The apparatus in the adult Pantosteus plebius Baird and Girard, the Rio Grande mountain sucker, is complex, particularly so in the modification of the anterior vertebrae. The Weberian ossicles are derived from components of the anterior three vertebrae and from independent connective tissue ossifications. Development is rapid, with the rudiments appearing when the fish are approximately 9 mm. long, and the ossicles reach their mature shape at about the 12 mm. stage.
Proceedings of the Iowa Academy of Science
©1960 Iowa Academy of Science, Inc.
Butler, John L.
"Development of the Weberian Apparatus of a Catostomid Fish,"
Proceedings of the Iowa Academy of Science, 67(1), 532-543.
Available at: https://scholarworks.uni.edu/pias/vol67/iss1/67