7. Moorish Idol
Moorish idol is one of smallest marine aquarium fish species found in the Indian ocean, Japan and South Africa. These species have special yellow and black ribbons within their body. Moorish idol is also social in nature, found in group of large numbers. They live in coral reefs and spend lots of time in surface of the ocean.
The Moorish idol, is a marine fish species, the sole extant representative of the family Zanclidae in order Perciformes. A common inhabitant of tropical to subtropical reefs and lagoons, the Moorish idol is notable for its wide distribution throughout the Indo-Pacific. A number of butterflyfishes closely resemble the Moorish idol. It is closely related to, if not a direct descendant of, the extinct Eozanclus brevirostris, from the Middle Eocene of Monte Bolca.
The Moorish idol got its name from the Moors of Africa, who purportedly believed the fish to be a bringer of happiness. Moorish idols are also a coveted aquarium fish but, despite their abundance and wide array of habitats, they are notoriously finicky and hard to adjust to captivity. Their omnivorous diet can be extremely difficult to replicate in aquaria, as the vegetation which they live on is normally exterminated and they unfortunately have a habit of snacking on corals and sponges which are extremely expensive.