Ichthyological terms, not general ones.
Purification process, often abbrevaited to DI, by which mineral ions are removed from water, usually via ion exchange over a specialised type of resin. The process does not remove non-ionic molecules thus organic cells such as bacteria tend to remain. Often used in conjunction with reverse osmosis to produce more-or-less pure water which normally requires a degree of remineralisation before being used in aquaria.
In phylogenetics, a trait present in an organism which was absent in the last common ancestor of the group being considered; an apomorphy. Also used to refer to traits present in the ancestral form that have subsequently been lost.
In icthyology, the nomenclatural act by which the type specimen of a previously or newly-established genus, subgenus, species, or subspecies is fixed via an express statement.
Used in 6 profiles
In biology, the occurrence within a species of two forms which differ distinctly from one another in one or more characters, e.g., colour pattern or morphology.
Used in 2 profiles
Median, rayed, unpaired fin located on the dorsal surface (back) of most fishes. Its main purpose is to prevent the animal rolling and enable it to turn sharply. Some species possess more than one dorsal fin, in which case the anterior one is referred to as the first.
Used in 860 profiles
Method of acclimation used for sensitive fish species in which the animals are first placed into a clean bucket or other container before water is slowly dripped in by siphon from the aquarium into which they are to be introduced. Can be carried out using a purchased kit or home-made using a length of airline plus an airline clamp.
A species spawning above the bottom which scatters demersal eggs randomly.
Used in 81 profiles
Subclass of Chondrichthyes, also known as cartilaginous fishes, that includes the sharks, skates and rays.
Used in 12 profiles
Genus of annelid worm of which two species, E. albidus and E. buchholzi, are cultured by aquarists to use as fish food.
Used in reference to a closed drainage basins with no outflow to other bodies of water, the bottom of which often contains a salt lake or salt pan. Water leaves only via evaporation or seepage.
Used in 7 profiles
Form of symbiosis in which one organism lives inside the other
Present in some microphagous fishes and comprises a paired dorsal diverticulum located towards the posterior of the pharynx. In the majority of species it's divided into two sections by additional gill rakers which trap small food particles.
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
Having water rich in nutrients, thus promoting the growth of plants, especially algae.
Used in 1 profile
Hypertrophication; process by which addition of artificial or natural substances, such as nitrates and phosphates, to a body of water increases the concentration of dissolved nutrients, this in turn stimulating the growth of aquatic plant life, especially phytoplankton, and typically resulting in depletion of dissolved oxygen. Negative effects include reductions in populations of fishes and other organisms incapable of withstanding this hypoxia.
Used in 8 profiles
A fish egg within which the embryo has developed to a point whereby the eyes are visible through the external membrane.
Device through which water is passed in order to remove suspended solid particles (mechanical filtration) or chemical impurities (biological filtration); any device which assists in maintenance of water quality.
Used in 470 profiles
Feeding behaviour in which solid, organic particles are filtered from the surrounding water. Normally involves some degree of specialised morphology.
Used in 1 profile
Specified area or region in which fish are caught or collected; place where fishes are reared.
Used in 25 profiles
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.