The gross anatomy of the blood vascular system of the Eel Anguilla anguilla.

Abstract

Summary. The gross anatomy of the Eel's circulation is described. The following points are noted:–.(a) the simplification of the cranial circulation owing to the absence of a pseudobranch; (b) the existence of forked ventral ends to the efferent branchials; (c) the origin of the coronary arteries; (d) the distribution of the gut arteries; (e) the unusual vascular supply of the pneumatic duct and gas bladder and its possible significance; (f) the tendency to asymmetry especially in the venous system. It is concluded that the Eel's vascular system is relatively unspecialized though the absence of a pseudobranch and the presence of the pneumatie duct capillary network must be regarded as specialized features. This work was carried out during the tenure of a maintenance grant from the Department of Scientific and Industrial Research