GROWTH, LIFE HISTORY AND MORPHOLOGICAL DIFFERENCES AMONG STREAM AND LAKE DWELLING POPULATIONS OF PUMPKINSEED (Lebomis -) AND ROCK BASS (A- m)IN CENTRAL ONTARIO

A Thesis submitted to the Cornmittee on Graduate Studies in Partial Fulfilrnent of the Requirements for the Degree of Master of Science in the Faculty of Arts and Science

TRENT UNIVERSITY

Peterborough, Ontario, Canada

O Copyright by Jeff K. Brinsrnead 2000

Watershed Ecosystems M.Sc. Program

June 2000 National Librafy Bibliothèque nationale 1*1 of Canada du Canada Acquisitions and Acquisitions et Bibliographie Services services bibliographiques 395 Wellington Street 395. rue Wellirigton Ottawa ON K 1A ON4 OnawaON K1AW Canada Canada

The author has granted a non- L'auteur a accordé une licence non exclusive licence aiiowing the exclusive pennettant A la National Library of Canada to Bibliothèque nationale du Canada de reproduce, loan, distribute or sell reproduire, prêter, distribuer ou copies of ths thesis in microform, vendre des copies de cette thèse sous paper or electronic formats. la forme de microfiche/film, de reproduction sur papier ou sur format électronique.

The author retains ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor substantial extracts from it Ni la thèse ni des extraits substantiels may be printed or otherwise de celle-ci ne doivent être imprimés reproduced without the author's ou autrement reproduits sans son permission. autorisation. G rowth. Life History and Morphological Differences Arnong Stream and Lake Dwelling Populations of Pumpkinseed (Lepomis gibbosus) and Rock Bass (rlnrbloplites rrrpustris) in Central Ontario

Jeff K. Brinsrnead

Variation in gron-th. lik history and morphology ivas esaniined anlong populrttions of pumpkinssed and rock bass captured tiom laks and Stream ecosystems of tkvo central Ontario sub-\\-atersheds- Back-calculated standard length at age data was

;iiicll>.zedto assess gron-th patterns anlong populations. ~vhileage at maturity. length at maturity and gonado-soniatic index were used to assess life history variations. Twenty- sis body nieasures wsre recorded to examine rnorphological \*ariation among the populations. The hypothesized growth and life history differences betwesn streams and lakcs nwe not supported. althougli variation was detected between sub-watersheds. Tlie obscn~ddifferences sesm to bs relatcd to the trophic status of the tuvosub-ivatersheds.

Xlorphological differences \vers observed betwsn the Stream and lake populations.

Strcnni tisli sèemed to ridapt to svimrning and foraging in lotic ecosysterns by having a niors îùsifortii body plan. sniatler tins and ri more anterior pIacement of the laterril fins as coniparcd to Iake tkh. ACKXOWLEDCEMEXTS

1 ~-ouldlike to taks this opportunip to thank al1 of the people who have offered thc'ir support throughout my time at Trent. Witliout thern. the completion of this thesis

\i.ouid riot be possible. 1 n-ould particularly like to thank my supenrisor. Michael Fos.

He n-as aln-a>.ssupportil-s. enthusiastic about rn>.research (sotnstimes e\.sn more so than

1) and he offtired great insight. especially duting the de\-elopmsnt of this project. i ~vould aiso like to tliank hini t'or alloiving me the latitude to choose my own direction in the de\-cloprnrnt and rslcution of this research. The other members of my supen-isory ccinirnittre. Sick blaiidrak and Tom Whiltans. deserve a great deal of credit for the dc.\.clopnient of the final product. Their insight and suggestions at coinmittee nieetings and throughout the researcli process wre in\-aluable. 1 would also like to thank Nick and

Kcith Soniers for introducing and ~valkin~nie through the wonderful ~vorldof inulti\*ariatcstntistics and Sick and Bsren Robinson for their help in understanding the

311alysisof rn~rpliometricdata.

.As III'. project in\.ol\.ed a large tie1d coniponent. 1 am of course indebted to the iiiany peopIe tliat assisted me ~\.ithtield collections. For this. 1 am grateful to: Manha

.Allen. Ste\.ti Bobrowicz. Steve Bo\\-man. Kara Brodnbb. Kim Caldwell. Mark Duffy.

L'nns Gatzke. Kate Ovsns. Aaron Todd (1 promise 1 won3 tell anyone that you can now identif? \-arious panfish by the trvaythsy tlglit on the line). Vanrssa Vaughan and of course llrirk Wilson (Yes Mark!!!). You made the sprin3'summer sampling seasons tùn and cnjoyable: e1.m u-lien UT didn't catch any fisli. got rained on or sat in a boat frerzing to death. I would like to thank al1 of the other "fish squeezers" in the Fox lab for al1 of the fun. jokes and horsing around. To: Deb Austen. Rhonda Bell. Rash Dhillon. Gloria

Gillespie. Jaks LaRoss. Scott McCaims. Jen Mercer. Kevin Parsons and Tom Pratt: 1 am surs that 1 would havs lost rny mind measuring fish six to eight hours a day without you.

Fiinding for this rssearch \vas provided by an OGS scholarship and the NSERC gant helongin~to Michad Fox. Access to sites on the north side of Rics Lake nras kindly pro\-idsd by the staff 3t Serpent Mounds Pro\-incial Park.

1 u-ish to thank al1 of the frisnds that 1 have made in the tirne that I havs spsnt at

Trcnt (and thoss ti-om past adventures) for their support and for offsring periodic (or oticn tiequcnt) di\,ersions frorn the daily grind. In this respect. I would particularly Iike to tliank the Friday night pub crowd (and thus. the statTat the Olde Stone. the

Peterborough Arms and the Lazy Dragon) and the guys that \vere in the hockey pool each ic-ir.

And last. bur definitely not Irast. 1 ~vouldlike to thank rny parents. Lois and

Yerne. and my brother Davs for their support throughout nqrgraduate studies. They u-ere

;~Iu.;Q.s rherc for me with encouragement when timss \vers tough. T.-\BLE OF CONTENTS

.. .-\cknowledgements ...... 11

Table of Contents ...... iv

List of Figures ...... \?i ... List of Tables ...... vil1

Lntroduction ...... Gensral Introduction ...... Growth and Litè History ...... introduction ...... Hypotheses ...... bI0rpli0l0~b . introduction ...... Hypotheses ......

.\lethods ...... Stuciy Design ...... Study Sites ...... Fish Collection ...... Physicd Habitat Parameters and Fish Community Strucrure ...... Cirotvth and Lit;: History .A nalysis ...... Morphology ...... Measurement Error in Morphological Variables ...... Statistical Design ...... Growth and Lit2 Histoq ...... M orphology ...... Results ...... GrowtIi and Lit: History Analysis ...... Lengh at Age ...... A ge at Maturiry ...... Lsngth at Maturity ...... Gonadosornatic lndes ...... Morphology ...... Sexual Dimorphisrn ...... Habitat Dimorphism (Univariate Analysis) ...... Habitat Dimorphism (.Lfulti\xriate Analysis) ...... Compririsons to H>pothrsis Matrices ......

Discussion ...... 70 Gron-th ...... 70 Lie History Parameters ...... 77 klorpholopy ...... 57 Habitat and Community Diftërences ...... 103 The Role of Genotqpe vcrsus Plienotypic Plasticity ...... 106

Conclusions ...... 109

References ...... 111

Appendis 1 .Sleans and Standard Errors for Morphologieal Variables ...... 127

Appendis 2 .PCA and DFA Loadings ...... 127 LIST OF FIGURES

Figure 1. Location of waterbodies used in this study relative to a number of major geognphicd tèatures of the Kawartlia Lakes Region of central Ontario. Sampling locations are shown as indicated in the abo\.e lsgend ......

Figure 2. Location of 9 homolo~ouslandmarks used in the rnorphologica1 analysis of pumpkinseed and rock bass (shown). Landmarks 1 through 8 are used to form the truss neni-ork. Other measures are described below ......

Figure 3. Mean standard length at age for (A) fernate purnpkinseed and (B) mals pumpkinseed. Vertical bars repressnt = 1 SE ......

Figure 4. Mean standard length at age for (A)female rock bass and (B) male rock bass. Vertical bars represent = 1 SE ......

Figure 5. Percent niaturit? at age for (A)tèmale pumpkinseed and (BI male pumpkinssed. Sampls sizes are indicatsd abo\:e each bar ......

Figure 6. Percent maturity at ags for (A) femals rock bass and (B) male rock bus. Sample sizss are indicated above each bar ......

Figure 7. Percent tnatiirity by length class (standard length) for (A) fernale purnpkinseed and (B) male pumpkinseed. Sample sizes are indicated abo\.s eacIi bar ......

Figure 8. Percent maturity by iength class (standard length) for (A) t'smale rock bass and (B) male rock bass. Sample sizes are indicated above each bar ......

Figure 9. Mean GSI for kmale rock bass. Vertical bars represent = I SE and sample sizes are indicated above each bar ......

Figure 10. Distribution of principal component scores plotted on the first t\vo PC axes for 25 morphological measures for (A)kmale pumpkinseed and (B)male pumpkinseed using the irariance- covariance rnatrix fiorn the residuals of the regession of each ~norphologicalmeasure vs. modified centroid ...... Figure 11. Distribution of principal component scores plotted on the tirst nvo PC axes for 25 morphological measures for (A) tèmale rock bass and (B) male rock bass using the variance-covariance matrix from the residuals of the regression of each morphoIogica1 measure \.S. modified centroid ...... 56

Figii i-e 12. Distribution of pumpkinseed fernale canonical \.ariate scores tiom the discriminant tùnction analysis (DFA) with 50?L ellipsoids about the centroid ofeach goup plotted on the tirst t\vo canonical ases. The DFA \vas pertbrmed on the residual shape \.ariation afier regressing each of the morphological variribies on the modified centroid (body size) ...... 60

Figiii-c 13. Distribution of purnpkinseed male canonical variate scores tiom the discriminant îùnction analysis (DFA) with 509.0 ellipsoids about the centroid of sach group pbttsd on the tlrst t\vo canonical axes. The DFA \vas pertorrned on the rssidual shaps variation afisr regressing each of the rnorphological variables on the modi tied centroid (body size) ...... 6 1

Figure II. Distribution of rock bass fends canonical \.ariate scores from the discriminant function analysis (DFA) nith 50% ellipsoids about the centroid of each group plotted on the tlrst t\xVocanoiiical axes. The DFA \vas perfomed on the residual shaps \-ariation after regx-sssiiig each of the morpholo_cical variables on the moditied centroid (body size)...... 64

Figure 15. Distribution of rock bass mals canonical variate scores tiom the discriminant function anal~sis(DFA) with 50?,0 eIIipsoids about the centroid ot'each group plotted on the tlrst two canonical axes. The DFX \vas pertom~edon the residual shape \-ariation after regressine each of the rnorphological \variables on the moditled centroid (body size) ...... 66 LIST OF TABLES

Table 1. Fish collection dates and saniple sizes ...... 19

Table 2. Summary of aquatic habitat parameters for the systems studied. Al1 data were collected in May and June 1998 (see Table 1 for dates). Mean July Temperanire taken fiom Crrrzcrdim Clitzzcrte .Vu/-t~zuls.1961 -1 990 f lhl~mre4) (Environment Canada 1993). Data for Water Velocity. Watsr Depth and Water Temperature are mean =SE. (A) Data for sites n-here pumpkinseed were collscted. (B)Data for sites n-here rock bass were collected ......

Table 3. Fish community of the four \vaterbodies atudied. Spscies lists 1~-erederived tiom Ontario Ministry of Natural Resources unpublished data ( 1970-1989. and the fùnnel trap and seine catches tiom the curent study. Species names are as per Robins et al. ( 199 1 ) ......

Table 4. A\.erage percent error ( \-ariability) for the 25 morphological \.anables rneasured (n= 15 for each species) ......

Table 5. Mean rock bass standard length at age (rnm=SE) by cohort. (A) Standard length at age for the 1995 cohort. (B) Standard lengh nt age hrthe 1994 cohort. Cohons prior to 1994 were not nnal>zed due tosmall sample sizes for tiiese cohorts. Watershed -RL' rskrs to the Indian Ri\.cr/Rice Lake sub-watershsd and Watershcd 'SL' refsrs to the Eels Creeh'Stony Lake sub- \vatershed ......

Table 6. Results of univariate test (ASCOV.4) for habitat dimorphisrn in pumpkinseed. Values are back-transfomeci (the ANCOVA used log transformed data) adjusted means (mm) for each of 15 \.ririables (ses Appendi'r 1 for unadjusted means and standard errors). Shaded cells indicate the r\vo populations cornpared are signitïcantly difirent (Bonferroni corrected. p

Table 8. Classification matris of pumpkinseed based on discriminant tunction analysis. Roivs represent the a priori groups (i.e. fish ti-orn the three populations that were sampkd) and columns reprcsent the ~Iassiticationof fish predicted fiom the discriminant hnction analysis ......

Table 9. Classitlcation matris of rock bas based on discriminant tùnction anal pis. Rows represent the cr priori groups (i.e. fisli fiom the tbur poputations that Lvere sarnpled) and columns represent the classitlcation of tish predicted fiom the discriminant function analysis ......

Table 10. Sumrnary of the results for the thret. methods in which pumpkinseed morpholog \vas testsd. Signiticant results for the two sexes are indicated by Q and ai. Direction of the ANCOVA rekrs to the sample in w-hich the adjustsd rneans \vers,*reatt'r (either stream or lake). The .WCOVA results were Bonferroni corrected to p<0.00S3. Variables u-ere considered signitlcant in the PC-A for -0.50>r>0.50 and ivsre considered signiticant in the DFA for -0.3O>r>0.30. Signiticant body shape differences esisted anions the three punipkinsesd populations (Mrilk's jL test) ......

Table II. Surnn~aryof the results for the three methods in which rock bass inorpliology \vas tested. Signi ticant results for the two sexes are inciicatsd by 2 and a*. Direction of the ANCOVA retèrs to the sampls in which tlie adjusted means were greater (either stream or lake). The ANCOVA results were Bonferroni corrected to p~O.0083. Variables were considered significant in the PCA hr-0.50>r>0.50 and were considered signiticant in the DFA for -0.30~>0.30.Significant body shapc dit'térences existed among the four rock bass populations (Wilk's ;l test) ...... 68 Grrrrul In trodrr ctiort

Variation in the ecologicat strategies used by different populations of the same tish species (Baltz and Moyle 198 1: Ehlinzer and Wilson 1988: Swain and Holtby 1989:

Cum-et al. 1993; Fox 1991: Robinson and Wilson 1995) and by different tish species

( Humphriss 1984: W'sbb 1984: Keivany et al. 1997) are cornmoniy obsewsd at a iwiery of gcopphical scalss. E~idencefor thsss divergent stratsgies has been dsrnonstrated across Ixgc seopphical scales. including di tTerences obsen-ed among continents (Gross

1979). latitudes (Soltie I9SS)- and \vatersheds (Baltz and Moyle 19s 1. 1982: Fox et al.

1997). .As ~vell.different scological strategies can be obsen-ed at much smaller scales. such as différences that esist anlong populations from different habitat t-vpes ~vithina single lake (Jonsson et al. 1988: Ehlinger 1990: Robinson et al. 1993. 1996: Robinson

:ind \irilson 1996) or stream (Beacham et al. 1989: McLauglilin and Grant 1994: Putman et al. 1995: McLaughlin and Soakes 1998). The utilization ot'diI-fsrent strategies allo\vs organisnis to espioit rssources in the ecological niche in which they are found (Elilinger and if'ilsnn 1988: Noltie 1988: Curry et al. 1993: McLaughlin and Grant 1994) and tmsirnize thsir litstirne reproductive output within the constraints imposed bj. tlieir eii\.ironnit-nt (Scliafft'r 1974: Hutcliings 1993 3.

-4 number of studiès ha\-e documented diftèrencss in morphology (Laper and

Clridy 1987: Snpain and Holtby 1989: Robinson et al. 1993: Robinson and Wilson 1995) aiid life histories ( BaItz and Moyle 1982: Fos and Keast 199 1 : Fos et al. 1997) among populations of the same fish species that are located in different environments. Variation in morphology potentiall y allon-s tishss to adapt to diffirent environrnents by providing

ad\.antngss in pertorniance for certain ecological tasks that are assumed to be re!ated to

indi\.idual titncss ( Ehlinger 199 1 ). Gross ( 1979) found variation in meristic traits and

sonie simple ~norphologicalcharcictsrs in manne. lake and Stream populations of

iiincspi ne sticklebacks (Ptlrtgirirts prrngirirrs) w'hich were considered to be advantagous

for sun'i\.lil in the differsnt scosystenis.

Diffcrenccs in life history traits ha\.e also been found to ofièr similar benefits

( Battz and bloyle 1952: Jonsson et al. 1988: Drake et al. 1997). One of the most dramatic

csamples is provided by Jonsson et al. ( 1988). These authors found life history

clifferences in four conspecitic inorphs of Arctic char (Salidiriirs cripiiitrs) in

Thing\.allavatn. Iceland. The tlsli adopted diverging liîè history strategies to occupy

Jiffercnt niches that ssistsd lvithin the lake. Drake et al. ( 1997) dsnionstrated that shitis

iri Iik history tactics. such as the size and ase of tlsh at rnaturity. Lvere beneticial for

popiilat ions of bluegill (Lepotiris triric-1-oclrir-ils)threatened by Iiigh ansling intensities.

.AItl~oughthers has been niuch research regarding population differsnces in

\-nrious t)pes of laks habitats. lit2 history and morphologica1 cornparisons behnx.n stream

and Iakc habitats are rare in the litsrature. However. some preliminary work has been

dons in this area (ses Gross 1979: Baltz and Moyle 198 1. 1982: Sw-ain and Holtby 1989:

Lei-in niid McPhail 1993). Gross ( 1979) compared the morphology of ninespine

sticklebacks tioni 16 sites across Europe. inchdinf stream. lake and marins habitats.

.4ltIiough dift'srences wers found among the habitat types in the Gross ( 1979) study. these di fferences were predominantl y based on meristic counts. not on morpho logical iiisasureriients. .Morphoiogy (Baltz and Moyle 198 1 ) and life history ditrerences (Baltz rind .LIo>rlt.1982) of tule psrcli (~istrrrocarpr~straski) have been studied in three isolated

California drainages. The lie histoty ditlërences in the tule perch were not directly related as adaptations to stream and lake habitats. althouzh this mechanism \vas suggested. Lnstead. the obsen-ed stmtegies were related to differsnces in environmental stribility aniong the thrse drainages. Again. the cornparison of tule perch morphoIokg

(Baltz and JIoylc. 195 1) kvas based prin~adyon meristic tmits (only four rnorphologicai rnerisiircs uws rscorded) and signiticant differencss ivere gensrally atmong the three cwgrapliically isolated u-atershsds. not bet~vsenstreains and Iakes. Swain and Holtby b

( 19x9) uscd a ssries of 33 rnorphologicai measures to examine differeiices in juvenile coho sdmon (Olrcor-lz~.rlclirr.skis~rrc.11) reared in strsam and lake habitats. These authors concluded the morphologica1 \variations obsewed bstween stream and lake juveniles wsre ridriptations to schooling in the Iakes and holding a temtory in the streams. Levine and

'IlcPhriil ( 1 993 ) compared the inorphology of threespine sticklebacks ( Grrstc.rosrt.us

~rc.ul~wtirs)in British Columbia. Maiiy ot' the n~orphoIo_sicaldifferences found by these authors w-ere rc1att.d to the trophic structures of the tish. although they atso found

Ji ft'crrncss in the overall body size of the fish and the depth of the body.

Thus. it appsars tliat morphological and liîë history differences as adaptations to li\.ing in current \-ersus still water habitats have not been n-dl studied in the past. The tirsr objective of this ressarch is to detemine if inorphological and life history differences cxist betwwn lotic and lentic populations of centmrchids. The second objective is to cliriracterize the body tom differences betlveen tlowing and still water habitats based on a niulti\-ariate analysis of rnorphologica1 measures.

Rock bass (.-lnrbloplitesr'i~pestris) and pumpkinseed ( Leponris gibbostrs) were sclccted for a comparison of laks and strearn populations in central Ontario. Centrarchids liri\.e hssn sho\\-n to be quite plastic in ternis of both lit2 hisrov (Fos and Keast 199 1 :

Fos 1994: Drake et al. 1997: Ehlinger et al. 1997: Fox et al. 1997) and niorpliological traits ( Ehlinger and Wilson 1988: Ehlinger 1990: Robinson et al. 1993: Robinson and

\\'ilson 1996: Robinson et al. 1996: Ehlinger et al. 1997). Rock bass are a common species in both Stream and lake environrnents throughout southern and central Ontario

(Carlandsr 1977: Scott and Crossman 1973). and pumpkinseed are otien the most abundant species in Mes. ponds and slow. quiet streams in south-central Ontario (Scott and Crossnian 1973). But pumpkinseed are also found in streams ~vitha modente

\-slocityof approsimately 0.3 to 0.5 rn s (personal obsenation). It is assumed tliat tlo~v

\ docitics of this magnitude should create a sufficiently diftèrent environment to induce difti.rr.nct.s in rnorpholo~and life history relati\-e to csntrarchid populations inhabiting

Ientic t.n\.ironrtisnts.

In soms instances. morphological and life history di tlèrences will be apparent e\.en n-hen habitat variability is subtle. such as n-ithin a single lake (Layzer and CIady

1987: Ehlinger and Wilson 1988: Jonsson et al, l9S8: Robinson and Wilson 1996:

Ehlinger et al. 1997). Conversely. streanis offer coinparatively more extreme variations in habitat type and structure. a less predictable tiequency of catastrophic events (Horowitz

197s: Baltz and ~Moyle1982: Pmirnouls 1983: Eadie et al. 1986: Noltie 1988: Ryder and Pcssndortkr 1989) and more arduous hydrodynamic conditions (Baltz and Moyte 1982:

'1lcLaughlin alid Grant 1994)- Therefore. tish inhabiting the more \variable. Iess predictabls and more hydrod_vnamically stresstiil stream snvironments are espected to adapt through di fferencss in their morphologv and life history strategies.

The results of this research wi Il be valuable to tisheriss managers ~vhoare iiiterestèd in nianaging populations of centrarchids as well as otlier game species. For csctmple. results kom this research may indicate wiiethsr or not it is appropriate to use a stock of tisli from a stream to rehabilitate a lake ecosystem. Fish introducsd to a i\acrbod>.niust be adapted to local snvironrnental conditions, othenvise indi\.idual tirness \vil1 suffer (Auer and Auer 1987: Gloss et al. 1989: Schofield et al. 1989: Pliilipp ct ;il. Iq93: Kerr et al. 1996). Fox et al. ( 1997) suggested that it ~vouldbe iiiappropriate to transplarit suntish across watsrshed boundaries due to diffèrences in genetics and [ifs

Iiistoq. strategies that wers adapted to specitlc sn\.ironrnents. They believed that their tindings n-ere also applicable to otlisr ganis species. Tlic interbrçeding that results from the introduction of mal-adapted genotypes niay break up adaptive gene cornpleses that li;i\.c besn established by naturai selectioii. This phenoriienon. knolvn as outbreeding deprcssion. tiiay have negative et'tècts on the liealth of the population (Fellsy and Avise

19W: Philipp et aI. 1993: Fos et al. 1997). Similar problenis ivould exist if mal-adapted lak tish arc iiirroduced to stream habitats or lice iwsa. There are nlany esamples where tliese tcpes of concems ha\-e not bcen considrred by fislieries managers in the past

(Kutkuhn 1% 1 : 'LiIc'uIurtry 1989: Philipp et al. 1993: Ssip 1995). This study is also interrsting tiom an evolutionaj standpoint as it \vil1 examine the role of phenotypic

di\-ergmcearnong tish inhabitin2 diffirent types of ecosysterns.

