The effect of salinity on osmoregulation and development of the juvenile fat snook, Centropomus parallelus (POEY).

Eurihaline fish support waters with different salt concentration. However, numerous studies have shown that salinity can affect fish development. Thus, the effect of salinity change from 20 to 5 and 35 on survival, weight, length, gill chloride cell ultrastructure and gill Na+, K+ ATPase activity was evaluated in Centropomus parallelus following short-term (6, 24 and 96 hours) and long-term exposure (30 and 60 days).

Hepatic alterations in the fish Rhamdia quelen contaminated with Folidol 600®.

This study has the aim of verifying the morphologic alterations in the hepatic tissue of Rhamdia quelen juveniles when exposed to 0.01 mL/L of Folidol 600. Techniques of light microscopy and transmission electronic microscopy were used.

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

The effects of contamination, through water or food, of a sublethal dose of the organophosphate methyl parathion were analyzed in tissues that are responsible for absorption (gills, intestine) and metabolism (liver), in the freshwater fish Corydoras paleatus. In gill respiratory lamellae, epithelial hyperplasia, edema, and detachment occurred, diminishing sooner after contamination by food than after contamination through water. In the intestine, lipoid vacuolization of enterocytes, apical cytoplasm, and an increase in goblet cell activity occurred mainly after ingestion of contaminated food.

Surface ultrastructure of the gills of the mullets Mugil curema, M. liza and M. platanus (Mugilidae, Pisces).

Mugil curema, M. liza, and M. platanus were collected from the southeastern and southern coast of Brazil.

Lethal effects of inorganic mercury on cells and tissues of Trichomycterus brasiliensis (Pisces; Siluroidei).

The uptake of heavy metals like mercury is rapid and tissue and cell pathologies are a consequence of its concentration in water and the time of exposure. For Trichomycterus brasiliensis, inorganic mercury is lethal above 0.1 mg.