Full text loading...
Zoological Science
Abstract
The ventricle of the fish heart is a chamber that exhibits great morphological and vascular variability among species. However, although the Neotropical region has the greatest taxonomic and functional diversity in freshwater fish, many considerations have been formed without previous knowledge of the ventricular morphology of these fishes. Thus, the purpose of the present study was to describe the anatomy, myoarchitecture, and distribution of coronary vessels in the ventricle of three species belonging to two representative groups from this geographical area, Leporinus elongatus, Hoplias malabaricus (Characiformes) and Pterodoras granulosus (Siluriformes), using gross anatomy and light microscopy. The species L. elongatus and H. malabaricus presented a pyramidal ventricle associated to a mixed myocardium, formed by compact and spongy layers. The mixed myocardium was also observed in P. granulosus, but associated with a sac-like ventricle. The compact layer of the species studied was formed by muscular bundles in longitudinal and circular disposition. The spongy layer constituted most of the ventricular myocardium and was formed by a complex network of trabecular sheets presenting muscle fibers also in longitudinal and circular disposition. Coronary vessels were present in the three species and were observed primarily on the surface of the bulbus arteriosus, later branching on the ventricular surface and penetrating the myocardium only at the compact layer level. These characteristics allow classification of the ventricles studied as type II. Although the type I ventricle is the most common type in teleosts, it is important to emphasize that this type has not been observed in any Neotropical freshwater teleosts studied to date.
The authors thank the Laboratory of Morphology of Aquatic Organisms (Faculty of Sciences/UNESP, Bauru) and the Aquaculture Center of UNESP for technical assistance. This research was financed by São Paulo Research Foundation (FAPESP), on protocol number 2014/14041-3.
All authors attest that they have no relevant financial interests that might influence the interpretation of the results.
MVBG worked on the morphological procedures, interpretation of data and writing of the manuscript. CKF, RAC and RHM collected the fishes and aided in the morphological procedures and interpretation of data. IBFV and CAV aided in the interpretation of data and final writing. In the end, all the authors have read and agreed with the final version of this work.
Data & Media loading...