Grorvth ut1 d L 1f2 History

/ut\-ocltrc*tiotr

Litè histo~.tlieory in\-ol\.ris trade-offs among factors such as the age and size at

imturity. gro~vthand tècundity schedulss: factors ~vhichalloiv organisms to masirnize

thcir lifetinie reproductik-e output and sun-ival (Schaffer 1973: Hutcl~ings1993). Since

tlic ultiniats soal ofany organism is to maximize its lifetime reproductive output within

the constraints detined by its snvironn~ent.it tvoukd seem intuitive that individuals should

begin to reproduce at the earliest possible age: but, this is not necessarily the case in man-

ccosystcms (Schaffer 1974: Baltz and iMoyle 1982: Fox and Keast 1991 : Hutchings 1993:

Fos 1994; Drake et al. 1997: Pratt 1998). There may be a ssvere cost associated witii

rsproductioii in tlsli. and rhis is otien at the expense of somatic groivth (Schaffer 1974:

Baltz and ,LIoyle 19SZ: Hutchings 1993). Siilce suwival is often dependent on gro\\'th to

a Iiirger size (e.g. to rsducs predation risks) it would seem in many cases that delaying

reproduction ~vouldbe ad\.antageous (Pratt 1998).

In reality. optimal litè history strategies depend on the biotic and abiotic en\.ironnient in w-hich the tlsh is found. Wlien adult mortality is niore variable than juimile mortality (~vhichis espscted in mors unpredictable environments such as strcrtrils where repeated periodic catastrophic elrents occur). t?sh reproduce at a younger agc, srnaller size and they invest more energy in gonad development so that they may successfùlly reproduce at least once during thsir life cycle (Baltz and Moyle 1982: Ryder

and Pssendortèr 1989: Fox and Keast 199 1 : RotT 1992). Conversely. fish reprod~ceat an

older ags. at targer sizes and reduce tlieir reproductive investnient when juvenile

niortality is more variable than adult mortality (Baltz and Moyle 1982: Rot'f 1992). The

obsenations of Baltz and Moyle ( 1982) supports this hypothesis. They found that adult

~tiortalityin tule perch \vas more variable in less predictablr environments. and

consequsntly tsmales kvere srnaller and younger at the time of first reproduction and the'

Iirid 1ar~t.rbroods than felnales tiom more stable a~vironments.Drake et al. ( 1997)

reportcd that both male and îèinale bluegill matured earlier and at srnaller sizss whsn

ridult niortrilit>.\vas high due to intensi\.e angling pressures. Jonsson et al. ( 198s)

clcscribed liîè history differences in Arctic char that \ver2 related to the occupation of

cliftkrsnt niches. differences in suscsptibility to predation. and espected monality rates.

Siniilarl>.. in stream ecosystems. rock bass wsre found to mature at a younger age ('ioltie

and Keenleyside 1987: Noltie 1958) cornpared to lake dm-elling rock bass reported in

utlier studies (Keast 1977; Gross and No\vell 1980). Noltie ( 1988) attnbuted the younger

agt' rit niaturity to Iiigher expected adult mortality rates in the more variabIs stream

ccosystems.

There is some a-idence tliat the gronzh rates of stream and Lake tish are different.

Thc ciiergetic cost of svimrning in lakes is les5 than the cost of swimming in the curent ofstrcaiiis. ndiich rnay in tuni Iead to an increase in the net rate of enera gain and

iiicrcascd gron-th for Lake fiçh. Levin and McPhail notcd that stream stickleback had a snia1lt.r body size than thoss collected from adjacent lakes. although they did not specificall'; test go\\-th in their study. Carlander ( 1977) reported that growth of rock bass

in an Oklahoma ressrvoir \vas greater than in its tributaries. Putman et al. ( 1995)

pro\-ided e\.idence that Illinois stream fish may gron- more siotvIÿ than their lake

countsrparts. although this obssnxtion w-as not actually tested statistically- Noltie ( 1988)

also sspsctsd that gron-th in Stream rock bass ~vouldbs reduced due to the more rigorous

cn\.ironnlent providsd by the Stream, although hs ultimately did not tlnd evidencs for

reducèd groit-th in lotic tish. The obsenrations of Noltie ( 1988) may be explained by

rcduced intrd-specitlc cornpetition in the stream tish or by greatsr access to food

rcsources such as invertebrates drifiing in ths currsnt (iMcLaughlin and Grant 1994) or

Iiiglièr qualit? food (Curry et al. 1993: McLaughiin and Grant 1994).

Hip O r lt CY CS

Brissd on the abo\.e literature re\.ie\\r. three life history h_vpotlissss were tested. It

113s bccri noted that strcani fisli ofien gron- mors slowdy than thoss from lake habitats

(Crirlandsr 1977: Noltis 19SS: Putman et al- 1995). As \vsll. it has been observed that

strcain pumpkinseed and rock bass in central Ontario are srnaller in size than lake tlsh

(pcrsonril obsenxtion). This latter result may be dus to diftkrences in the growtli or life

Iiistory strategies of the fisties. Lik History Hypothesis 1 (LH 1 ): It is hypotliesized that

strcain populations \spiIlgrow more sIowIy in the mors energetically costly strearn

cii\.ironnisnt than \vil1 the adjacent lake populations. Life History H_vpothesis3 (LHZ):

Fishcs \\.il1 bs youngsr and smallsr at the time of tlrst reproduction in streams. which are mors variable ecosystems. than in lakes. Life History Hypothesis 3 (LH3): Stream fCmriles \vil1 ha~rea hisher reproductive invc-stment (as measured by ~onadosomaticindex

- GS 1) coniparsd to lake femalss.

.\forp/tc~lo~~

/~III-(I~/;KI~UII

\vParïationin n-iorphological characteristics can provide fis11 with enhanced pcrtormancs abilitiss in certain types of aquatic habitats. Morphological difîèrences have bscn documentsd in a number of fish species across different Irike habitats. including pirinpkinseed (Robinson et al. 1993: Robinson and N'ilson 1996). bluegill (Laper and

Chdy 1 957: Ehlinger and Wilson 1988). ninespine stickleback (Gross 1979; Ksi\-any et al. 1997). Arctic char (Jonssoii et al. 1988) and Trinidadian pppies (Poecilicl 1-ericrilcm)

( Robinson and Wilson 1995).

Diftkrênces in several anatomical featurrcs of ninespine sticklsback: inciuding the riuinber of \.ertsbme. gill raksrs and t'in spines. body depth and pelvic spins iength: ivere rcportsd b'. Gross ( 1979) in marine. lake and Stream snvironments. Other studies

( Ehliriger and Wilson 1988: Ehlinger 1990) have demonstrated that different morphs of blucgill csist within lakes depending on the type of habitat in whicli the tlsh is found.

Fish tiom heavily \-egetated Iittonl arsas had larger tins and deeper bodies than those t'roiii open-\vater. pelagic habitats ( EhIinger 1990). Elllinger and Wilson ( 1988) also round that pectoral th{vere located more postsriorly in tlsh that were adapted to

\-egt'tated habitats. Thsss traits are suitable for the tine manoeuvres that are neccssary for foragin- in tliis type of habitat (Webb 1984; Elilinger 1990). Conversely. pelagic bluegills nPeremore fusitorrn in shape. had shorter pectoral fins (Ehlinger 1990) and had

niors anteriorly placsd pectoral tins (Ehlinger and Wilson 1955). These adaptations are

niorc suitabls for tlsh that forage in open waters. where they must cruise larger distances

to locats prey ( h'ebb 198-1: Elilinger 1990).

Trophic dimorphism has been shown to occur in purnpkinsred popularions

in habit in: lakes \vithout conspeci fic bluegilt populations. In the absence of blurgill.

puinpkinszsd rnay develop tn-O morphs: the more typical littoral fonn and a pelagic

\.xiation that is more bluegill-liks in its morpiiology. Although many of the differences

in the tn-Oforms are related to the tèeding apparatus of the fish. pelagic fish wre also

longer and more fusifonii than littoral fish. and had longer pectoral tins (Robinson et al-

1993 ), Again, these fcatures n-ere considered to be adapti~tfor foraging in open water habitats (Robinson et al. 1996). Robinson and Wilson ( 1996) reported that the obserwd

Jitf'crenctts lvere lar~elydus to phenotypic plasticity. although variations in genotype also iippcrircd to bs intlusncing the iiiorphology of the tish.

.Ilorphological adaptations related to flouring water have primarily been studied uing sa1 iiioriid species ( Beachani et al. 1989: Swain and Holtby 1989: McLaughlin and

Grant 1991: blcLaughlin and Noakes 1998). although other species have been studied as

\i.cll (Baltz and ~Moyle198 1: Levin and ,McPhail 1993). Fish found in tlo\vinzo \vater

~rensrallydisplay a more tùsifonn body shape to reduce drag wlien orientatsd in an b

Lipstremt direction (Baltz and Moÿls 19s1 : Webb 1984: McLmghlin and Grant 1993:

'LIçLaughlin and Noakes 1995: but ses Levine and McPhail 1993). Although the width of the body has not been exarnined in past studies (Bdtz and Moyle 198 1 : Beacham et al. 1989: Stvain and Holtby 1989; McLaughlin and Gnnt 1994). Ryder and Pessendortkr

( 19S9) suggest that tlsh with ri more füsiform body plan may in tàct be \vider.

Largt'r tin sizes (Beacham et al. 1989: Swain and HoItby 1989) and a more

antsrior placement of the lateral lins (Webb 1984: S\vain and Holtby 1989: Jobling 1995)

n.ould protpide stream fish with increased manoeuverability. Bassd on the tleld

obscn.ritions of McLaughlin and Noakes ( 1998). it appears that tisli holding position in

tlo~i-ingivatsr are usin: their lateral tins to maintain an upstrcam direction \\-hile fonging

for in\ et-tebrates caught in the current.

McLaughlin and Grant ( 1994) also demonstratsd that brook trout (Scdi.eliittis

/bi~rimrli.~)keding in faster current liad a shrillon- caudal psdunck to reduce ensrgy loss

iii rccoil. They cunsidered this to be adripti\-s for sustained su-inlming in currents of

higher ~,elocit>-.According to Webb ( 1954). tkh adapted to sustained :;\vimming should

h1.e ri large niuscle mass in the caudal psduncle. Thus. the caudal peduncle would have a siilaller depth (in the dorsal-\-entra1 plane) to reducs recoil. but would presumably ha\-e

;i grc'ater n-idtli (in the lateral plane) to accommodate the extra muscle mas Ptior to the currcrit research. differences in body \\,idth ha~xnot been \veII studied amon? habitat t~pcs.and a ir~uIti\.ariatrapproach has gensrally not been ussd to detsct morphological

Jiffercncss bet\vsen streani and lake tlsh (but see Swain and Holtby 1989).

Hipotlic~s~s

Briscd on the abovs litsrature. it can be Iiypothesized that strearn centrarchids will

Iiri\.e characteristics that produce less drag on the fish and allow for stronger swimniing in the currsnt of lotic ecosysteins. ,MorphoIogy H4vpothssis 1 (M 1 ): Stream tishes will be more tiisiforn~in shape than thsir Lake counterparts to reduce drag when svimming in the current. Thus. it is predicted thrit strsrim tkhes will have ri more shallow body. which nia'. in tum ha\-san intluence on the body \\-idth of the tlsh (aithough this trait has

_cenerai1y not bssn includeci in past morphological studies). Morpiiolog~Hypothesis 2

(b12): Stream tishes \vil1 have longer and \vider peI\-ic. pectoral. anal and dorsal fins to ailon- thc ttsh to orientate itisslf in the currsnt. The lateral fins are used for tirie

~iianotxn-rssand maintaining orientation in a desired direction. LvhiIe having larger anal and dorsal tins \vould increass stability. ,Morpholog Hypothesis 3 (iM3) The caudal pcduncIc ot'stream fishes will be more robust. It is predicted that the depth of the caudal peduncle n-il1 be reducsd and the width \vil1 be increased so that it is more circular in cross-section. bIorphology H-vpothesis 1 (M4)The lateral fins \vil1 be placed inore aiitt.riorly in strsarn fisl~ssfor orientation in the current and strong steady sn.imming. 5IETHODS

S~I~L?B*Design

To in\,estigate the differences in tïsh gou-th. lit2 histories and morpholo~~

betn-esn streanis and lakes. fish were cornpared using a paired stream-lake design. Fish

sampled tiom sach streani were compared to tlsh from an adjacent correspondin2 lake

ccoçysteni. BJ. comparing tlsh m-ithin the same gsographical unit (i-s. watershed). the

eft2ct of a nun~berof estrancous spatial \rariablss were controlled. Some of the variables

eIi~ninatedby this desip that have been sliou-n to affect tish life histories and

ii~orphologyin past studies include: latinide (Noitie 198s). cliniate (Lotspeich 1980:

\Iiiishall et al. 1953) and u-atershed diftèrences (Fox et al. 1997). By directly comparing

iiiultiple stream-lake pairs. it can be dstennined if obsenred Stream and lake dit'terences

are coiisistent among the ~Wariouspairs. As ~vell.both pumpkinseed and rock bass were

studicd in independent tests to detemine if the obsewed differences are consistent across

tu-Orelated spccies.

Srrit@ Sites

Rice Lake. Indian River. Stony Lake and EeIs Creek are pan of the Kawartha

Lrikes rssion of centra1 Ontario (Figure 1 ). This area is north of the Oak Ridges Moraine

physioppliic unit and is approximately 1 10 km northeast of Toronto. Ontario. The

Kau-artha Lakes are part of the Trent-Severn Watenvay. which connects Georgian Bay

(Lake Huron) to the Bay of Quinte (Lake Ontario). For the study design described above. Stony Lake #

Y Dummer Lake Clear Lake j

Indian River

Hashngs

Keene 3 Otmîbee R

Figure 1. Location of waterbodies used in this study relative to a number of major -oeographical features of the Kawartha Lakes Region of centra1 Ontario. Sampling locations are shown as indicated in the above legend. Rics Lake and indian River are considered a stream-lake pair. and Stony Lake and Eels

C'reek arc comprise the other stream-lake pair.

Ricc Lake is a shallo\v lake \vit11 a surface area of 100.1 km'. an average depth of

2.4 m and a masimum depth of 10.0 m (Buttle 1992). The major tributaries entsrinf tkotn the north are the Otonabee, lndian and Ouse Ri\-ers- While there are no large rivers

III thc soutliem n.att'rshed. a numbsr of small strsams do enter the lake from both the

110rth and th< south. The only outlet is at the northeast end of the lake throush the Trent

Ki1.t.r.

Ricè Lake has a higli degres of nutrisnt enrichnient and large blooim of algae are cornmon in the sumtnsr ~nonths(Ifrile and Hitchin 1976: Buttte 1992: Mercer 1998). in the suInmers of 1995 and 1996. Rice Lake had a mean sumrner chloropliyll a valus of

14.6 L-.b L and ri mean Secchi depth of 1.92 m (Mercer 1998). Data from 1976 indicats that this higlily enriched environment lias esisted for soms time with a total pliosphorus

\.;~Iuc of 49 L. a niean sumnier chlorophyll a value of 1 S.6 &CLand mean Secchi dcpcli of 1.3 ni (\Vile and Hitchin 1976). Rics Lake rscei\~eshigh lsvels of enriched runot't' tiom agricultural lands u-ithin its natershed. As u-eI1. it is located at the bottom end of thc E;ai\*anhaLakcs il-atershed and siibsequentIy receives nutrient inputs from the cottrigsd lakes found upstrsam and tiom upstream to\vns incIuding Peterborough and

Lrtkc'tÏcld.

hlost parts of the laks are covered by thick ~veedbeds tliat consist largely of n.ater miltoil (.Cfj.r-iop/g-llrrn~spp.). curleÿ Idpondweed (Porcrnzogerort cr-isprr-s)(Wile

1974: \fThall 1995; Nicholls et al. 1996). watenveed (Elodea ctrnudensis). tapegrass ( Ii~llistl~t-i(~ (III~~~CCI~ILI) and coontail (Cerurop~llunrdet~rersrurt ) c Wiie 1974: WhalI

1995 ). Thsre are soms nearshore areas of the lake that are largely dsvoid of vegetation due tu \valve action and'or tlie clearing ofbertches. OveralI. Rice Lake can be classified as eutrophic xcording to the criteria of Home and GoIdman ( 1994).

The Indian River tlon-s south into Rice Lake. entering the lake to the south of the

\.illagt. of Keene. The origin of Indian River is at the south end of Duminer Lake. lvhich iii turn is connectsd to Stony Lake by a short stream- Like many of the ri\.ers entering the

Trent-Severn Systent. flolv is controlled by a numbrr of dams dong the length of the ri\.er- Tlie predominant land use in the watsrshed is a-gïculture. and ninoff from the land n-iakcs this a relati\xly productive system.

Stony Lake is srnalier than Rice Lake. with an area of 28.7 km2. but it is much dwper. Stun). Lake has a niean depth of 5.9 m and a maxiniurn deptli of 33.0 m. Tlie lake is di1.idt.d into tu.0 basins: a shallou-. niore productive west basin. and a desper. Iess producti\.e cast basin. The inlet to the Iake is from Lo~~esickLake at Burlcigh Falls (~vest basin ). and the major tributariss are Eels Creek and Jacks Creek. n-Iiich enter the east basin ot'Stony Lake from the nonh. The outlsts are througli the narrows into Clear Lake and 1.in a smrill stream that tlon-s south into Durnmer Lake. Since the sites used for the current study are located on the east basin of Stony Lake. al1 reîèrences to Stony Lake

Iit.rèatier refer to the east basin. unless othenvise indicated.

Sutrient enrichment is less important in Stony Lake compared to Rice Lake. perhaps because the mixsd deciduous-coniferous forests of the north shore are largely intact. agriculture is less preciominant in the watershed. and the portion of the watershed north of the lake is Iocated on the relatively nutrient poor soils of the Canadian Shield

( N'iIe and Hitchin 1976: Buttle 1992). A mean total phosphorus value of 10 .uglL \vas

recorcied for Stony Lake in the summsr of 1976. while the mean chlorophyll a

concentration \vas 3.3 ,u@Land the Secchi depth \vas 4.3 rn (Wile and Hitchin 1976).

Lntortunately. more recent IimnoIogical data hrStony Lake n'ere not available,

Sc\~rthslsss,based on the 1976 data and the obsened characteristics of the tu+olakes.

tht' trophic status of Stony Lake \vas obviously louw than thrit of Rice Lake in the

sumrntlr of 1998. The aquatic \qetation of Stony Lake is much more sparss than in Rice

Lake ( \Vile 1 974: Biittle 1992 ). with pond\-eeds (Poruinog,.eror~spp.). water milfoil. mon trii 1. inuskgrass (Chur-crspp.) ( Wile 1974: Chamberlain 1 990). ~vatenixxd(Efodecr spp. ). tapegrass and pickerel~veed(Ponreckr-ia cor-dcua)as the predominant species of su bmergtld \-egetation ( Chamberlain 1990). Based on the available data. Stony Lake ivoulJ bs classifieci as mesotrophic by the cntt-ia of Home and Goldman ( 1994).

Eels Creek flotvs in a southerly direction into the east basin of Stony Lake. The u-atershed is Iocatsd on the granite of the Canadian Shisld and the surrounding vegetation is predoniinantly cornposed of coniferous and mixsd tbrests. The tlou- of EeIs Creek is

Iriryl>.unregulated (cotnprtred to other rivcrs in the Kawarthas) ~vhich.combined with tlic iinpsmicable undzrlying rocks. causes periodic severe spring tlood events. Such an e\-ent occurred in the spring of 1998 prior to tkld sarnpling (K. Invin. Ontario Ministry of

Satura1 Rèsourcss Bancroft District. personal communication). The productivity of Eels

Crcck is substantially lotver than tliat of Indisin River due to the differences in watershed cliarxteristics. The soils of the Eels Creek watershed are thin and relati\-ely infertile. and

the estensi\-e forests are lrirgely intact.

The four n~ritzrhodiesin this study are interconnected through two patlin-ays. As noted pre\-iously. the major ourlet to Stony Lake is through Clear Lake. whicli is connccted to Rics Lake \.ia Katcliiwanooka Lake and the Otonabee River. Stony and

Rice 1akc.s are also connected \.ia a small strram that tlows into Dummer Lake and tïnalIy into indian Ril9er. Thus. Indian River and Rice Lake can be considered a sub-watershed, and Eels Creek and Stony Lake cm be considered a sub-watershed n'ithin the larger

Kali-artha Lakes wacershed.

Fislt Colluctiutt

-411 tish were sanipled in the late spring and early summer of 1998 (just prior to the bretxiing season of pumpkinseed and rock bas in central Ontario for that year). csccpr tor the indian Ri\.sr pumpkinseed population. ivhich \vas collscted I 1 Aupst to

27 August 1997 (Table 1). By coltecting the rock bass from the lakes and their adjacent strcams nithiri a perïod of hvo to three iveeks. ditkences in date could be eliminated as a potcntiril contounding factor. Linfortunately. this fias not possible for the pumpkinseed populations.

The collection of pumpkinseed from Indian River pro\-ed to be dit3icult. although

37 specirnens ivere obtainrd from threr sites in Aupst 1997 (Figure 1 ). Only four pumpkinsced were collected from Indian River in the spring of 1998 and were added to the prrvious sunimer's catch. Thus. only a small sample (n41) was available for Table 1. Fis11 collection dates and sample sizes.

Pun~pkinseed 5- 12 Juns 1998

1 Rice Laks - Vegetated Rock Bass 1 Indian River Rice Lake

15- 18 June 199s rnorpliological and growth analyses. Due to the latc collection date in 1997. the Indian

Ri\.t.r specimsns could not be used for the analysis of reproductive investment. but they could be used for the ags and Iength at rnaturity analyses. In the spring of 1998. ptimpkinsred were collectcd from h1.o sites on Rice Lake to compare morphological ciit'krences betwsn vsgetated and unvegetated sites. The pumpkinseed population of

Ecls Crcck \\-as sparse. and thus pumpkinseed were not collsctsd tiom tlither Eels Creek or Stony Lake. Sample sizrs hrthe thres pumpkinseed and four rock bass sarnples are i~icludedin Table 1.

The location of al1 sample sites is indicated on Fibmre 1. Sites were seiected based on four criteria: abundance of pumpkinseed and.'orrock bass. suitable water vclocity. sasy acccss. and the presznce of sitnilrir physical habitat. Physicd habitat parameters are describeci in Table 2. All stream tish \vers sampled corn locations with tlom. ntes of

.. .. crt'a~t'rtlim 0.25 nijs (i.s. riftle and run habitat types). Although the fisli likely do not rcsiJ~in this Faster mo\.ing water al1 of the the. it is obvious that tliq are utilizing the rc.sourct.s of the riftle and run habitats. Sarnpling sites ivere betn-een 50 and 100 in of strcaiii channel length or shorelinr length (for lake sites). Stream sites were separated from thsir adjacent lake by a distance of rit least 1 km and a minimum of one rapids or

\vaterfrill. This n.ould make the migration ofcentrarchids benveen habitats unlikely

(nlthoilgli somr stream juvzniles may occasionally be swept downstream into lake cn\.ironnic-nts).

\Vire tiinnel traps ( 100 cm length ?r 60 cm diameter. 1 cm mesh six) were used to collsct riIl strearn samples. Lake tlsh were collected from the nearsliore littoral zone Table 3- Summaq of aquatic habitat parameters for the systems studied. Al1 data were collecteci in May and June 199s (see Table I for dates). Data for Water Velocity. Water Depth and LVater Temperature are mean = SE. Mean July Temperature taken from Ctrrrtrdicrtr C/N?zarc.Vat-nlcrls. 1 96 1- / 990 l Ir'dtrnre 4) (Environment Canada 1993). (A) Data for sites m-here pumpkinseed were collected. (B) Data for sites where rock bass u-ere collectsd.

lndian River Ricr L. - Vesetated Saniplc Size 9 6

\!'riter L't.locit> (ms't 0.3 I =0.02

\\'riter Depth (ni) O.S8=0.0S 1.16=0.I I

\\'xt'r Tenipemture ( "C I l9.6r0.2 10.0=0

i'egtirat ion Dcinsip -= I O0o -- 1O0o

Dom inmi Substrats S izs Stons ( IO- 100 mm) Stone ( 10- 100 mm) Sand (0.5- I .O mm)

\!cm Jul! .Air Temperature 20.3 (Peterborough - 20.5 (Peterborough - 20.5 (Peterborough - , C)and Cliriiats Station Trent uni ver si^ ) Se\vage Treatrnent Setvags Treatnient Location Plant) Plant

Ele\ation (ni) 1 90

Indian River Rice Lake Eels Creek Stony Lake

6 6 3

O=O 0,36=0.05 0=0

1.4 1 =O27 1 -05=0.13 1.17=0.26

20.2=0.2 19.0=0.4 19.3=0.3

Doriiinmt Substratt. Sizs Stone Stons Cobble Stone ;10- 100 inni) ( 10- 100 nim) ( 1 00-300 rnni 1 (10-100 mm) ilcin Jul!, Air Tempenture 20.5 19.5 19.6 :"C)and Cliniate Station (Peterborough - (Apsley) :Apsley) Location Saïrige Plant)

190 245-260 240 using ri combination of tunnel traps and beach seines (15 m x 1.5 m. 6 mm mesh sire).

