Large, pincer-like claw of a crustacean or arachnid, as seen in lobsters, crabs, scorpions, etc..

Water filtration method by which dissolved chemicals are removed via use of synthetic adsorbents, ion exchangers, insoluble oxides, zeolite, or activated carbon, these usually being placed within the filter unit or sump.

Ability to detect and differentiate chemical stimuli in an environment.

A sensory nerve cell or sense organ that responds to chemical stimuli such as smell or taste.

A v-shaped line or stripe.

Refrigeration device, normally installed inline with filtration equipment, used to maintain cool conditions in an aquarium. Often used in tandem with a thermostat.

Genus of unicellular, ciliated protozoa; some species are parasites of the skin and gills in freshwater fishes.

An organism, organ or body part containing genetic tissue of more than one type due to mutation, transplant, genetic engineering, etc.. Also spelled 'chimera'.

Any member of the Chironomidae, a family of nonbiting midges with larvae normally found in freshwater. The larvae of some species are produced commercially for fish food and commonly referred to as 'bloodworm'.

Nitrogen-containing polysaccharide which forms the principal constituent of arthropod exoskeletons and the cell walls in some fungi.

Composed of or resembling chitin.

Any of various compounds containing nitrogen and chlorine, some of which are used as bactericides. Chloramines are often used to purify drinking water because they're more stable than chlorine and produce fewer harmful by-products, but they're considered harmful to fishes.

Highly irritating, toxic, gaseous element of the halogen group typically used as a disinfectant, bleaching agent and in purification of drinking water. Considered harmful to fishes.

Division of mostly freshwater eukaryotic algae, informally referred to as chlorophytes and containing the true green algae and stoneworts under modern systems of classification. Like higher plants members possess chlorophylls a and b and store food as starch.

A chlorophyll-containing plastid found in the cells of green plants and some algae within which photosynthesis occurs.

Primitive, cartilaginous skeletal structure enclosing the brain and inner ear formed in the embryo and usally becoming ossified at a later stage. Retained as cartilage throughout life in some fishes.

A pigment-containing or pigment-producing cell that can alter the colour of the skin by expanding or contracting.

A strand-like structure found in the nucleus of cells that contains DNA and associated proteins. Carries the genes determining heredity.

Plural of cilium.

Any member of a group of protozoans characterised by possession of cilia.