"Dr. Peden's contribution was financed by the British Columbia Provincial Museum. Our work was supported by grants from the National Research Council of Canada to J. R. Nursall and G. E. E. Moodie.

Moodie, G. Eric E.

Reimchen, Thomas E.

The Canadian Field-Naturalist

WinnSpace Repository

'S'lTHE CANADIANFIELD - NATURALISTVolume 871973THE OTTAWA FIELD-NATURALISTS' CLUBOttawa Canada1973 Notes 173Endemism and Conservation of Sticklebacksin the Queen Charlotte IslandsThe Queen Charlotte Islands, located off thecoast of northern British Columbia, have longbeen noted for their endemic biota (Dawson1880). Recently Foster (1965) has assessed thestatus of the mammal and bird faunas. He in-dicates that of the seven mammalian speciesoriginally present, four are subspecifically distinct,and one, the extinct caribou deserved specificstatus. Among the birds there are three endemicsubspecies. The invertebrates have not beenthoroughly studied; however, Bousfield (1958)has described a new species of amphipod re-stricted to the islands. Calder and Taylor (1968)note 11 endemic taxa of vascular plants, over 2%of the total. Among the non-vascular plants thereis apparently a similar high proportion of endemics(Scholefield, cited in Calder and Taylor, 1968).These studies suggest that, as on many islands,isolation and a different selective regime have con-tributed to divergence of the biota relative tomainland forms.Studies of the freshwater fishes of the islandsreveal atypical forms of the threespine stickleback{Gasterosteus aculeatus) as well. The purpose ofthis note is to outline the degree of differentiationin some of the stickleback populations and to drawattention to trends which could threaten thesurvival of some of them. Research on the stickle-backs of the Queen Charlotte Islands began in1966 and the results of a study of sticklebacks inMayer Lake are described by Moodie (1972a, b).A population in Boulton Lake is the subject ofdetailed study by one of us (T.E.R.). We andothers have sampled over 24 additional lakes andstreams and the results of that survey will bepublished shortly.Although G. aculeatus is a variable species,generally the freshwater form known as leiurus(Figure lA) is a thick bodied fish with threedorsal spines and one pair of ventral spines form-ing the major part of the pelvic fins. They lackscales but there is a series of lateral bony plates.The number of these plates usually ranges fromfour to 35 but the average in fresh water is aboutfive to 10. The body color is pale yellow with ir-regular patches and stripes of olive and brown.For a detailed description of eastern Pacific coaststicklebacks and their variation, papers by Hagen(1967) and Hagen and Gilbertson (1972) shouldbe consulted.Figure 1. Gasterosteus from the Queen CharlotteIslands. (A) Leiurus from Woodpile Creek, in theMayer Lake drainage, approximately 55 mmstandard length; (B) "Black" specimen from MayerLake, approximately 70 mm standard length; (C)specimen from Boulton Lake lacking the seconddorsal spine and both pelvic spines, approximately50 mm standard length.In the Queen Charlotte Islands many stickle-back populations show variations in these charac-ters which well exceed the normal range. InMayer Lake, on Graham Island (largest of theQueen Charlotte Islands) there are two kinds ofsticklebacks. Those inhabiting the three tributarystreams of the lake are like the typical leiurusdescribed above. In the lake proper there is adifferent form, termed the "Black" stickleback(Figure IB). Black sticklebacks are nearly twicethe length of leiurus, they are very melanistic,much more streamlined, and differ in at least sixother morphometric and meristic traits. The Blackstickleback appears to meet the criteria of thebiologically defined species (Moodie 1972a, b).There are at least three other lakes on GrahamIsland containing similar giant, melanistic stickle-back populations. Because the typical leiurus formin the Queen Charlotte Islands tends to occur inrestricted and hard-to-sample environments, wecannot say whether these other populations of174 The Canadian Field-Naturalist Vol. 87large melanistic sticklebacks exist parapatricallywith leiurus as in Mayer Lake or not. However,in Drizzle Lake we have taken many