Other Marine Creatures
There are a wealth of creatures that live in the ocean and can be kept in an indoor aquarium. Sea urchins, hermit crabs, crabs, shrimp, starfish and many more. Each adds its own unique quality to a tank, and some are extremely useful for keeping algae levels down. Sea urchins, for example, are excellent glass-cleaners in an indoor aquarium. Shrimp are an extremely beneficial addition for your fish, as they clean off the parasites and keep your fish healthy. Hermit crabs exist in many colours, two particular examples being the red-legged hermit crab and the electric blue hermit crab. This is a list of just some of the species suitable for an indoor aquarium.
Shrimp
Two shrimp you are likely to see on sale for indoor aquariums are skunk shrimp and peppermint shrimp. Skunk shrimp are the larger of the two, with a yellow underside and a scarlet red topside with a white line down the middle. These shrimp are quite striking, and are a healthy addition to any marine tank. They will take up a spot and wait for the fish to approach for cleaning, or the fish will tilt its head, signaling the shrimp to begin. Many people feel these shrimp can be quite shy and remain hidden, but I have a pair in my tank and they are, quite frankly, one of my favourite creatures and the most mobile. Skunk shrimp also breed regularly, but the young shrimp inevitably become fresh meat for the parents and everyone else in the tank! Peppermint shrimp tend to be smaller, with pink bodies and speckles. These shrimp sway from side to side continuously, and can be quite an amusing addition.
Starfish
Starfish can be seen in many colours and sizes, with differing numbers of 'legs'. Some starfish burrow under the sand, whilst others retreat into caves and rocks. If a starfish damages a limb, it is capable of regenerating itself and growing a new limb. Starfish are bottom dwellers, feeding on sponges, crustaceans, molluscs and the sediment on the ocean floor. They're a wonderful addition to any aquarium, are good for a community tank and help to eat any excess algae from the glass.
Sea Urchins
Sea Urchins come in many shapes and sizes, and almost every colour imaginable. A common addition to a reef tank would be the Black Spined Urchin. These are generally jet black, with some electric blue and neon orange markings. Be warned, these starfish can grow up to a foot long spikes, and their bodies reach a diameter of 8 or 9 inches. They are quite incredible to watch, and move deceptively quickly. Don't worry about your fish - they are instinctively aware of the spines, and are quite happy to take food from between them! It's important to take care when handling these creatures - if a spine becomes lodged into skin, it will usually break off and have to be surgically removed. Don't be alarmed - I've had my urchin for 18 months now and no surgery has been required!
Crabs
Crabs are usually found in an indoor aquarium, and if you buy live rock, you may find you gained a few that were hiding in a cave! They're cave-dwellers, generally feeding from the rock surface. Occasionally crabs may become aggressive towards fish, but the fish will soon learn which caves to avoid!
Hermit Crabs
Hermit crabs can add a fantastic splash of vivid colour to an aquarium. They roam everywhere, and eat from the rock surface. Hermit crabs regularly shed their skins as they grow, and during this period they can be very vulnerable. They must hang out of their shells while they shed, leaving themselves unprotected. Every so often they will have to exchange their shell for a larger one, and in a community of hermit crabs this can lead to aggressive battles over a new home.
Snails
Snails are wonderful algae eaters and help to keep an aquarium clean. A common addition to an indoor aquarium would be the Turbo snail. They are really quite beautiful, with black-and-white striped heads. They seem to constantly be eating, and can reproduce quite easily, so make sure you keep their numbers in check if you have them in your tank. Snails will also feed on seaweed and green material.
