Histopathology of the fish Corydoras paleatus contaminated with sublethal levels of organophosphorus in water and food

Gills of juvenile fish piaractus mesopotamicus as histological biomarkers for experimental sub-lethal contamination with the Organophosphorus Azodrin®400

“…However, the extent of each detachment and of disorders of the epithelial cells was most impressive at that time. This was also observed by Richmonds and Dutta (1989) in Lepomis macrochirus after 48 h of exposure to the OP Malathion, and by Fanta et al (2003) in Corydoras paleatus. This possibly occurs because freshwater fishes are hyperosmotic in relation to the environment, what favours the influx of water through the lesioned epithelium, increasing the hydropsy, and consequently the epithelial detachment (Machado and Fanta, 2003).…”

“…Therefore, nontarget aquatic animals may be exposed to the insecticide in levels that can vary from sub-lethal to acute and lethal (Thangnipon et al, 1995). According to Fanta et al (2003) many pesticides that remain at sub-lethal levels in the aquatic environment for shorter or longer periods are not detected because they do not cause the immediate death of fish. However, at sub lethal levels, OP pesticides can change significantly some physiological and biochemical processes, and even the morphology of several tissues when they enter the fish organism (Silva et al, 1993;Sancho et al, 1992).…”

“…Histological alterations constitute excellent biomarkers of exposure to toxicants because they represent the result of biochemical and physiological changes (Hinton et al, 1989). The most common injuries in gills are epithelial detachment (Machado and Fanta, 2003;Mallatt, 1985;Richmonds and Dutta, 1989;Schwaiger et al, 2004), hyperplasia (Annune and Ajike, 1999;Dutta et al, 1993;Fanta et al, 2003;Oliveira Ribeiro et al, 1996), fusion of secondary lamellae (Capinpin, 1994;Karan et al, 1998;Thophon et al, 2003) and aneurysm (Stentiford et al, 2003;Thophon et al, 2003;Van den Heuvel et al, 2000). Piaractus mesopotamicus is a freshwater native fish from tropical and subtropical rivers of the Paraná-Paraguay Basin and from flooded areas of the Pantanal region (State of Mato Grosso, Brazil) (Severi et al, 1997;Lima et al, 1998).…”

Histopathological changes in the gill and liver tissues of freshwater fish, Cirrhinus mrigala exposed to dichlorvos

“…Alterations in the liver may be useful as markers that indicate prior exposure to environmental stressors. In another study, cloudy swelling, bile stagnation, focal necrosis, atropy and vacuolization have been reported in the Corydoras paleatus exposed to methyl parathion (Fanta et al, 2003). Hyperplasia, vacuolation, disintegrated blood vessels, disrupted hepatocytes, focal coagulative necrosis, disorganized hepatic canaliculi were observed by Sarkar et al (2005) in Labeo rohita exposed to cypermethrin.…”

Impact Assessment of Sewage Effluent on Freshwater Crucian Carp Carassius auratus using Biochemical and Histopathological Biomarkers

“…Similarly, histopathological changes have been widely used as biomarkers to evaluate the health of fish exposed to contaminants, both in the laboratory (Thophon et al, 2003;Wester and Canton, 1991) and in field studies (Hinton et al, 1992;Schwaiger et al, 1997;Teh et al, 1997) due to target organ toxicity. Furthermore, alterations in organs are normally easier to identify than alterations in function (Fanta et al, 2003), and serve as warning signs of potential damage to animal health (Hinton and Lauren, 1990). Therefore, antioxidant defense and histopathology have been accessed in fish in the field and in laboratory studies (Hinton et al, 1992;Regoli et al, 2002;Schwaiger et al, 1997;Teh et al, 1997;Valavanidis et al, 2006;van der Oost et al, 2003).…”