Morphology and ultrastructure of the gut in Spadella cephaloptera (chaetognatha)

Journal of Morphology
Jean ArnaudVanina Pasqualini

Abstract

Structural and ultrastructural studies on the gut of the chaetognath Spadella cephaloptera, as well as observations on the feeding behavior of specimens bred in the laboratory, were conducted. The gut displays four distinct zones: pharynx, esophagus, and intestine, to which are connected a pair of diverticula, and the rectum, differing in length, shape, and cellular composition. The intestine alone represents ∼90% of the gut length. Upon ingestion, food in the intestine is submitted to successive backward and forward peristaltic movements until digestion has ended. Ultrastructural observations have identified five distinct cell types from granule morphology and the presence or absence of cilia at the apex of the cells. Three of the types undoubtedly correspond to secretory cells. They are the (1) pharyngeal, (2) esophageal, and (3) light intestinal ciliated cells, which could be, respectively, implicated in (1) mucous, (2) enzyme, and (3) both mucous and enzyme secretions. The fourth type, which corresponds to dense intestinal ciliated cells, displays all the characteristics of cells specialized in the absorption of macromolecules and intracellular digestion. The products of this digestion could be temporarily stored inside den...Continue Reading

References

Jan 1, 1986·Annual Review of Biochemistry·I MellmanA Helenius
Aug 1, 1985·Cell·W G Dunphy, J E Rothman
Jan 1, 1983·The Journal of Cell Biology·R M SteinmanZ A Cohn
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Dec 1, 1981·The Journal of Cell Biology·R A Crowther, B M Pearse
Jul 1, 1988·Journal of Morphology·Jean ArnaudJacques Mazza

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Citations

Aug 8, 2019·Cell and Tissue Research·Patrick R H Steinmetz
Jun 30, 2006·Biochimica Et Biophysica Acta·Nacim ZouariYoussef Gargouri

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