Fish u-ers sacriticed in CO1 sanintsd water and stored on ice for transport back to the lab.

All tish it-ere frozen \rithin sight hours of being sacrificed. Fish n-ere not treated with tisatii-es or presen-ritil-esto avoid distonions that could affect tlisir morphological traits

( Leslic and Moore 1986).

Physical Habitat Parameters and Fish Cotmirrrri@ Structwe

At sach collection site (both Stream and lake sites). physical habitat parrimeters i\.ere asscsssd (thrse replicates at each site) to compare the structure of the habitat ri\-ailablo to tish at tIiat particular site (TabIe 2). Al1 parameters wre rneasured iitimediately adjacent to one of the set funnel traps. Tliess parameters inçludsd \vater

\-clocit>-.vtlgtation dsnsih. substrate diameter. water temperature. elevation. mean July air tsniperature and water depth. Generally. al1 sites (streams and lakss) \vers selected to bc sintilar for 311 panmeters. except water \.elocity. to reduce the number of confounding factors.

ij'atcr \.clocity [vas nisasured using a hand held Py-my Gurly current meter.

Iregctrition density was estiinated as percent cover in a 1 m .u 1 m quadrant which was raiidomly selected at each site. Substrate panicle six was measured as the median axis of cacli particle: that is. neither the longest nor the shortsst asis. but the intennediate width of the particle wliich is at right angles to the longest and shortest measure

(Stantield et al. 1996). Based on this measure, subsuate was classifird as muck. clay. silt. sand. pcbble (0.5- 10 mm diameter). stone ( IO- 100 mm). cobble ( 100-300 mm). boulder ( 300- 1000 mm) or bedrock (> 1000 mm). Surtàce water temperatures were recorded at tlic time of sampling using a hmd-held thennometer. At each site. \vater temperature \vas measured t\.ith in the mid to late afiernoon (approximateIy 4:30)\vhen Stream temperature is at a maximum (Stoneman and Jones 1996). Elet,ations were taken off the 1985

Crinadian Departnient of Energy. Mines and Resources Topographie Maps. Mean July temperatures tvere estimatsd tiom Cmucliail Clinicire ;Vor-nwls. / 96 1- 1990 f l i~lrmr4)

( Ent.ironmt?nt Canada 1993). Station Peterborough Trent Lniversity (UV22'X.7S01 S'W)

\\.as us4to represent Indian Ri\.er. Station Peterborough Se\vage Treatment Plant

(14"17'5. 7S"19'\V) \vas used to represent Rice Lake. and Station Apsley (44"46'N.

ÏS"O5'IV) u-as used to represent Eels Creek and Stony Lake. it should be noted th altliough pumpkinseed were collected tiom indian Ri\-er in the tàll of 1997. habitat data collccted in the springsumrner of 1998 were ussd so the Indian River data tvould be comparable to the Rics Lake data.

Fish community data \\-ers also collected for each of the n-aterbodiss sainpled

( Table 3 ). Pressncs-absence data u-ers compiled tiom the tiinnel trap and seine net catctics. and ti-orn Ontario Ministry of Natural Resources (OIMXR)records for each site

(OMSR. unpublished data). The OMNR records obtained contained data tiom 1929 to

19S9. Specitls that only occurrsd in the records prior to 1970 Lvere not included in the com~~iuiiitydata for this study. Table 3. Fish communiry of the tour waterbodies studied. Spscies lists were derilred from Ontario klinistry of Xatunl Resources unpublished data ( 1970- 1989)and the tùnnçl mp and seins catches from the currsnt study. Species names are as per Robins et al. ( 199 1 ).

Indian River Rice Lake Ston? Lake Anpuillidae .-1~nerican eel (-4t~grd/u ro.srmfu/ C~prinidüe coin nion carp ( C :l~rirms~w-pio ) cornnion shiner (Li~il~scwr-tlirrns) 20 Ideri sh iner ( \.o~~,~?li.r/>t~tt-sC~~~-.SO/~WC-LLS ) b taclinose sli incr (.\.on-r>pi.siicrdrolcpis) spot~ai1 shiner ( .\ orropis i~ir&-ot?i~~s- tÏnescale d3ç5 ( Piic~-rittrcsrrèogu~u.~) bluritnosc minnuu- (Pirrtqhcrl~s~torurtts) blacknose dace (Rititii~.hrl~j.sarr~~rlrlzrs) longnose dace (Rlri~rii-hr&-s~wrur~r~rde') crwk c hub (.Cc.ntorilw cirror?t~cu/mu) falltish ~.l;'r?roii/i~.vcorpordis) Ca tostomidae ir h itc suciitr (i;uosmnrrrs ~-oninri~rsotlT) Ictaluridac broun bu1 lliead (..-Ini~~iur-i~vri~ihu/osirs )

vooh >il\ erside (LrthiJ~*\~li~.~sicbc-nllu.) Jüs terostcidac xooh sticklsback (C'td~tcr~a1consrutt.s) Zottidac ncwlèd sculpin (C'UI~ILShrdr) Itntrarchidue och bass (.-l nrhloplir~~sr-rpw-is) )umphinsced ( LLp)ntis,qrhhosirs)

) 1 ucgi ll ( Lq?orrtI.\ »iu~.,.oc-iiirus) mal lrnouth bass (.\lit-roprt.rru- ~iolnrni~~ui] rtrgerriouth bass ( .\ licropr~rzrs.~~l//?lOidfl) 1 Iach crappic ( P onioxir ~~igronruc-riftr~c~~s-) 'crcidae wvzi drtner ( Erlr~v)sron~u~~ilt.) el lu\\ perch ( Pcnw IIui-~'w~r~.s) o~pcrcli( f CJ~L-~~ILIL-u~I-~~L~s) r al lc' e (SrizosrLp~lio~i rimwt?~ ) Grodi uri d L Ïjie History -4nabsis

Fish n-ere than-ed and rinsed. and the wet weight was recorded for each fish

befors any measurements were taken. Sis to eight mid-lateral scales were removed tiom

the Isft side of the tish just beluw the mid-lateral line near the tip of the pectoral fin

(Carlander 1982) and impressions of the scales were made on acetate slides. TIiese slides

\\.cre \.ie\ved rit 46.5~rna@fication using a microprojector. Annuli tiom the scale

impressions were identiticd by the method described by Regier ( 1962) to age the

sptxinicn. Grou-th n-as analyzed by the Fraser-Lee method (as reported in Carlander

19s 1 ) n.hicli uscs the back-calculatzd Iengtlis at annulus formation to represem length at

Lige.

The gonads of males and kmales wsre re~novedand inspected to determine the

scx. inaturity status and reproductive investinent of the tish. Age and Iength at rnaturity

u-ere coriipared for niales and fernales using the "pivotal" age and Iength c1asses for the

popiiiations. n-here "pi\.otal" is detined as the earliest class at wliich at least 50% of

iiidi\.idurtls are sesually mature ( Fos and Ksast 199 1 ). The Gonadosornatic Index (GSI -

tlic ratio of gonad mas to somatic tissue tnass) uras calculatcd for fsmales only. as an

iiidicator of reproducti~.eallocation in the difirent populations. GSI compansons of

ii~dcsnwe not used because nides allocatcr a large and variable arnount of znergy to nest building and defrnce. Thus. GSI niay not bs an appropriate indicator of reproductive iii\.cstment in male centrarchids (Vollestad and L'Abse-Lund 1990: Danylchuk and Fox

1994). Fernale GSI could not be comprired arnong pumpkinsesd populations because only une female pumpkinseed was collected from Indian River during the 1998 breeding season. The othsr fernales in the Indian River population were collected in August and

Scptsmber 1997 and could not be used for GSI calculations because pumpkinssed ovaries art. spsnt and sggs rire partially rsabsorbed by Iats summer. Altliough the collection dates

tor the Esis Creek and Stony Lake rock bass populations ivsre late compared to the rcgulrir spaivning psriod for this species (Scott and Crossman 1973). no tèmales Lvere tbund to ha\^ gonads thrit \vere partially spent. The spring of 1998 had been cooler than norn~al.n-hich likeIy caused this delay in the onset of reproduction.

~\forphofo~*

.lIorphology of adult tish LX-asanal-vzsd usirig a modification oftlis box truss design ( Humpliries et al. 198 1 : Strauss and Bookstein 1982) that is similar to the tnisses uscd in other studies ofcentrrircIiid niorphology (Ehlinger 199 1 : Ehlinger et al. 1997).

The tniss design included 14 inter-landmark distances bassd on 8 homologous points

(Figure 2). This method ofkrs more complete coverage of the biological form of a tlsh. espccialljr in ternis of depth. than traditional niorphornetric measures (Strauss and

Bookstsin 1982: Winans 1984: Bookstsin et al. 1985; Coni et al. 1988). -4s wsll. tmsses are able to compensate for random rneasuremcnt errors that may occur. and enors are inore reridiIy idsntified than \\fith traditional niorphornetric mesures (Bookstein et al.

13SS ). In addition. sweral traditional morphometric measures were used to repressnt the zirth of the fish (fivs nieasureriisnts). tin sizes (sis measurements). the position of the C pcctoral tins (onc mcasurement). standard length and total length. Typically. rneasures such as girth are not well rspresented in truss designs (hr.Mandnk. persona1 Figure 2. Location of 9 homologous landmarks used in the morphological analysis of purnpkinseed and rock bass (shown). Landmarks 1 through S are used to fonn the tniss network. Other measures are described below.

Truss Network 1 -2 Predorsal 1 -3 Prepelvic 14 Preanal 2-3 Body Depth 24 Anterior Dorsal-Antenor Anal -7 -5 Dors31 Fin Base 34 Anterior Pt-lvic-Anterior Anal 4-5 Antsrior Anal-Posterior Dorsal 4-6 Anal Fin Bar 6 Dspth at Anterior of Caudal PrduncIe 5-7 Lt-ngth of Caudal Peduncle (Dorsal Plane) 6-7 Caudal Peduncle Tnrss 6-8 Length of Caudal Peduncle (Ventral Plane) 7-8 Depth at Postericr of Caudal Peduncle

Other ibleasures 1-9 Prepectoral Pectoral Fin Length - Length of pectoral fin ray Pectoral Fin Width - Length from end of 1'' ray to end of 1st ray Pelvic Fin Length - Length of 1" soft pelvic fin ray (Le. ray nest to pelvic fin spine) Peivic Fin Width - Length corn end of pelvic spine to end of last pelvic ray Dorsal Fin Depth - Length of 1" sofi dorsal ray Anal Fin Depth - Length of 1" sofi anal fin ray (Le. ray next to anal Fi spine) Interorbital - Width fiom orbital bone to orbital bone Width at Insertion of PectoraI Fins (Le. width at 9 above) Width at Anterior of Caudal Peduncle - Maximum width at anterior end of caudaI pedunde (Le. width at 5-6 above) Horizontal Gape - Width at the posterior terminus of the maxillary bones communication). A modified csntroid was calculated from the sum of the squares of al1 cxtsrnal body measures on the fish (i-e. measurements 1-2. 1-3. 2-5. 34. 3-6. 5-7. 6-5 and

7-S in Figure 2). The moditied centroid \vas compared to the traditional centroid mesure

(n-hich includes interior rneasures 2-3.1-5. and 6-7 in Figure 2) used by other authors

(Strauss and Bookstzin I9SZ; Eh!inger 199 1 : Robinson et aI. 1993. 1996). For al1 selm tisli populations anal-vzed. the nvo measures were higlily corrdated (Pearson ~0.997. p

.AI1 morphoIogical measures were taken on the left side of tish that were pinned to

3 \\'hite styrofoam background using Ultra-Cal Mark III digital calipers (Fred. V. Fowler

Co.. Inc.). The rneasurements were electronically input into a coinputer sprcadsheet using tlie softn-are EsCaliper Ver. 2.00 ( Palmer 1994). When one of the left fins of the mid-

Imml pairs [vas damaged. ri measurement from the intact right tln \vas included instead.

If both tins u-ere damaged. a blank \vas recorded.

.\f~~crs~rt.~~nic~,~rError- il? .llorp/~ologic.nlI irricrhkes

.A\.erage nleasursment errors (i.e. the variability associated with rneasursrnent tccliniquc) for the 28 morphological measures \vers detennined by measuring a sub- satnplc of 15 tish a second tims. The pumpkinssed that uxre re-rneasured came fiom the

Rice Lake Laegetated population. and the rock bass that were re-rnsasured were from

Indian Ri~w.Tlis percent error was generally less thail 5% (Table 4). which is within acccptabIe lirnits for tnorphological analyses (Winans 1984). Some of the smaller Table 4. X\.srage percent error (~Variability)for the 38 morphological variables rneasured (n= 15 for each species).

Pumpkinseed Rock Bass Pectoral Fin Length 2.56 3.7 1 Pectoral Fin Nridth 5.68 4.05 Pelvic Fin Length 3 -66 3 -30 Pt.1i.i~Fin Width 1.00 5.05 Aiial Fin Dcprh 5 -23 5.14 Dorsal Fin Depth 4.03 3-34 Standard Ltlngh 1.93 OS7 Tot31 Letigth 0.70 036 Prcdorsal 1-33 1.30 Prepe tvic 1.70 1.59 Prcpsctoral 3 -42 1.56 Body Depth 0.79 1-29 Prsnnril 1.94 1-85 Antcrior Pcliric-.Anterior Anal 3-11 3.77 Antcrior Dorsal-Anterior Anal 1-32 1 .OS Dorsal Fin Length (Base) 1.28 1.14 Arial Fin Leiigth (Base) 4.52 1-33 Anterior Anal-Posterior Dorsal 4.65 1.3s Anterior Psduncls Deptli 1.85 3 20 Caudal PsduncIe (Dorsal Plane) -.' 93 4.57 Caudrii Pcciuncle (Ventral Plane) 5.72 4.03 Posterior Caudal Peduncle Depth 1.79 1.93 Caudal Pcduncle Tniss 2.90 2.48 Interorbital 3 -39 2.76 Ii'idth at Pectoral Fin Insertion -.-7 53 - -.' 75 \17icltliat Anterior Caudal PeduncIs 3 -96 5 .36 \\'idth at Postcrior Caudal Peduncle 6.70 8.55 Horizontal Gape 6.65 6.66 incasures hrid errors that nrere slightly pater than 5% because small measurement errors are magni tled u-hsn tliey are reported as a percentage of a small original measure.

The largest percent error \vas calculated for the width of the caudal peduncle at the insertion of the caudal tin for the rock bass. This is a veT small nieasure for both species

(4.1 ro 5.9 rilm for rock bass: 4.1 to 5.4 mm for pumpkinsecd). Due to the high percent crror (8.5O.0 in rock bass). this measure \vas exduded from further analyses. As ~vell.this nisasure could bs considered redundant becauss the anterior width of the caudal peduncls

(rit the posterior insertions of the dorsal and anal tins) ivas also measured. Total length naelitriinated trom further analyses because the caudal tins of a number of fish were drin-iagsd (possibIy due to ag,l~ressi\rebeha\-iour. nest buildins in the males. or damage u.1ic.n the tlsli wsre fiozen) resultins in a number of bianks in the data set. Although body lerigth has sometimes besn included in past morphological studies (see Bodaly 1979:

Gross 1979: Baitz and Moyle 198 1 : Beacham et al. 1989). standard length \vas eliminated tiorii thc morptiolo~icalanril>.ses of the current study because Iength components \vere iiicludsd in a nun~berof the other \-ariables that were measured. Thus, size had to be cliininated as a conhunding variable in the remaining 25 morphological measures either hy using the modified centroid in ri cot.anate analysis or ivith multivanate techniques.

Stutisticd Design

Glwic-th crild LCfi. Hisror?-

Brick-calculatsd standard lengths were used to detennins if there were difkrences in thc rate ot'growtli among the populations. Length at annulus formation for the tivo sexes kvas analjed separately for both species of tish. Analysis of variance (ANOVA)

it-as usèd to compare length at age after the assumptions of this test (data norrnality and

hoinogeneity of the \.ariancss) \vers met by log tx-ansfoming the data. Rock bass growth n.as also tssted by colion to drtsmine if thert: lvere sipiticant ~vithinpopulation differenccs due to differences in years (e.g. climatic dit-erences). Several cohorts could not be tested in this manner because of small sample sizes. Pumpkinseed were not tested hy cohon dus to the small size of the indian River samples. Back-calculated len@s at iigc 1 n-ere not useil in ;in? of the gro~vthanalyses because tIsh may be born at different tiincs during the breedins season (Le. early spring vs. late spring). making the lengh att~iiiicdb>. the end of the ~ro~vingseason quite \variable (Carlandsr 1977: Bericharn et al.

1989).

Fish t\-ere grouped by age and lengh ( 20 mm increments) to compare the psrcsntage of tish that n-ere mature in the pivotal age and size classes for each species.

The proportion of mature males and fernales was anaiyzed usin2 a G-test. For rock bass. al1 pairs of populations LX-erecompared. so the results of the G-test Lvere Bonkrroni corrcctccf (results wwc considerèd significant at p<0.0083 becauss sis tests were run).

GSI for fernale rock bass \vas analyzed using ANCOVA with gonad weight as the dcpei~dent1-ariable and body ~veightas tl-tc covariatc. Both variables were log. trnnsfornicd to mcet the ANCOVA assumptions ol'nomla1ity and homogeneity of

\.nriancss. When the assumption of paraIlelisrn \vas not met in ANCOVA. ANOV.4 of the GSI i.alues \vas used to test for differences. This requires that tliere are no size effects related to GSI: i.e.. GSI does not increase or decrease as the size of the tlsh increases.

GSI \\-as not relatsd to standard length in tliis study ($=O. 17. p=0.09).

.\ futp/10/ogl-

Pior to rilorphological analysis. the populations were tested for sexual

Jimorphism. a phenornenon which has been shown to occur in bluegill (Ehlinger 199 1 ).

Ehiin~ertound that fernales were more t-usiform. Lvhereas males were more gibbous and

Iiad a mort. robust caudal psduncle. Ssxual dimorphism was tested for the 25

~ilorphological\xriables using ASCOVA. with each morpliological measure as the dcpciiderit \aiable and the nloditied centroici as the covariate. Al1 variables were 10% transfcmncd to make them approsimately linear. This \\.as necessary because the riiodi tied centroid is a suin of the squares (cun-ilinsar)nisasure. w-hersas the individual riiorptiological measures are linear. .II\ Bonkrroni correction factor was not utilized in tliis rinalysis because the purpose \vas to diminate sesual dimorphism as a potential contounding hctor. Therefore. analyzing the srses separately if it seemed possible that tlic populations ivere sexuaIIy dimorphic (Le. at p

DiI'tSrences bstween Stream and Lake fish (habitat dimorphism) were also conipared using ANCOVA (after the ANCOVA assumptions of linearity and parallelism werc \.cri ticd). Only the i 5 measures that rrlated directly to the original hypotheses (see introduction for thess inorphologicd h>potheses) n-ere included in this analysis. This riicthod allowed hypotheses regarding specitlc masures to be tested directly. A Boiikrroni correction factor was used for each test of habitat dimorphism. and results n-ere considered significant at p<0.0033.

For the purpose of data exploration. a principal cornponents analysis (PCA) was nin on the xxiance-co\.ariance matris of the log, transformed inorphometric data. By dctlnition. the tlrst principal componsnt (PC) represents size and the subsequent non- tri[-id nes describe the shape of the tish (Somcirs 1986. 1989). although thers is s\id

:tiialyzed as prirnarily shape information. Also. as msntioned previously. rsmoving the tlrsr PC risis as size is inappropriate becauss thers may bs some shape infonnation includsd on this mis and tl~erem;ty be size information related to the subsequent ases.

Sizc \vas rcmoved statistically by taking the residuals from the regression of the log, transtormsd rnorphological \mariables vsrsus the log transformed nioditied centroid

( Ehlinger 199 1. 1995: Robinson and Wilson 1995: Robinson et al. 1993. 1996). The rcsiclcals um-e ussd in the subsequent PCA for analyzing shape independent of size. The rcsultrint PC scores were not correlated with the rnoditied centroid or standard length

(rO. 10). Thus. it was assurned that analyzing the residuals effsctively removed the size component of the measures and the analysis represented a remaining shape comporient. The residuaI data were also analyzed using discriminant îùnction analysis

(DF.4). This test calculates the distance betwesn LI priori groups (based on sex and habitat in tliis crise) in multivariate space based on the combination of variables that pro\.ide the triasimum separation (blanly 19SG).

Finrilly. to determine if the differences in morphology corresponded to the type of habitat tioni \!hich tlsh ivere sanipled. a hypothesis matris was constructed for each study sptlcics based on the h_tpothesis that morphoiogical changes \vere due to the presence of tlon-ing\vatsr. In these matrices. sites that \vers assumed to be similar (i-e. laks vs. Iake or strerirn \.S. stream) assigned a \-due of O and sites that nrereassumed to be cornpletely different (Le. Stream \-S. lake) \vere assisned a value of 1 (thus. t\vo distance ii~ritrices\vsre created). These hqpothesis n~atricesivere compared to summary niatnces of the inorphological ~xiablssiising a Mantel test follouing the method of Douglas and

Endlsr i 1952). The summary matrices used the rneans of the morphological variables

( Crossniari and Mc.4llister 1986: Somers and Green 1993) for cach population so that thq. could be comparsd to the hypothesis matrices. The habitat and fish comrnunity data n-cre aiso compared to the hy~othesismatrices using a Mante1 test. Separate univariate statistical tests uxre not used to test for habitat differences among the sites due to the sriiall sample sizes in the habitat data (Table 2). A11 univariate tests were considered to be signi ticant at p-4.05. unless othenvise indicated. RESULTS

Grolvtlt utrd LIJé History Attalvsis

Lc'i2grIl ut -4s

Thrcs samples of pumpkinseed (Indian Ri\.er. Rice Lake vegetated and Rice Lake un\.ègstrited~Lvere anal-vzed for length at age to test hypotliesis LH I (Figure 3). A single bod>--scalcintercept of 23 was calculated tiom al1 three saniples. and \vas used in the bxk-calculrit ion of standard length at age (Carfander 1982). This intercept was similar to tlis purnpkinsesd body-scais intsrcepts from sevcn diftkrent studies reported by Carlander

( 19,YZ). The intercepts tiom thsse studiss ranged tom 18 to 32. \vith an average of 23.2.

Fernales at rige L did not slion. a signifiant difference in length arnong the three populations (p=0.087). although the lake t'isli (\-egstatd=66S=mm. un\-egetated=6 1.8= 1.1 mm) nwe slightly larger than thoss samplsd from Indian Ri~~er

(59.2=2.5 mm). As ndl. there \vas no signitlcant difference behveen age 3 Rice Lake tt.nirilss collected froni vsgetated and urivegtated sites (p=0.23) Only one age 3 tèmale ptiinpkinsssd nr3s collected from indian Ri\-er. tlius the stream tlsh could not be conipart'd to the tu-o Rice Lake samples. There were also no signitlcant differences an~oiigage 2 and 3 males (p=O.-ll and p=O. 15 respectively - Figure 3). Based on the riicrin Icngth tit annulus tonnation. age 3 males tlom Indian River (53.2=2.3 mm) rippearsd to be considerably snialler than the t~vuRice Lake samplcs

(unt~egctrited=92.5=2.Zmin. vegstated=92.8=3.1 mm). although this result was not strttistically significant. Due to the lack of significance in these tests. it was detemined Females

-Indian ----- Rice Unveg ---Rice Veg

-me- Rice Cornbined

Males

I ndia n Rice Unveg i i 1- - - Rice Veg I 1 - - - - Rice Combined /

Figure 3. Mean standard Iensth at age for (A) female pumpkinseed and (B) male pumpkinseed. Vertical bars represent = 1 SE. that the pumpkinseed data do not support hypothesis LH 1: although there was a trend that

suggested that lake tish may be larger for each length at age than stream fish.

