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Vol. 43 No. 4, 2004
Bifurcating Pattern of the Ventral Aorta and Distribution of
the Branchial Arteries of Hagfishes (Myxiniformes), with Notes on the
Taxonomic Implications
Hin-Kiu
Mok1,* and Charmion B. McMillan2
1Institute
of Marine Biology, National Sun Yat-sen University, Kaohsiung, Taiwan
804
2Scripps Institution of Oceanography, 0202, University
of California, San Diego, CA 09093
Hin-Kiu
Mok and Charmion B. McMillan (2004) Intraspecific and
interspecific variations in the position of the bifurcation of the
ventral aorta, the distribution of the afferent branchial arteries on
the ventral aorta, and connections among the efferent branchial
arteries, carotid artery, and medial dorsal aorta of hagfishes are
reported. Numbers of afferent branchial arteries on the medial section
and side branches of the ventral aorta varied to a certain degree
within and among species according to where this aorta is bifurcated.
Intraspecific variation is considered low, and the presence of
interspecific variation makes the related characters valuable for
taxonomy. Whether the ventral aorta bifurcates, the distance of the
position of bifurcation from the heart, and the number of afferent
branchial arteries arising from the medial section of the ventral aorta
were applied to identify species and to interpret hagfish phylogenetic
interrelationships.
Key words: Circulatory system, Hagfishes,
Myxiniformes, Systematics.
*Correspondence:
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