Wrasse fish are a large family of colorful fish that includes around 500 different species. Usually wrasse fish are relatively small and don’t grow much bigger than 8 inches (approximately 20 cm) although there are examples that are much bigger than this. Due to the large number of species included in the family, the fish are found in a range of different locations including the Pacific, Atlantic and Indian oceans. A distinguishing feature of wrasses is its protractile mouth, which allows the mouths to extend forward. Many wrasse fish are eaten by humans.
Wrasse usually live in shallow regions. This means they are commonly found in coral reefs as well as near the shore. Although they live in large oceans it’s unusual for the fish to be found in deep regions.
Despite the small size of wrasse they are carnivorous and hence feed entirely on other animals. The diet of the fish consists mainly of small invertebrates that are caught using the wrasse’s strong jaw. Several techniques have evolved amongst wrasse fish for catching prey including swimming behind larger fish in order to find any invertebrates which may have been moved by its path.
An interesting characteristic of many wrasse is that they are able to change sex. Before the fish enters adulthood it is a mix of both female and male. The larger fish go on to become male fish because they can hold territory more effectively. Juvenile fish are known as Initial Phase while Terminal Phase refers to mature adults. Wrasse fish are also known as sexually dimorphic, which means that there is a difference in appearance between male and females.
Another distinguishing feature of wrasse is that they usually have thick and large lips. In many cases the lips are also folded. Due to the interesting structure of the jaw and lips the family has been studied greatly by scientists who want to understand more about the biomechanics of the jaw.
Cleaner wrasse are a sub-section of the family which has developed a different method for finding food. These fish come together at areas known as cleaning stations. At these stations the wrasse fish will clean the parasites and bits of dead skin from other fish in order to eat. In some cases they will also eat live tissue. Surprisingly, it is relatively uncommon for these wrasse fish to be eaten by predators even though they are legitimate prey.