Abstract
Food habits of two sympatric species-pairs of skates (Raja erinacea-R. ocellata and R. radiata-R. senta), which occur off the east coast of North America were investigated. Stomachs from over 1600 specimens of the 4 species were collected during winter, summer, and autumn of 1969 and the winter of 1970. Diets of R. erinacea and R. ocellata consisted largely of amphipods, decapod crustaceans and polychaetes. However, R. ocellata consumed relatively more fishes and polychaetes and less decapods than R. erinacea. These two skates ate many of the same species but in different proportions; R. ocellata tended to feed on infauna and R. erinacea tended to feed on epifauna. Food preferences of the two species may be correlated to the difference in shape of the mouth and number of tooth rows. R. radiata and R. senta both fed heavily on decapod crustaceans and euphausids, but polychaetes were relatively more important to R. radiata and mysids were relatively more important to R. senta. R. radiata had a very diversified diet and fed on both epifauna and infauna. The diet of R. senta was very restricted and consisted almost entirely of epifauna. Diets of the two species-pairs were similar, but isopods and bivalves were more important to the R. erinacea-R. ocellata pair and euphausids and mysids were more important to the R. radiata-R. senta pair. These differences may reflect differences in the benthic communities with which the species-pairs are associated. Amount of overlap in resource utilization of the pairs of skates was compared with that of some other congeneric organisms.
Similar content being viewed by others
Literature cited
Bigelow, H.B. and W.C. Schroeder: Fishes of the western North Atlantic. Part 2. Sawfishes, guitarfishes, skates and rays [and] chimaeroids. Mem. Sears Fdn mar. Res. 2, 1–588 (1953a)
——: Fishes of the Gulf of Maine. Fishery Bull. Fish Wildl. Serv. U.S. 53, 1–577 (1953b)
Bousfield, E.L.: Shallow-water gammaridean Amphipoda of New England, 312 pp. New York: Comstock Publ. Associates 1973
Brown, W.L. and E.O. Wilson: Character displacement. Syst. Zool. 5, 49–64 (1956)
Connell, J.H.: A predatory-prey system in the marine intertidal region. I. Balanus glandula and several predatory species of Thais. Ecol. Monogr. 40, 49–78 (1970)
Croker, R.A.: Niche specificity of Neohaustorius schmitzi and Haustorius sp. (Crustacea: Amphipoda) in North Carolina. Ecology 48, 971–975 (1967)
Fitz, E.S. and F.C. Daiber: An introduction to the biology of Raja eglanteria and Raja erinacea as they occur in Delaware Bay. Bull. Bingham oceanogr. Coll. 18 (3), 69–97 (1963)
Grosslein, M.D.: Groundfish survey program of BCF Woods Hole. Comml Fish. Rev. 31 (8–9), 22–35 (1969)
— and E. Bowman: Mixture of species in subareas 5 and 6. Red Bk (Int. Commn N.W. Atlant. Fish.) 3, 163–207 (1973)
Holden, M.J. and R.N. Tucker: The food of Raja clavata Linnaeus 1758, Raja montagui Fowler 1910, Raja naevus Müller and Henle 1841 and Raja brachyura Lafont 1873 in British waters. J. Cons. int. Explor. Mer 35, 189–193 (1974)
Kohn, A.J.: Food specialization in Conus in Hawaii and California. Ecology 47, 1041–1043 (1966)
—: Microhabitats, abundance and food of Conus on atoll reefs in the Maldive and Chagos Islands. Ecology 49, 1046–1061 (1968)
Leim, A.H. and W.B. Scott: Fishes of the Atlantic coast of Canada. Bull. Fish Res. Bd Can. 155, 1–485 (1966)
McArthur, R.H. and R. Levins: The limiting similarity, convergence, and divergence of coexisting species. Am. Nat. 101, 377–385 (1967)
McEachran, J.D.: Biology of seven species of skates (Pisces: Rajidae), 127 pp. Ph.D. dissertation, College of William and Mary 1973
— and J.A. Musick: Characters for distinguishing between immature specimens of the sibling species, Raja erinacea and Raja ocellata (Pisces: Rajidae) Copeia 1973, 238–250 (1973)
——: Distribution and relative abundance of seven species of skates (Pisces: Rajidae) which occur between Nova Scotia and Cape Hatteras. Fish. Bull. U.S. 75, 110–136 (1975)
Nilsson, N.A.: Interactive segregation between fish species. In: The biological basis of freshwater fish production, pp 295–313. Ed. by S.D. Gerking. New York: Wiley 1967
Orians, G.H. and H.S. Horn: Overlap in foods and foraging of four species of blackbirds in the potholes of central Washington. Ecology 50, 930–938 (1969)
Pinkas, L., M.S. Olophant and I.L.K. Iverson: Food habits of albacore, bluefin tuna, and bonito in California waters. Calif. Fish Game Fish. Bull. 152, 1–105 (1971)
Pratt, S.D.: Benthic fauna. In: Coastal off-shore environmental inventory, Cape Hatteras to Nantucket Shoals. Mar. Publ. Ser. Univ. Rhode Isl. 2, 5-1 to 5-70 (1973)
Richards, S.W.: The demersal fish population in Long Island Sound. II. Food of the juveniles from a sand-shell locality (Station 1). Bull. Bingham oceanogr. Coll. 18 (2), 32–72 (1963)
—, D. Merriman and L.H. Calhoun: Studies on the marine resources of southern New England. IX. The biology of the little skate, Raja erinacea Mitchill. Bull. Bingham oceanogr. Coll. 18 (3), 5–67 (1963)
Sameoto, D.D.: Comparative ecology, life history, and behavior of intertidal sand-burrowing amphipods (Crustacea: Haustoriidae) of Cape Cod. J. Fish. Res. Bd Can. 26, 361–388 (1969)
Schopf, F.J.M. and J.B. Colton, Jr.: Bottom temperature and faunal provinces: continental shelf from Hudson Canyon to Nova Scotia. [Abs.]. Biol. Bull. mar. biol. Lab., Woods Hole 131, p. 406 (1966)
Shannon, C.E. and W. Weaver: The mathematical theory of communication, 117 pp. Urbana: University of Illinois 1949
Smith, F.E.: The benthos of Block Island Sound. The invertebrates their quantities and their relations to the fishes, 213 pp. Ph. D. dissertation, Yale University 1950
Tyler, A.V.: Food resource division in a community of marine fishes, 78 pp. Ph. D. dissertation, University of Toronto 1968
—: Computer programs for analysis of feeding heterogeneities related to predator body size. Tech. Rep. Fish. Res. Bd Can. 121, 1–48 (1969)
—: Food resource division among northern, marine, demersal fishes. J. Fish. Res. Bd Can. 29, 997–1003 (1972)
Whittaker, R.E.: Gradient analysis of vegetation. Biol. Rev. 42, 207–264 (1967)
Zaret, T.M. and A.S. Rand: Competition in tropical stream fishes: support for the competitive exclusion principle. Ecology 52, 336–342 (1971)
Author information
Authors and Affiliations
Additional information
Communicated by M.R. Tripp, Newark
Virginia Institute of Marine Science Contribution No. 727.
Rights and permissions
About this article
Cite this article
McEachran, J.D., Boesch, D.F. & Musick, J.A. Food division within two sympatric species-pairs of skates (Pisces: Rajidae). Mar. Biol. 35, 301–317 (1976). https://doi.org/10.1007/BF00386641
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00386641