The Emperors, emperor breams and pigface breams (Lethrinidae) are a family of fish belonging to the perciformes order and exclusively of marine environments. They live in the coastal waters of tropical Africa and the Indo-Pacific. In the Atlantic, there are only records of a single species Lethrinus atlanticus. They are often found on sandy bottoms, including seagrasses, mangroves and coral reefs, down to depths of 100 meters.
The mouth of Emperors, emperor breams and pigface breams is small to moderate in size, and it is situated in a terminal position on the head. The body can reach up to 1 meter in length in some species. The color is usually silvery, grayish, olive green, greenish, bluish, brownish or reddish at the base. Often with dark spots or stripes, and may have dots or stripes of blue shades on the head.
Emperors, emperor breams and pigface breams have a single continuous dorsal fin, which is composed of 10 spines followed by 9-10 soft rays. The anal fin has 3 spines and 8-10 soft rays. The pectoral fins have 13-15 rays. The pelvic fins have 1 spine and 5 rays. The shape of the caudal fin is emarginate or forked and has 7-9 rays.
Mainly carnivorous, Emperors, emperor breams and pigface breams feed at night. Their food includes invertebrates and fish. Some species have robust molars that allow them to crush the shells of molluscs and crabs. Several species are protogynous hermaphrodites, that is to say that in the absence of a male, one of the females performs a sex change and becomes the dominant male of the group.
The Lethrinidae famili are generally solitary species, or form small groups, although during the breeding season can generate large congregations of specimens.
There are 38 described species in the Emperors, emperor breams and pigface breams family, all classified within 5 different genera (Gnathodentex, Gymnocranius, Lethrinus, Monotaxis and Wattsia.