Clownfish or anemonefish are fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

es from the subfamily Amphiprioninae in the family Pomacentridae

Pomacentridae

Pomacentridae are a family of perciform fish, comprising the damselfishes and clownfishes. They are primarily marine, while a few species inhabit freshwater and brackish environments . They are noted for their hardy constitutions and territoriality...

. Twenty-eight species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 are recognized, one in the genus Premnas

Maroon Clownfish

The maroon clownfish, Premnas biaculeatus, is a species of clownfish that is found in the Indo-Pacific from western Indonesia to Taiwan and the Great Barrier Reef. They can grow up to be about 17 cm , and as they grow, they become more aggressive towards other clownfish. It is also known as the...

, while the remaining are in the genus Amphiprion. In the wild they all form symbiotic

Symbiosis

Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...

 mutualisms with sea anemone

Sea anemone

Sea anemones are a group of water-dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Zoantharia. Anthozoa often have large polyps that allow for digestion of larger...

s. Depending on species, clownfish are overall yellow, orange, reddish or blackish, and many show white bars or patches. The largest can reach a length of 18 centimetres (7.1 in), while the smallest barely can reach 10 centimetres (3.9 in).
Clownfish are native to warmer waters of the Indian

Indian Ocean

The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...

 and Pacific

Pacific Ocean

The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 oceans, including the Great Barrier Reef

Great Barrier Reef

The Great Barrier Reef is the world'slargest reef system composed of over 2,900 individual reefs and 900 islands stretching for over 2,600 kilometres over an area of approximately...

 and the Red Sea

Red Sea

The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...

.