The Distribution of Crustacean Zooplankton in Northern Ontario, Canada Author(s): W. Keller and J. Roger Pitblado Reviewed work(s): Source: Journal of Biogeography, Vol. 16, No. 3 (May, 1989), pp. 249-259 Published by: Blackwell Publishing Stable URL: http://www.jstor.org/stable/2845261 . Accessed: 15/02/2012 17:04 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact
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Journal of Biogeography (1989) 16, 249-259
The distributionof crustacean zooplankton in northernOntario,Canada W. KELLER and J. ROGER PITBLADO* OntarioMinistry of theEnvironment, 199 Larch Street,Sudbury,Ontario, Canada P3E 5P9, and *GeographyDepartment,LaurentianUniversity, Sudbury,Ontario,Canada P3E 2C6
Abstract.The occurrenceof crustaceanplanktonspecies was investigatedin 337 lakes widelydistributedacross the northern portionof Ontario,Canada. General east to west patternsobservedincludedincreasesin the occurrenceof Chydoruscf.sphaericus(O. F. Muller)andAcanthocyclops vernalis(Fischer),disappearanceof Eubosmina longispina (Leydig) and Eubosmina tubicen(Brehm) and generally reduced occurrence of Cyclops scutiferSars and most daphnids except Daphnia galeata mendotae Birge and Daphnia retrocurvaS. A. Forbes. Along a southto north gradient, the occurrence of Leptodiaptomus ashlandi Marshincreasedgreatly,Tropocyclopsprasinusmexicanus Kiefer became very rare and Daphnia middendorfiana Fischerappeared in a large numberof lakes. Secondary south to northpatternsincludedincreased occurrenceof Leptodorakindtii(Focke), Sida crystallina(O. F. Muller)
INTRODUCTION Over a decade ago, Anderson(1974) lamentedthepaucity ofcomprehensive, regionalsurveysofCanadian crustacean plankton communities,revealing major 'gaps in our knowledge of the geographical distribution,ranges of environmentaltolerances, and basic ecology of many planktoniccrustaceanspecies', sentimentsalso expressed earlierby Patalas (1971). Fortunately,in the intervening yearstherehas been an increasein the numberof regional in Canada, addressing surveysofzooplanktondistributions someoftheseconcerns(e.g. Sprules,1975a,b, 1977; PinelAlloul,Legendre& Magnin,1979; Carteretal., 1980; Roff etal., 1981; Carteret al., 1986; Hebert & Hann, 1986). While numeroussynopticsurveyshave been conducted whollyor partiallywithinOntario (Rigler & Langford, 1967; Carter, 1971; Patalas, 1971; Brandlova, Brandl & Fernando,1972; Sprules,1975a,b; Carteretal., 1980; Jermolajev & Fraser,1982; Keller & Pitblado,1984) substantialgaps remainin our knowledgeof the zoogeographyof planktonicCrustaceain thevastarea ofthenorthern partof the Province.Publishedzooplanktonsurveysundertaken withinthisarea have been limitedin the numberof lakes examined,or geographicalextent.These surveysincluded 249 lakes in northeasternOntario (Keller, 1981; Keller & lakes in a small area of northPitblado, 1984), forty-five westernOntario(Patalas, 1971) and forty-seven lakes inthe Killarneyarea ofnortheastern Ontario(Sprules,1975a,b).
and Acanthocyclops vernalis (Fischer), and decreased occurrenceof Diaphanosoma sp., Holopedium gibberum Zaddach, Leptodiaptomus minutus Lilljeborg and Mesocyclopsedax (S. A. Forbes). Withinour studyarea, geographicrestrictionson the distribution of some species were evident,and the relative occurrenceof many species was related to general lake type. However, major differencesin species occurrences betweenregionscould not be explainedsolelyon thebasis ofvariationsinwaterqualityconditions.The biogeographical impactof QuaternaryGreatlakeansubage inundations leading to negative species interactions apparently influencedthe observedpatternsin species occurrence. Key words. Zooplankton, northernOntario, limnology, glaciation.
The moreextensivesurveysof easternCanada by Carteret al. (1980) and Roffet al. (1981) included all of southern Ontario, but littleof northernOntario. Brandlova et al. (1972) includeddata forsome northwestern Ontariolakes, butonlyconsideredthe distribution of Cladocera. In summary,data are particularly limitedforlakes in the extreme northernand northwestern portionsof the province,particularlynorthof 480 latitudeand westof 830 longitude. During 1981, the crustaceanplanktoncommunitiesof 137 'Northwestern'Ontario lakes were sampled by the Ontario Ministryof the Environment(M.O.E.). These data, togetherwith previous collections of crustacean planktonin 161 'Northeastern'Ontariolakes (Keller, 1981; Keller& Pitblado,1984,excludinglakes withpH
