As the types of Swim-bladders are arranged by Dr. Henry C. Tracey in his paper on "The Morphology of the Swim-bladder in Teleosts," the swim-bladder of the gar-pike is in many respects primitive while in others specialized.
Proceedings of the Iowa Academy of Science
©1925 Iowa Academy of Science, Inc.
Potter, George E.
"The Swim-Bladder of a 65 MM. Gar-Pike (Lepidosteus platystomus) Embryo,"
Proceedings of the Iowa Academy of Science, 32(1), 407-414.
Available at: https://scholarworks.uni.edu/pias/vol32/iss1/105