Date of Award
Environmental and Forest Biology
Donald J. Stewart
The Bowfin genus Amia has been considered monotypic since 1896, when 12 nominal species were synonymized with Amia calva without scientific analysis or rationale. Since then, only three studies have explored morphological or genetic variation within the genus, all of which found some degree of separation among populations. To further test the 1896 monotypy hypothesis, we analyzed morphological variation of newly collected Bowfins between South Carolina (SC, type localities of A. calva, A. lintiginosa, and A. cinerea), Lake Huron (type localities of A. ocellicauda and A. occidentalis), and Lake Erie (type localities of A. canina and, perhaps, also A. piquotii). Results showed significant differences for 15 morphometric and five meristic characters between SC (five sites combined) and Jakes Erie and Huron (with data for those two lakes combined). Within the Great Lakes, 13 morphological and two meristic characters were significantly different between Lake Erie and Lake Huron. Finally, within SC, five samples from lower coastal plain sites differed significantly from a sample from an upper coastal plain site for at least 10 morphometric and five meristic characters. Consequently, I reject the 120-year-oJd monotypy hypothesis. Amia oce/licauda was the second nominal species described (from Lake Huron), and therefore among nominal taxa (other than A. calva), it has priority and should be resurrected as a valid species. Morphological variation between lakes Erie and Huron, though not as clear, suggests that there likely exists further complexity within the genus. Likewise, in South Carolina there are indications that two species could be present, and that also begs further analyses. The discovery of multiple species of Bowfins raises concerns for conservation and management; a growing market for Bowfin caviar could have detrimental effects on population sizes and genetic variation.
Polumbo, Jay, "Morphological Diversity of Bowfins (Amia spp., Amiidae) Among the Laurentian Great Lakes and South Carolina" (2016). Honors Theses. 110.