Asymmetrical Patterns of the Efferent Branchial Arteries in Acanthopterygian Fishes

Comparison of the efferent branchial artery anatomy in representatives of six acanthopterygian fish orders showed, in several species, an asymmetrical arrangement based in the connection between the right posterior efferent branchial arteries and the coeliac-mesenteric trunk. The asymmetries were frequent among scorpaeniform, tetraodontiform, and zeiform representatives, whereas beryciform and perciform specimens showed symmetrical arrangement of their efferent branchial arteries. The right posterior efferent branchial-coeliac mesenteric trunk alignment is connected to the dorsal aorta through a transversal aortocoeliac anastomosis which receives, in several tetraodontiform and zeiform species, the anterior efferent branchial arteries. Thus the anterior-most dorsal aorta disappears in these species.