All Symphysodon species have a laterally compressed body shape. , however, extended finnage is absent giving Symphysodon a more rounded shape. It is this body shape from which their common name, “discus”, is derived. The sides of the fish are frequently patterned in shades of green, red, brown, and blue. The height and length of the grown fish are both about 20–25 cm (8–10 in).
7. Mantis Shrimp
Mantis shrimp appear in a variety of colours, from shades of browns to bright neon colours. Although they are common animals and among the most important predators in many shallow, tropical and sub-tropical marine habitats they are poorly understood as many species spend most of their life tucked away in burrows and holes. Although it happens rarely, some larger species of mantis shrimp are capable of breaking through aquarium glass with a single strike from this weapon.
8. Moorish Idol
One of the most difficult fish to keep in a home aquarium (and very expensive as well), to most aquarists Moorish idol are the pinnacle of the hobby. You may think you’ve seen them before, but you’re probably getting them confused with another species, the Bannerfish (also known as the False Idol). With distinctively compressed and disk-like bodies, moorish idols stand out in contrasting bands of black, white and yellow which make them look very attractive to aquarium keepers.
Also known as Anemonefish, Clownfish are some beautiful fish which generally consist of a yellow/orange body with white stripes along with black lining along it’s fins or black body with yellow/orange areas along it’s lower body and fins , though this depends upon the species of Clownfish and they come in various displays. Many show white bars or patches. The largest reach a length of 18 centimetres (7.1 in), while the smallest barely reach 10 centimetres (3.9 in).
10. Rainbow Parrot Fish
Named Parrot fish because of their calcareous bird-like beaks. Parrot fish use these beaks to crush and eat the small invertebrates that live in coral. Much of the sand and sea floor of coral reefs are actually remains of meals from the parrot fish, they chew the coral, eat the invertebrates and spit out the leftover calcium. In most species, the initial phase is dull red, brown or grey, while the terminal phase is vividly green or blue with bright pink or yellow patches. The remarkably different terminal and initial phases were first described as separate species in several cases, but there are also some species where the phases are similar.