Cichlids are one of the largest and strangest groups of vertebrate fish — fish with backbones — on Earth. They’re popular as pets and farmed in aquaculture, and scientists have been studying them ...

Below are some reasons why some fish species are aggressive: Fighting for food. Some fish will always compete for food. An aggressive fish will fight off other fish that are perceived to be a threat ...

Cuckoo catfish may be the worst parents ever. Rather than raising their own cannibalistic offspring, they force other fish species to raise them in their own mouths. But how do they do it? New ...