Four populations of rock bass (Indian Ri~rer.Rice Lake. Eels Creek and Stony

Lakc) n-cre analysd for diftkences in Itingth rit age (Figure 4). ,A common body-scale

iritercspt u-as also used for back-calculatin~length at annulus torrnation for the four

populations. Fernales rit ase Z and 3 showed signi ticant differsnces in length at age

! p4.W 1 ). The Tukey test revealed siPiticant difkrsnces between sub-n-atersheds (Le.

Indian Ri~wand Ricc Lake rock bas \vsre larrer than those from Ecls Creek and Stony

Lrikc). but not betweeri the stream and lake populations. Signiticant sub-\vatershed di t?krt.nce uPertlalso found for rise 4 finiales. except that the diftèrence betnetn Indian

Ri\-tir ( 1 IS.9=2.0 mm) and EeIs Creek ( lOS.l=3.2 mm) w;is not statistically signiticant

(Tuksy test. p=0.062). The ANOVA for age 5 tSmales showed significant ditlèrences for length rit age (p<0.05). but the Tukey test did not re\.eaI any signiticant differences bctn.sen populations. .A similar trend u-ith dit'tèrencss between sub-watersheds uras still c\-idcrit. u.ith Indian Rit-er and Rice Lake rock bass being larger tl-ian those in Srony Lake and EeIs Crcek.

Rock bris males at ags 2. 3 and 4 also displaysd sigrii tlcant differences between siib-\vaterslieds. As ~~11.Eels Cresk males n-sre signiticantly stnrtller than Stony Lake tna[es. Eels Creek males uwe 6 1.0=0.9 mm at age 2. 84.1 = 1 -4 mm at age 3 and W.6= 1.2 rnm at ags 4. ~vliereasStony Lake males wers 66.1 = 1.1 mm at age 2. 90.8= 1.7 mm at age

3 and 10S.2=3.0 mm at age 4. Both Rice Lake and Indian River males were larger yet.

The only signiticant difference in age 5 males was betu-een Indian River ( 141.3=3.5 mm) and Eels Creek ( 1 16.3=3-3 mm). Sub-\vatershed differences could not be detected for this last age cIass because there \vere no maies cokcted fi-orn Stony Lake older than age

4. The sub-watershsd differencrs found for the rock bass length at age data gsnerdly

\\.err inconsistent u-ith hypothesis LH 1. althoush the Stony Lake fish were significantly larger for sach lengh at 3gc than the Eels Creek fish.

Generally. tliers \vas no ciifference bsnveen the 1994 and the 1995 rock bass cohorts in tsrrns of Iength at acge \vithin sach of the four tvaterbodies (p>O.OS). The one cscepiori \\-as tor tlic body length at age 2 for the Rics Lake males (pcO.0 1). At the time of the formation of the second annulus. the a\?eragestandard Isnsh for the 1994 colion lias 80.1=1 .O mm. \vhereas it \vas 75.3=1 .O mm in the 1995 cohort. Despite this. there

\\.as no sipiticant diftsrence betn-een the Rice Lake male cohons for leiigth at the formation of annulus 3 (p=O.OS). Thus. diffirences in grouPthbetnxen the cohorts within the populations \vas not considered to be a confounding factor. Furthemore. testing for inter-population differences using only tish of the sanie cohort (both the 1991 and the

1995 cohorts !\.ers tssted) producsd rcsults that uwe simiiar to the analysis including the brick-calculatsd lencgths frorn al1 cohorts coinbined. Tlius. h'ipothesis LH 1 also \vas not supportcd by the cohort analysis as dit'tèrencss wsre again found bstween the sub-

\\.~?tcrsheds.not bet\vesri tile Stream and lake tlsh as \vas prsdicted (Tabie 5).

:lgc .LImlo-;Q.

Hypothesis LH2 \vas partially supported by the female pumpkinseed age at niaturitg data. Thc pivotai age at manirity for pumpkinseed feniales was 2 for indian Table 5. Mean rock bass standard length at age (mm=SE) by cohort. (A) Standard Iength at rigc for the 1995 cohort. (B)Standard lenC@hat age for the 1994 cohort. Cohorts prior to 1994 nwt. not analyed due to small sample sizes for these cohorts. Watershed 'RL' rekrs to the Indian River, Rice Lake sub-\vatershed and Watershed 'SL' refers to the Eels C'rcck. Storiy Lake sub-waterslied.

Femrilss

Length at Length at Age 2 Ags 3

Indirin Riter

Ricc Lake

Eels Crsek

5ton~Lake

Femrilss Males - - Lengtfi rit Length 3t Length at .42e 2 .+Le 4 Agt' 3 Ri\ a- fe~nalssand 3 for Rice Lake fernaIes (Figure 5). The proportion of mature Indian

Ri\w k~ritiles(71?0) was si-mitlcantly dit'fsrent hmRics Lake females (26%) at age Z

(Ci-test. p

The pi\.otril age for fernales in al1 four of tlie rock bass populations was 3. The pi\.otril age for males lvas also 3. escept for the Eels Creelc males. tvhereas had a pivotal age of 4 (Figure 6). Indian River kmales bsgan maturing earlier than any of the other t1irc.t. populations. At age 2. 360; of Indian Ri\.er fernales Lvere mature. lvhereas no t;.rii:ilcs \\-cre mature at age 2 in aiiy of the other populations (3 result that may be due to the sniall sarnple sizss of the age 2 kmales). Only 70'6 of Eels Creek females were niatiw rit rzge 3. ~vhile100q of females in the other populations were mature by age 3.

Differcnces in percent maturity bet~veenage 3 Eels Creek flsh and the other populations u-erc signiticant for the Ricr Lakz (n=26) and Stony Lake (n= 16) populations (p<0.0083). but n-ere only marginally signiticant for the Indian River population (n= 13. p=O.OOSS).

Rock bass niales frorn indian Ri1.t-r also began maturing earlier than the other r11rt.c populations. LX-itli55OG of Indian River niales being mature at age 2 (Figure 6). In dit. cittit'r populations. no males lvcre mature bshre age 3. although this result should be

\-critiec! \\-itti 1arp.x sample sizes. As with the fernales. Eels Creek males matured siyiiticantly later than thoss frorn the otl-ier three populations. OnIy 10% of Eels Creek tnrilt's u-ers mature at age 3. xhereas 6796 of indian River males. S 194 of Rice Lake males and 87"" of Stony Lakz males Lverr manire at age 3. Thcre were no significant

Jiftèrences in ags at maturity among the Indian River. Rice Lake and Stony Lake A. Females

B. Males

Figure 5. Percent maturity at age for (A) female pumpkinseed and (B) male purnpkinseed. Sample sizes are indicated above each bar. A. Females

Males

. .l ndian E Rice Eels El Stony

Figure 6. Percent manirity at age for (A) fernale rock bas~and (B) male rock bass. Sample sizes are indicated above each bar. populations at ags 3. The rock bass data generally did not support hypothesis LH2. As espcctsd. the Indian River tish rnatursd earlier than the Lake tlsh. but the Eels Creek tish uwe t'ound to mature Iater tlian any of the other thres populations.

L~vlg~h.-If -\lf~twi(~-

Lcngth at maturity u-as also anal-yzed to test hypothesis LW. For pumpkinseed fcn~alss.the smallest iengtli class at n-hich 3t Ieast 50°'0 of individuals wre tnature (the pi\atal kngth class) m-as 70-90 mm standard lsngh (Figure 7). There \vas no significant difkrencs betw-een Indian Ri\.er and Rice Lake in the proportion of mature females for tlii'; length class (G-test, p=0.60). The pi~wotallength class for pu~npkinseedmales ivas

50-70 mtu standard lèngh (Figure 7). The proportion of mature Indian River males

9 -0 ('2 U) n.3~not signiticantly different than the proportion of mature Rice Lake males

( 5Yo. p=0.23) for the pi\-otal length class. The lack of statistical sipiticance indicates tlirit the pumpkinsssd lengli 3t maturity data \vas inconsistent w*ith hypothesis LH2.

Ttîc pi\-otal length class for al1 populations of rock bass (both sexes) \vas 90-1 i O iiini stri~idrirdlengtli (Figure 8). except for the EsIs Crsek males. n-hic11did not rsach crrsater than 50" 0 matunty until 1 10- 130 mm standard len-th. Al1 Indian Ri\.er. Rice b

Lake and Ston'. Lake femaIes were mature at 90- 1 1 O mm. whsrsas only 72% of Eels

Creek ferniilès were mature in this length class. This dityerence was statistically sigiiiticant for Rice Lake and Eels Creek and for Stony Lake and Eels Creek (p<0.0083). but dix to a smaller sarnple size. there was not a significant differencs between lndian

Ri\w and Eels Cresk (p=0.025) ttvhen the Bonferroni correction factor was considered. A. Females

. H l ndian

Standard Length (mm)

lndian O Rice

50-70 70-90 90-110 110+ Standard Length (mm)

Figure 7. Percent maturity by length class (standard lena@) for (A) female pumpkinseed and (B) male pumpkinseed. Sample sizes are indicated above each bar. A. Females

Ilndian l ERice ' Cl Eels i El Stony

70-90 90-110 110-130 130+ Standard Length (mm)

B. Males

. H lndian

ERice I O Eels OStony

1

79-90 90-1 10 110-130 130+ Standard Length

Figure 8. Percent maturity by length class (standard length) for (A) female rock bass and (B) male rock bass. Sample sizes are indicated above each bar. Sirice thrw populations had 100Y0 maturity for the pivota1 length class. ditlèrences in the proportion of mature flsh were tested on the length class 70-90 mm for Indian River (36%0 mature). Rice Lake (0"t) and Stony Lake i25?.o)fernales. Thsre \vers no signiticant ciifferences among these three populations for the smaller length class.

For the length class 90- 1 10 mm, 89% of Indian Ri\-er males were mature. 559.8 of

Rice Lake males u-ere mature. Zooof Eels Creek males were mature and SZOGof Stony

Lake males n-ere mature, Si-ait'rcant difièrences existed benveen Indian River and Eels

Crctk and Stony Lake and Eels C'reek. .MI other comparïsons \vers not statisticaliy sigiiiticmt. H>pothesisLH2 \vas not supported by the rock bass length at maturity data.

Gotrrrtlosonirtric-I~ztltx

So signitlcant differsnces in GSI \vere found betwxn streain and lalit. tèniales or bet\vt.en sub-\i-atersheds. Although the results \vers not si_eniticant. a sub-LX-atershedtrend u-as again apparsnt (Figure 9). Mean GSI values for the Indian Ri\-er and Rice Lake popdations \vers almost identical (1.k0.6 and 4.k0.5 respectivsly). whereas the Stony

Lake and Eels Crcek populations had somenhat louper GSI values (3.5=0.3and 2.9=0.6 tcspc.cti\.ely). H>pothesis LH3 usnot supported as thsre \vas virtually no diftkrence in throck bass GSI \.aIuss benveen the streanl populations and their corresponding lake populations. l ndian Rice Eels Stony

Figure 9. Mean GSI for fernale rock bass. Vertical bars represent i I SE and sample sizes are indicated above each bar. .lf orphology

,Si.i-ir~tlDinlot-plli.s~~r

Pumpkinseed exhibited sesual dimorphism in 14 of 26 variabies (p

[vers Bonferroni corrected (p<0.002), 3 of the 26 variables in the pumpkinseed stiIl sliuu~sdsssual dimorpliism (length of snout to anal fin. base of anal tin. and interorbital

\\.idth) and 6 of 26 \-anables sho~vsdselvual din~orphismin the rock bas (lsngth of snout to anal tln. base of anal fin. intsrorbital u+idtli.body depth. depth of the caudal peduncle. and distance betnresn the peli.ic and anal tins). Therefore. the sexes u-ere anal-vzed scparatsty for inter-habitat differences in morpholog.

H~rhif~rrDitrrotplri.sni (C'rtii.~xt-ic~ru.-iilu~sis)

Fe\v signiticant differences i\.ere huiid bsnveen pumpkinseed samplsd fiom the

\.egctated and unvegetated habitats in Rics Lake. For sach ses. the maximum depth of tlic rina1 tin \\,as significantly largsr and femals pectoral tins \vert- sipitlcantly wider in tlic uri\.egetatsd saniple than in the L-sgetatedsarnple. The lvidth of the caudal peduncle

\\.ris also signitïcantly greater in \-egetated tkmales as compared to fen~aksfroni un\qctated sites. Duc to these signiticant diffèrsnces. the Rice Lake tkh fioni vegetated itrid un\.egetated habitats were not pooled.

Pumpkinseed of both sexes tiom Indian River had longer pectoral fins than those ti-0111eitlier un\-egetated or vsgetated habitats in Rice Lake (see Table 6 for adjusted nisans frotii the ANCOV.4, and -4ppendi.u 1 for unadjusted means and standard enors). In

tlirse of tiis tour habitat comparisons. the tndian River population had a more robust (Le.

less deep. but \vider) caudal peduncle (agrees ~vithhypothesis 343). although there \vers

no signiticant ditErences benveen the Indian River and Rice Lake vegetated females.

Gensrally. Rice Lake tish had a pater body depth (agrees with .M I ). deeper anal fins

(agrees uitli 512) and more posteriorly placed pel\.ic fins (agrees ~vithM4): although

thest' trends u.ere not signitïcant for the cornparison of lndian River and \.egetated Rice

LACkmales. .As WH. the dorsal fins of unvegetated Rice Lake fenlales were deeper

rlim those of lndian River females (inconsistent uith M2). The rcsults fiom the test of

dorsal tln depth w-ere inconclusi\.e for the male pumpkinseed bscause the regression

dopes of the zi\SCO\'.A were signiticantly diffcrent (test of parallelism).

Rock bass of borh sexes sanlpled frein Rice and Stony Lrikes had longer pectoral

tins than the tins of the coinciding Stream populations \vithin the same sub- vate ers lied.

although this dit'terence u-as not statistically significant for the cornparison of Rice Lake

and Indian Ri\.cr fcmales (inconsistcnt nith b12 - see TabIs 7 for adjusted insans tioin the

.ASCOV.A- and Appzndis 1 tbr unadjusteci nieans and standard errors). The Rice Lake

rock bas had longer and \vider pel~ictins. longer and dseper anal tins and (for fen~aIes cml!.) desper dorsal fins than the Indian River fis11 (inconsistent with MZ). Although Eels

C'rcek tlsh had \vider pel\.ic tins (bcised on the adjusted means) than Stony Lake tlsh

(rigrces \vith 312). this result \\-as not statistically signitïcant. For male rock bass. both the pcctoral and peI\-ic fins wsre more postsriorly placed in the Rice Lake sample (a,orees n.itli M-I) and the Rics Lake tish had a greater body depth (agrees with .M 1). There were tCn-cr significant ditrersnces benvesn the Eels Creek and Stony Lake rock bass populations. As noted previously. the pectora1 tins of the Stony Lake Iish urere longer tlim thosc of the Eels Creek fish. Also. the body width at the point of the insertion of the pectoral tins \vas signitlcantIy greater in the Eels Creek fish. but this resu1t wris for the knialcs only.

H~rhittrrDimor-phisn~ f.\,frrltii.~~t-iatr .-lr~ci~-l-i.~)

For purnpkinset-d fendes, the broktln stick mode1 of determining the non-tri\.iaI rises \{.as not appropriate becâuss the tirst mis of the PC.4 ~vouldha\-t. been trivial according to this stopping rule. Thus. a scree plot of the eigen\*alues(espressed as a pcrcciiragri of the total variation in the PCA) for each axis \vas analyzed (K. Somers. pcrsonril communication). There \vas a break in the dope of the scree plot after the fourth risis. indicatiiig that the tirst 1 axes of the PCA were non-trivial. These tirst 4 axes accourited for sreater than 50°/0 of the total variation in the PCA. The t~voRiçe Lake sub- populations of pun-ipkinsesd were somewhat separated ti-om one another on the axis PC- 1

(Figurc 10.4) and the Indian River population was largsly separated from the t~voLake populations on PC-2. The i-ariables that wsre most highly correlated (-0.50 >r>O.SO) to tfic tlrst axis included body \\idth at the i~isertionof the pectoral fins. prepelvic length.

\$.idth of the caudal peduncls and horizontal g3pe (also correlated ~vithPC-4). Variables that loaded on PC-2 included anal and dorsal fin depths. body depth and the caudal peduncle Iengtli (\ventral plane). The length and width of the pectoral tins tvere Iieavily loaded on PC-3 and the length of the pel~icfins were significantky correlated n-ith PC-4

(3sunlnlar); of the PC Ioadings is included as Appendix 11). A. Pumpkinseed Females

O lndian O Rice Unvegetated A Rice Vegetated

B. Pumpkinseed Males

O Indian O Rice Unvegetated A Rice Vegetated d

Figure IO. Distribution of principal component scores plotted on the first two PC axes for 25 rnorphological rneasures for (A) female pumpkinseed and (B) male pumpkinseed using the variance-covariance rnatrix from the residuals of the regession of each morphological measure vs. modified centroid. The scree plot of the eigenvalues was again used to determine the non-trivial axes for the pumpkinseed males because the broken stick model was inappropriate. The tlrst 2 axes tor the pumpkinseed males were non-trivial. but they accounted for only 28% of the

\.ariation in the PC.% Again the vegetatsd and unvegetated Ricr Lake populations ssemed to be minimally separated on PC- 1 (Figure 1 OB). \vhereas the Indian River population n-as separatsd from the lake populations on both PC-1 and PC-2. The depth cit' tlie anal and dorsal tlns were loaded hea\.iIy on PC- 1. ~vith6.3')h of the total variation in the PC.4 being attributed to the depth of the and &i (an additional 1.6?0of the

\.ririrition \\.as loaded on axis 3 for this variabis, although this axis \\-as considered trivial).

Tlie Ieiigth of the caudal peduncle was highly correlated with PC-2 (w-[tha srnalier cornponent relrited to PC- 1 )- The horizontal gape of the fish \\.as also higtily correlated

11.i th PC-2 and accounted for 4.0°O of the total variation.

Tlie tlrst 4 axes of the PCA for rock bass fernales wsre non-trivial by the broken stick model and accounted for greater than 53"; of the total \variation in the PCA. The tour populations seemed to be someu.liat separaced by sub-n-atsrsheds n-ith Eels Creek and Sron? Lake in the irpper Iefi region of Fi-cure 1 1A (Stony \vas fùrther ssparated from

Erls Crcek in this sanw direction) and Indian Ri\.er and Ricé Lake in the lower region of the plot. It should be noted that the sepantion betu-een EeIs Crsek and Indian River rock bris n-as not distinct. Indian Riwr and Rice Lake were funher separated fiom one mother on PC- 1. Variables that were highly correlated to PC-I included: anal and dorsal tln depths. the length of the base of the anal tin. the body depth (2 measures) and the iriterorbital distance. Body ~vidth.caudal peduncle width and horizontal gape were A. Rock Bass Females

a O lndian O Rice a Eels X Stony

B. Rock Bass Males

O lndian t3 Rice A Eels ------X Stony

Figure 1 1. Distribution of principal component scores plotted on the first two PC axes for 25 morphological measures for (A) frmale rock bass and (B) male rock bass using the variance-covariance rnatrix from the residuals of the regession of each morphological measure vs. modified centroid. Iciadcd on PC-2 dong n-ith the kngth of the pectoral tins. No variables were highly

correlated nith PC-3 and the width of the pectoral fins and the length of the caudal

peduncle u-ere loadsd on PC-4.

In the PCA of the rock bass males. the tlrst 1 ases were also non-trivial by the

broken stick rnodel and accounted for approximatsly 54% of the variation. While Indian

Rii,cr and Rice Lnkc wsre iar~elyseparated on PC- 1 (Fiprs 1 1 B). the Eels Crcek and

Stony Lake males n.ert. not as distinctly separated. Peivic fin length and width ris well as

anal tln and dorsal tin dspths wre signiticantly correlated n-ith the tirst PC axis. The

fength of the caudal peduncle was liighiy correlated with both PC-1 (dorsal measure) and

PC-3 (\-cnrrninieasurs). Loadings on PC-2 were highsst for body depth, caudal peduncle

clcptli. body tvidtli at tlis insertion of the pectoral tins and the horizontal Lape. The only

\-ririable that \vas significantly correlatsd u-ith PC-4 was the prepelvic measurs. but it

riccou~itsdfor t'ej Little of the total variation in the PCA (only 0.4550).

Rssiduals t\.src: ais0 anaI_\;zedusing a discriminant function analysis (DFA)-

Gc~wralbody shaps diffsrsnces wre detected in both t'smale (Wilk's À = 0.152. F =

3.753. p 0.001) and male (Wilk's À = 0.133. F = 5.169. p c 0.001) pumpkinseed. For

piin~pkinsesdkmales. YS.5"; of tish were correctiy classified brick to their a priori

croups (Table 8): that is. they wre succsssfully assiged to their original population C

(Indian Riwr. Rice Lake unvrgetated or Rice Lake vegetated). based on their position in iiiulti~.ariatespacc. This is supported by tlis -Mahalanobis distances that n-ere calculated

for al1 pairs of populations. The Indian River population was funher from the un\.egctnted and the vegetated lalie populations (D'= 12.0 and 17.5) than the lakc Table S. Classitication rnatrix of pumpkinseed based on discriminant hnction analysis. Ro\vs represent the a priori Croups (Le. tish from the thrre populations that were sampled) and columns rspressnt the classitication of fish predicted from the discriminant hnction ancîlysis.

,-1 Priori Groups lndian River 1 97.3

Total 1 88.5 1 87 lndian Rivcr 1 100 1 I?

Total 1 82.2 191 populations were from one another (D2=5.S - see also Figure 12). but the sepantion betu-ern the t\vo lake samples \vas still sinificant (p

Stream tsrnrilss Lvsre separated tiom lake females on Canonical Asis 1. 1%-hereas fCnides from the t~-olake habitats were scparatsd on Canonical Asis 2 ( Fisure 12). .\sis

1 xcountcd for 69.3'; of the variation in the DFA and it \vas highly correlated

(-0.30=.r>0.30) w-ith the ~.ariabIesthat distinguished Stream and lake tish. including: the t-iirisiniiin-idcptli of the anal fin. prepelvic length, body depth and the depth of the caudal pcduncle at the insertion of the caudal fin (for DF.4 toadintgs see Appendix II). Asis Z descrïbed 30.7!/0 of the variation and \\.as highly correlated with the width of the pectoral tins and the Isnsth of the caudal peduncls (on the dorsaI surtàcs). These t\vo variables

Lï.crc best able to distinguish the tish tiom the Rice Lake unvsgetatsd and the Lndian

Ri\-cr (also un~~egetated)populations from the Rice Lake vegetated population.

ln the pun~pkinscedmales. 82.2" 1 of the fisli u-sre corrcctly classitled to their a pl-iori groiips. iricluding 100°G of the lndian Ri\w tkli (Table S). Stream tlsh u-ere iiirisiiiially separated from the unvegetated and vegetated Rice Lake samples (D'=XI and 25.8). w-hercas the t~-Olake populations ivere much closer together (~'=3.7). although this separation was also signiticant (p

\\.as scparated tiom the lake saniples on Canonical Axis 1. which accounted for 87.9% of the i-ariation in the DFA (Figure 13). Pumpkinseed Fernales

Rice L. - Veg

Figure 1 2. Distribution of pumpkinseed fernale canonical variate scores froin the discriminant function analysis (DFA) with 50% ellipsoids about the centroid of each -zroup plotted on the first two canonical axes. The DFA was perfomed on the residual shape variation after regressing each of the morphological variables on the modified centroid (body size). Pumpkinseed Males

0 lndian R. CI Rice L. - Unveg. O Rice L. - Veg. Axis 1

Fikgire 13. Distribution of pumpkinseed male canonicd variate scores from the discriminant function analysis (DFA) with 50% ellipsoids about the centroid of each croup plotted on the fint two canonical axes. The DFA was performçd on the residual t shape variation afier regressing each of the morphological variables on the modified centroid (body size)- Asis 1 \vas most highly correlated with the pectoral tÏn lsngth. Other variables thrit nzrc correlatsd to Axis 1 includs maximum dspth of the ana1 tln (r=0.23) and the

ri~asirnuniJspth of the dorsal tin (r=0.2 1 ). Axis 2 only accounted for 12.1 !/O of the

1-arintion (the t\vo lake samples uere ssparated on this axis) and tvas hizhly correlated n.it1i only tlis depth of the anterior caudal peduncle. The variables that maximally separated the ri-iale groupings wers not the same as those that separatsd the fernales in inulti\.ariatt. space.

