Soft Corals and Polyps

Soft Corals and Polyps have around 2,500 species known and the specie are highly diverse in appearance. Some resemble anemones whereas others will grow to huge structures. The majority of of species that will interest aquarists will contain symbiotic algae and will need plenty of lighting.

Soft corals and polyps will influence their neighbours by either sting them or by releasing noxious compounds from their tissues. To prevent a single specimen from dominating the aquarium, you will need some form of removing the noxious chemical from the water, generally a protein skimmer will do the job.

Squirrelfish

The red colour, large eyes and fitful movements of these attractive fish are reminiscent of terrestrial squirrels. The eye size of the squirrelfish is an adaptation for nocturnal living in sheltered areas near the base of coral reefs, where it is vital to gather as much light as possible form the gloomy surrounding.

Certain species are known as soldierfish, which is often used interchangeably with squirrelfish, but in zoological terms, only the sub family Myipristine can be correctly described as soliderfish.

Hawkfish

The predatory hawkfish are so called because of their habit of swooping down from the above on their victims, similar to the birds of prey.

Long pectoral fins enable these fish to rest securely on a rocky perch, so that although they may sway in the current, they will not be swept away by the swell. This is important as they lack a swim bladder, so they find it difficult in maintaining their buoyancy in the water.

Gobies

Gobies are the largest and adaptable group of fish species that can be found in marine, freshwater and brackish waters in both tropical and temperate regions. Gobies number some 267 genera and 2,100 described species with many more to come. All but about 200 are marine; mostly tropical and subtropical reef.

The small size of most of the species and the fact they are relatively easy to keep makes them idea for a home aquarium, where some species have successfully breed. Males often guard the eggs, which maybe laid in crevices of rocks, and the young rapidly grow.

Most species live in, on, or near the bottom and are of small size. One super goby species attains a gargantuan eighteen inches, but almost all his kin are less than four inches in total length. The family contains the world's smallest fishes and vertebrate. Trimmatom nanus of the Indian Ocean females reach a mere 8-10 mm.

There are other goby species only slightly larger. Many of the gobies live in close association with invertebrates such as sponges, shrimps and sea urchins; regardless of goby size, they become the center pieces of an aquarium when maintained with them.

Due to their size Goby are bite sized candy bars to many fishes like  Triggerfish, large angelfish, basses... most anything with a big enough mouth will suck them down.

Many species of gobies are naturally short lived so its recommended to start out with young individuals.

Butterfly fish

The elegant swimming motion of these fishes has been likened to the flight of butterflies fluttering in the garden. Butterfly fish tend to be brightly coloured, making them very popular as a marine fish in an aquarium.

Some species that subsist entirely on coral polyps in the wild are difficult to switch to a substitute diets. Good water parameters (quality) is absolutely vital when keeping any butterflyfish, since they will readily show signs of illness if the pH starts to fall, long before other fish sharing the same tank suffer.