largemelanistic sticklebacks from the open water andfrom an inlet stream to the lake a very fewsmaller fish that may be the leiurus form.Figure 2. Gasterosteus from Boulton Lake, clearedand stained with alizarin red S. Upper specimenwith all dorsal spines present: center specimen withsecond and third dorsal spines absent; bottomspecimen with first and second dorsal spines absent.In other lakes we have found unusual variationin spine number (Figure 2). In four lakes, one,two, or all three dorsal spines may be absent in10 to 90% of the fish. In Boulton Lake the pelvicspines and girdle are polymorphic, so that thespines and virtually all of the girdle are absent in70% of the individuals collected (Figure IC).Such spine loss, even of very low percentages, isalmost unheard of in extant forms of Gasterosteus.No instances are mentioned by Hagen andGilbertson (1972) in their survey of the specieson the west coast. We are unaware of significantloss of spines among the well studied Gasterosteuspopulations of Continental Europe. Therte is,however, a population in Lough Ree, CountyRoscommon, Ireland in which some individualslack the first and second dorsal spine although thefrequency is not known (David Marlborough,personal communication). The only comparablepopulation that we know of in North America ison Texada Island, British Columbia, and is understudy by J. D. McPhail and others. The lateralplates also show variation beyond the normalrange. There are populations in three lakes inwhich most individuals completely lack plates. Inother lakes most fish have only one or two platesper side. The only other localities of which weare aware, where such loss occurs are in southernCalifornia, Algeria (Miller and Hubbs 1969) andTexada Island (McPhail, personal communica-tion).In summary, there are populations of G.aculeatus in the Queen Charlotte Islands thatshow degrees of melanism, gigantism, spine loss,and lateral plate reduction, which are seldom ornever exceeded elsewhere in this widely distributedcoastal species. Although our investigation is in-complete and the causes of the peculiarities of thesticklebacks are far from understood, there arealready some obvious correlations between theirmorphology and environmental variables. Most ofthe populations showing lateral plate reduction orspine loss occur in lakes with no outlets and ap-parently no other species of fish. The absence ofboth competitors and predators has seeminglyallowed the sticklebacks to evolve novel adapta-tions to their ecologically unusual environments.In contrast, those lakes which contain salmonidsand cottids are generally populated by largersticklebacks with relatively long spines and highernumbers of plates.This multitude of isolated populations, manyof which display morphological variation almostunknown elsewhere, and all within modest dis-tance of one another, offers a rare opportunity tostudy natural selection, competitive interactions,and predator-prey relationships. Considerationshould be given to the maintenance of some ofthe more extraordinary populations. Fortunately,most lakes are inaccessible and the negative effectsof civilization will not reach them for some time.However, this is not the case for a few lakeswhich also happen to contain the most unusualpopulations. Boulton Lake is situated within 200m of the Masset - Port Clements highway. Becausethe loss of spines and lateral plates in this popula-tion appears to be a result of the absence of pre-dators, the introduction of game fish such astrout would probably lead to the elimination ofthis distinctive population.At present there is no need for trout introduc-tions because native stocks meet the demands offishermen. We spent the summers of 1967, 1968,and 1969 on Graham Island and were in the areafor 1 -month periods in 1970 and 1972. Duringthat interval we saw an increase in trout fishingfor sport and subsistence. Although the stickle-1973 Notes 175back populations in Mayer Lake may not be ad-versely affected by such fishing, we fear over-fishing in some lakes may lead to pressure tointroduce game fish in lakes such as Boulton.Greater angling activity may also lead to intro-ductions for the sake of the simple desire to havemore different places to go