MEDVKI) KT AL.: STOMACH CONTENTS OF SANPHAK SHARKS. 



average meal size should be considered to have been 

 somewhere between the two values. It would then 

 appear that the average meal size of the sharks cap- 

 tured was substantially less than the estimated 

 stomach capacity (13.0% BW). The mean stomach 

 content weights found for various time intervals of 

 the day in this study suggested that sandbar sharks 

 contained more food in their stomachs between 0130 

 and 0430 than during other times of the day (Fig. 2). 

 The evidence was not overwhelming but these 

 results do agree with a study by Medved and Mar- 

 shall (1981), indicating that night hours may be a 

 period of increased feeding activity for the sandbar 

 shark. 



Although this paper has provided a quantitative 

 description of the stomach contents of the sandbar 

 shark, data concerning stomach contents alone are 

 not sufficient for estimating food consumption. As 

 pointed out by numerous researchers, the amount of 

 food in a fish's stomach is a function of both the rate 

 of ingestion and the rate of gastric evacuation (Eg- 

 gers 1977; Thorpe 1977; Elliott and Persson 1978; 

 Jobling 1981). However, when combined with detail- 

 ed information concerning gastric evacuation, the 

 results of this study will provide the basis for the con- 

 struction of an appropriate model of food consump- 

 tion for the sandbar shark. 



ACKNOWLEDGMENTS 



We would like to acknowledge the management 

 and staff of the Wallops Island Marine Science 

 Center for their cooperation. This study was sup- 

 ported by the Narragansett Laboratory of the Na- 

 tional Marine Fisheries Service, the Montauk (New 

 York) Captains' Association, the National Wildlife 

 Federation, and the Society of the Sigma Xi. It con- 

 stitutes a portion of a thesis submitted by the first 

 author in partial fulfillment of the requirements for 

 the degree of Ph.D. in oceanography at the Graduate 

 School of Oceanography of the University of Rhode 

 Island. Special thanks go to Ann Durbin and Howard 

 Winn for reviewing the manuscript and to Jim 

 Donovan. Jeremy Donovan, Brad Thompson, Herb 

 Morgan, and Todd Stephens for assisting with the 

 field work. 



LITERATURE CITED 



Bajkov, a. D. 



1935. How to estimate the daily food consumption of fish 

 under natural conditions. Trans. Am. Fish. Soc. 65:288-289. 

 Bass, A. J., J. D. D' Aubrey, and N. Kistnasaivtv. 



1973. Sharks of the east coast of southern Africa. I. The genus 

 Carcharhinus (Carcharhinidae). S. Afr. Assoc. Mar. Biol. 

 Res., Invest. Rep. 33, 168 p. 



Hic.ELOW, H. B., and W. C. Schroeder. 



1948. Sharks. In A. E. Parr and Y. H. Olsen (editors). Fishes 

 of the western North Atlantic, Part One, p. 59-576. Mem. 

 Sears Found. Mar. Res., Yale Univ. 

 Carey, F. G., J. W. Kanwisher, 0. Brazier, G. Gabrielson, J. G. 

 Casey, and H. L. PiiATT, Jr. 



1982. Temperature and activities of a white shark, Carcharo- 

 don carcharias. Copeia 1982:254-260. 



Casey, J. G. 



1976. Migration and abundance of sharks along the Atlantic 

 Coast. In W. Seaman, Jr. (editor). Sharks and man -a 

 perspective, p. 13-14. Fla. Sea Grant Program, Rep. 10. 



Clark, R., and K. von Schmidt. 



1965. Sharks of the central gulf coast of Florida. Bull. Mar. 

 Sci. 15:13-83. 



Davis, G. E., and C. E. Warren. 



1971 . Estimation of food consumption rates. In W. E. Ricker 

 (editor). Methods for assessment of fish production in fresh 

 waters, p. 227-248. I.B.P. Handbook, No. 3, 2d ed. 

 Diana, J. S. 



1979. The feeding pattern and daily ration of a top carnivore, 



the northern pike (Esox lufius). Can. J. Zoo!. 57:2121-2127. 



Durbin, E. G., A. G. Durbin, R. W. Langton, and R. E. Bowman. 



1983. Stomach contents of silver hake, Merlucciiu? hilinearis, 

 and Atlantic cod, Gadus nwrhua, and estimation of their daily 

 rations. Fish. Bull., U.S. 81:437-454. 



Edwards, R., and R. Hennemuth. 



1975. Maximum yield: assessment and attainment. Oceanus 

 18(2):3-9. 

 Eggers, D. M. 



1977. Factors in interpreting data obtained by diel sampling 

 of fish stomachs. J. Fish. Res. Board Can. 34:290-294. 



Elliott, J. M., and L. Persson. 



1978. The estimation of daily rates of food consumption for 

 fish. J. Anim. Ecol. 47:977-991. 



Gulland, J. A. 



1978. Fishery management: new strategies for new condi- 

 tions. Trans. Am. Fish. Soc. 107:1-11. 



1983. Fish stock assessment: a manual of basic methods. 

 John Wiley, N.Y., 223 p. 

 Hennemuth, R. C. 



1977. Some biological aspects of optimum yield. In H. Clep- 

 per (editor), Marine Recreational Fisheries 2, Proceedings of 

 the Second Annual Marine Recreational Fisheries Sympo- 

 sium, p. 17-27. Sport Fishing Institute, Wash., D.C. 



1979. Man as a predator. In G. P. Patil and M. L. Rosen- 

 zweig (editors). Contemporary quantitative ecologj' and 

 related econometrics, p. 507-532. International Co-operative 

 Publishing House, Fairland, MD. 



HOLDEN, M. J. 



1966. The food of the spurdog, Squalm acanthias (L.). J. 

 Cons. Perm. Int. Explor. Mer 30:255-266. 



Holt, S. J., and L. M. Talbot. 



1978. New principles for the conservation of wild living 

 resources. Wildl. Monogr. 59, 33 p. The Wildlife Stx'iety. 

 Inc., Washington, D.C. 



JOBLlNG, M. 



1981. Mathematical models of gastric emptying and the esti- 

 mation of daily rates of food consumption for fish. J. Fish. 

 Biol. 19:245-257. 

 Jones, B. C, and G. H. Geen. 



1977. Food and feeding of spiny dogfish (Squalus acanthias) 

 in British Columbia waters. J. Fish. Res. Board Can. 34: 

 2067-2078. 

 Lawler, E. F. 



1977. The biology of the sandbar shark, Carcharhinus plum^ 



401 



