Cichlid Glossary

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Updated: December 9, 2007

Here you will find definitions and descriptions of words associated with cichlid fishes and cichlid aquariums. I will gradually add words as time permits. Use your browser's Search function (typically Ctrl-F) to find words.

Some of the basic anatomical terms, i.e. names of fins, are illustrated here.

Air pump
There are many designs of these things but the function is the same, to provide a constant supply of air to the water in an aquarium. This helps oxygenate the water directly but also by churning up the surface of the water allowing for greater oxygen exchange at the surface. The pressured air from an air pump may also be used to drive various types of filters or other aquarium accessories. The most common type of air pump uses a vibrating rubber diaphragm to pump air. These types of pumps are useful for a couple of aquariums. Larger pumps use pistons or compressors. Large aquarium setups often use blowers.
Anal fin
The posterior, ventral fin, i.e., the fin on the belly near the tail.
Towards the head. The opposite of posterior which means towards the tail.
A blower is a special type of air pump often used in large setups, ie. dedicated fish rooms, hatcheries or commercial operations. A blower is expensive initially ($200-~$500) but can supply lots of air for many dozens of tanks. Typically, one constructs a manifold (closed loop) of PVC piping of 1/2 inch to 2 inch diameter running around the fish room. Connect the blower to the manifold and be sure there is an escape valve that is always partly open so that the blower does not build up too much back pressure. You then attach screw-in air valves to the PVC whereever you want an air outlet. This process is surprisingly easy to do and works very well. You get lots of air and it is much easier and cheaper than trying to plug-in and hookup dozens of regular aquarium air pumps. Blowers are rated in horsepower (hp). A 1/8 hp blower will supply enough air for at least 50 aquaria. The biggest downside to blowers is that while they supply lots of air, that air is not under great pressure and so cannot supply air to high-resistance devices, such as an airstone in greater than two feet of water.
Caudal fin
The tail fin. Caudal fin shape varies tremendously amongst cichlids. The shape is often constant within a sex of a species but may vary between the sexes and often various between species. Specific terms refer to the approximate shape of the tail, e.g. a lunate caudal fin looks like a crescent moon. A square caudal fin has a vertical posterior edge.
Caudal peduncle
The narrowest portion of the tail, i.e. that part of the body which is narrowest just before the tail fans out.
On the top of the fish
Dorsal fin
The fin on the top of the fish, i.e. on its back. Cichlids tyipcally have a single dorsal fin. Some other kinds of fishes have more than one dorsal fin (in which case the one closest to the head is called the first dorsal and the one closest to the tail is called the second dorsal or soft dorsal). On many cichlids, the dorsal and anal fin may have long extensions on the trailing edge. These may be much longer than the caudal fin. Really long dorsal fin extensions are often a sign that a fish is a male, though this need not be the case.
The gills are located on either side of the posterior portion of the head. Normally you can't see them; they are the flesh-coloured objects you see when a fish flares open its gill covers.
Gill Cover (Operculum)
The hard bony plate covering and protecting the delicate gills. Many cichlids have bright colors on the operculum. These might be lines, areas of color or distinct blotches.
An electrical device used to maintain the water temperature in an aquarium. The heater cord plugs into the wall and main body goes in the tank. Modern heaters are typically completely submersible and have a thermostat inside that allow you to set the temperature you desire. In large operations, it is preferable to heat the room containing the aquaria, rather than to put individual heaters in each tank. Heaters are rated in Watts. A 50 Watt heater is fine for a 10 gallon tank. A l70 gallon tank should have something like a 200 Watt heater. I highly recommend the heaters made by Ebo-Jager. I have used them for 15 years. They are an excellent product.
Heaters do very rarely get broken (sometimes large cichlids smash them). If this happens, be sure to unplug the heater before trying to remove it from the tank. When this happens, the fish usually do not suffer any ill-effects (contrary to what you might think).
An aggressive behavior seen when two fish face each other and grab each other's mouth. This may last for seconds or minutes. It is used as a test of strength and willingness to hold position. Territorial cichlids will lip-lock with neighbors to assert boundaries. Potential spawning partners will lip-lock to test each other prior to mating. Lip-locking often leads to minor lip damage that will heal within a few days, though occasionally it can lead to more serious problems like a dislocated jaw.
Rock dwelling cichlids of Lake Malawi.
Nuchal hump
An enlarged forehead region typically found on male cichlids from Central America but also on some females and on some African cichlids, e.g. Cyphotilapia frontosa. The exact function of the nuchal hump is debated, but it seems to serve as a secondary sexual characteristic, i.e. it is a way females identify and evaluate males as potential breeding partners.
See Gill Cover.
Pectoral fins
The two fins (one on each side) located behind the head, on the side of the body.
Pelvic fins
The pair of fins located on the underside of the body, often underneath the pectoral fins. These may be quite small in some species, and very long in others.
A submersible water pump. There are various designs and uses of powerheads. One common kind attaches to the vertical stem of an undergravel filter and pulls the water up the tube with more force than the typical bubbling airstone system.
Towards the tail. The opposite of anterior which means towards the head.
Rift Lake
One of the large lakes found in East Africa. Typically referring to Lake Malawi (also called Lake Nyassa) or Lake Tanganyika. Lake Victoria is sometimes called a Rift Lake because it is near the others, although technically it isn't truly a rift lake.
Shell dweller
A cichlid which typically lives and breeds inside the abandoned shells of certain snail species coming from Lake Tanganyika. In some species, both the males and females live in the shells. In others, only the females do: the males are too large to fit inside. In the latter case, males may have a harem consisting of many shells and the females inside them. Males may even steal the shells (and females) of other males.
Sponge filter
A simple, but effective form of filtration. A current of air is passed through the center of a sponge such that as the air rises, it draws water into the sponge, thereby filtering the water. Sponge filters are very easy to clean (rinse and squeeze in water) and last years. Plus, baby fish don't get trapped in them like so many other filters. There are several styles of sponge filters ranging from square sponges to long cylinders to tall cylinders.
Undergravel filter
A method of filtering aquariums involving plastic plates that cover the bottom of the aquarium. These plates have slits in them and places for one or more vertical stems. The plates of an undergravel filter must be completely covered in gravel. Water is driven up the stems which causes replacement water to be sucked through the gravel. The gravel serves as a filtering medium. Undergravel filters can keep a tank very clean BUT they have several serious drawbacks. Cichlids like to dig and in doing so expose the plates, thereby destroying the filter. Also, cleaning an undergravel filter is messy and requires removing everything from the tank (including the fish). I do NOT recommend undergravel filters for cichlid aquariums.
Towards the belly of the fish.



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