1 General Anatomy of the Gills
1984; Academic Press; Linguagem: Inglês
10.1016/s1546-5098(08)60317-9
ISSN1557-8011
Autores Tópico(s)Fish biology, ecology, and behavior
ResumoPublisher Summary This chapter describes the general anatomy of the gills in fish. The gills form a highly characteristic feature of fishes and their presence has a marked effect on the anatomy and functioning of the rest of the animal. A gill septum separates two adjacent gill pouches and a series of filaments is attached to its surface. In the most primitive groups, the septum forms a complete partition between the pharynx and the outer body wall. Its extension forms a flap-valve for the next posterior slit. In more advanced groups, there is a progressive reduction in the septum and the consequent freeing of the filaments at their tips. Filaments form the most distinctive respiratory structure of fish gills and are sometimes referred to as “primary lamellae.” In adult fish, the number of filaments does not increase so markedly as during the juvenile growth period, but there is a very significant increase in the length of each of them as the fish grows. The lamellae are the most important units of the gill system from the point of view of gas exchange. The rest of the basic anatomy is directed to providing a suitable support for these structures and to enable the water and blood to come into close proximity.
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