Signitlcant body sliape ditTerences were also evident in both kmale (Wilk's A =

0.0697. F = 7.1 S 1. p < 0.00 1) and male (Nrilk's A = 0.0982. F = 5.392. p < 0.00 I ) rock hass. The DF.4 \vas able to correctly classi- 90.2% of rock bass females to the four a priori groups (Table 9). Al1 four populations (Indian River. Rice Lake. Eels Creek and

Ston- Lake) nrere separritsd by signiticant Mahalanobis distances. The Rice Lake and

Iiidinii Ri\-er populations \\.ere lvidely separarcd ( D'= 14.2). whercas the Eels Crsrk and

S ton' Lake populations nwe srparated b). a much smal ler distance ( D2=53). There was sonie separation bet~vesnthe stream tïsh and the corresponding lake tïsh on Axis 1. but tlicse populations \\.ers primarily separated on Axis 2 (Figure 14). The sub-w-atsrsheds i\.cre separatsd on Canonical Asis 1.

Asis I accounted for 60.5% of the total \.ariation calculated by the DFA. The bod?. depth. caudal peduncls depth. iliterorbital and horizontal gape were high1y correlated tvith this first Asis. Tlie streams \\.ers primanly separated tiom the lakes on

.-\sis 2 u-hich nccounted for 29.6O.6 of tlie total \m-ïation. This axis was highly correlated u-itli the position of the pectoral tin insertion. caudal psduncle depth and the iength of the Table 9. Classiticrition matris of rock bass based on discriminant hnction analysis. Rov..s represent the (1 priori goups (ix. tish tiom the four populations that were sampled) and coIurnns represent the classification of tish predicted from the discriminant function

- - -. :1 Priori Sample Groups S ize - - tndian River

Rice Lake

Eeis Creek Stony Lake Total tndian River

Rice Lake Eels Crsek Stony Lake Total Rock Bass Females

0 lndian R. Rice L. 0 Eels Cr. A Stony L.

Figure 14. Distribution of rock bass female canonical vanate scores from the discriminant function analysis (DFA) with 50% ellipsoids about the centroid of each croup plotted on the first two canonical axes. The DFA was performcd on the residual C shape variation afier regressing each of the morphological variables on the modified centroid (body size). caudal peduncle. Axis 3 accounted for only 9.5"b of the total variation and was

significantly correiated to the pectoral fin Iength. the body width at the insertion of the pcctoral tin and the interorbital distance.

For the male rock bass, 85.3"; of individuals were correctly classitied to their corresponding cr priori groups (Table 9). Again. al1 four populations \vers separated by sigiiticrint Xlahalanobis distances. The largcst separation \vas betw-een Indian RilVrrand

Rics Lake (D'=! 5.7) n-hile the sepantion betwsen Eels Creek and Stony Lake was much ilIr 8.Canonical .-\sis ! separated the Stream and take populations (cspecially for Iiidiaii River and Rice Lake) and accounted for 61?0 of the total variation (Figure 15).

Sepxation bt.t\\.een the sub-watersheds was rslati\-sly minor cornparrd to the separation bet\i-ecn streanis and lakes. The sub-watersheds were separated on Canonical Asis 2 u.liic1.i reprcseiitsd 29"b of the total \;.ari;ition in the DFA.

Xxis I \\.as signi ticantly correlated to the placement of the pectoral fins and the bod~.depth of the fish. The second Axis wrts sigiticantly correlated to body depth. caudal psduncle depth and the horizontal gaps of the males, A11 of the \.anables relateci to .\sis 1 and 2 for the malc rock bass wre also found to ssparats the kmalr rock bass.

Thc tliird .\sis rcprêsentsd only 6.7% of the total variation and \\.as highly correlated to thItinstti of the lateral tins and the length of the caudal peduncle. Results tiom the uni\-ariats analysis and the turo multivariate analyses (PCA and DFA) are summarized for both spccies in Tables 10 and 1 1. Rock Bass Males

0 lndian R. 0 Rice L. 0 Eels Cr. - O 5 Stony L. Axis 1

Figure 15. Distribution of rock bass male canonicaI variate scores from the discriminant tùnction analysis (DF.4) with 5OoA eIlipsoids about the centroid of each group plotted on the first two canonical axes. The DFA was performed on the residual shape variation afisr regressing each of the morphologicril variables on the moditled centroid (body size). Table 10. Summary of the results for the thres methods in which pumpkinseed morphology neas tsstcd. Signiticrint results for the t\vo sexes are indicated by 9 and a. Direction of the .ANCOV.;\ rsfers to the sainple in tvhich the adjusted means nwe greatsr (either Stream or Iake). The .i\NCOV.4 results were Bonferroni corrected to p<0.0083. VariabIes tvere considered signiticant in the PCA for -O.SO>r>O.SO and were considered signiticant in the DFA for -0.30>r>O.30. Signiticant body shape di fferences existed anlong the three puinpkinsesd populations (Wilk's À test).

Vm-iables Related ro 1 H?pothesis 1 T>.peof Test 1 Prediction . Orisinril H>potheses Tested O Supportsd b> ASCOVA* r1NCOV.A PCA DF.4 .;\NCOVA? Direct ion

Bod: Deprh XI 1 -2 .-C Lak;S~rtl;tni - 't'es

Bo+ N idtti 3t Psctorril Fins hl I No I'cctonl Fin Length hl2 - .- Stream:-Lahe = . --- Yes Pectoral Fin N idth XI2 - No PcI\ ic Fin Length hl2 - No Pcl\ ic Firi \4'idth M3 No Anal Fin Depth hl2 - .-.. Lahr:>Strcram = . = No Dorsal Fin Dspth b12 (IR-UN) Lahs: Stream s. =- No .Anal Fiii Base IM2 No

Dorsal Fin Base b12 = (IR-LN) Stream -.Lake Yrs (partiall? )

Dcpth .\nt. Caudril Psduncie M 3 ?( I R-VE) Lale t3reri1n -. Yes (parial1) ) Dcpth Post. Caudal Peduncle hl3 = .Y( 1R-LN) Stream >LaLe No

Bad> N idth at Ant. C. Pedunclc b13 2 (IR-UB) Stream: Lake = Yss (panially) 1 f3-cpcl vic Lerigt h bl4 .-.- r. Lake-.Strsani 2 Y es i ,

* IR-CiS = Signiticant di fferences csistsci bmveen the lndian River and Rice Lake ünvegrtated populations onl~. IR-\!E = Signiticant differences esisted betu.ern the lndian River and Rics Lake Vegstated populations only ** S .A iridicatss variables chat were not included in original h'potheses. These variables uwe addsd becriuse the accounted for a large portion of the variation in either the PCA or the DFA. Table 1 1. Summary of the resuIts for the three methods in u-hich rock bass morpholo,_"v was tcsted. Signiticant results for the t\vo sexes are indicrited by ? and d. Direction of the ASC0V.A refus to the sample in which the adjusted means \$-ersgrsater (either Stream or Inke). The .=\SCOVA results Lvrre Bonferroni corrected to p<0.0083. Variables u-ere considered significant in the PCA for -0.50>r>0.50 and m-ere considered significant in the DF.4 for -0.30>r>O.30. Signiflcant body shape differences esisted amons the four rock bass populations ( \i'ilk's ;? test).

Variables Relatsd to Hypothes Type of Test Prediction Originr?l H>pothesrs Tssted Supponed by ANCOVA* ANCOVA ANCOVA? Direction Bad: Drpth MI Yes (partially) 1

Bo+ hVidth;lt Pectoral Fins hl 1 :( EC-SL) Pectonl Fin Lerigth hl2 Lake:- Stream Pcctonl Fin \{.idth MZ Pei\ ic Fin Length hl2

Pcl~ic Fin N'iddi 312 2. Y( 1 R-RL) Anal Fin Depth 342 =.?(IR-RL)

Dorsal Fin Depth bI2 ( I R-RL)

.-Inal Fin B3sc SI2 f.:(IR-RL) Dorsal Fin Base LI2 Y(IR-RL) -- 1 Dcptli .-Inn Caudal Peduncle hl3 Depth Post. Caudal Peduncle 1 hl3 1 ;(IR-RL) Lake's tream - - Bod? N'idtli nt .Ani. C. Pcduncls 1 b13 1 ;(IR-UN) Stream >Lake Yes (partially) 1 Prcpsl\ is tength 1 hl4 1 =*( 1 R-RL) Yes (partiall)) 1 Prcpecturril Lcngth 1 M-4 1 Y( I R-RL ) C. Pediiiiclc Lcngth (Dorsal) 1 N A'* 1 --\ C. Peduncle Length (Ventral) N. A Horizontal Gape N ,A

* IR-RL = Sigiticrint dit'fsrences esistsd bet\teeri the Indian Riiw and Rics Lake populations only EC-SL = SignitÏcant dift'srences esisted bet\i.een the Eels Creek and Stony Lake populations onl?. ** S .-\ indicntes \,xiables that wsrs not included in original h>,pothsses. These variables were added bscause the> accounted for a large portion of the variation in either the PCA or the DFA. Conrpar-isoilsto H1porlw.sÏ.s Matrices

Generally. tlsti morphology was not sibpitkantly correlated to the h.ypothesis matrices that I\-sre constructed (p>O.ZO) and the conslations wre weak (0.20

The ti~atrisof habitat \.ariables LX-ashigIi1y corretated to the hqpothesis n1atri.u (r=0.92) and the tish community data nwe moderately correlated to the hypothesis matrix

(r=0.16). .As stated above. none of the correl:ttions associated with the Mantel Tests ivere statisticall~.signifiant (p>0.10). This may be mislsading. since the Ioivest possible p-

\-ducs in tlic tests \x-err: p>O. 17 for the pumpkinseed and p>O. 10 for the rock bass due to tlis sniall niatrix sizes (3x3 matrices for the pumpkinseed data and 4x4 matrices for the rock bass data). DISCUSSIOS

GOwlt

The hypothesis LH 1. that stream tish would grow more slowly than Iake fish was iiot supponed by the lsngth at age data for the t\vo species. Tliere \vas no signiticant diffcrence in the grotvth rate of the lake and stream populations of pumpkinseed. although the lake tish !vers somewhat larger for exh length at age. Liken-ise, in the rock bass

Iengtli at rtge data. there \vas no sigmificant difference in the gro\.th rates of the indian

Ri\-erand Rice Lake populations. These results aLTee \vit11 thoss of Noltie ( 1988) and

C'um et al. ( 1993). Soltie ( 1988) predicted that stream rock bass \vould grou- more slo\ily than their Iake counterparts becausr the more variable and risorous environment

O-ouldbr limiting tu go\\-th. Hon,e\.er. Noltie found that stream rock bass did not grow mort. slo\~l>~than laks rock bass in soutlism Ontario. Despits tliis. studies re~~iewedby

CarIrinder ( 1977). Soltie ( 198s) and Levin and .McPhaiI ( 1993) all reported a reduction in the iiiasiniuni size and agr of stream tish. Soltie ( 1988) interpreted the thesr ubssn-atiotis ris an indication of the niore stresshl environment provided by streanis or duc to tlls carly maturation of the streani tïsh. Althougli it is not rnentioned by Noltie. the rcducsd masiniuni size ofstrearn fis11 in his study could also have been related to a dit'fcrsncr. in the reproductive effort of the stream tish as conipared to the lake tish.

Curry et al. ( 1993) aIso did not tind differsnces in the gro\\-th of young-ot'the-year brook trout benvsen stream and laks habitats. although thry did tind that the range in

Icngtli and age of the tish was greater in their stream sites. They attributed the range

\-ariations to differences in social beliaviour. as oung-of-the-year brook trout display size-dspendent tenitorid behaviour in streams. but not in lakes. This situation would not cxist tor adult csntrarchids.

Dèspite the increased eiiergetic costs of living in stream habitats (McLaughlin and

Grant 1994: hIcLaughlin and Noakes 1998). gron-th rates can be similar to those obsen-ed in lakes because prey in stream scosystzms may be of highsr quality or may be mors reaclily available ivhen thsy are driiling in the current. Less ensrgetically favourable prcy items such as crustaceans and terrestrial insects. n-hich take Ionger to digest as their esoskeletons contain mors chitin. may bc more abundant and consumed more ofien in lrikcs and slower moving watsr (McLaughlin and Grant 1993). Curry et al. ( 1993) also tbund that the enerq content of prey captured b). youny-of-the-year brook trout in strcaitis \\-as yreater than the prey of lake tisli. Thus. there is an energstic trads-off hm\-ren reniaining in quiet ivaters and consuming poorer quality prry. and esprnding more energ? to capture high quality prey in tlowing water. Depending on the costibenefit ratio of tliis trade-off (nhich \r-ould Vary in streams dependin, on the exact composition of the diet and the current idocity ivhere the tish is holding position). it is reasonable to iissunie tlirit snergy budget differences between tish from the tuo types of ecosystems could be quits \variable and difticult to predict.

Although gro\vtli is an important componsnt in detrmining the titness of tish

(Constantz 1979: Healey and Heard 1954: Mittelbach 1984: Danylchuk and Fox 1993:

Robinson et al. 1996). it is not always possible for tish to maximize their groivth rates because groivtii is intimately tied to the environnientai conditions in which the tish is found (Constantz 1979). III the current study. dit-erences in rock bass gowth were obssn-sd bet~veensub-~vatersheds: that is. the Indian River and Rice Lake populations rrrsu- filster thm the Eels Creek and Stony Lake populations (Figure 3). As well. growh L in the Eels Crtsek rock bass population n-as even less than in the Stony Lake population.

The latter rzsult is consistent u-ith data obtainsd for brown trout growth by Jonsson

( 1985 1. ti.liere streani tish \twe found to gro~vmore slotvly than Iake tish in the sanle u-atershsd. Jonsson ( 19S5) detennined that the dit'fsrence in the growth rate uras due to tlis more rigorous en\.ironrnent of the Stream. rather than genetic differences. Trout transplantcd from tlis ri\-sr to the lake and \.ic.ë i-ersa gre~vat an equivalent rate when they

\\-ers rsared in the san-ie habitat. This seeined to indicate that. at least in some cases. the cost of holdins position in the stream can be greater than the benefit of having higher qiiaIit>. or more abundant food items. .As noted pre\iousIy. it is likely ttiat the cost'benetït ratio uf the trade-off bet~veenfood quality and the increased energetic deniand of holding position iii the curent can bs quite \.ariable- Thus. depending on the ratio. the net rssult could be increased or decreased gro\vth in streams. or no net diff'rence betwsen stream and laks groii+th.

Thc sub-n.atsrsl.ied differences in growth inay funher be ssplained by difierences in trophic status. Drake et al. ( 1997) reported rhat bluegill grov-th \vas reduced in lakes that

Iiad lowr Ievels of nutrients. Reznick et al. (1996) suggssted that diftèrences in ci~~.ironnientalparanieters. such as trophic statu. may have a sirnilar affect on gram-th in

Trinidadian guppics. The waterslieds of Stony Lake and Eels Creek arc located prirnarily on the thin mils of the Canadian Shield. where the rnixed conifer-deciduous forests are largely intact. Conversely. Rice Lake and Indian River are located on much deeper soils and the surrounding land use is predominantly a,..ncultumi (Wils and Hitchin 1976;

Buttle 1992). The trophic ditTerences benvsen the sub-watersheds are also retlected in

u-ater chemisty parameters such as the concentrations of total phosphorus. chlorophyI1 a

and the Secchi depth for the t~volakss (ses .Methods for values). Trophic status mriy

intiusnce the quantity of food a\.ailable or the quality of aquatic habitat for supporting

tisli populations.

The diffsrencs behc-een Eels Creek and Stony Lake srowth could be t'unher

ex plained b!, trop hic differcnces. Strearns are largely dspendent on allochthonous

proccssss t'or the input of nutrients. ~vhereaslakes may be more enriched due to autoclithonous processes such as the recycling of nutrients froni witliin (Ryder and

Pcssndorfer 1989). Once nutrients enter the stream, they are rapidly tlushsd downstream and are renia\-ed froni tliéir point of origin (Vannote et al. 1980)- In Mes. tvhere the residsnce tinic ofu-ater is much lonp. nutrients coIlect in the various strata or in the sedinients of the lake. In nortli temperate lakes. these collected nutrieiits are recycled tn-ice a >.carduring periods ofsprin? and bll turnover within the lake iRyder and

Pcscndortkr 1989: Rossi and Premazzi 199 1 : Horne and Goldnian 1994). This recycling of iii sirrr nutrirnts genrraily plays a signiticant role in the nutrient budget of a lake and rcsults in rhc higher trophic status associated with lakes as compared to adjacent strearns.

As mentioned abovs. an increase in trophic status could Iead to an increase in the quality or quantity of food resources for tish. Nutrient recycling in Stony Lake would i~iakethis systein more productive than Eels Creek, which flows over the nutrient poor

Canadian Shield. This may also be consistent with the tindings tiom Rice Lake and Indian River. as it appears tliat growth in the lake may be sligiitly greater than in the

streritii for both of the species studied (atthough there were no signiticant ditTerences in

the Isngth at age data bstn-een these tm-O systems).

Since the t\vo sub-\\vatersheds are interconnected (primarily by the Otonabee

Ri\.t.r Trent Canal and, to a lesser extent, through Dummer Lake). the systeni can also be

\.ic~-sdin the contest of the River Continuum Concept (RCC) proposed by Vannotr et al-

(' 19 80). in the RCC. srrearns are viswed as a continuous. Ionginidinaily linked system in

u-hich biological and ecos-stem-levd processes in downstream areas are intimately

linkçd to those in upstreani areas. Tlis fouiidations of the RCC are based on trophic

rcsporiscs in the ecosystsm i\-ith a continuous gradation from nutrient poor upstreani sites

that rire dependent on allochthonous sneï_(rq.inputs to the more enriclied don-nstream sites

u-ilers autoclithonous cnergy inputs are more important (Vannote et al. 1980: Minshall et al. 1983). The RCC seems to ot'tèr a reasonable esplanation th- the obsen-ed grouzh diftkrenccs bet~i-eenthe uppsr ( Eels Creek and Stony Lake) and lowr ( Lndian River and

Ricc Lake) sub-watsrsheds. altliough this hypothesis is complicated becauss the edge of the Canadian Shisld bisects the system.

According to Schlosser ( 199 1 ). the gro~vthand sun.i\.al of stream tlshes is strongly irit'luènced by the snvironrnsntal heterogeneity and temporal environmental variabiIity of tlic streani reach. These factors tit nicely into the tiamework of the RCC. u-hich predicts that t.n\.ironmental heterogenrity will increase in a do~vnstreamdirection and temporal en~.ironnicntal\ariability will increase in an upstream direction. The increased cil\-ironnlsntal heterogeneity and increased stability found in do~vnstreamareas (Indian Ril-er and Rice Lake) reduces the magnitude of ecological and environmental stressors.

and fai-ours gron-th in the early litè stages of fishes.

Although the RCC seems to o&r a reasonable explanation in this case. the va1idity

of cornparing the resuIts of the current study to the RCC is limited because the original

inodel. as described by Vannots et al. ( 1980). does not includs any reference to

intt.rconnectsd lakes ivithin a lassr \vaterslied. Subsequent modifications to the RCC

( \irard and Stanford 1983: Cummins et 31. 1983: Minshall et al. 1985) propose that lakes

and inipoundments act as a reset rnechanism on stream systems. and that biological and

t.cos>,stcm-le\-elprocesses are either shitled in an upstream or a downstream direction.

L'titortuiiatsly. this ambiguity regarding the response of the system dotvnstream of a laks docs riot Iead to any specitic predictions or testable hypotlisses. Furthennore. Ryder and

Scott ( 1988) note that although a single lake may act as a reset mechanism. a series of

lakcs could largsty slirninats the continuum pattern.

Contrary to the results of the current research. 3 number of other studies ha\-e failed to support the prtldictions of the RCC and its rnoditications. including data tiom Iake-tkd strciiriis ( bIalmq\.ist and Bronmark 19S5 ). a nuniber of Seiv Zealand streams (Ryder and

Scott 1 %SI. large ri\w systsms (Sedell et al. 1989) and rivers that are frequently associatcd ivith their tloodplain (Junk et al. 1989: Quiros and Cuch 1989). Thess problcms have led to tlic drvelopmrnt ofa nuniber of other pandigms for the predicrion of riverine biology and ecology. such as the Senal Discontinuity Hypothesis ( Ward and

Stantord 1983). the Riparian Control Hypothesis (Cummins et al. 1983. 1984). the Flood

Pulse Concept (Junk et al. 1989). the Downstream link or D-link Theory (Osborne and \Vils>- 1992) and the Riverine Productivity Mode! (Thorp 1994). Each of these paradi&ms

ot'krs a slightly ditlèrent explanation regarding the effsct of spatiaI variables on

biologicül and scological processes in a manner similar to that of Schlosser ( 199 1 ).

Dcspite criticisms of the RCC. none ofsubsequcnt hypotheses listed above seern to offer

a bstter ssplanation of the growth trends obsenled behveen the sub-watersheds.

Other estraneous \.ariabIes such as latitude. climate and elevation wsrs not

ccmsidered iniportant factors in deterrnining rock bass grondi. Although Noltie ( 1988)

reportsd rhnt rock bnss growth \vas relatrd to latitude. it is unlikely that this is a factor in

the current study bscause the most northerly sample site on Eels Crsek was only about

O"30' north of the Rice Lake sites. It is also unlikely that crither climate or eIs\.ation

\i-ould ha\*ea signiticant sffect on groib-th in the WO sub-~vatersheds.The difference in

ititnn Jul>-teinpsraturs \\.as less than 1°C bstwécn the Eels Creek and Rice Lake sites

(Table ZB). -4s n-ell. the devation of Stony Lake is only 50 m greater than tliat of Rice

Lake. and tlic tnasiniurn de\-ation dift'srence between sites used in this smdy \vas

approsimately 70 m.

Dcspite tlie relati\.ely homogeneous climate across the study area, differeiicss in

11-atcrtcmpcraturs cannot be rulcd out, sincs the only data available ivere those rneasured

at tlie tiine of sampling. AIthough \trater temperatures ivere quite similar at the time of snrnpling. tlie data rnay not bs indicative of the conditions that exist throughout the year.

For esample. the strsam banks of Eels Creek are generally \vell vegetated, which may act to moderate summer \vater temperatures. As urell, there could be diffcrences in the cround ivater contributions among the waterbodies. Differences in water temperature are b considercd to be an important factor in deteminin? the growth rate of tlsh (Carlander

1977: Xoltie 198s: Fos and Keast 1990: Putman et al. 1995).

L ifè Histoty Purameters

The hypothesis LW. that Stream tish ivould mature at a >.ounger age and a smaller

sizc thari lake tish \vas partially supported by the data fiom this study. Pumpkinseed

fimiales in Indian Ri\w reproduced at a younger ase than the fernales in Rice Lake, but

t!ic're \\,as no dit'fersnce in the size at maturity. Fernale lndian River rock bass also

niaturd at a J-uungerage. but again tliere [va.; no difterence in the proportion of mature

knialès in the pivotai len~hciass. Data froni the Esls Creek rock bass did not support

t!iis h>pothesis as both male and tèrnale rock bass from Eels Creek \vere older and larger

tlim tliose of the other three populations at the time of tlrst reproduction.

