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Glossary: bivalve

February 15th, 2012 — 2:18pm

A mollusc belonging to the class Bivalvia which includes clams, oysters, mussels, scallops, etc.. Members are characterised by possessing a shell comprising two hinged valves.

Glossary: blackwater

February 15th, 2012 — 2:18pm

In ichthyological and aquarium literature typically refers to water rich in humic acids and poor in nutrients such as that associated with ancient peat swamps or parts of the Amazon river drainage, and thus differs from clearwater and whitewater. Fish species inhabiting such environments typically require similar conditions in captivity, especially if wild caught.

Glossary: bloodworm

February 15th, 2012 — 2:18pm

The freshwater larvae of certain midges which appear bright red due to their high haemoglobin content. Some species of the non-biting Chironomidae family are produced commerically for fish food with the larvae frozen or freeze-dried..

Glossary: bloom

February 15th, 2012 — 2:18pm

A population explosion of phytoplankton such as algae.

Glossary: blue-green algae

February 15th, 2012 — 2:18pm

See 'cyanobacteria'.

Glossary: body depth

February 15th, 2012 — 2:18pm

The vertical distance between the dorsal and ventral margins of the body measured at the base of the pectoral fin where it joins the body. In most icthyological works the greatest dimension, normally anterior to the dorsal fin, is taken but in some cases body depth is measured at the origin of pectoral, pelvic and […]

Glossary: bogwood

February 22nd, 2012 — 9:44am

Non-petrified wood that has been preserved in a peat bog, often used as decoration in aquaria.

Glossary: bony fishes

February 15th, 2012 — 2:18pm

See Osteichthyes.

Glossary: boulder

February 15th, 2012 — 2:18pm

A rock with grain size in excess of 256 mm diameter.

Glossary: brackish

February 15th, 2012 — 2:18pm

Refers to water with a salinity between that of freshwater and seawater, technically 0.5 – 30 grams of salt per litre, equivalent to 0.5 – 30 parts per thousand (ppt).

Glossary: branched rays

February 15th, 2012 — 2:18pm

A soft or segmented fin ray which is distally forked/divided into two.

Glossary: branchial

February 15th, 2012 — 2:18pm

Relating to, of, or resembling the gills of a fish.

Glossary: branchial arch

February 15th, 2012 — 2:18pm

One of the bony or cartilaginous arches situated on either side of the pharynx that form the support for the gills.

Glossary: branchial cavity

February 15th, 2012 — 2:18pm

Cavity located inside the mouth and enclosing the gills; also known as 'gill cavity'.

Glossary: branchiostegal membrane

February 15th, 2012 — 2:18pm

The membrane, sometimes referred to as the gill membrane, connecting the branchiostegal rays and enclosing the ventral portion of the branchial cavity. Normally extended when the opercle of a fish is open, sealing the branchial cavity and creating a vacuum in the mouth, and also used during threat, courtship and other communicative behaviours in many […]

Glossary: branchiostegal ray

February 15th, 2012 — 2:18pm

One of the dermal, bony (sometimes cartilaginous), bilaterally paired, flattened struts inserting on the epihyal and/or ceratohyal (sometimes the interhyal and hypohyal) that supports the branchiostegal membranes.

Glossary: breeding cycle

February 15th, 2012 — 2:18pm

In fishes, the period of time between hatching and first spawning within a particular generataion.

Glossary: breeding line

February 15th, 2012 — 2:18pm

A group of identical, pure-breeding diploid or polyploid organisms, distinguished from others of the same species by a unique phenotype and genotype. Important in production of line breeding ornamental fish strains.

Glossary: breeding stock

February 15th, 2012 — 2:18pm

Fishes raised and stocked for captive breeding.

Glossary: breeding trap

February 24th, 2012 — 2:35pm

Net or plastic container suspended or floated in an aquarium and used to isolate gravid female livebearers or fry collected from the main aquarium. Available in a number of designs, with plastic ones generally containing two compartments separated by a grille or opening large enough that fry, but not adults, can pass through.