Results for “GH”

GH

Abbreviation for general hardness.

Used in 53 profiles

Western Ghats

Mountain range extending southwards down the western side of India from the borders of Gujarat and Maharashtra states, through Maharashtra, Goa, Karnataka, Tamil Nadu and Kerala as far as Kanyakumari district in Tamil Nadu. The Ghats are a UNESCO World Heritage Site and represent one of the eight hottest hotspots of biological diversity in the world, and is home to a number of endemic fish species.

Used in 44 profiles

Palghat Gap

Also known as the 'Palakkad Gap', a low mountain pass representing the major break in the Western Ghats mountain range. The Nilgiri Hills rise to around 1100 m AMSL north of the gap and the Anaimalai Hills approximately 2000 m AMSL to the south, with average elevation within the gap 144 m AMSL. The gap has been shown to represent a biogeographic barrier restricting gene flow between populations of numerous species including Indian elephant and various birds.

Used in 1 profile

abiotic

Non-living. Abiotic factors in an environment include such items as sunlight, temperature, wind patterns, and precipitation, for example.

acidic

Acid; tending to form an acid; having a pH less than 7.0; having a relatively high concentration of hydrogen ions.

Used in 435 profiles

activated carbon

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.

adsorption

The process by which molecules of a substance are attracted to and accumulate on the surface of another substance, such as a solid, but do not enter it. Activated carbon is highly adsorptive.

Aeromonas

A genus of rod-shaped, gram-negative bacteria found in fresh and salt water, soil, and sewage. Various species affect fishes while others are pathogenic to amphibians, reptiles, and higher animals including humans.

agonistic behaviour

Social interactions related to fighting. A broader term than 'aggressive behaviour' as it also includes threats, displays, retreats, placation, and conciliation.

algae crab

Loose term used to describe any type of crab useful in an aquarium because it eats algae and/or diatoms. In marine aquaria this would include Sally Lightfoot, Emerald and various species of hermit crab. In freshwater the micro-crab Limnopilos naiyanetri fills the same role.

algae shrimp

Somewhat misleading vernacular name for the freshwater shrimp Caridina multidentata Stimpson 1860, a popular addition to freshwater aquaria due to its reputation for consuming algae, though in reality it is unable to survive on a diet of algae alone. Formerly referred to as C. japonica De Man 1892 (that name is now regarded as a junior synonym of C. multidentata) and also known as the Amano shrimp. Exhibits an amphidromous life cycle in nature and is thus difficult to breed in captivity, though it has been achieved.

alimentary canal

The passage (including the oesophagus, stomach, and intestines when present) along which food passes through the body from mouth to anus.

anus

Opening at the lower end of the alimentary canal through which solid waste is excreted.

Used in 90 profiles

apomorph

An organism existing in an evolutionary state that represents a morphological advance compared to a previous state. Occurs at an evolutionary branching point and is subsequently carried through only a single descendant group.

aragonite

Naturally-occurring, crsytalline form of calcium carbonate with a notable buffering capacity. Popular as a substrate or substrate additive in marine and freshwater aquaria where pH and hardness must be maintained at high levels, and has a more rapid, effective effect than coral sand, for example.

artesian well

A well, normally deep-drilled through impermeable material through which water is then rises via natural hydrostatic pressure.

Used in 1 profile

autotroph

An organism capable of synthesising its own food via inorganic light or chemical energy, e.g., green plants, algae.

axial

Located on, around, or in the direction of an axis running antero-posteriorly through the centre of a fish. Opposite of radial.

Used in 2 profiles

batch spawner

A fish species which deposite eggs on more than a single occasion throughout a particular spawning season rather than within a short period.

biological species concept

Most popular concept of species in vertebrate zoology. Defines species as members of populations that do or potentially could interbreed and produce fertile offspring in nature, regardless of appearance, therefore somewhat more restrictive than the phylogenetic species concept. In theory species are thus separated from one another by some form of reproductive isolation, though in practice this does not always hold true. Often abbreviated to BSC.