-4lthough ags at maturity is ofien in\.srsèly relatsd to the growth rate of fish.

prirticuirirly the ju\-mils to adult gro\vth ratio (Stearns and Koellri 1986: Hutchings 1993:

Fos 1994: Bertsch>~and Fox 1999). tlis data tiom the current study do not sntirsly support

tliis idm. The slo\v grov-ing Ecls Creek rock bass did indeed mature later than the tàster groi\+ingIndian River or Rice Lake populations. This agress nith the empirical data of

Hutchings ( 1993). Fox (1991) and Drake et al. (1997) as we11 as the mode1 of Stearns and

Eioella ( 1986) \\.hich predicts that organisms that have retarded gron-th due to tlisir cn\.ironnient \vil1 delay the onsst of tnaturity. But. if juvenile gron-th was the only factor to be corisidsred. then the slo~vgrowin_o Stony Lake population w-ould aiso be expected to mature later than the faster gro~vingIndian River and Rice Lake populations. AIso. it n.ouid be sspected that Indian River tish (both pumpkinseed and rock bass) would grow

more quickly in their juvenile stage than Rice Lake fish based on their earlier age at

~naturity. E~videncs\vas not found for either of these results.

According to Fos ( 1994). the age at maturity and reproductive allocation in

puriipkinseed may be less attècted by grou-th than in some other species. sucli as the

brook trout studied by Hutchinp ( 1993). because reproduction is Iess energetically costly

ias msasured by GSI) tbr pumpkinseed. Rot't'( 1992) suggests that the mortality rate of

tisli pior to reaching tnaturity rnay be the most important factor in shaping life history

strategics. Based on ttiis principle. Fox ( 1 991) suggests it is possible that age-specitic

nionality niay be more important than gro\vth in determining pumpkinseed life history

charxteristics (although. this may be more appropriate for explaining di fferei~cesin

rcproducti\.e in\.estrnsnt rather than differences in age at rnaturity - ses discussion in

Bsrtsch>.and Fos 1999). it tbllows tliat reproduction is also less snergetically costly for

rock bass than for brook trout because the GSI values obtained for rock bass in the current study n-ere comparable to those reported by Fox ( 1994) for pumpkinseed.

In fluctuating snvironments u-here adult mortality is more variabk thm juven ile tnonality. such is the case in streams (Baltz and -Moyle 1982: Ryder and Pesendorfer

1989). it is espected that organisrns would reproducc at a younger age and would invest

11iore hea\.ily in each reproducti~reevent (Roff 1981: Hutchings 1993). Empirical support

113s been pro~eidedtiom studies of a number of species located across habitats nith dit'krcnt de~recsof \.ariability. including Gila toprninnoivs (Constantz 1979). tule perch (Baltz and Moyle 1982). brook trout (Hutchings 1993). pumpkinseed (Fox and Keast

199 1 ) and rock bass (Noltie and Keenleysids 1987: Noltie 1988).

Rock bass in the Middle Thames Rivcr (Ontario) began maturing at age 2 and al1

tisli \i-ere found to be mature by age 4 (Noltie and Keenleyside 1987: Noltie 1988). These

authors compared the stream age at maturity values to otl-ier values reported in the

literature for nearby lake populations of rock bass. Ln one such population. ~vhich\\-as

studied by Gross and 'c;ow-ell ( 1980). the males did not mature until age 7. Thus. ir was

concludeci that stream rock bass mature earlier than their lake counterpans. Fox and

tieast ( 199 1 ) tound that pumpkinsesd inliabiting small ponds in central Ontario had hi~h

cxpected monality rates due to periodic h>-poxic conditions in the winter months. These

fis11 rnatured at an earlier age and increased their reproductive investment compared to

adjacent laks populations. presuniabIy so they could reproduce at least once befors a

se\.t.rc. n-interkill e\.eiit.

The early maturation of the Indian River fernales (both species) in the current study

semis to corroborate the obssn-ations of otlier authors (Baltz and Moyle 1982: Noltie and

Kccnlej-side 1987: Xoltie 1988). Although the aforernentioned authors attributed the

carly nirituratio~iof stream tish to differential adult rnortality in the more variable stream

cn\.ironment. this mechanism cannot be i-erified in the current study because monality

data wrc not collected. Based on the age structure of the four populations studied. there

is rio a-idencs to indicate that dift'srential adult monality is occumng. but this may due to tlic smal l sarnple sizes collectsd for some age classes. As well. unlike the data reported by Soltie and KeenIeyside ( 1987). the pattern1 of earIy maturation does not seem to be

applicable to the males of the currsnt study. nor to the Eels Creek rock bass population.

GSI \dues for fernale rock bass Ivere not found in the literature. but the GSI values

obtrtinsd in the currsnt study seem reasonable compared to other species of centrarchids.

Rock bass GSI ranged from an average of 2.9?'0 in Eels Creek to 4.3% in lndian River.

Rosenblum et al. ( 1994) reported tliat largemouth bass kmales in a Florida hatchery had a

GSI \-due of 4.5 7=O.36?,0 for fish fed a diet of t'orage fish. Fos ( 1991) reportsd that mean

GSI in pumpkinseed ranged from 3 to 991; for the 27 populations that he studied. In a

subset of these populations. the GSI of lake pumpkinseed \vas reported to be

rqqxosimately 5°*~.nhereas pumpkinseed inhabiting two small ponds with replar

11-interkillwents had an a\*erageGSI of approsimatsly 10°.O ( Fos and Keast 199 1 ). It

sliould be noted that the Rice Lake pumpkinseed of the current study Lvere comparable to

tliosc col lectsd by Fox and Keast ( 199 1 ) with an merase GSI \-alue of 4.2%. This value

coiilci riot be cornparsd to the Indian Ri\.er population because this sarnpls \vas colIected

in lats sunlmer. Pumpkinseed collscted at this time would have begczn reabsorbing their

unspatvned sgs(Crivelli and Mestre 1988; Danylchuk and Fos 1994).

The tlnal lit's history hypothesis. hqpothesis LH3. which stated that Stream fish

~.ouldha\-s a higlisr reproducti\.e investment (GSI) than lake fish. was not supported. As u.ith the grow-th results. tliere was a possible sub-\vatershed trend evident with the lndian

Ri\.er Rice Lake populations iia~vinga greater GSI than the EeIs CreeidStony Lake populations (Figure 9). although these differences were not statistically signi ficant. The

GSI of tlic Eels Crcek rock bass was the lo~vestof the four populations sampled. and Eels Creck tish matured significantly later than the other populations. This is contrary to the tindinss of Baltz and Moyle (1 982). These authors reported that Stream kmales maturl-d at a younger age and produced a larger brood than lake fist~.The rssults of Baltz and hfoyle are also cupported by the theon/ of SchatTer ( 1974) and Hutchings ( 1993) in which it is predicted that reproductive in~~estmentwill increase as the ratio of adult mortality to j u\-etiilc rnortality increases.

One potential explanntion for the Ion. reproductive in~~estmentand late maturit). esliibited by the Eels Creek tèmales is that juvenile tnortality is high reiati\-e to adult riio~qalit>~in this population (i-e.the ratio of cidult to juLvenileniortality is lower in this streain: not higher as \vas prsdicted by the author). Reduced sunival in jul-enils fish is demographically similar in consequence to a reduction in the parents' reproductive i t-ivestment (in tenns of total number of offspring produced). and tktus sliould result in a dccrèrzst. in the reproducti\.e in\.estment of the population (Schafter 1974). Constantz

( 1979) tbund that Gila topminnon- in an Arizona wash experisnced a breeding season of unpredictablè lerigtli in tvhich the chance of reproductive success was extremely variabte.

Due to the Io\{. chance of producing offipring that ~vouldsurvive to maturity in any givsn

>.car. it u-as found thrit the pensration tims in the population was increased and adults rcduced thrsir reproducti\-e sftbrt to increase their chance of successfully o~mnintering and reproducing in thc folIo\\.ing ysar. In this case. reducing the reproducti\.e investment pro~idssa tltness advantase because the total litètime reproductive output is increased by in\.csting energ-towards sun-iving to breed in subsequent ysars. Since data on mortality rates were not collected in the curent study. it cannot be

determined if the Eels Creek population actuaIIy has a high juvenile mortality rate relative

to that of adults. .Althoush this is a plausible expianation. a possible reason tbr increased ji~~.cnilr:mortality could not bz identitled hr Eels Creek. Hsnce. it may be more

appropriate to search for potential causes that u-ould explain the early maturity of the

othcr three populations. The following tivo explanations relate to the hypothesis that

higher ndult rnortality n-ill result in earlier rnanirity and higlier reproductive investment

(Schafft'r 1974: Roff 1984: Hutchings 1993).

High tishing pressure selectively rèmoves older and larger fis11 from the population

riieaniiig that the adult mortality rate is increased whik the juvenile mortality rate remains

unchringcd (Drake et al. 1997). Both Rice Lake and Stoiiy Lake are popular fishing

locatio~is\r.ith both local and \.isiting recreationd anglsrs, as many sportslnen travel tTom

Seu- \r'c>rkStats to the Kawanlia Lakss (Lewies 1976: Bell 1982: OMNR 199 1 ). lndian

Ri\-cralso seerns to receive relatively high angling pressure. as a number of anglers wre er~counteredduring sampling and discarded fishing gear \vas obsened on the Stream banks. Conversely. most of the lowt-r reaches of Eels Cresk (the areas that lvere sampled in this study) arc part of the Peterborough Crown Ganis Resewe. where fishing and the iiuinber of con\.eiiient access points are restricted. The espected increase in the adult mortality rate in Indian River. Rice Lake and Stony Lake from fshing would seiect for ertrly niaturation and an increase in reproductik-e in\-estment (Baltz and Moyle 1982:

Hutchiiigs 1993: Drake et al. 1997). IVhils this explanation serms to tït the trend observed. there is a major problem. In

a population that is bsing heavily exploited by angling, it is expected that the ju\.enile

crou~hrate n-ould bs greater ( Regier and Loftus 1972: Drake et al. 1997). tish wouId C

niature rit rt smallrr six. and postniaturational grotvth would be reduced (Drake et al.

1997). AIthough gron-th \vas greater pior to marurity (at age 3)and mature tïsh Lvere in

hct srnalkr in tlis thrre more heavily exploited populations. tliere is no evidence (Figure

4) that suggests the change in grou-th rate toilowing maturiry in the relativety unexploited

Eck Creek population tvas ditTerent than that of the other three populations.

Lik history traits can also be affected by the ~psof predator cornmunity to ~vhich

fis11 are sub,ected (Crowl and Co~~ich1990: Rsznick et al. 1996; Abrams and Rowe 1996:

Pratt 199s). [t is possible that the nature of the prsdation pressure in Eels Creek is

different than that experienced by the other three populations. bluskellunge are abundant

in the tlsh communitiss of Indian River. Rice Lake and Stony Lake. whereas this species

rtppears to bs absent in Eels Creek. based on the data coIlected by the ORlNR and the

tisIJ obssn.ations of the curent study. The only pisci\-ore that is common in Eels Creek

is the sniallmouth bass (OLMSR.unpubiished data: persona1 obsen-ation ). The size of potciitial prey items for this species is more limited than for n~uskellunge.due to the sinri1lc.r Cape size of the sma!linouth bass. Hoyle and Keast ( 1988) demonstrated thrit a rclatsd species of esocid. the grass pickerel (Esox cmei-icarltls ~~er-t~~ici~lcrti~s).wras able to

çonsunie considerably larger prey items than largemouth bass (same gsnus as sniallmouth bass. .Ui~'t-opt~~t-i~s)in laboratory experiments. The gape différence betwsen muskellunge and sinallmouth bass would be much greater than that of psspickerel and largemouth bass. Thus. the life histories of the Indian River. Rice Lake and Stony Lake populations riiriy be intluenced by the presence ofa large piscivore that could prey on both juvenile and nduit rock bass. Rock bass in Eels Creek ~vouldesperience a much shortsr window- of 1-uliierability to predation. as the more severely gape limited smallmouth bass could onIl. ked on the sinaller ju\.snile rock bass (Scott and Crossrnan 1973: Probst et al.

1984).

The non-selective predation hypothesis (-4bramsand Rowe 1996) predicts that in situations \vlisre predators do not prefsrentially select prey based on size or age (i.e. inortality rates due to predation arc siriiilar for a11 age and'or size classes of thci prey spscics) organisms hmthe prey population should mature at an eariisr age to increase tlieir cliance of propagating before being consumed. Although this hypotliesis has been supporteci by srnpirïcrtl data on Trinidadean guppies (Reznick et al. 1996). Pratt ( 1998) hund that it \\-as not able to esplain lit2 history differences among central Ontario pumpkinssed populations. Thus. the non-selective predation Iiypothssis may not bs appropriate tor explaining liîè history differences in othsr centnrchids.

Insterid. Pratt ( 199s)found that the age-specitic predation hypothesis (Law 1979: hlichod 1979: Roff 1992) pro\.ided a mors appropriate explanation for his results. This li>pothesis suggests tliat tish \\dl increase the allocation ofak-ailable energy to growth at tlic cspensc of reproduction ivhen juvenile niortality due to predation is liigh compared to dult rnortality. In the presence of gape limited predators. the prey species matures later and has a leu-et GSI value. \vhicli allows it to gron- larger and escape the early life stage in ~vliichpredation vulnerability is the greatest. This may resemble the situation of the Eels Cresk rock bas. as it is likely that they are only vuinerable to prsdation by stnallniouth bass when tlqare small. It should bs notsd that although Eels Creek rock bass gron-th is slow. the îish are not investing energ in reproduction at young ages.

Instecid. it is liksly that the fish are shunting sner-g fiom reproduction to somatic growtli to escape thc \\.indon. of predation vulnzrability. Coupled \vitfi the slow gro~vthrate of tlis Eels Creek population (~vhichcan bs attributed to en\.-ironmentalditfirences, as discussed pre\.iousIy), age-specit'ic predation could cause the fish to delay reproduction for an additionaf year \vhile they continue to grow.

Con\-ersely. \\.lien predation on al1 age classes is squal. or m-hen prsdation pressure on oIder tish increases. the prey species reproducss earlier and in\.ssts niore heavily in cadi reproductive event. Musksllunge in Indian River. Rice Lake and Stony Lake may consunle al1 ags classes of rock bass in an iinselective manner: which. in accordance ii-ith the a~e-specitic hqpothesis. would result in an earIier ags at rnaturity and increassd reproducti\.e in\-sstment. As wsII. the high potential predation rates at these tliree sites inay ha\-t. indirect effects on the prey species. By reducing the density of the prey species

(rock bas in this case). food wouId becomc more abundant for the remaining rock bass duc to reducsd intra-specitic conlperition (Abrams and Rowe 1996). Increasing the food rcsourcc ri\ailable to the remaiiiing rock bass couid cause the intlated growth rates obsen-sd in these three populations (especiaIly true of the Indian River and Rice Lake populations). which in tum results in a younger age at rnaturity and greater GSI (Steams and Koella 1986: Hutchings 1993: Fos 1994). Despite the apparent congnience between the age-specitlc predation hypothesis and the rcsults of the current study. this explanation is based on speculation. It has been assunied thrit thers are differences in the predation patterns that occur in Eels Creek comprired to the other three sites (Le. increased predation on ju\.eniles vs. similar predation rates on al1 life stages) which result because predators are gape lirnited.

.\ltliougli muskellunge arc capable of ingesting larger prey items than smalIrnouth bass. iiiust predaturs tliat are assumrd to be gapr lirnited consistently consume prey that are snialler thnn ivhrit is expected accordine to optimal foraging theory (Hoyle and Keast

19S7: Pratt 1998). While it is possible for rnuskellunge to consume al1 but the largest rock bass. the numbsr of mature rock bass actually consumed by ~nuskellungecould be quite srnall (Scott and Crossinan 1973). .As well. thsre are unsubstantiated reports that riiuskellunge ha\-s been caugiit by angiers in Eels Creek at locations that are sevenl kiloiiietrrs Lrpstream from the sampling sites used in the current study. Although these reports h;l\.c not been documented or officially \.erit'ied by OMNR records. it is likely that inuslie1lulige do inhabit soine reaches of Eels Creek. but they may be con tined to certain localiztld areas. Thus. it is unkno~vnn-hether or not the Eels Creek rock bass collected in tliis study hn-ecorne in contact ivith these Iaqe piscivores at soms point in their life.

But. it is probably safc to assume that muskeIIunge are. at very least, less common in Eels

C'reek tlian in any of the other thres systems studied.

II is tinlikely tliat the sub-ivatershsd differences observed in this smdy couid have becn an anifact of the order in wliich samples were collected. Danylchuk and Fox ( 1993) provided evidence that lik liistory parameters. sspecially GSI. change as the breeding season progresses. They found that GSi in pumpkinseed generally reached a peak in late

XIay and early Juns and then decreased throughout June- July and Augwst. This ivas not a

problem in the current study becausr the population with the Ionest reproductive

allocritioi.i (Eels Creek) was sampled imniediately after the population that had the highest

GSI (Indian Ri\-er). If timing had been a factor. it \vould be expected that Stony Lake

(siiniplcJ last - 1 S Juns to 26 June) u-ould Iia\.e had the lowest GSI values and Rice Lake

(sarnpled tirst) u-ould have had the highest GSI 1-aluss: but. this \vas not the case. .As

\\.cil. no partially spsnt gonads wers obsened in fernales of an- of the four populations.

Finally. it should be noted that the lack of life history differences aniong the stream

and iake popuIations exarnined is not necessarily evidence that these ditferences do not

csist. Annual \par-iation in life history traits. dus to the environmental conditions of the

prt'\iws year. can be quite high (Fos and Keast 199 1. Fos 1994). Life history

diftèrenctx may have been apparent if streani and lake fish were cvilectsd over multiple

>.cars or across more uaersheds. Thus. it seetns that life history characteristics in strearn

2nd lakc tlsli rcquire tùrther snidy to eitlier contirm or retùts the current results.

.~~O~P/JU/O~J*

~Iorpholo~icalstudies have been used to answer a wide \-aricty of biological and

ecological questions relating to the adaptive nature of dit'ferent organisms. Pretious

studies by systrmatists have used variations in morphology to differentiate closely relatrd

species (cg. Humphries 1984: Keivany et al. 1997). and to sepante hybnds from pure parental stocks (e.g. Nirft' and Smith 1978). Numerous ecoIogical investigations have uscd inorpholo~yto describe adaptations of single species to their environment via riatural sclecrion. Some of thèse studies have investigated morphological dit'ferences tliat arise duc to spatiriL geographic diftèrences (Gross 1979: Baltz and 1Moyle 198 1 : Douglas and Endler 1982: Corti et al. 1988). litè histo- ditt'erences (Jonsson et al. 1988: Ehlinger et al. 1997). or habitat differences within a single lake (La_vzerand Clady 1987: Ehlinger and \\'ilson 1 9SY: Robinson et al. 1993: Robinson and Wilson 1996) or river system

(btcLriughiin and Grant 1994: McLaughlin et al. 1994).

In ternis of the gènerd morphology of the species. Webb ( 1983) ~vouldclassit'y p~iri~pkinswd3s "median and paired tïn propulsi\.s" s\vimtnsrs. This body form is c1iarrictsrizt.d by deep. short- latrirally compressed bodies with mid-Iaterally inssned pcctorai and pel\-ic tins. Thess riiorpliological tèatures make tliese tlsh well suited for foraging ar Ion- spesds and niaking tine manoeuvres. Overall. rock bass ha\-e a more tùsiform body shape. and n-ould fall somen+herebet~vsen Webb's classes and could be considsrcd a generalist in ternis of their locornotor propulsive mechanisms. While the rock bass retains some of the more gibbose fentures of the pumpkinseed. it is more streanilincd and sorns\vhat resembles the genenlist body hm of Jficroyrer~~s-Fish of tliis gcnus are more adapted to anibush predation techniques. but are also able to snfim at sustaiiied spseds and cruiss for lûtsr distances (Webb 1984).

General body shaps difierences between Stream and laks tïsh Lvere evident based on tlis miilti\-ariate morphometric analysis. The PCA produced very rough groupings that

Jispl3>.ed considerable overlap arnong the study populations (Figures 10 and 1 1 ).

Difirenccs in body tom were more clearly rvident in the DFA. although there was still son~soverlap among the populations on the Canonical Ases (Figures 12 through 15).

The DFA u-as able to separate the groups more clearly than the PCA because the

discriminant hnction is calculated using the variables that will provide the maximum

sr.parrition among the o priori groups (bfanly 1986). For the DFA. stream and lake tish

\i-cre generrilly separated on the tirst Canonical A'tis. n.hich accounted for a Feater

percentrigs of the \variation thari the subsequent rixes. In the case of the rock bass fernales.

strcarn alid lake ttsh ~i-ereseparated on the second Canonical .%sis. Ho\vever, the Eels

Creek ancl Stony Lake rock bass kmales \vert: clustered quitc tightly. an obsenration that

is also rstlected by the fen- significant dit2èrcnces bet~veenthe populations in the

uni\-ariate test of n~orphologicaldiff'srences.

The degrse of o\.erlap on the Canonical .Ases and the few tish at the estreme ends of the asss suggests tliat fis11 do not fa11 into two discrete categories (i-e.a discrete stream rnorpli and a discrets lake morph). Robinson and Wilson ( 1996) tound that purnpkinseed

foniwd a unimodal distribution of pelagic and littoral niorphs. The general body shape of iiiost indit.idua1 tish was located at an inteimediats position on this distribution sonie\vhers betn-een tlie sxtreme pelagic and the estreme littoral forrns. The intermediate foniis \\.t'rr' found to haiesa rcduccd condition tàctor and slower gro~vthcompared to the rnorc esrreme body toms (Robinson et al. 1996). These fish had reduced energy resenres for use during periods of lo~vresourcs abundance. when compared to the more sxtreme body toms. Fish w-ith estreme body toms displayed better ovsrall sun:ivorsliip. gro~vth. rcproducti\.e success and. thersfore. iiicreased relative fitness. Thus. it was concluded that habitat spccialists had an advantage over the habitat genenlists. Thé intemediate itiorph \vas called a --pumpkinseed-of-alI-tndes but master of none" by Robinson et al.

( 1996).

It is possible that the situation in the curent study could be sirnilar. in that some

streaiii tish are retaining some of the characteristics common to lake tlsh u-hile some lake

tish haies charactsristics similar to those obsened in the stream tish. Again. these

interniediate fonns may have reduced titness relatit-e to the extreme Stream and Iake

fonns. rtltliough this hypothesis was not testsd in the current study. Despite the overhp

on the Crinonical Ases. it is likely that streain and lake tish are more reproductively

isolatcd thm the littoral and pelrigic tlsh studied by Robinson et aI. ( 1993. 1996) and

Robinson and Wilson ( 1996). The plots of the Canonical Scores (Figures 12 to 15)

ii~ciicatcthat the ssparation among the stream and lake fish in multi\.ariate space is greater

tfian that of' the aforementioned littoral and pslagic tish.

Dsspits the o~:erIap betu-sen stream and Iake morphs. geater than 80°h of

indi\-idual tish tiom sach species and ses ivere correctly classifisd back to their proper cl

priori Croup by the DFA. The accuracy of the ~Iassitlcationranged from a lo\v of 82.290

tbr punipkinseed males to a higli of 90.20/0for rock bass tèrnales (Tables S and 9).

Siinilar ranges of accuracy have been obtained in other studies that ha\-e used this

statisticril technique to assess morpliology. The DFA cdculated by Baltz and Moyle

( 198 1 ) \vas able to correctly predict a fish's native uatershsd based on its morphology

\i.itli a succsss rate of 9690. In separate studies of pumpkinseed trophic dimorphism in

Nc~k.t'ork Stare lakes. tish wre correctly assigned to their trophic group 8 1 "/o. 89%

(Robinson et al. 1993) and 8.19'0 of the timê (Robinson et al. 1996). Although the DFA was able to correctly classit'y pumpkinsssd to either the

\-cgetated or uni~egetatedRics Lake habitat type u-ith a high degree of accuncy. there u-erc feu- signitlcant diffsrsnces found in the indiividual morphological traits behveen the tua habitat types. The differences that urere found lvere generally inconsistent with rèsults found in the litenture. The depth of the anal tln and the width of the pelvic tins

\i.crc greatcr in tish ti-on1 uni-egtttatcd habitats as compared to tish tiom \-egetatsd habitats. This obsen-ation appears contrac. to the fndings of Ehlingsr and Wilson ( 1988) and Robinson et al. ( 1993). These authors found that fish in unvegetated pelagic habitats

Iiad smaller fins than thoss captured from more heavily vegetated littoral habitats. The

Iargrr fin sizes hund in littoral tish are usehi for the tins manoeuvres that are necessary for toraging in hi@ily structured habitats (Webb 1984). Hoivever. it should be noted that the open \\-atsr sites in the currsnt study do riot nieet the 'pelagic criteria' of Robinson et al. ( 1993). but the results are still inconsistent \\.ith the hypothesis of Webb ( 1984). [t is rilso intsrssting to note tliat Robinson et 31. ( 1993) did not find sesual diniorpliisn~in puiiipkinswd, \\-hich is contrac. to the bluegill results of Eiilingsr ( 199 1 ) and the current stiid)..

