Why does this fish has such a big head?
So this is a flowerhorn cichlid and these aren't actually wild fish but the product of artifical selection by humans, meaning other cichlid species have been selectively bred to produce hybrids with these large heads and bright colourations (a process similar to dog breeding). Cichlids are a particularly significant group of fish in artificial selection because of their ability to rapidly develop new species over only a few generations.
In these cichlids, the large heads (formally known as nuchal humps) are believed to have a function in mate attraction, perhaps as a prominent display of bright colours.
However, it's more likely flowerhorn cichlids developed such large heads because we designed them that way for aesthetic purposes or perhaps for its unique appearance.
