A New Lamprey, Ichthyomyzon hubbsi, from the Upper Tennessee River System

Abstract

MATERIAL.-Holotype, Cornell University Fish Collection No. 20324, an adult male, 107.5 mm. in total length, taken in Nottely River, a tributary of Hiwassee River, Tennessee River System, 8 miles south-southeast of Blairsville on Georgia Highway Routes 19 and 129, Union County, Georgia, on April 10, 1947, by Robert D. Ross, Royal D. Suttkus and Raney. Five other specimens, C.U. No. 10985, 102.7 to 122.3 mm. total length, including 3 males and 2 females, were taken in the same collection and are designated as paratypes. From the Little Tennessee River system the following are available and are designated as paratypes: C.U. No. 19532; a male 129.8 mm. and a female 125.1 mm. in total length, captured in a small tributary of the headwaters of Little Tennessee River at the north city limits of Dillard, on U. S. Highway 23, Rabun Co., Georgia, on March 25, 1951 by Richard H. Backus, Ronald W. Crawford, James N. Layne, Roland L. Wigley, C. Richard Robins, and Raney. University of Michigan Museum Zoology Fish Collection Nos. 136313 and 136314, 2 males and 12 females, 117.9 to 150.0 mm. long, taken in Oconaluftee River near Smokemont near Great Smoky Mts. National Park and Cherokee Indian Reservation line, Swain Co., North Carolina, on April 10 and 11, 1941 by Cowan Wikle; and U.M.M.Z. No. 141202, one male, 130.9 mm. long, from Raven Fork of Oconaluftee River above Ravensford, Swain Co., N. C., captured about June 1, 1943, by Cowan Wikle. Studied but not designated as paratypes was one ammocoete from the latter locality, and U.M.M.Z. No. 129556, 14 ammocoetes, 32 to 118 mm. long, from Oconaluftee River, about 1 mile south of Ravenswood, Great Smoky Mts. Nat. Park, Swain Co., N. C., collected by Carl L. Hubbs and family, on October 10, 1937. Also studied was U.M.M.Z. No. 136212, the remnants of one male and two females that were dead upon collection by Cowan Wikle, in Oconaluftee River, Cherokee Indian Reservation, N. C., on April 26, 1941. Also available in the University of Michigan Museum of Zoology are a large number of Ichthyomyzon ammocoetes, according to curator Reeve M. Bailey whose assistance in loaning specimens is much appreciated. These have not been used because of doubt as to their specific identification. DIAGNOSIS.-A small, nonparasitic lamprey with a deep body, and low first dorsal and anal fins. Trunk myomeres 55-59 (mean 57.2 in adults). Snout short and buccal disk small. Dentition weak. Supraoral cusps normally 2; when a third cusp is present it is median in position and usually minute. Infraoral cusps 7 to 11 (mean 9.5). Circumoral teeth 20 to 27 (mean 22.3). Teeth in the anterior row 3-4 (mean 3.7). Teeth in the lateral rows 5 to 7 (mean 5.9). Bicuspid circumorals 5-10 (mean 7.7). Teeth only slightly, if at all, cornified. Transverse lingual lamina moderately bilobed, and lacks or has minute denticulations. Dorsal lateral line organs dark. Presumed to have been derived from the parasitic I. bdellium. DEscRIPTION.-Counts and measurements were made using the methods described in detail by Hubbs and Trautman (1937: 27-40) in their excellent revision of the genus Ichthyomyzon, and are given in the same order so as to facilitate comparison with the known species of Ichthyomyzon. Measurements were made with dial calipers reading to one-tenth of a mm. See Vladykov (1949) for illustrations of structures mentioned herein. Measurements of the types are given in Table I and myomere and tooth counts are given in Table II. The myomere count of 11 ammocoetes from Oconaluftee