H~pothssisbI 1. that strearn tish \\.ould be more fùsiform than lake tlsh. \vas csncralijp supported by this study. In both species. the depth of the body was significantly L lcss in the streani fisli. but there \{.as gsnerally no difference in the body width (i-e. from the inscnion of the lefi pectoral tin to the insertion of the right pectoraI fin) behveen srrcain and Iaks tish. The reduction in body depth agrees with the tlndings of other studies of tish niorphology. Fis11 inhabiting ecosystems with more strenuous il>-drodynaniicconditions. such as streams, tend to develop a more tùsiforrn body shape to

reduce the amount of drag induced by the current (Webb 1984: McLaughlin and Grant

1994: Ryder and Pesendorî'sr 1989). Cornparativély. tish w-ith a more gibbosè body shape

sut'tsr niuch Iiigher drag penalties when swimming. Bronmark and Miner ( 1992) found

that crucian carp (C~rr-crssircscur-msim-) lvith deeper bodies had a 3290 increase in drag at

a s\viiiinii~i~spesd of 10 cniis in small ponds. The added drag penalty u.ould decrease the

su.irnniing pertorrnancs of the fish. ivhicli coufd in tum affect its foraging efficiency.

\Vith the increassd burden of su-imming in the Stream dus to the hydrodynarnic conditions. it is expected that sslection pressures ivould favour the development of

iiischanisnis tliat alla\\. sustained su.iniming actiL0ityto be n~aintained. Fish selected for sustriincd su.irnmins ability rire gensrally more tùsifonn (Le. ha\.e a reduced body depth). rire round in cross-section and have a pater proportion of red muscle tissue: wl~ereas iiiorc sedentan. lakc tish are gsnerally more gibbose. more laterally conipressed (or oblong in cross-section) and ha\-e a larser percentage of ~vhitemuscle tissue (Ryder and

Pessndorfer 1989).

Lab and tield studies sho~.tliat tish use steady snhming in tlowing ivater for holding position in the \vater column and for orientating themselves in the current (Webb

i 99 1 : bIcLaughlin and Grant 1994). This t)pe of sivimniing mechanism is necessary. as strearii dndlers appsar to svim at a tàster rate (based on the number of cycles per unit tirnc o 1' the c;ludal peduncIe), -et thcy inove less relati~meto the bottom of the channel

\\-lien in hster moving u-ater (McLaughlin and Grant 1994). Steady swimming haç been fourid to be two to four tinies less eneqstically costly than unsteady swimming (Webb 1 99 1 ). so this type of locomotion should be favoured. Despite the energetic disad\-antages. h.IcLaughlin and Noakes ( 1998) found that some degres of unstsady su-imniing (m-liichis used in acceleration. deceleration and turning in still water habitats

(Jubling 1995)) does occur in tield situations. McLau~hlinand Noakes ( 1998) explained ththis is necessa? because the organisni is required to adjust to the ebbs and surges in curreiit \-cIocity that occur in narural streanis. Unstzady swimrning is ais0 used u-hen the tkli changes positions in the \vater column or changes location relative to the strerim bottoni. especiall>-N-lien acceleration in an upstream direction is necessas.

The use ofcurrent refuges in the stream (cg. boulders or submerged log) niay alIo\\. the tish to reduce its need for unsteady s~virnmingand allow it to maintain its position \\aith steady swimniing at a sloiver rate. The use of even small-scale current refuges reductid si\-iinming costs in brook trout by 10% on average. ahile fonging ability u-as riot aft'sctsd (McLaughlin and Noakes 1998). Thus. the use of such habitat structure pro\-idsd indi\-iduals nith an energetic ad\.antage. Pumpkinseed and rock bass inhabiting streanis likcly use such refuges and backwater areas to reduce suimming costs. it is quite likel>-tliat strsnm centnrcliids only utilize the faster tlo~vingwater when they are feeding on in\.ertebratss cauglit in the current. and this feeding would occur froin sheltered locations whenever possible.

Another esample of the nred for steady swimrning ability is found when fisii of the samc species occupy both pclagic and littoral habitats (Layzer and Clady 1987: Ehlinger

199 1 : Robinson et al. 1993: Ehlinger et al. 1997). In a study of sesual dimorphism in bluegill. Ehtinger ( 199 1 ) demonstratsd that the more fusiform fernales were better suited to cruising and fonging in open Lvarer habitats. ~vhilernaks Lvsre more gibbose and

reniaincd in more heavily vegetated littoral habitats. Pumpkinseed also display trophic

Jirnorphism in some lakes where conspoci tic bluegill competitors are absent (Robinson et

al. 1993). The t~von~orphs differed in terms of their feeding apparatus and in overail

body shript.. Pumpkinseed of both sexes inhabiting pelagic shoal habitats were more

tùsitorni (a body rnorph that resembles that of bluegill) tlian their littoral counterparts. In

tliis case. the pelagic pun~pkiiiseedwcre thought to inhsbit the niche let't vacant by the

absence ot'bluegill. Since both stream tlsh and pelagic lake fish use prolonged stsady

SN-irnniing.it is not surprising that they ha\-s bot11 adapted more tùsiforrn body morphs.

Contrxy to the predictions of h>pothssis .M 1. Stream and lake tlsh were not found

to tiri\.s a ciifference in body nidth at the insertion of the pectoral fins. Wfiile this

dinicrision has not been rneasured in tnost pre~~iousstudies of ~norphologicaldiftèrences

iii tlon-ing n-riters (e.g. Baltz and bloyie 19s1 : Bsaclian~et al. 1989: Bodaly 1979:

XIcLaughlin and Grant 1991). it !vas espected that Iia\+inga reduced body depth may 1iaL.e

ail influence on the body n-idth of the tlsli. According to Ryder and Pessendortkr ( 1989).

mort tùsifOrn~tish are typically niore round in cross-section than gibbose tish. This

obsen-cttion rnay be duc to both a reduced body depth and an increased body width.

Thc signitlcant difference betuwn the Eels Creek and Stony Lake tèniales for this

trait. and the non-significant differences in the niean body width for the other con~pririsonsmay indicate that stream tlsh are somewhat wider than lake fish. but further study n-ould be required to [-sri@ this. It is possible that a tish u-ith a more narrow body

\{.ouid Iia\.e greater ditticulties in maintaining its orientation in the current. A fish that is more tlat and disk-like may catch more of the current side-on, which w-ould make it ciifticult to rnaintain an upstream heading or to swim at an angle to the direction of the currc't~t.Con\-cirsely. the espected differences in body width may not have been well supportcd in this study due to constraints on body shaps that are related to the inusculaturc and physiolosy of the fish (Webb 19S3). A tish \vouId require a certain body hnii (skelstal structure) to support the rnuscularure netded for sun;i\-ing in its eii\.ironnic.nt. Since body n-idth adaptations have not been studied extensively, this seems to bc an areri of tish morpholo_o)rin w-hich tbture researcli should bs directed-

Generally. the fins of the stream pumpkinscied and rock bass were not found to be larpthan in the lake tish. While stream pumpkinseed pectoral fins were longer than those of lake purnpkinssed. in most cases the Iength andor width of the tins \\.as actually grcriter in the lake tish. The depth of the and and dorsal fins \vas greater for lake tlsh of G bot11 species and al1 tin sizss (pectoral. pelvic. anal and dorsal) were pater in the lake du-siling rock bass. These results \\*erecontrary to the prsdictions of h+vpothesisM2. as it

\\.ris espècted tliat stream centrarchids \vould use Iarger paired lateral tins for holdin~ position and for orientating theniselves in the current and that largsr dorsal and anal tins

\\.ouid bs uséd for stability in the tlo~ving\vater.

For salinonids. it has been found that fish inhabiting areas with faster current

L-cbciticsIiad larger lateral tins (Beacham et al. 1989). It appears that fish in current are using their tins to maintain an upstream heading in the rapid and often turbulent flow

(blcLaughlin and Noakes 1998). Larger fins would move a greater volume of water and

[na? reduce ener-g espenditures from additional fin beats. Larger tins may be used by Stream tish in conjunction with steady swimming. a propulsive mechanism observed for

Stream tisIi. in tield situations (Webb 199 1 : McLaughlin and Noakes 1998). According to LVebb ( 1984). tïsh adapted to prolonged steady swimming would have a laqer tin area relative to body size. The dorsal and anal tins of stream coho salmon have also been tound to be fargcrr (S~vainand Holtby 1989). although these authors esplaincd that this n-iay be duc to increased temtorial behm-iour in the stream. Temtorial tlsh use larger dorsal and anal tln margins to create the illusion of increased body size.

Despite the 3boi.e arguments. bat-ing larser tlns could also be viewed as a contradiction to the predictions of hydrodynamic theory because having larger fins in tlon-ing \vater could create a larger drag poteritial for the tish. The use of lateral fins incrsasss the surtàce area of the tish when it is viewed head-on. If fish are orientated in riii upstrcam direction to forage on aquatic insects drifiing in the current. then the increase iri siiriice area ssposed to the current would result in a sreater drag coefticient. This u-ould reduce the distance CO\-eredper tail beat. or alternatively w~ouidmean that a tish

\i-ouId 1-la\-eto increase its tail beat frequency to hold position in the current (Webb 199 1 :

XIcLaughlin and Xoakes 1998). Sirnilarly. an increase in the surtàce area of the dorsal and anal fins would be detrimental when a tisli is not oriented precisely in an upstream direction. as the fins would catch the current in the same manner that a sail catches the n.iiid. Ttius. it appears that optimal fin size may be a trade offbenveen the use of larse tlns hrorientation and maintaining position versus the extra drag that is created by these largsr tins. Although lateral tins are used extensi\.ely by strsam tish, it seems likely that smaller tins are actually more ad\.antageous in lotic ecosystems and large tins may be better suitsd tbr the fins manoeuvres that are required in lentic ecosystems. In a study of semal

Jiniorphism in biuegill. Ehlinger ( 199 1 ) sspIained the larger lateral fins obsewed in riiales vers ri mschanism for increasing their agility for nest dsfsnce and fonging in the itiorc higlil>.stmctured littoral zone. Femafes had srnallsr lateral tins and \vere adapted to more open pslagic habitats. Ehlingsr and Wilson ( 1988) showed that littoral blusgill had longer pectoral tins compared to tïsh in pelagic habitats. It appears that the Stream tish from the curent study may ressmble the pelagic rnorph found in some lakes. as botli ripes of fish seem to be adapted for extensive steady swimming through a more tùsiform body plan. Likw-ise. large dorsal and anal tins may provide additional stability in still n.ater habitats rathsr than in tlo\t.ing ivater habitats.

Dsspits the above esplanation. thers appsars to be some contradiction in the publislied litsraturs reiated to the cn~ironmentalconditions that \\.il1 select for large

\usus small tin size. As stated previously. Beachain et al. ( 19S9) found that ju\-enile siilmoiiids tiad largcir tins in hster tlowing water. yer McLaughlin and Noakes ( 1998) iinply that strsam tish n-ith larger lateml tins u-ould sufkr a greater drag penalty.

Siitiilarl~..the results of Ehlinger and Wilson (1988) and Ehlinp(1991). suminarized

aboi^ (pre~iousparagapli). conflict with those of Robinson et al. ( 1993) who obsewed tliat pelagic pumpkinsred had longer pectoral tins than did the conspecitic littoral puiiipkinsesd. The interpretation of this result by Robinson et al. (1993) was chat the optirnal morpholog of pectoral tins is complex and could not be drscribed by common leiigth measures. It is possible that the selection pressures on the morphology of tish fins. as n.eI1 ris other traits. are mucli more complss than simply adapting to lifc in tlokving

\.ersus still \vater or li~vingin littoral versus pelagic habitats. A more probable esplanrition is that tlsh can easily and rapidly change tlie size (width) and shape of their tins nith the nluscles attached to the tin rays. This could mean that selection acts on tlis abilit'. of the tish to control the size of its tins. not on fin size itself- Thus. tish may retain more or lsss ribility to change tlis size and shape of their fins depending on the requirsments of their habitat. it is also possible that the aforementioned habitat dit'ferences do not esert a selection pressure on the morphology of tish tins. Instsad. tln niorpholog>-ma- bs dt-tenninsd by othsr factors or a combination of tàctors not exarnined in tliis stud-- or other prel-ious studies.

The hy~othesisb13. that stream îïsh niIl have a more robust caudal peduncie than lakc. tish (reduceci depth but greater width). n-as partialIy supported in this study. In piimpkinsesd. stream tish had a more shallow depth at the anterior end of the caudal pcduncle (aIthough this differsnce \vas only significant for males) and stream fisli had a u.ider caudal peduncie (although this result \vas on ly signi ficant for fernales). However. thsre \\-ere generrlly no signiticant difirences in the width or depth of the caudal pt'duncle in rock bass.

For prolon~ed.constant speed s\vitnming strearn tish require a caudal peduncle that is inuscular. let capable of large amplitude beats to increase the fonvard thst poiver of

the tish ( iirsbb Joblinc+ 1995). To allow for faster. more pou-erful swimming. strean-i tisli aIso need to be able to make thess large amplitude caudal peduncle ciisplacsments rit hish frequencies. A shallow caudal peduncle with a large muscle mass

(i.e iiicreased u-idth) allows the fish to maximize thnrst whils reducing enera lost in rccoil (\irebb 1984. I9SS: Jobling 1995: McLaughlin and Noakt-s 1998). Field collsctions ofju\.enile brook trout tiom sites of variable current \.slocity in the Credit

Ri\-er. Ontario \vatershed found that fish in hster \vater had ri more shallou- caudal peduncle i \IcL;iughIin and Grant 1391). Altliou~hthe ~vidthof the caudal psduncle \vas iiot rneasursd by McLaughlin and Grant. it liksly wauld be grsater in streani îish to contriin the increased muscle rnass nscessary for prolonged steady su-imming (Webb

1 WI).

it is curious that in the Stream tlsh of the current study. the depth of the anterior caudal psduncle \\+as smaller. n-hersas the dspth at the posterior of the caudal psduncle u.as greatsr. That is. the depth of the caudal peduncls \vas more constant along its length for strsani fish as comparsd to laks tkh. Whils it \vas sxpected that the sntire psduncle u.uulJ bc lsss dsep in strsani tisti. enrrgg losses in recoil would be reduced as long as the lateral surface areri of the caudal peduncle is rel;iti\.ely small. Aiso. the posterior depth of the cn~~ddpeduncle in streain tlsh \vas rneasured froni the dorsal irisenion of the caudal tln tci the ventral insertion of the caudal tin. if the base of the caudal tin was Iarger in the strcani tisli. tlien the depth of the caudal peduncle at the insertion of the tln ivould also be

2rsritt.r. Xlthough caudal tln dimensions wert not measured in the current study. b

\IcLaughIiri and Grant ( 1994) report that tish captured from faster floiving u-ater had larssr caudal fins. The tinal morphological h>pothesis (MI)stated that the latenl fins of strsam tish n.ould Iiave a niore anterior placement thm in lake fish. The prediction that the pelt-ic

tins 1%-ouldbe niore antenorly placed in stream fish was reasonably well supported. tvhiIe the prsdiction regarding the position of the pectoral tins tvas larsely unsupported. In the puiripkinseed. onl-. the pelvic tins of both sexes were Iocated more antsriorly in stream fish. Both tlie pelvic and the pectoral tins of stream rock bass werc gsnerally locatc-d ri~orcanteriorly. but this resuIt lvas on& significmt for the mals fish.

Although literarure on the placement oftlit: lateral fins is scarce. there is some theoretical and smpirical svidencr that supports tlie obsenation that stream tish have pt.l\.ic tins tliat \vue Iocated in a more anterior position than those of lake tlsh. The inore aiitcrior insertion of the lateral tins allo\vs for additional manoeu\-rability in tish (IVebb

13S-t: Jobling 1995). an adaptation uhich is necesan/ for stream tish that must orientate and niriintain tlisir position in tlwving ivater. McLaughlin and Noakes ( 1998) reported that tish rssiding at sites \vit11 tàster current velocities were using their pectoral tins to hold an upstream hsading in the more turbulent tlo\v. Thess authors used the frequency of fin bats as an indicator of the degree to \vliich a fish \vas using its paired lateral tins to niaintain its position. Sn-ain and Holtby (1 989) also found that juvenile coho saIrnon in strcalns had more anteriorIy placed pectoral and pelvic fins than lake tlsh.

T\i-o \variables that \vers not includrd in the original lry-potheses were hund to load sigrritlcantly in the multivariate morphometnc analysis. The length of the caudal pcduncie (or: both the dorsal and the ventral surfaces) ivas peater in stream rock bass tlian in Iake rock briss. This coutd be considercd consistent with hypothesis M3. .-l\ccordingto Webb ( 1984). fis11 that use prolonged. constant speed swimming require a caudal pttduncle that i s capable of large amplitude. high frequency dispiacements. As discusscd pre\-ious1)-. a namou- caudal peduncle reduces recoil and allows tlie etttcient use of liigii tail beat frequencies. Having a longer. more narrow caudal peduncle w-ould allow the tish to increase the amplitude of its tail bats. n-ithout appreciabiy increasing enerm

Ioss duc to recoi1. That is. the increased cost fiom recoil of having a caudal peduncls n itii it grmer are3 (dus to the increased kngth) is more than otTset by the increase in tlinist pcilver from increasing the amplitude of tail beats. The ditTersnccs in the length of the caudal peduncle u-ers not obsen-ed for pumpkinseed.

Tlirre is also evidencs (froni the loadings in the inuItivariatè tests) that the horizontal gapr ofstream tish n-as pater than that of laks fish. although this difîèrence

[\.as iiot statistically signiticant in tlie univariate test. This difference was likely found bt.criusc gape \vidth is highly correlatsd n-ith the body nidth at the insertion of the pectoral tins (r=0.96. pc0.05). It is also possible tliat variations in the niorphology of the f,LL ,d- ing apparatus of tish niay retlect diftSrencss in diet. if prey \\.ers larger in one habitat t'pc thaii thc otlier. This csplanation is purely speculatit-s as data wxe not collected in tliis study to citlier support or reîùte this dietac. hdypothesis.

It is evidcnt froni the above discussion that the obssnred niorphological difkrences in the curent study were not always in agreement between the hvo species studied. nor were the obsen-ed rrsults always consistent \rith the previous litsrature. -4lthough the results hrmany of the variables were consistent benveen the ttvo species (i.e. if for a certain trait. stream pumpkinseed were larger than lake pumpkinseed, then stream rock bass n-ould also be larger than lake rock bass). there were some exceptions (Tables 10 and 1 1 ). For example, the length of the pectod tins and the length of tlie dorsal fin base n.ere srcater in Stream purnpkinseed and in lake rock bass. These inconsistent results should not corne ris a surprise. as there are a number of ssaniples of conflicting results in tlic literaturé.

-4s mentioned pre\-iously. Elilinter and Wilson ( 1988) found that blusgill inhabiting the littoral zone of lakes in Miciiipn had lon~erpsctorai tins than conspecitlc pelagic bluegill: u.hereas. Robinson et al. ( 1993) reportsd that the length of the pectoral tins of purnpkinseed (both of these species are tiom the genus Lt.ponzis) were pater in pelagic. ris oppossd to littoral. tkh. Sirnilarly. both Beacham et al. ( 1989) and Swain and Holtby

( 1989) fourid that salmonids inhabiting fursr Rowing uvaterliad greater bod!. depths and

Leisine and McPhaii ( 1993) found sirnilar results in threespine sticklèback. The obsen.atioiis of these authors w-ould not bc: espectsd based on the theory of Webb ( 1983.

198s) or the snipirical s\-idsnce reported in the current study and by otlier authors (Baltz and bloyle 19s 1 : McLaughlin et al. 1994).

.Additionall~..Bodaly i 1979) found t\vo morpl~ologicalforn-is of lake whitetlsh

(Co~-~go~iil.sc*lrrpc.u/0t-nzis). a benthic morph and a pelagic morph. in five different Yukon

Iakes. The tu-o body rnorplis appearsd to have suites of differences for tlie measured morpliological variables. Although the tw-o morphs could be consistently distinguished n-ithin a single lake. the sets of diftèrences that di~tin~ishedthen1 were not consistent riinong tlic tix-e Iakes. Bodaly suggestsd chat the among-Iake diflerences may 1ix.e occurred because the fis11 were not only adapting to the two niches availabls in each lake. but \vers also adapting to environmental diffsrences that exist among the lakes. Similar

rnschanisms may be intluencing the morpholog of the tïsh in the current study. Despite

lia\-ing selectsd sampling sites w-ith similar types of physical habitat (except for the

parameters to be directly testsd: i-e.. flolv and percent vsgetation in Rics Lake).

cn\-ironniental di ffersnces bstw-esn the tn-O Stream sites and between the t\vo lake si tes

ma-' have esened significant sslsction pressures on the body shape of tish. Such

differènces rirnong strearns and among lakes. combined ivith the setection pressures that

esist bct\i-sen strearns and lakss. may have contributed to the rnorphological differences

obsen-ed. As \vell. there niay bc difftlrent selection pressures eserted on the tn-O différent

speoics. This tvould esplain n-hy sorns of the results were not consistent betwesn the

purnpkinssed and the rock bass.

Habirat ait d Com nt rr nity Differett ces

Only tlis morphology data from the male punlpkinsced provided svidence for the

h>pothcsisthat morpliolo~n-ould be directly related to the presence or absence of

ilon-irig u-rttcr (based on the matris correlations tiom the Mantel Test). The tèmale purnpkinseed and rock bass (both sexes) n~orpliologydata were not related to this h~potliesis.a result that \vas not unexpected. Since it is extremely diflïcult ro control for al1 sstraneous \.ariables in a st-udy invol~.ingspeciniens collsctsd in the tïeld. it is Iikeiy tliat ri iiurnber of otlier sslsction pressures. beond the prssence or absence of tlo~ving water. also had an intluence on tish nlorplioloa. Nevertheless. rnany of the ~iiorphologicaldifferences obsewed between stream and lake tish. such as the reduced body depth in stream tish. did sesm to be adaptive to inhabiting flowing water.

The matrix comprissd of the habitat variables was similar to the hypothesis matris.

This result \vas also expected because al1 sites were selected to be similar for vegetation densit>*.depth and substrate size (Table 2). Since the _seo+mphiclocation of the sites nras similar. n-ater temperature and inean July temperature were also similar. Thus. the major know di tfirence betn-cen sites \vas the prssence or absence of tlo\ving nvatèr:~vhich is the sarile diffsrence that the Iiypothesis matrices n-ers brised upon.

The structure of the tish cornmunities was somewhat siniilar in the two streams and in the tn-O lakss. but \kvasquite different betlveen streams and lakes. Rice Lake liad twice ris iiiany tisli species as Indian Ri~wand the Stony Lake tish community liad a species richricss tliat \vas more than 1 5O0,o of the species richness of Eels Creek. Although specics richiiess psr unit ara is generally greater in streams than in lakes (Eadie et al.

19S6: Ryder and Pessndort'sr 1989). the surtàce rireas of Rice Lake and Stony Lake are large. and subsequently the lakes conrain more species. To make stream and lake tlsh

çomiiiunities comparable. this study w-ouid lia\-e to be repeated usin3 much smaller lakss or ponds that have more depaupsrate fish communities.

Dcspitc the dit'tcrences in comniunity structure, competition likely did not affect tisli n~orphologyor life histories. Bluegill are considered to be the main competitor of puiiipkinsecd. espccially at the juveiiilz stage (Mittslbacli 19SS: Osenbers et al. 1988.

