Ichthyological terms, not general ones.
Calcareous structures contained within the inner ear of most fishes, functioning to provide a sense of balance in a similar way to the inner ear in humans, as well as aiding in hearing. Also known as ear bones, ear stones or statoliths. Accumulate layers of calcium carbonate and gelatinous matrix as a fish ages, these forming structures comparable to tree rings which can be used to ascertain the age of an individual, even to the precise day.
Used in 1 profile
Reproductive strategy in which fertilisation occurs internally and the eggs develop inside the body of the mother until hatched, at which point live offspring are born. There is no placental connection between mother and embryo unlike in viviparous species.
The pectoral and pelvic/ventral fins, both of which occur in pairs and are analogous to the fore and hind limbs in higher animals.
Used in 58 profiles
Development of similar forms or traits in related, but separate, species descending from the same ancestor, but occupying different clades.
Used in 8 profiles
A compressed accumulation of partially-decomposed, chiefly vegetable matter typically found in certain marshes, bogs, and peat swamp forests throughout the world. It forms via breakdown of various plants and other organic materials in water when full decomposition is prevented due to localised acidic, anaerobic conditions. As a result of this somewhat specific nature the organisms inhabiting peaty environments are often stenotypic and found nowhere else. Peat can be used as a fuel when dried and thus has industrial importance in some countries. Also used in aquaria, especially in order to simulate blackwater habitats, either in pure, artificially-granulated or liquid extract form.
Used in 268 profiles
Type of tropical moist forest lying over a thick bed of acidic peat, over 60% of which occur in Indonesia and Malaysia. Typically contain water with very low pH (<4.0) that is stained brown due to the release of various organic compounds from the decaying peat and thus often referred to as blackwater swamps. Usually contain some permanent water but also flood seasonally. Highly biodiverse when in pristine condition, with many species found nowhere else on earth, though increasingly subjected to intensive drainage, burning and subsequent conversion to agriculture in recent decades.
Used in 89 profiles
Of, relating to, living or occurring in the open sea rather than coastal or inland habitats.
Used in 180 profiles
A hole or pattern of holes made by, or seeming to be made by, piercing or boring, especially if occurring in a line or series.
Used in 1 profile
Sudden and rapid drop in pH, usually occurring in aquaria or ponds with poor buffering capacity. Can be fatal to fishes.
Any salt or ester of phosphoric acid. The presence or addition of excessive phosphates in aquatic ecosystems can have significant ecological effects such as eutrophication, and they are one of the primary contributors to algal growth in aquaria if allowed to accumulate. Conversely, they may be actively added to heavily-planted set-ups in the form of liquid or other supplements in order to encourage plant growth.
Chemical process occurring in the cells of plants, algae and certain other organisms by which carbon dioxide is converted into organic compounds, especially sugars, using the energy from sunlight.
Generic term applied to numerous non-parasitic flatworms of the class Turbellaria. Also a genus within that class, Planaria. Various species occur in aquaria where they're most often associated with accumulation of uneaten food or organic material and normally considered pests.
The occurrence of different forms, stages, or types in individuals or multiple organisms of the same species independent of sexual variation.
Used in 2 profiles
One of two types of body form occurring in coelenterates, comprising a hollow cylindrical body with a ring of tentacles around the mouth.
Group of individuals of a given taxon occupying a particular geographic area or specified habitat.
Used in 487 profiles
Form of paedomorphism characterised by retention of juvenile features in an adult individual via accelerated maturation.
Undergoing accelerated sexual maturation, often with associated retention of juvenile features in adults.
Used in 16 profiles
Accessory or spurious gill, often located on the inner surface of the operculum in various fishes, that is usually small and sometimes completely obscured beneath the epithelium. Also referred to as pseudobranchia.
Uncommon; occurring infrequently.
Used in 178 profiles
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.