Levels of Total Mercury and Health Risk Assessment of Consuming Freshwater Stingrays (Chondrichthyes: Potamotrygoninae) of the Brazilian Amazon.

Mercury is an element with potential risk to fish and those who consume it. Thus, this study aimed to determine the levels of total mercury (THg), carry out a health risk assessment related to the consumption of the freshwater stingrays , and determine the physical and chemical properties of the water where stingrays occur. Stingrays of the species were obtained from the Amazon River, and samples of the animals' musculature were collected to determine THg levels.

Dietary lysine requirements of Colossoma macropomum (Cuvier, 1818) based on growth performance, hepatic and intestinal morphohistology and hematology.

This study aimed to determine the dietary lysine requirements of juvenile Colossoma macropomum tambaqui based growth performance, hepatic and intestinal morphohistology and hematology. Tambaqui were fed with levels of 6.60, 9.