Lungs and gas bladders: Morphological insights.

摘要: Abstract This paper summarizes the main morphological tracts exhibited by lungs and gas bladders in fishes. The origin organ location, presence of a glottal region, inner architecture, characteristics exchange barrier pulmonary arteries have been reviewed two types air-breathing organs. With exception dorsal (bladders) or ventral (lungs) from posterior pharynx, none traits analyzed can be considered specific for either bladders. is exemplified analysis morphology lung Dipnoii Polypteriformes bladder Lepisosteiformes. All them are obligate air-breathers show lung-like (pulmonoid) organ. However, while lungfish Lepisosteiformes occupy position highly trabeculated, polypterid occupies shows smooth surface. Structural ultrastructural differences also highlighted. Noticeably, large part surface area Australian covered ciliated epithelium. A restricted respiratory may help to explain incapability this species aestivate. basal teleosts displays more complex than that observed primitive species. appear divided into non-respiratory portions, exhibit intricate shapes, invade adjacent structures gain additional functions. increase functional complexity appears prelude loss