The objective of the present work was to study the functional anatomy and the comparative morphometry in the medium and posterior intestines and in the piracanjuba (Brycon orbignyanus Valenciennes, 1849) (Characiformes, Characidae, Bryconinae) piloric cecum. Anatomofunctional and morphometric studies were carried out in the medium and posterior intestines and in the piloric cecum of this specie with omnivore feeding behavior. By means of these studies, it could be concluded that the widding pattern of the intestinal rings, in N derived, presented, in the second size class, frequent variations in the medium intestine, but was compatible to the other species with similar feeding behavior. The morphometric studies showed that the total intestine length of the intestinal rings and its gauge exert, probably, a specific function on the nutrients absorption. The relations among the mucous fold arrangement and the food transportation speed in the medium intestine suggest that the traversal and obliquous patterns delay the feed progress in the aboral direction, allowing a larger digest period, better feed nutrients profit, contributing for the fecal mass preparation. The length and the piloric cecum gauge increased as fish developed, and the mucous pattern had the same anatomical characteristics as the intestine.
anatomy; nutrition; fresh water fish; piracanjuba; teleoste
