The pseudobranch, also pseudobranchia is the reduced first
gill arch of a
fish (on the inner surface of the opercle, near the junction of the preopercle) as well as a reduced "false" gill in some
gastropods.
In
teleost fish, the pseudobranchs are mostly without
respiratory function, and in
elasmobranchs they are the gill arch of the
spiracle Spiracle or spiraculum may refer to:
* Spiracle (arthropods), opening in the exoskeletons of some arthropods
* Spiracle (vertebrates), openings on the surface of some vertebrates
* Spiraculum, a genus of land snails in family Cyclophoridae
Cycl ...
. The function of the pseudobranch is unknown, but it is believed that it supplies highly oxygenated blood to the optic choroid and retina
and may have baroreceptor (pressure) and thermoregulation functions. It may also be a site of oxygen chemoreception.
External links
Picture of trout pseudobranchPseudobranch description incl. picture
References
Fish anatomy
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