Results for “od”

protogyny

Form of sequential hermaphroditism in which female offspring become male at some point during their life cycle.

proximal

Located close to or towards the point or origin of attachment or a central point of the body. Opposite of distal.

Used in 60 profiles

pseudotympanum

Translucent, triangular area in the humeral region, behind the opercle, without muscle and where the anterior part of the gas bladder is in direct contact with the skin. It is hypothesised to function as a hearing aid in many juvenile characoids and is present in adults of certain species, notably members of the family Cheirodontidae.

Used in 2 profiles

pterygiophore

Bony or cartilaginous structures via which the rays of the median fins articulate and connect to the body.

Used in 31 profiles

quarantine

Period of isolation, often enforced post-import or purchase of new fish(es) in aquaria, in order to prevent transmission of pathogens or parasites.

Used in 14 profiles

red algae

Any member of the division Rhodophyta.

refractometer

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.

reverse osmosis

Form of purification, often abbreviated to RO, that removes dissolved salts and other impurities from water by applying pressure to it on one side of a semipermeable membrane. Pure water molecules are able to pass through the membrane while the majority of others are not, with more-or-less pure water the result. Sometimes used in combination with deionisation to remove additional mineral ions. Pure water can be harmful to fishes and is normally remineralised to some degree using proprietary products.

Used in 2 profiles

robust

Strong; vigorous; sturdy. Often used to describe the general body form of a fish.

Used in 246 profiles

runoff

Rainwater entering a water body as surface water rather than entering the water table or evaporating into the atmosphere.

Used in 9 profiles

salt bath

Treatment against various parasites which involves placing a freshwater fish in a solution of saline water with the salt concentration and period of exposure variable depending on the size of the fish and severity of infection. Similar to a salt dip in that parasites are killed via osmotic shock, but of longer duration.

scale

Dermal, plate-like structure covering the body in many fishes.

Used in 653 profiles

scute

Horny, bony external plate or modified scale found in some fishes.

Used in 11 profiles

serial spawner

A fish species spawning in multiple bursts within a given period, typically in response to some environmental stimulus or cue, e.g., rainfall.

shimmies

Behavioural symptom that indicates deteriorating water quality or disease in which an individual appears listless with fins normally clamped to the body and displays an abnormal, 'shimmying' swimming action. Particularly typical in poeciliid livebearers.

shoal

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

sibling species

One of two or more very closely-related species that are reproductively isolated from one another but almost indistinguishable in morphologically and/or behaviourally. May occur sympatrically and even interbreed but are incapable of producing fertile hybrid offspring. Sometimes referred to as cryptic species.

Used in 3 profiles

skin

In vertebrates, the thin, membranous layer of external tissue forming the protective covering of the body.

Used in 399 profiles

spine

See fin spine; also a hard, pointed, protective outgrowth or process elsewhere on the body, e.g., a preopercular spine; the spinal column of a vertebrate.

Used in 414 profiles

squamation

The arrangement of scales on the body; the condition of possessing scales; scaled; scalation.

Used in 12 profiles