Definition of blood gill in English:
blood gill
noun
Zoology(In some invertebrates) a diverticulum of the body wall containing a blood-filled space but few or no tracheae, through which gases or ions may pass to or from the surrounding medium; especially such a structure in the aquatic larvae of certain insects (e.g. chironomid midges), originally supposed to be a respiratory organ but now thought to be concerned mainly with osmoregulation; usually in plural.
Origin
Late 19th century. After German Blutkiemen (plural, 1889 or earlier).
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