fishing. The mostserious threat to lakes which lack predators, suchas Boulton, is that trout will be introduced by theprivate action of well meaning citizens. If gamefish must be introduced we hope the introductioncan be restricted to the many suitable lakes anddrainages which presently lack fish of any sort.In California the plateless sticklebacks weregranted protection (Miller 1972) only after intro-ductions had considerably altered the gene pooland environment (Miller and Hubbs 1969). Inthe Queen Charlotte Islands Foster (1965) sug-gests the extinction of the caribou may have beenhastened by the introduction of deer. Surelyadequate protection for at least some of theendemic sticklebacks of the Queen CharlotteIslands should be established before irreversibleenvironmental changes occur.We are most grateful to Alex E. Peden for re-viewing the m.anuscript, for providing photo-graphs, and for help in the field. Dr. Peden's con-tribution was financed by the British ColumbiaProvincial Museum. Our work was supported bygrants from the National Research Council ofCanada to J. R. Nursall and G. E. E. Moodie.Literature CitedBousfield, E. L. 1958. Fresh-water amphipodcrustaceans of glaciated North America. CanadianField-Naturalist 72: 55-113.Calder, J. A. and R. L. Taylor. 1968. Flora of theQueen Charlotte Islands. Part 1. Systematics of thevascular plants. Research Branch, Canada Depart-ment of Agriculture, Monograph Number 4, Part 1.Dawson, G. M. 1880. Report on the Queen Char-lotte Islands 1878. In Geological Survey of Canada,Report of Progress for 1878-1879. pp. 1B-239B.Foster, J. B. 1965. The evolution of the mammalsof the Queen Charlotte Islands, British Columbia.Occasional Papers of the British Columbia Pro-vincial Museum, Number 14.Hagen, D. W. 1967. Isolating mechanisms in three-spine sticklebacks (Gasterosteus). Journal of theFisheries Research Board of Canada 24: 1637-1691.Hagen, D. W. and L. G. Gilbertson. 1972. Geo-graphic variation and environmental selection inGasterosteus aculeatus L. in the Pacific Northwest,America. Evolution 26: 32-51.Miller, R, R. 1972. Threatened freshwater fishes ofthe United States. Transactions of the AmericanFisheries Society 101: 239-252.Miller, R. R. and C. L. Hubbs. 1969. Systematicsof Gasterosteus aculeatus, with particular referenceto intergradation and introgression along the PacificCoast of North America: A commentary on a re-cent contribution. Copeia, 1969: 52-69.Moodie, G. E. E. 1972a. Morphology, life historyand ecology of an unusual stickleback (Gasterosteusaculeatus) in the Queen Charlotte Islands, Canada.Canadian Journal of Zoology 50: 721-732.Moodie, G. E. E. 1972b. Predation, natural selec-tion and adaptation in an unusual threespine stickle-back. Heredity 28: 155-167.G. Eric E. Moodie^Thomas E. Reimchen"'^Department of BiologyUniversity of WinnipegWinnipeg, Manitoba R3B 2E9"Department of ZoologyUniversity of LiverpoolP.O. Box 147Liverpool L69 3BX, EnglandReceived February 13, 1973Accepted March 22, 1973Is the Grey Squirrel Invading Nova Scotia?While motoring through the village of Habitant,near Canning (Kings County, Nova Scotia) onthe afternoon of November 5, 1972, I saw a GreySquirrel {Sciurus carolinensis) running acrossthe lawn on the property of Roy Hazel. Havingno previous record for this species in Nova Scotia,I was greatly interested, and visited the area a fewdays later to make some enquiries. At the Hazelresidence I was informed that the animal had beenseen frequently during the previous several weeksand as far as anyone in the community knew, ithad arrived there under its own 'steam.' Subse-quently I called on others in the neighborhoodand two told of having seen it running along anoverhead telephone cable.Still not completely satisfied that the squirrelwas not an escaped pet, I enquired over our localradio station (CKEN) asking if anyone had lost

Endemism and Conservation of Sticklebacks in the Queen Charlotte Islands

http://winnspace.uwinnipeg.ca/bitstream/10680/1298/1/Endemism%20and%20Conservation%20of%20Sticklebacks%20in%20the%20Queen%20Charlotte%20Islands.pdf

Endemism and Conservation of Sticklebacks in the Queen Charlotte Islands

Abstract

Similar works

Full text

Available Versions

WinnSpace Repository