ISSN:
1432-2056
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Summary The gills of the euphausiid crustaceans — Euphausia superba Dana, Meganycliphanes norvegica (Sars) — contain two longitudinal channels separated by epithelial tissue. These channels, functioning as afferent and efferent vessels, are connected at regular intervals by transverse channels in the gill filaments. By contraction of the gill muscles the krill is able to draw back its gills against its body wall, thus reducing water-current resistance. By increasing the haemolymphic pressure, the gill filaments can perhaps be unfolded again. Besides the muscle cells and supplying nerves, fine-structural observations revealed several cell types in the euphausiid gills, considered from their morphological characteristics to be transport cells, respiratory cells, secretory cells serving a transepithelial ion transport, gas exchange and secretion. A further cell type (flat cells) presumably has a regulatory and/or filtering function on the haemolymphic current. The components are arranged in a complex order, reflecting the functional efficiency of the organs concerned. Similarities are pointed out with dendrobranchia of Penaeus.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00443194
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