|Changes in the structure and ultrastructure of the intestine of Spadella cephaloptera (Chaetognatha) during feeding and starvation experiments|
Perez, Y.; Casanova, J.-P.; Mazza, J. (2000). Changes in the structure and ultrastructure of the intestine of Spadella cephaloptera (Chaetognatha) during feeding and starvation experiments. J. Exp. Mar. Biol. Ecol. 253: 1-15
In: Journal of Experimental Marine Biology and Ecology. Elsevier: Tokyo; Oxford; New York; Lausanne; Shannon; Amsterdam. ISSN 0022-0981, more
|Authors|| || Top |
- Perez, Y.
- Casanova, J.-P.
- Mazza, J.
Ultrastructural changes in the intestinal epithelium of fed and starved specimens of Spadella cephaloptera are described. Animals were maintained in a circulating natural sea water system and fed with Artemia salina nauplii. After a period of acclimation, they were individually isolated, deprived of food for 24 h and submitted to controlled feeding experiments. The absorption develop in the intestinal absorptive cells (A-cells) 5 min after the ingestion of prey and consist in the formation of endocytotic vesicles and endosome-like vacuoles. During the following steps up to 10 h, a second type of digestive vacuole containing electron-dense material, and probably corresponding to a lysosome-like compartment, appears. Throughout this time, the vacuoles progressively arrange in columns, the youngest at the top and the oldest at the bottom of the A-cells. In addition, large lipid inclusions appear in the apical cytoplasm. The ultrastructural changes of the intestinal secretory cells (S-cells) is less marked, but the number of granules largely diminishes during the first 30 min after the ingestion of prey. In starved specimens, major changes in A-cells occur between the sixth and tenth day of starvation and consist in the increase of endosome-like vacuoles. Lysosome-like vacuoles containing dense material are not observed. At the same time, necrosis features are evident in S-cells. After 30 days of starvation, necrosis features are observed in the totality of the intestinal epithelium and the specimens die few days later.