Abstract
Systematic relationships within the sea anemone genus Metridium have been problematical for many years. The genus has been considered to consist of a single, highly variable species, M. senile (L.), which has been divided into several somewhat arbitrary morphs. One, the “clonal” morph, is characteristically small, found in shallow water and reproduces both sexually and asexually. Another, the “solitary” morph, may grow very large, is found to great depths and has been thought to reproduce primarily, if not exclusively, sexually. The existence of a second species, M. exilis, described by Hand (1955), has been questioned (Riemann-Zuerneck, 1975). In the present study, the taxonomic status of the morphs and species of Metridium was examined by starch-gel electrophoresis to analyze genic variation at 16 enzyme loci in samples of the two morphs of M. senile and M. exilis collected at 3 locations on the Pacific coast of the USA (Bodega Bay, California; Monterey Bay, California; Puget Sound, Washington) and at 1 location on the Atlantic coast of the USA (Maine). Intrapopulation levels of gene enzyme variation were quite high (P 0.95=47.9,, and H=15.1), and some genetic differentiation among geographically separated populations of a single morph was seen, particularly between Atlantic and Pacific coast populations of the clonal M. senile. However, genetic differentiation (D) among pooled populations of M. exilis, clonal M. senile and solitary M. senile was much greater (D=1.14). Thus, the genus Metridium contains not one highly variable species but three distinct species, each with a relatively narrower ecological range and a relatively less variable morphology.
Similar content being viewed by others
Literature Cited
Ahmad, Mahmud and J. A. Beardmore: Genetic evidence that the “Padstow mussel” is Mytilus galloprovincialis. Mar. Biol. 35, 139–147 (1976)
Avise, J. C.: Systematic value of electrophoretic data. Syst. Zool. 23, 465–481 (1974)
Ayala, F. J.: Genetic differentiation during the speciation process. Evolutionary Biol. 8, 1–78 (1975)
Ayala, F. J., D. Hedgecock, G. S. Zumwalt and J. W. Valentine: Genetic variation in Tridacna maxima, an ecological analog of some unsuccessful evolutionary lineages. Evolution, Lawrence, Kansas 27, 177–191 (1973)
Ayala, F. J. and J. R. Powell: Allozymes as diagnostic characters of sibling species of Drosophila. Proc. natn. Acad. Sci. U.S.A. 69, 1094–1096 (1972)
Ayala, F. J., M. L. Tracey, D. Hedgecock and R. C. Richmond: Genetic differentiation during the speciation process in Drosophila. Evolution, Lawrence, Kansas 28, 576–592 (1974)
Borden, D., E. T. Miller, G. S. Whitt and D. L. Nanney: Electrophoretic analysis of evolutionary relationships in Tetrahymena. Evolution, Lawrence, Kansas 31, 91–102 (1977)
Brewer, G. J. and C. F. Sing: An introduction to isozyme techniques, 186 pp. New York: Academic Press 1970
Bryce, D. and A. Hobart: The biology and identification of the larvae of the Chironomidae (Diptera). Entomologist's Gaz. 23, 175–217 (1972)
Bucklin, A.: The reproduction and population biology of Metridium (Coelenterata, Actiniaria), 181 pp. Ph. D. thesis, University of California, Berkeley, California 1980
Carlgren, O.: A survey of the Ptychodactiaria, Corallimorpharia and Actiniaria. K. svenska VetenskAkad. Handl. 1, 1–121 (1949)
Dando, P. R., A. J. Southward and D. J. Crisp: Enzyme variation in Chthamalus stellatus and Chthamalus montagui (Crustacea: Cirripedia): Evidence for the presence of C. montagui in the Adriatic. J. mar. biol. Ass. U.K. 59, 307–320 (1979)
Farris, J. S.: Methods for computing Wagner trees. Syst. Zool. 19, 83–92 (1970)
Fox, D. L. and C. F. A. Pantin: Colors of the pulmose anemone Metridium senile. Phil. Trans. R. Soc. (Ser. B.) 230, 415–450 (1941)
