Though extremely plant like in appearance, sponges are actually one of the most primitive animals in the sea. In the ocean, live sponges can be found in an infinite variety of colors and shapes. Most of them are relatively small, but some varieties can grow to over 6 feet in diameter.
Rotifers (Brachionus plicatilis) are very tiny animals measuring between 130-200 micrometers. Rotifers are often raised as food for live corals and fish larvae. They are the ideal starter food for species of fish such as clownfish fry which have tiny larvae with very, very tiny mouths....
Flatworms can be controlled in the aquarium by a couple of methods. The safest and most effective way is to syphon them out during water changes. This will not always rid them from the system 100% but is a means of keeping them under control....
Homotrema rubrum is a type of foraminifera and they are composed of many single-celled organisms with shells. Depending on the species, the shell may be made of organic compounds, sand grains and other particles all cemented together, or crystalline calcite....
It is encountered throughout the tropical western atlantic and at Ascension Island in mid-Atlantic. It can be found near ocean reefs and at least 150m. These worms have also been encountered in the mediterranean sea, in the coastal waters surrounding the Maltese archipelago....
Great free member of the clean up crew. They eat mostly diatoms and other microalgae films on the glass and liverock. They are found more often on glass than liverock and will eat algae. They are rapid breeders and can multiply in your tank but this may not be an issue....
Copepods are small crustaceans that can be used as live food for saltwater aquarium fishes, corals and other invertebrates. Almost any marine aquarium will benefit from the addition of copepods. Aquarists that maintain refugium as a part of their overall system should definitely add copepods directly to their refugium on a regular basis....
They can be in various colours and the main colour to be worried about is green as the Green Brittlestar (Ophiarachna Incrassata) which can grow up to 20" across and can consume fish (including clowns, damsels, and ornamental shrimps....
There are reported to be three species of Asterina that are commonly imported with live rock. The 0.5cm, whitish ones appear to be pure algal feeders. This is the species we are most likely to experience in our reef aquaria. A few are known to eat SPS corals, one is vivid green and the other 1cm+ across the arms at maximum size....
Often seen under the substrate or crawling over rocks these small crustaceans are a wonderful creature to have in the home aquarium as they feed on left over foods and fish waste as well as detrius on rocks....