Ichthyological terms, not general ones.
Type of biological filter comprising a vertical column within which sand or other fine-grained filter medium is held in suspension, i.e., a fluidised state, by a continual upward flow of water. The many fine grains of filter media provide a huge surface area for bacterial colonisation.
Fine-grained silicate material commonly used as substrate. Often but not always chemically inert, and can therefore be used as a buffer.
Used in 846 profiles
The vertical distance between the dorsal and ventral margins of the body measured at the base of the pectoral fin where it joins the body. In most icthyological works the greatest dimension, normally anterior to the dorsal fin, is taken but in some cases body depth is measured at the origin of pectoral, pelvic and first anal. Fins or fin bases are not included in the measurement, however.
Used in 85 profiles
Class of ray-finned fishes, so-called because they possess fin rays. Contains 95%+ of known fish species.
Used in 1 profile
Modified, flexible anal fin rays present in males of some fish species (families Hemirhamphidae and Goodeidae) giving the fin a 'notched' appearance. Not used for insemination like the gonopodium in members of the family Poecillidae but to clasp the female during mating.
Used in 5 profiles
The upper angle between a fin and the body of a fish, most often used in reference to the pectoral fin.
The typically narrow section of the body located between the posterior of the dorsal and anal fins and caudal fin origin. Its depth is measured vertically at the narrowest point.
Used in 394 profiles
Dermal, bony growth or spicule normally protruding from one or more fin rays or scale margins. Present on parts of the body or fins that come into contact with the female during spawning in males of some fishes.
Used in 9 profiles
Located on the dorsal side of the caudal fin; elongate bone which supports the caudal fin rays, positioned above the urostyle and posterior to the last neural spine.
Used in 8 profiles
Length of a fish specimen measured from the tip of the snout to the end of the medial caudal fin rays, i.e., the deepest point of the 'fork' formed by the fin. Tends not to be used in systematics.
Modified anal fin used in copulation for the transfer of male gametes to a female. In many cases only the anterior part of the fin is modified.
Used in 24 profiles
In species possessing more than a single dorsal fin, the space between the first and second fins.
Of or relating to the neck or throat. Sometimes used in reference to a fish possessing pelvic fins located in front of the pectoral fins.
In ichthyology, the counting of quantitative characters, such as the number of fins, fin rays or scales.
Used in 8 profiles
The distance between the dorsal fin insertion/origin and caudal fin base.
Used in 2 profiles
Measurement taken from the tip of the snout to the midlateral, posterior edge of the hypural plate or posterior edge of the last vertebra, thus excluding the caudal fin. May also exclude the length of the lower jaw should it project beyond the snout. It is the standard scientific measurement used for most fish species because the caudal fin easily becomes damaged in preserved specimens. Abbreviated to SL.
Used in 48 profiles
In the fins of fishes, the space between the subterminal margin and fin tip.
Processed, porous, highly adsorptive form of carbon also known as activated charcoal or active carbon. Used in aquaria to remove toxins such as chlorine, chloramine, some heavy metals, and especially organic molecules, but exerts no action on ammonia, nitrite, nitrate, phosphate or inorganic salts. Since it has a finite surface area it requires periodic replacement if employed long-term, and should be removed if a tank is being treated as it will remove most medications. Cannot be 'recharged' by heating in a microwave or domestic oven.
Tapering or pointed. Used to describe the shape of the caudal fin in some fishes.
Used in 59 profiles
Used to refer to the margin of a fin from its origin to its apex.
Used in 22 profiles