Grassle, J. P. and J. F. Grassle: Sibling species in the marine pollution indicator Capitella (Polychaeta). Science, N. Y. 192, 567–569 (1976)
Hammatt, D. L.: Reproduction of Metridium marginatum by fragmental fission. Am. Nat. 40, 583–591 (1906)
Hand, C.: The sea anemones of central California. Part III. The Acontiarian anemones. Wasmann J. Biol. 13, 189–251 (1955)
Harris, H. and D. A. Hopkinson: Handbook of enzyme electrophoresis in human genetics, 259 pp. New York: American Elsevier 1976
Hedgecock, D.: Biochemical genetic variation and evidence of speciation in Chthamalus barnacles of the tropical Eastern Pacific Ocean. Mar. Biol. 54, 207–214 (1979)
Hoffmann, R. J.: Genetics and asexual reproduction of the sea anemone Metridium senile. Biol. Bull. mar. biol. Lab., Woods Hole 151, 478–488 (1976)
Hoffmann, R. J.: Evolutionary genetics of Metridium senile. II. Geographic patterns of allozyme variation. Biochem. Genet. 19, 145–154 (1981)
Lakovaara, S., A. Sawra, P. Lankinen, L. Pohjola and J. Lokki: The use of isoenzymes in tracing evolution and in classifying drosophilidae. Zoologica Scr. 5, 173–179 (1976)
Levene, H.: On a matching problem arising in genetics. Ann. math. Statist. 20, 91–94 (1949)
Manwell, C. and C. M. A. Baker: A sibling species of sea cucumber discovered by starch gel electrophoresis. Comp. Biochem. Physiol. 10, 39–53 (1963)
Murphy, P. G.: Collisella austrodigitalis sp. nov.; a sibling species of limpet (Acmaeidae) discovered by electrophoresis. Biol. Bull. mar. biol. Lab., Woods Hole 155, 193–206 (1978)
Nei, M.: Genetic distance between populations. Am. Nat. 106, 283–292 (1972)
Purcell, J.: Aggressive function and induced development of catch-tentacles in the sea anemone Metridium senile (Coelenterata, Actiniaria). Biol. Bull. mar. biol. Lab., Woods Hole 153, 355–368 (1977)
Riemann-Zuerneck, K.: Actiniaria des Südwestatlantic: II. Sagartiidae und Metridiidae. Helgoländer wiss. Meeresunters. 27, 70–95 (1975)
Sassaman, C. and C. P. Mangum: Patterns of temperature adaptation in North American Atlantic coastal actinians. Mar. Biol. 7, 123–130 (1970)
Selander, R. K. and D. W. Kaufmann: Genic variability and strategies of adaptation in animals. Proc. natn. Acad. Sci. U.S.A. 70, 1875–1877 (1973)
Sneath, P. H. A. and R. R. Sokal: Numerical taxonomy — the principles and practice of numerical classification, 573 pp. San Francisco: W. H. Freeman 1973
Stephenson, T. A.: The British sea anemones, Vol. 2. 426 pp. London: Ray Society 1935
Tracey, M. L., K. Nelson, D. Hedgecock, R. A. Shleser and M. L. Pressick: Biochemical genetics of lobsters (Homarus): genetic variation and the structure of American lobster populations. J. Fish. Res. Bd Can. 33, 1108–1119 (1975)
Uchida, T.: Report of the biological survey of Mutsu Bay. 33. Actiniaria. Sci. Rep. Tôhoku Univ. (Ser. 4) 13, 281–317 (1938)
Verrill, A. E.: Classification of polyps. (Extract condensed from a synopsis of the Polypi of the North Pacific Exploring Expedition under Captains Ringgold and Rodgers, U.S.N.). Ann. Mag. nat. Hist. (Ser. 3) 16, 191–197 (1865)
Walsh, P. J. and G. N. Somero: Temperature adaptation in sea anemones: physiological and biochemical variability in geographically separate populations of Metridium senile. Mar. Biol. 62, 25–34 (1981)
Williams, R. B.: Catch-tentacles in sea anemones: occurrence in Haliplanella luciae (Verrill) and a review of current knowledge. J. nat. Hist. 9, 241–248 (1975)
Author information
Authors and Affiliations
Additional information
Communicated by N.D. Holland, La Jolla
Rights and permissions
About this article
Cite this article
Bucklin, A., Hedgecock, D. Biochemical genetic evidence for a third species of Metridium (Coelenterata: Actiniaria). Mar. Biol. 66, 1–7 (1982). https://doi.org/10.1007/BF00397248
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00397248