gill


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gill

(gĭl)
n.
Zoology The respiratory organ of most aquatic animals that obtain oxygen from water, consisting of a filamentous structure of vascular membranes across which dissolved gases are exchanged.

gilled adj.

gill

  1. the respiratory organ of aquatic animals. External gills, as in tadpoles, are produced by the embryonic ECTODERM; internal gills, as in fish, are developed from the pharynx and are thus endodermal (see ENDODERM). Gills are usually well supplied with blood vessels, and interchange of oxygen and carbon dioxide takes place across the extensive surface area (see COUNTERCURRENT EXCHANGE). Gills also occur in many invertebrates, for example, in insects such as the caddis fly larva and molluscs such as oysters. Occasionally, unusual structures act as gills, for example, the walls of the rectum in certain dragonfly nymphs, water being pumped in and out via the anus.
  2. the spore-carrying lamellae in basidiomycete fungi, located underneath the cap or ‘pileus’.

gill

external breathing apparatus of fish. Very susceptible to a wide range of diseases.
Enlarge picture
Gill system of fish. By permission from Aspinall V, O'Reilly M, Introduction toVeterinary Anatomy and Physiology, Butterworth Heinemann, 2004

gill disease
an infectious disease of aquarium and salmonid species of fish caused by Flavobacterium bronchiophila. Also in Crassostrea angulata caused by an iridovirus and in larval shrimp caused usually by a Leucothrix spp. bacterium. Chronic, proliferative inflammation causes the gill filaments to be swollen and may be clubbed or fused. Called also bacterial gill disease.
gill parasites
the following external parasites are commonly found on the gills, and elsewhere on the skin, in aquarium fish: Gyrodactylus elegans—a monogenetic fluke; Diplozoon barbi, D. paradoxum—monogenetic flukes; Ergasilus sieboldi—crustaceans. Freshly caught seahorses may carry the crustacean Argulus spp. Pond fish may carry the anchor worm Lernaea spp. These are all visible with the naked eye and can be removed manually.
References in periodicals archive ?
Gill Industries provides world class manufacturing, prototyping, product design, engineering, testing and analysis from its TS16949, QS9000 and ISO 14001 certified facilities.
Gill didn't want to comment on The Property Bureau (UK), as investigations were "ongoing".
I refused treatments because I was in so much shock, but Gill changed my mind.
With help from Scottish Slimmers, Gill was able to beat her fast food habit and the pounds disappeared.
Mr Spencer said Gill, of Eastcroft Road, Grangetown, Middlesbrough, then shouted a racial slur at the family.
Badal's media advisor Harcharan Bains declined to comment on the Congress allegations and said the statements made in the book have not been made by KPS Gill.
In total, Gill's rescue animals currently include four sheep - three belonging to Gill - as well as three goats, two Shetland ponies and eight chickens, which are all housed in different locations.
GILLS Fish and Chips has recently undergone a huge refurbishment of its flagship store in Wallsend and is looking to share the new technology with all its customers.
Asked in court whether Mrs Keogh delivered the blow, Mr Gill said: "No.
Gill, 42, said yesterday: "I don't remember any of this.
Last week, Arizona Cardinals rookie wide receiver Robert Gill set the Internet ablaze after posting a video in which he (http://www.
Jonathan Gill of Leominster was arraigned in Worcester Central District Court Thursday morning.