2003/12/01 by Howard S. Gill, Claude B. Renaud, François Chapleau +2 · 2 citations
Environmental Science · Agricultural and Biological Sciences · #Parasite Biology and Host Interactions #Fish Biology and Ecology Studies #Fish Ecology and Management Studies #Lampetra #Monophyly #Biology #Sister group #Zoology #Cladistics #Clade #Phylogenetic tree #Lamprey #Paleontology
paper · doi:10.1643/ia02-085.1
openalex publication_date 2003/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Relationships among the 18 extant species of parasitic lamprey (Petromyzontiformes) were determined using a cladistic analysis of 32 mainly morphological characters. Because previous analyses support all known fossils as phylogenetically older or the same age as living lampreys, a composite agnathan fossil was used as an outgroup. A consensus of three equally parsimonious trees revealed a trichotomy between a monophyletic northern hemisphere clade and the southern hemisphere genera Geotria and Mordacia. The monophyletic status of the northern hemisphere lampreys and their classification in a single family Petromyzontidae was corroborated. It is suggested that the two southern hemisphere lamprey genera be retained as distinct families. Among northern hemisphere species, Ichthyomyzon and Petromyzon form a monophyletic group sister to the remaining genera. Caspiomyzon is sister to Tetrapleurodon Entosphenus Lethenteron Eudontomyzon Lampetra, with Tetrapleurodon in turn being sister to a group comprising Entosphenus and a clade containing Lethenteron and its sister group Eudontomyzon Lampetra. Differences in many characters are related to differences in modes of feeding and behavior. In a phylogenetic context, dentitional characters are resolved as related either to blood feeding (Petromyzon, Ichthyomyzon, and Mordacia) and hypothesized to be plesiomorphic, or to flesh feeding (Eudontomyzon, Lampetra, and Geotria).