Well, this is the first article of the new year....hopefully my editorials will continue to prove interesting and useful to those of you out there. Before I begin, I would like to take a moment to let you know that the contributing editor that was featured in last month's article was forced to retract her application for personal reasons. As a result, we are very interested in anyone out there who may be interested in filling in this spot. We have a large community of Suite101 members that are interested in cichlids and would like to meet this large interest with a separate topic area on Suite101.
In this article I will begin the first of a few articles aimed at educating those of you out there about a particular group of aquarium species - invertebrates. The basic definition of an "invertebrate" is an animal without a backbone. You may find it surprising that more than 95% of all species on earth are invertebrates. Obviously this includes a large number of animals that do not live in water. When most aquarists think of invertebrates, immediately anemones come to mind. The truth is that anemones are only a small fraction of the invertebrates that can be kept in an aquarium - invertebrates also include worms, crabs, shrimp, clams, sponges, corals, gorgonians, polyps, octopuses, slugs, sea urchins, starfish, and the list goes on..... Most are aware of the difficulty in keeping invertebrates in an aquarium (typically it is recommended for only the experienced aquarist); however, the first step toward having an aquarium that includes invertebrates is to gain an understanding of the different types of invertebrates and their characteristics.
This article will focus on corals, one of the more well known subsets of invertebrates. The most common corals are separated into hard, soft, pulse, or mushroom. I will begin with hard corals. Hard corals are interesting in that they continue to grow by forming new polyps above old ones that have died. These new polyps form skeletons by extracting calcium carbonate from the ocean (this is the same substance that causes your water pipes to reduce in diameter). This process occurs over and over, generating more and more skeletons atop one another and forming the coral. Hard corals require water temperatures at least in the 70's and a great deal of light (sunshine). It is by no coincidence that corals are found in tropical areas where both situations are provided. As for food, hard corals are generally happy consuming small pieces of squid or fish in the marine aquarium.
