concentration (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC). Normal haematological characterization was performed considering state of maturation of gonads, sex and seasons. Normal values were determined for fish captured in a unpolluted area and them compared with those coming from fish captured in a polluted site. Laboratory studies were also conducted to expose fish to sublethal hypoxia during 48 h and 96 h. Fish used for laboratory experiments were collected from a quasi pristine area, transported to an aquarium and acclimated during two weeks before starting the experiments. Wild fish exposed to pollution present significantly higher values of Er, Ht, Hb, MCH and MCHC than fish captured in an unpolluted area. Discriminant analysis shows that Hb is the parameter that more clearly reflects the differences between wild populations exposed to different environmental conditions. Laboratory studies show that Hb and MCHC present a significant increase after 48 and 96h of oxygen restriction, thus confirming that hypoxia could be responsible for the differences observed during field studies. Results suggest that an ecotoxicological stress, due to the release of pollutants causing oxygen depletion in water bodies (e.g. biodegradable products), derived in an adaptative haematological response of Corydoras paleatus by increasing the efficiency of oxygen uptake and transport.
