Gilbert Rahm and the Status of Mesotardigrada Rahm, 1937.
The tardigrade class Mesotardigrada was erected on the basis of the description of Thermozodium esakii by Gilbert Rahm in 1937. In some characteristics, T. esakii is intermediate between members of the classes Eutardigrada and Heterotardigrada. The class Mesotardigrada is known only from Rahm's published drawings of T. esakii; no voucher specimens are known, and subsequent attempts to collect it at the locus typicus have been unsuccessful. Among the possible explanations for this situation are that Rahm may have collected specimens of a more typical tardigrade, but misinterpreted what he saw. Alternatively, changes in habitat in the area may have led to the tardigrade's extirpation. Perhaps T. esakii is a rare species, such that recent sampling efforts have been insufficient to rediscover it. Finally, Rahm's 1937 description may be an attempt at deception. Until physical evidence of T. esakii is found, the species, and by extension the class Mesotardigrada, should be considered nomen dubium.
Natural and Mathematical Sciences Area, St. Mary's University, Calgary, AB, T2X 1Z4, Canada.
Gary T
GT
Grothman
2Department of Biology, Fresno City College, Fresno, CA, 93726, U.S.A.
Carl
C
Johansson
3College of Marine and Environmental Sciences, James Cook University, Townsville, QLD, 4811, Australia.
Glen
G
Chilton
4Transdisciplinary Research Integration Center, Research Organization of Information and Systems (ROIS), Toranomon 4-3-13, Minato-ku, Tokyo 105-0001, Japan.|5National Institute of Genetics, ROIS, Yata 1111, Mishima, Shizuoka 411-8540, Japan.
Hiroshi
H
Kagoshima
6National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, Japan.
Megumu
M
Tsujimoto
7Department of Biology, Keio University School of Medicine, Hiyoshi,Yokohama 223-8521, Japan.
Atsushi C
AC
Suzuki
D000818:Animals; D016477:Artifacts; D002965:Classification; D013048:Specimen Handling; D058467:Tardigrada / Q000033:anatomy & histology* / Q000145:classification* / Q000502:physiology
Mesotardigrada; Tardigrada; Thermozodium; hot spring; nomen dubium