A New Nonparasitic Species of Lamprey of the Genus Entosphenus Gill, 1862, (Petromyzonidae) From South Central California

Abstract

A new nonparasitic lamprey from the Friant-Kern Canal, east of Delano, California, is described and illustrated. The holotype (number CAS 35987) is deposited in the California Academy of Sciences, San Francisco, California. The species is distinguishable from all species of the genus Entosphenus by: 1) low number of trunk myomeres — 53 in the ammocoete and between 54 and 57 (average 55.5) in transformed specimens, whereas in other species the range is 58-73; 2) reduced dentition with typical numbers of teeth — 2 supraoral cusps, 1-1-1-1 inner lateral teeth on each side of the disc, 9-12 (average 10.3) posterial teeth; 3) only 3 velar tentacles, whereas in other species the number of tentacles varies from 5 to 18; 4) small size of transformed specimens, 117-142; and 5) restricted distribution. The description is based on the study of eleven newly transformed individuals and one ammocoete.