mammals when different methods arc 

 used. To compMcate the picture fur- 

 ther, Riggs (I'JftO). using a buffered 

 system at a pH of 7.4. observed that 

 animals of varying size had identical 

 Pso's at that pH. 



In order to make meaningful evalu- 

 ations of the dissociation curves in 

 marine mammals, the in vivo ^002 

 and pH need to be determined. Rieu 

 and Hamar (1968) point out the dif- 

 ficulties of drawing a representative 

 arterial blood sample although these 

 arterial data have been collected from 

 one species. Tiirsiops iruncalus, by 

 Ridgway (1968). In short, more work 

 needs to be done. 



ACKNOWLEDGMENTS 



We thank k. Suwa and E. Wahren- 

 brock of the Anesthesia Department. 

 University Hospital, San Diego, Cali- 

 fornia, for making the Dissociation 

 Curve Analyzer available for our use. 

 and the staff of .Sea World for their 

 cooperation. 



This study was supported in parts 

 by grants from the Oceanography 

 Section of the National Science Foun- 

 dation (Grant #GA-3I297) and the 

 Bureau of Medicine (Project #MF- 

 12524014). 



Ridgway, S. H. 1968. The botllcniise dolphin 

 in biomedical research. In W. I. Guy 

 (editor). Methods of animal experimenta- 

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 New York. 



Ridgway, S, H,, and D, G. Johnston. 1966. 

 Blood oxygen and ecology of porpoises 

 of ihree genera. Science (Wash., D.C.) 

 15I:456-4.S8. 



Ridgwav, S. H., J. G. Simpson, G. S. Patton. 

 and W. G. Gilmartin. 1970. Hemato- 

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 J. Am. Vet. Med. Assoc. l.';7:S66-575. 



Rieu, M„ and M. Hamar. 1968. Prelimi- 

 nary results concerning the gas oT arterial 

 and veinous blood in Dcli'luiui.\ dclphu 

 and Sli'iR'llu .vma. Report for ONR, 

 Contract NF6 10527 l)006.V 



Riggs, A. 1960. The nature and significance 

 of the Bohr effect in mammalian hemo- 

 globins. J. Gen. Physiol. 43:7,37-752. 



Schmidt-Neilsen, K... and J. L. Larimer. 



1958. Oxygen dissociation curves of 

 mammalian blood in relation to body size. 

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Sjostrand, T. 1953. Volume and distribu- 

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Hamilton (editor). Handbook of physiol- 

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 Division, Environmental Science Information Center, 

 NOAA. Washington. DC 20235. 



MFR PAPER 1053 



Feeding of a Captive Gray Whale, 

 Eschrichtius robustus 



G. CARLETON RAY and WILLIAM E. SCHEVILL 



LITERATURE CITED 



Bartels, H. 1971. Blood oxygen dissocia- 

 tion curves: mammals. In P. L. Altman 

 and D. S. Dittmer (editors). Respiration 

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 Handbook. Fed. Am. Soc. Exp. Biol., 

 Bcthescda. 



Bernharl. F. W., and L. Skeggs. 1943. The 

 iron content of crystalline human hemo- 

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Duvelleroy, M. A., R. G. Buckles, S. Rosen- 

 kaimer. C Tung, and M. B. I. aver. 1970. 

 An oxyhemoglobin dissociation analyzer. 

 J. Appl. Phvsiol. 28:227-233. 



Horvalh. S. M.. H. Chiodi. S. H. Ridgway. 

 and S. Azar, Jr. 1968. Respiratory and 

 electrophoretic characteristics of hemo- 

 globin of porpoises and sea lion. Comp. 

 Biochem. Physiol. 24: 1027-1033. 



Laurie. A. H. 1933. Some aspects of res- 

 piratKtn in blue and fin whales. Discov- 

 ery Rep. 7:363-406. 



Lawson. H. C. 1962. The volume of 

 blood — a critical examination of methods 

 for its measurement. In W. F. Hamilton 

 (editor). Handbook of phvsiologv. Circu- 

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Lenfant, C. 1969. Physiological properties 

 of blood. In H. T. Andersen (editor). 

 The biology of marine mammals, p. 95- 

 116. Academic Press. New York. 



ABSTRACT 



Ihc fcc'diiii; of 11 captive yi'iirlini.; ft'iiuilc Eschrichtius robustus wirs oliscrvcd 

 wliilc (II villi; with Iwr «.v well as from llw surface. Slie sucked food off the lioliom 

 wliile \wiinniiiii; lipped over ahinil 120" so ilnil her c /uiA Ui/\ nearly parallel 

 to the lioUoni. .An increase in inoulli viiluine is apparently caused by action 

 of llie toni;ue, resulliui; in sironi; suction, dnriny; wliich ilie lower lip is opened 

 and food enters tlie inoiit/i. How food is separated from water and mud or 

 detritus is not l^nown. Tlie idiserved f>eluivior is protial^ly natural and illuminates 

 earlier records oj sionnuli cinuents. e.\teriuil inarl\iiis;s. and asyninielrii id 

 haleeii. Clearly, iniuli needs to he learned ahout tlie niecluuiisin of feeding; of 

 hideeii wluiles. I'liis species' feediiii; liahits nitiy he unic/ue anioiii; tliein. 



INTRODUCTION 



Observations on the food of Escli- 

 rielitius rohustus (Lilljeborg, 1861), 

 the gray whale, have, been summar- 

 ized by Zimushko and Lenskaya ( 1970) 

 and Rice and Wolman ( 1 97 1 ), indicat- 

 ing that the diet consists predom- 



inantly of benthic animals, moslK am- 

 phipods and a few other crustaceans; 

 incidental items include polychaete 

 worm tubes, shells, gastropod opercula, 

 feathers, kelp, bits of wood. sand, 

 mud. and gravel. Tomilin (19.^7, p. 

 -346-347) suueests that Eschrichtius 



