smelt, Hypomesus pretiosus; and shiner perch, 

 Cymatogaster aggregata. Scars from attacks by 

 lampreys were occasionally seen on juvenile 

 salmonids, usually just below the dorsal fin. 

 Scars were noted less commonly on other species, 

 but some were noticed on a wide range of sizes of 

 fish, including adult pile perch, Rhacochilus rur- 

 al. Two of the ocean-caught lampreys were taken 

 while attached to a herring and a smelt of un- 

 known species that anglers were using for bait. 



Feeding Habits 



Beamish (1980) presented data on the feeding 

 habits of the river lamprey, mentioning sal- 

 monids and Clupea as common prey. Miller 4 ob- 

 served what he considered significant predation 

 by the river lamprey on chinook salmon 60-120 

 mm long in Elliott Bay, Wash. 



In the present study, 141 of the 225 specimens 

 from marine water were examined for evidence 

 of feeding. Only four had empty guts. Gut con- 

 tents of 30 specimens (OS 6857) captured 4 June 

 1979 from the Columbia River estuary were ex- 

 amined for identifiable material. Fragments of 

 muscle tissue, intestine, liver, ovary, scales, and 

 bones were present in some combination in all 

 guts examined. Scale and bone fragments identi- 

 fied as clupeid were found in 14 guts, one of 

 which also contained a worn lamprey tooth 

 lamina and a scale from a salmonid. The sal- 

 monid scale had an ocean-type nucleus and re- 

 sembled scales of chum salmon, Oncorhynchus 

 keta. Clupeid scales from five guts were identi- 

 fied as being from American shad, which 

 migrate up the Columbia in great numbers 

 during June. Scale fragments from six guts were 

 thought to represent Pacific herring. One gut 

 had no recognizable clupeid remains, but held a 

 small salmonid scale with two freshwater 

 annuli, thus probably being from a smolt steel- 

 head, Sal mo gairdneri. 



The guts of 9 of 10 specimens (OS 6858) taken 

 31 August 1979 from the Columbia estuary con- 

 tained recognizable clupeid remains. One con- 

 tained an American shad scale and three held 

 fragments thought to be from Pacific herring 

 scales. Seven contained forked intermuscular 

 bones. In addition to clupeid remains, two guts 

 held fragments of unidentified salmonid scales. 



Acknowledgments 



We are grateful to Terry Durkin, Greg 

 Hamman, Richard Ledgerwood, David Miller, 

 and Walter Receconi for their help in supplying 

 information and specimens. James D. Hall, 

 Howard F. Horton, and Richard A. Tubb re- 

 viewed the manuscript and made helpful sug- 

 gestions. 



Literature Cited 



Beamish, R. J. 



1980. Adult biology of the river lamprey (Lampetra 

 ayresi) and the Pacific lamprey {Lampetra tridentata) 

 from the Pacific coast of Canada. Can. J. Fish. Aquat. 

 Sci. 37:1906-1923. 

 Kan. T. T. 



1975. Systematics, variation, distribution, and biology of 

 lampreys of the genus La mpetra in Oregon. Ph.D. Dis- 

 sertation, Oregon State Univ., Corvallis, 204 p. 

 Myers. K. W. 



1980. An investigation of the utilization of four study 

 areas in Yaquina Bay, Oregon, by hatchery and wild 

 juvenile salmonids. M.S. Thesis, Oregon State Univ.. 

 Corvallis, 234 p. 

 VLADYKOV, V. D., AND W. 1. FOLLETT. 



1958. Redescription of Lampetra ayresii (Giinther) of 

 western North America, a species of lamprey (Petromy- 

 zontidae) distinct from Lampetra fluviatilis (Linnaeus) 

 of Europe. J. Fish. Res. Board Can. 15:47-77. 



Carl E. Bond 



Department of Fisheries and Wildlife 

 Oregon State University 

 Corrallis, OR 97331 



Ting T. Kan 



Department of Fisheries anil Wildlife 



Oregon State University 



Corrallis, OR 97331 



Present address: Papua Neiv Guinea University of Technology 



Lae, Papua New Guinea 



Katherine W. Myers 



Department of Fisheries ami Wildlife 



Oregon State University 



Corrallis, OR 97331 



Present address: Fisheries Research Institute 



University of Washington, Seattle, WA 9H195 



4 Denny M. Miller, formerly Research Assistant, University 

 of Washington, Seattle, WA 98195, pers. commun. April 1968. 



167 



