title: Excretion in the house cricket (Acheta domesticus): ultrastructure of the ampulla and ureter.
abstract: An ultrastructural analysis of the ampulla and ureter of the cricket, Acheta domesticus, is presented. The excretory system of the cricket is unusual in that the 112 Malpighian tubules do not attach directly to the gut, but fuse to form a bladder-like ampulla which is joined to the colon by a muscular ureter. The ampulla consists of two cell types, primary and regenerative. Primary cells secrete large numbers of membrane-bound vesicles into the lumen and also appear to be involved in fluid reabsorption. Regenerative cells are very small and form a layer just beneath the basal lamina of the ampulla. They are believed to differentiate and replace sloughed off primary cells. The ureter is a muscular tube lined with cuticle which connects the ampulla (endoderm) with the colon (ectoderm). The probable origin and significance of the morphological modifications of the excretory system are discussed.
authors.affiliation: Department of Biology, University of Southwestern Louisiana, Lafayette, Louisiana 70504, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Spring
authors.forename: S W
authors.initials: SW
authors.lastname: Parker
authors.forename: S R
authors.initials: SR
authors.lastname: Hazelton