Poisonous fish - a group of fish whose organs and tissues are poisonous due to their chemical composition. For example, many fish have poisonous blood (eel, moray, carp, etc.), mucus (lamprey), liver of some sharks, ovaries and caviar of scalozuba, intestines, skin, milk, caviar and liver (dogfish), caviar and peritoneum of marinka and ottoman.

Fugu fish, for example, contains a lethal dose of tetrodotoxin in its internal organs, mainly in the liver and caviar, gall bladder and skin. The fugu's liver and caviar are the most poisonous, so they are not eaten, and the other parts of the body can only be eaten after careful special treatment.