Ichthyological terms, not general ones.
Instrument used to measure salinity or specific gravity via the refractive index (basically, the degree that light bends when shined through something) of a liquid. Most models are designed to measure sodium chloride or brine solutions and not seawater which contains a more complex range of salts and minerals, but usually more accurate than a hydrometer nevertheless.
A region that has remained unaltered by a climatic change event and provides an area where relict species are able to survive; in aquaria the term is used to describe an aquarium or other container maintained within a larger system, usually displayed alongside or beneath it, where certain organisms that would not survive in the main aquarium can be maintained.
Deliberate release of an organism or group of organisms into an area or habitat previously inhabited by the taxon but from where it has been lost. Primarily carried out for conservation purposes using specimens taken from captivity or relocated from a different area.
Used in 5 profiles
An organism or group of organisms that exists as a remnant, typically belonging to a formerly abundant group in an environment much changed from that in which it originated; a surviving species from an otherwise extinct taxon.
Used in 5 profiles
Form of niche differentiation by which two species partition (divide) a resource based on behavioral or morphological variation in order to ensure their mutual survival by reducing competition.
Used in 11 profiles
Division of eukaryotic algae containing thousands of species, most of which are multicellular and inhabit marine environments, e.g., many seaweeds.
Used in 3 profiles
Any of a series of slender curved bones articulated to the spine in pairs, serving to protect the thoracic cavity.
Used in 50 profiles
Narrow fissure or zone of faulting formed via tensional stress in the earth's crust. When such forces are strong or prolonged enough to split the crust apart a central section will typically drop down or subside, sometimes forming a rift valley with steep walls as the gap widens. Water may become impounded in the valley, forming a rift lake.
Used in 5 profiles
Chemical extracted from the roots of certain plants, used as a broad-spectrum insecticide, piscicide, and pesticide.
Used in 1 profile
In ichthyology, a collection of fishes made from a particular locality or specified area.
Used in 8 profiles
Genus of aquatic fungi, some species of which attack fishes. Normally a secondary pathogen attacking previously damaged tissue and causing cellular necrosis alongside other epidermal damage. Generally visible as a whitish or greyish filamentous fungus and thus commonly referred to as cotton-wool disease.
Tightly-aggregated group of fishes, normally of the same species, which tends to orient and move in the same direction; the act of schooling. Often confused with shoal.
Used in 135 profiles
Formal binomial or trinomial name of a species used in zoological nomenclature.
Used in 26 profiles
Difference in colour pattern between males and females of a single species.
Used in 4 profiles
A group of fishes, normally of the same species, that remain close to each other for some reason. Differs from a school in that individuals are not necessarily swimming together in the same direction. Also used to refer to a shallow area in a water body.
Used in 101 profiles
Sharp, pointed, piercing organ normally formed from a modified spine and secreting venom from glands at its base when present in fishes; the act of stinging; the wound or pain caused by stinging.
Used in 110 profiles
In ornamental fishes, a group of related individuals developed via selective breeding and sharing common features not present in other strains of the same species.
Used in 44 profiles
Close, long-term association between two different biological species. Often obligatory and often, though not always, with a mutual benefit for both organisms.
Used in 2 profiles
Occurring within the same, specified geographical area, but without interbreeding and not necessarily competing for the same resources or dwelling in the same habitat. Opposite of allopatric.
Used in 195 profiles
Swelling located at the tip of the lower jaw in some fish species.
Used in 5 profiles