Fish Terms

About Angelfish and General Fish Terms

Adipose fin – Fleshy, small fin behind the dorsal fin and in front of the tail fin.

Albino – An albino angelfish is yellow with red eyes. See lethal gene.

Ammonia – An element from fish waste. It comes from food and other organic waste.

Antibiotic – Pharmaceutical chemicals used to treat bacteria that infect fish.

Aquaculture – Fish raised in quantity for commercial purposes.

Binominal naming system – The scientific naming system developed by Linneaus in the 1700s and used to name living things. The system goes from general to specific. See Linnaeus.

Biomass – Living and dead organic material in the aquarium. It includes bacteria, waste and anything involved in oxygen consumption.

Biotope – A natural habitat, where an aquarium is set up to simulate the conditions a fish lives in naturally.

Blackwater – A blackwater stream is one that contains rotting leaves, wood, and other vegetable matter. This matter turns the water tea colored. It is the natural habitat of freshwater angelfish.

Blackworms – A species of worm, Lumbriculus variegatus, that is an excellent fish food.

Bloodworms – The larvae of midges. Fed live, frozen or in the freezedried form. They are an excellent fish food.

Brine shrimpArtemia salina is a form of food to condition breeders and feed baby fish.

Canister filter – A mechanical filter that is a closed canister, which sits beside the tank, or hung on the side. Mechanical, biological or chemical methods filter as water flows through the canister.

Carnivore – A meat-eating animal that eats other living animals.

Caudal fin – Fish’s tail fin.

Caudal peduncle – Place where the tail fin connects to the body.

Chloramine – Chemical compound used by municipal water utilities to disinfect water.

Chlorine – Element water utilities use to disinfect the water supply.

Cichlids – The fish family Cichlidae. Angelfish are in this scientific family.

Cladistics – Grouping living things with anatomical similarities, and grouping them forward from a common ancestor.

Community tank – An aquarium tank that contains groups of different types of fish.

Crepuscular – Animals that are most active at dawn and dusk.

Cross-breeding – Breeding the same fish species of different varieties. See hybrid.

Culling – Removing the weakest and least desirable fish babies.

Dither fish – Fish that swim in the open. Encourages other timid fish to not hide.

Dorsal fin – Top fin.

Dwarf cichlids – Small cichlids from South and Central America and Africa.

Fish broker – Acquires fish from local suppliers and ships them to destination. Usually from the Far East and ships to America and Europe.

Flooded forest – South American forests in South America that become submerged during the rainy season.

Food chain – Food sources for fish and other living beings. This term is synonymous to food web.

Fungicide – Chemical used to kill fungi.

Fungus – Organism that will infect fish and cause open sores and wounds.

Gravel vacuum – A tool to siphon water from an aquarium. It loosens gravel and removes trapped debris.

Hardness – The amount of minerals in water. Water with a high concentration of calcium and magnesium is called hard water. Water with a lesser amount is called soft water. See soft water.

Herbivore – Plant eater. An organism that’s diet is vegetation.

Hybrid – Fish or other organism made by breeding two varieties in the same species together or two different species. See cross-breeding.

Ich – A parasite that feeds off fish. It is a white spot that appears on a fish.

Ichthyology – Study of fish.

In-breeding – Breeding a fish or animal to its close relatives. Excessive in-breeding will weaken the animal.

Lateral line – Line of lateral scales on fish that are sensitive to movement. Helps fish maneuver.

Lethal gene – Genetic mutation that kills the fish. Albinoism is an example that kills Angelfish. See albino.

Linnaeus – Carolus Linneaus devised the binominal system to classify organisms. See binominal naming system.

Loricariids – Catfish with sucker mouths found in the Amazon River Valley waterways where angelfish live.

Meristics – Defines and groups fish by traits, primarily according to their scales and fins.

Methyline blue – Chemical used to control fungus on fish spawns.

Mutation – A permanent change in a gene characteristic.

Nitrate (NO3) – The last step of the nitrogen cycle that harms fish in different ways.

Nitrite (NO2) – The second, middle, step of the nitrogen cycle. NO2 is made from ammonia.

Nitrogen cycle – The nitrogen cycle is the cycle that bacteria decompose fish waste into chemicals useful for plant health. The process leaves behind nitrites that are harmful to the fish. Water changes dilute the nitrites and make them less harmful.

Nuchal lump – A formation of fat and flesh that grows on male cichlids foreheads as they get older.

Nuisance algae – Algae that overgrows in the tank and takes it over.

Omnivore – An animal that eats both meat and plants.

Operculum – Fish gill cover.

Ovipositor – The tube on the bottom of a female angelfish that deposits eggs. A tube on males deposit sperm.

Quarantine tank – A separate aquarium used to keep sick fish in for observation. Can be used to keep new fish before introducing them into the primary tank.

Parasites – Organisms that live and feed on other animals.

Parasite life cycle – Stages of growth parasites go through.

Pectoral fins – Fins on the sides of the fish.

pH – The degree of acidity or alkalinity of water. 7.0 is neutral.

Piscine – Anything that refers to fish.

School – A large group of the same species of fish that swim together.

Shoal – A group of fish that move as a unit. Less organized than a school.

Soft water – Water that contains a low concentration of calcium and magnesium salts. See hardness.

Standard length – Abbreviated SL. The method of measuring fish for scientific purposes. It is from the tip of the nose to the peduncle. Doesn’t include tail fin.

Taxonomy – The scientific classification of all living things. See Linnaeus.

Theront – The ich parasite when it is on the fish. It can be visually seen on the fish at this stage.

Tomite – The ich parasite becomes free swimming. This is when the parasite can be killed.

Trophont – The ich parasite leaves the fish to live in the gravel.

Ventral fins – Fish fins directly below the gills.

Water changes – This is to reduce the concentration of nitrites in the tank water. This should be done at regular intervals.