1992: Fos 1994). The presence of blusgill lm been associated witii delayed maturity and decrçased reproductive investnient in pumpkinseed (Fox 1994). The absence of bluegill in a lake could aiso confound morphoIogical assessments. as pumpkinseed have bcen shonm to display trophic dimorphism in this situation (Robinson et al. 1993. 1996:

Robinson and Wilson 1996). This was not a probIem in the current study. as bluegill

\sVerrprcscnt at al1 sites u-here pumpkinseed were collectsd. Rock bass compete with other csntrarchids. particularly pumpkinseed and smallmouth bass. This cornpetition is

Iikely mosr se\-ere at the ju\-mile stage u.hen the fish are primarily contlned to the littoral zone in lrzkss (Scott and Crossmm 1973). Centrarchid cornpetitors were present at al1 sites ~vliersrock bass \ver2 collected.

Predation ma>.have h3d an intluence un the obsewsd lik liistory (as discussed pret.ic,usly) and rnorpholagical differences in Eels Creek rock bass. As previously stated. large predators in Eels Creek are rare or absent ~vhilerock bass at the other sites may be iiitluènced by the prssence of muskellunge. Bronmark and Miner ( 1993) found that crucim carp associated n-ith a large gape-limited predator. the northern pike (E.sox

Ilrc-i1r.v). had dseper bodies during their jiivenile stage so they would escape the window of liigli predation \-ulnerribiiity more quickly. Once the carp escaped the period of greatest

\-iilrierribility ( at approsinlatsly I 50 mm total Isngth ), energ rssources were allocated to

tmxth in lcngth and their body depth to length ratio decreased. A similar predation a\.oidrincc mschanism could cxist in the rock bass of the current study. If this were tme. rock bass in lndian River. Rice Lake and Stony Lake would have deeper bodies until a considerably later Iik stage than the Eels Creek fish due to the relative abundance of large prcdators in the first three ecosystems. Although it wras obsenred that the lakc tish were dscper bodied than the Stream t'ish. there \vas no evidence that Lndian River tish were desper bodied than Eels Creek flsh. It is unlikely that predatfon \vould have intluenced

pumpkinseed. as both large and srnall predators known to prey on pumpkinsesd (Scott

and Crossnian 1973: Pratt 1998) Lvere present in Indian Ri\.er and Rics Lake.

The Rule of Gerrot).pe versus Pirertotypic Plasticiry

Although the role of gentxic dit'tsrences \?ersusphenotypic plasticity cannot be

dctermined hmthe current study. this is a topic worth discussing in light of the current

rcsulrs. it n.ould be interestins tto continue tliis study to determine if the obseneed ciifferences in morpholo~and lits histories are dus to genetic difierences among the

populations or are plastic responses to the environnient. Generally. it is dit'tlcult to relate ubsenable phenotyic differences. such as life histones and morphology. to genotypic cIifferences that cm bs analped in the lab. Different selsction pressures t>~icallyact on thest. obscn-able phenotqpes than on genetic rnarkers such as allozymes (Jonsson 1985:

Corti et al. 198s: Fox et al. 1997). But- the roIe of genotype \.ersus phenotypic plasticity cm be tested indirectly using transplant espsriments such as those of Jonsson ( 1985). Fox

( 1 994 ) and Robinson and Wilson ( 1 996). Phenotypic plasticity can otTer detiniti~x fïtnsss rid\.rintagss O\-srcharacteristics that are rigidly contined by genetics. This can be dcmonstrated tor both litë history and morphological adaptations.

Jonsson ( 1 985) pro\-ided evidence of l itè history differences bet\veen freshwater du.elling and sa-run migrant bron-n trout (Sufnlornirrtr) in Nonvay, Aithough the tlvo croups of fisIl \\.ere foiind to spawn in the same tributanes of a single Iake. thers was & c\-idt'nw that both genetics and environment played a role in the development of the contrasting life histories. Eni-ironmental factors were deemed important because srilmonid life histonss can be manipulated by changing the availability of food resources or the temperature at ivhich the fish are reared. These two parameters are knoivn to affect both growth and tltiiess in tish (Balon 1953). Genetic differences ivere also implisd bccause broii-n trout tiom tiiu geographically prosimate Xonvegian lakes differsd in tlleir tendeiic>.to beconle sec? ~liigrantsor to rsmain in ti-eslin-ater. Difkrences in food ribiiiidaiice bctii-sen thc lrikes n-cre determincd not to be a factor. and it ivas assunisd that

-censtic cli\.ergsnce [vas rssponsible since the tivo populations had been isolated for over

6000 >.cars. Grou-th differsnces in Stream and lake populations of the freshwater broivn trout ii-ersdue to phenotypic plasticity. When progeny of thess tish ivsre raised in a conir-iion en\-ironment, the di tferences in growth rate were no longer apparent (Jonsson

1985). Reproducti\.e investment has also been shoivn to be extrernely plastic. Fox

( 1994) used a transplant sspenment of pumpkinseed to demonstrate tIiat tish reared in a tislilcss pond ivith an abundant in~w-tebratetbod resource greiv hster and allocated niore eiiergy to reproduction than tish of the same stock that wre reared in thsir nati~~eIaks.

Both genetics and environmental di ff'sre~icesha\-s been show to intlusnce tish ri~orpliologyris well. Jonsson et al. ( 1988) arped that phenotypic plasticity seemed to be rcsporisibls hr four morphs of Arctic char in Thing-allavatn. Iceland. Genetic difkrsncss arnong the tour morptis in the lake ivere found to be niuch smaller than differences n-ithin a single niorph across different Icelandic lakes. It seems that the ciiffersnt ~norphs\vers adapted to exploit the different niches available in the lake.

Dcspite this. the four morphs did seem to be rsproductively isolated within the lake. The ailthors did not observe any cross-breeding anlong the morplis. and reproduction was cent.rall>.isolated due to temporal and spatial ditferences in spawning events ~vithinthe b laks.

Robinson and Wilson ( 1996) detemlinsd that trophic dimorphisn~in pumpkinseed u.as attributable to phenotypic plasticity (537'0) and genetic differences ( 14%) in a rcciprocd transplant ssperiment. Fnwere bred fiom ttvo parental stocks of puinpkinsssd. a pelagic stock and a littoral stock. iï-hich were knou-n to display rnorpIiological dift'srences. Botli of these stocks originated froni Parados Lake. Ncw

'i'urk. The tnujuvsnile stocks tl-ere then raised in a cornmon pelagic and a common littorril cn\.ironment for 75 days. Xlthough the stocks retainsd some of thsir original charactt.ristics ex-en aftsr the period of rearing in the common en~~ironment(which xcou~itsfor the 149 O that was detennined to be genetic). (11s pelagic tlsh reared in the littoral en\~ironnienthad bsgun to appear more like littoral tish and the littoral fish raised in the pelagic environment displayed signiticant pelagic characteristics. Thus. it was dèterminsd that the rnorphology of the tn.o stocks of tlsh \vas quite plastic. Although it is siispcctsd that the Stream and lake tish examined in the current study likely have been reproducti\.ely isolated longer than the fish studied by Robinson and Wilson (. 1996). it

\i-ould bc interesting to adapt thcir experiment to invzstigate the roIe of phenotypic plasticity in the development of the obsen-ed dit'ferences in gro\vth. litè history and tiiorphology found ben\-sen streani and Iake en\-ironments. COSCLUSIONS

It appears that the factors intluencing the life history patterns and gowth of puiiipkinsesd and rock bass are quite cornplex. While there is some evidence that streani tish reproduced at a younger age than lake fisb. tliis doss not ssplain al1 of the obsen-ed results, [ncreased fisliing pressure and'or a higher ridult mortality rate due to predation in

Iriciian Ri~ver.Ricc Lake and Stony Lake may be responsibls for the decrease in rock bass rige at maturit>. and increased rsproducti\:s in\-estment- Aiternatively. ju\*enile nlortality in Eels Crcek may be pater tIian in the othsr three populations for soms unknoivn reiison. Sons of these altsmati\.e h-vpotheses are able to esplain the reduced go\\-th of thc' Eels Creek population. This obsenxtion may be due to other environmenta1 factors such as the trophic status of the ecosystsm. the quality of a\-ailable habitat. water teinperaturc diflerences and'or diftèrences in popuIation density. The e~psctedlife

Iiistoq. dit'terencss bet~veenstreain and Iaks habitats gerierally wsre not supported in tIiis srud>.. but gron-th and possible lit3 history diftèrences wsre found benvsen the sub-

11-atcrsIiedsstudisd.

llorpliological differences wsre found betwecn streams and 1akt.s in bot11 riiul ti varirite space and for speci tic indi~vidualmeasures- Stream fish had a reduced body ciepth. smaller tins and a more anterior insertion of the pelvic fins than did laks fisli.

Thsss attributes appear to allow the Stream tish to forage more efficiently and conserve ciierg). in tliis more ~~O~OUSenvironment. Consistent dit'tèrences in the morpIiology of thc caudal peduncle \vers generally not found behveen Stream and lake fish. it is Iikely tiiat sslsctiori presslires other than the intluence of flo\v (such as diet) may also be contributing ta the obsemed ditTerences in morpholog amon2 habitats. Although conipetitioii and predation can attèct fish morpho10,-. this mschanism !vas not tested in the current study. Based on the presence of known cornpetitors and predators at al1 srudy sites. it is unlikely that either of these factors affectcd the rnorpholosy of pumpkinseed and rock bass. Further study would be required to detsnnined if the observed dityerences in tisli gron-th. lik Iiistories and rnorphology are due to genetic variations. phenotypic plasticity or a combination of the two. Abrams. P..L\.. and L. Rowe. 1996. The eficts of predation on the age and size of niaturity of prey. E\.olution. 50: 1052- 1 O6 1.

Auer. S.-\.. and 3l.T. Auer. 1987. Field evaluation of barriers to \valleye egg and lama suni\-al in the Lon-er Fos Ri~~er.Cirisconsin. American Fisheries Society Symposium. 2: 93-101.

Balon. E.K. 1983. Episenic mechanisms: retlections on svolutionary processes. Cm. J. Fish. Xq. Sci. 10: 2015-2055.

Baltz, D.M.. and P.B. Moyls- 198 1. hl~rpli~n~etricanalysis of tule perch i~stnmcarprrs [niski) populations in three isolated drainages. Copeia. 198 1 : 305-3 1 1.

Baltz. D.M.. and P.B. Moyle. 1982. Life history cliaracteristics of mle perch (~i:~~~~~-o~~tr~p~rsfi-rlski)popultions in contrasting rsnvironments. Env. Biol. Fish. 7: 229- 2-12.

Beactiart-i. T.D.. C.B. Murray. and R.E. Witliler. 1989. Age. morptiology. and biochemical generic \.ariation of Yukon River chinook saIrnon. Trans. Am. Fish. Soc. 1 18: 46-63.

Bell. D. 1983. Stony and Clear Lakes creel csnsus. Ontario .Ministry of Natural Resources. Peterborough. Ontario.

Bcrtschy. K..%. and kf .G. Fos. 1999. The intluence of age-specitic ~un-i\~orshipon pumpkinsssd suntïsh life histories. Ecology. 80: 2299-23 13.

Bodaly. R.-4, 1979. Morphological and ecological di\wgence n-ittiin the lake whitefish (Cr~wgo~lrr.sc.l~rycuf01-11zis) species cornplex in Yukon Territop-. J. Fish. Res. Board Can. 36: 12 11- 1222.

Bookstein. F.L.. B.C. Chernoff. R.L. Elder. J.M. Humpliries. G.R. Smith, and R.E. Strauss. 1985. Morphometrics in st.olutionary biology. Acad. Xat. Sci. Phil. Spec. Publ. 15: 1-277.

Bronmark, C.. and J.G. Miner. 1992. Predator-induced phenotypical change in body n~orpholo~>.in crucian carp. Science. 258: 1338- 1350.

Buttle. J.M. 1992. The Ka~varthaLakes. p. 79-95. 111 W.P. Adams and C.H. Taylor, eds. Peterborough and the Kawarthas. 2nd edition. Hsritage Publications. Peterborough. Ontario. Carlander. K.D. i 977. Handbook of tieshwater tlshery biology. volume 2. Life history data on cenrrarchid tishes of the United States and Canada. The Iowa Strite University Press. Anies. [on-a. 43 1 p.

Carlander. K.D. 198 1. Caution on the use of the regression method of back-calculating lengtli tiorn scale measurements. Fisheries. 6( 1 ): 24.

Carlnnder. K.D. 1482. Standard intercepts for calculating lengths fiom scale measurerntlnts for some centatchid and percid fishes. Trans. Am. Fish. Soc. 1 1 1 : 332-336.

Chanibt.rIain. J..A. 1990. Wetland management plan for Stony and Clear Lakes. Trent- Severn CVatcnvay. Peterborough, Ontario- 1 t Op.

Constantz. G.D. 1979. Lit2 history patterns ofa livebearing tish in contrasting eri\.ironnients. Oecologia. 40: 1 S9-20 1 -

Corti. M.. R.S. Thorps. L. Sola. V. Sbordoni. and S. Cataudella. I958. Multivariate rnorplion~stricsin aquaculture: a case study of sis stocks of the common carp (Cip-i11lr.s cuipio) tiom Italy, Can. J. Fish. Aquat, Sci. 45: 1543-1554.

Crii-elli. LI..and D. Mestre. 1988. Life history patterns of purnpkinseed. Leponzis gi.ihh.sus. introducsd into the Camarps. a mediremnean wstland. Arch. Hydrobiol. 1 1 1: 440-466.

Crossnian. E.J.. and D.E. Mc.i\llister. 1986. Zoogeography of tieshu-ater tishes of the Hudson Ba).. Lnga\-a Bay and Arctic ArchipsIago drainages. p. 53- 104. /tr The zoogcograpliy of Sorth American freshuater tishes. C.H. Hocutt and E.O. Wiley [eds.]. 1i'iIt.y and Sons. New York.

Crou-1. T.X.. and A.P. Covich. 1990. Predator-induced life-history shitis in a fieshvater snail. Science. 247: 949-95 1.

Cummins. K.\\:.. G.W. Minsliall. J.R. Sedrll. C.E. Cushing. and R.C. Petersen. 1984. Stream sccsystem tfieory. Verh. Internat. Verein. Limnol. 22: 18 18-1 527.

Cunlrnins. K.lV.. J.R. Sedell. F.J. Swanson. G.W. iMinshall. S.G. Fisher. C.E. Cushing. R.C. Pctcrsen. and R.L. Vannote. 1983- Or~anicniatter budgets for Stream ecosystems: problcms in their evaluation. p. 399-353. ln J.R. Barnes and G.W. Minshall [eds.]. Stream ecology: application and testing of general ecological theory. Plenum Press. New York.

Cu-,. R..\.. S. Allen. M.G. Fos. and G.E. Morgan. 1993. Growth and food of young-of- the-year brook charr. Suli.~.lintr.s-fut~~it~aIis.in lake and creek environrnents. Env. Biol. Fish. 37: 13 1-138. Danylchuk. A.J.. and MG. Fox. 1994. Seasonal reproductive patterns of pumpkinseed (L~unzisgihbosus) populations with varying body size characteristics. Can. I. Fish. Aquat. Sci. 5 1 : 490-300.

Douglas. h1.E.. and J.A. Endler. 1982. Quantitative matrix cornparisons in scological and r.\.olutiona~in~estigations. J. Theor. Biol. 99: 777-795.

Drake. MT.. J.E. Claussen. D.P. Philipp. and D.L. Pereira. 1997. A comparison of b1uegill rsprociiictive strategies aiid growth among lakss with ditTerent fishing intensitiss. S. Am. J. Fish. Manage. 17: 496-507.

Eadie. J.M.. T..k HurIy, R-D. Mont~omsrie,t and K-L. Teather. 1956-Lakes and rivers as islands: specics-area relationships in the fish hunas of Ontano- Env. Biol. Fish- 15: S 1 - $9.

Elilinger. T.J. 1990. Habitat choice and phsnotye limited fesding ettlcisncy in bIuegill: indi\.idual differences and trophic polymorphism. EcoIog. 7 1 : 856-896.

Eh1 inger. T.J. 199 1. Allometry and analysis of morphomstric variation in the bluegill. Lcpmtis nzucr-oc hi^-ir5-. Copeia. 199 1 : 317-357.

Ehlingsr. T.J.. M.T. Gross. and D.P. Philipp. 1997. Morphological and growth rats dittèrences bettveen bluegill males of alternative reproductive Iife histories. K. Am. J- Fish. .Glanage. 1 7: 533-542.

Elilinger. T.J.. and D.S. NriIson. I9SS. Comples foraging pol>morphism in bluégill suntïsli. Proc. Natl. Acad. Sci. US.4. 85: 187s-1852.

Enviroimient Canada. 1993. Canadian climats normals, 196 1 - 1990 (volume 4). Canadian Clinlate Prog-rim. En\-ironment Canada. 1 ZS p.

Fcllq.. J.D.. and J-C. At-ise. l9SO. Genetic and morphological variation of bluegill populations in Florida lakes. Trans. Am. Fish. Soc. 109: 1 OS- 1 15.

Fos. L3.G. 1994. Gron-th. densip. and interspecific influences on pumpkinseed sunfish lit2 liistories- Ecolop. 75: 1 157-1 17 1.

Fos. M.G.. J.E. Claussen. and D.P. Philipp. 1997. Gso-mphic patterns in genetic and life histop variation in pumpkinseed populations tiom four east-central Ontario \vatersheds. S. Am. J. Fish. Manage. 17: 313-556. Fos. M.G.. and A- Keast. 1990. Et'fects of winterkill on population structure. body size. and prey consumption patterns of pumpkinseed in isolated beaver ponds. Crin. J. 2001. 6s: 2189-2495.

Fos. X1.G.. and A. Ksasr. 199 1. Ef-t'ect of o\.envinter mortality on reproductive [ifs history characteristics of pumpkinsesd (Leponlisgihbosiis) populations. Crin. J. Fish. Aquat. Sci. 4s: 1792- 1 799.

Gloss. S.P.. C.L. SchotieId. R.L. Spateiiolts. and B.A. Ptonski. 1989. Sunival. growth. reproduction and diet of brook trout (Su/i~e/itr~rsjôtztit~aIis)stocked into lakes afier liming to mitigats acidity. Can. J. Fish. Aquat. Sci. 46: 277-256.

Gross. H.P. 1979. Geographic variation in European ninespine sticklebacks. Pllngirirrs prtigirilr.~.Copeia. 1979: 405-4 12.

Gross. kt .R.. and W.A. Noudl. 1980. The reprociucti\-e biology of rock bass. .-lnz6/opiitt'.s ~-upesrr*is(Csntntchidae). in Lake Opinicon. Ontario. Copeia. 1980: 452-493.

Hcaicy, !VI .C.. and W. R. Hsard. 1984. Inter- and intra-population variation in the kcunditl. of chinook salrnon (Oticor-/zinchrrsrshart~.~.schu) and its relevance to life history thcon.. Cm. J. Fish. Aquat. Sci. 4 1: 176-453.

Horne. .A.J.. and C.R. Goldrnan. t 994. Lirniiolog. 2nd edition. McGraw-Hill. Inc. Xew 1-ork.276 p.

Honi-itz. R.J. 1978. Temporal variability patterns and the distributional patterns ofstream tlslics. Ecoi. Monogr. 48: 307-32 1.

Ho>,le.J..k. and A. Keast. 1987. The effect of prey rnorpholo-q and size on handling time in a piscivore, the lrirgemouth bass (.L/i~i-opre~-rissulnzoiCit>~). Can. J. Zool. 65: 1972- 1977.

Ho>k.J.A.. and A. Keast. 198s. Prey handling tims in t~vopisci\-ores, Esox u~ncr-i~~~tlirs i.c~/-uri~.lr/utu.sand Micr-opterris salrnoides. with contrasting moutli morphologies. Cm. J. 2001. 66: 5.10-542.

Humpliries. J.M. 19S-t. Qp-ittodotr iut-ecrrnciirs.n-sp.. a t?hh species of puptish from Lriguna Cliichancanab. Copeia 1 : 58-68.

Humphries. J.M.. F.L. Bookstein. B. Chemoff. G.R. Smith. R.L. Elder. and S.G. Poss. 198 1. %tulti\.ariatediscrimination by shape in relation to size. Syst. Zool. 30: 29 1-308.

Hutch ings. J .A. 1 993. Xdaptive l i fe histories e ffected by age-specific survival and growth ratc. Ecology. 74: 673-651. Jobling. M. 1995. En\-ironmental biolocoq- of fishss. Chapman & Hall. London. U.K. 4533.

Jonsson. B. 1985. Life history patterns of freshwater resident and sea-mn migrant bro\vn rrout in Nom-ay. Trans. Am. Fish. Soc. 1 14: 152- 194.

Jonsson. B.. S. Skulason. S.S. Snorrason. O.T. Sandlund, H.J. Malmquist, P.iM. Jonasson. R. Gydemo. and T. Lindem. 1988. Lik history variation of polymorphic Arctic charr (Sul\vliilrrs trlpiiirrs) in Thinpdlavatn. Iceland. Can. J. Fish. Aquat. Sei. 45: 1537-1 537.

Junk, \it'..J.. P.B. Bapley. and R.E. Sparks. 1989. The tlood pulse concept in river- tlciodpiain systems. p. I 10- 127. In D.P. Dodge [ed.] Proceedings of the internationri1 large river s)rnposiurn. Can. Spec. Publ. Fish. Aquat. Sci. 106.

Keast. A. 1977. klechanisms espanding niche ~vidthand minimizing intraspecitlc cornpetition in two centrarchid fishes. 111 ih4.K. Hecht. W.C. Steere and B. Wallace [ed.]. E\-olutionary biology. Vol. 10. Plenum Publialiing Corporation, New York. 333-395.

Kei\-an>..IV.. J.S. Kelson. and P. S. Economidis. 1 997. Validi ty of Ptlilgi[i~is/zellmicr~s Stephanidis. 197 1 (Telsostei, Gasterosteidae). a stickleback tish fiom Greece. Copeia. 1997: 558-564.

Kerr. S.J.. B.W. Corbett. D.D. Flowers. D. Fluri. P.E. Ihssen. B.A. Potter. and D.E. Seip. 1996. \irailep stocking as a management tool. Percid Community Synthesis, Walleye Srocking \\;orking Group. Ontario Ministry of NaturaI Rssources. Peterboroush. Ontario. 80p.

Kutkuhn. J.K. 198 1. Stock detlnition as a necessary basis for cooperative management of Great Lakss tish resources. Cm. J. Fish. Aquat. Sci. 38: 1476- 1478.

Lrin.. R. 1979. The cost of reproduction in annual meadowgrass. -4m.Nat- 1 14: 399-4 17.

La~zsr.J. B.. and M.D. CIady. 1987. Phenotpic variation of young-of-year bluegills ( Lcpmis triuc.rochii-ris) among microhabitats. Copeia. 1987: 702-707.

Leslie. J.K.. and J.E. Moore. 1986. Changes in lengths of tïxec! and presenled young ti-cshwatsr tish. Cm. J. Fish. Ayuat. Sci. 43: 1079-1 O8 1.

Lavin. P.A. and J.D. McPhail- 1 993. Parapatric lake and Stream sticklebacks on northem Vancoutw Island: disjunct distribution or parallel evolution. Can. J. Zool. 7 1 : 1 1 - 17. Len-ies. R. W. 1976. The fisheries of the Kawartha Lakes. p. 53-106. in The Katvartha Lakes \vater management study - water quality assessment ( 1972- 1976). Ontario Ministry of the En\.ironnisnt and Ontario Ministry of Xatunl Resourcss. Toronto. Ontario.

Lotspeich. F.B. 1980. Watsrsheds as ttis basic ecosystem: this conceptual fmrnstvork provides a basis for a natural ~Iassitlcationsystem. Wat. Res. Bull. 16: 58 1-556.

bIant>v. B.F.J. 19S6. Multi\~ariatestatistical methods: a primer. Chapman and Hall, London.

XIalniq\-ist. B.. and C. Bronmark. 1985. Rsversed trends in the benthic community structure in tuu confluent strsrims: one spring-fed. the other lake-kd- Hydrobiologia. 121: 65-7 I .

.\IcLaughlin. R.L.. and J-W..L\. Grant. 1994. h4orphological and behavioural ditTerences among recently-emerged brook char. Salt-elinus fontinalis. foraging in SION-- m. fast- running nVater.Env. Biol. Fish. 39: 289-300.

'L,lcLaughlin.R.L.. J.W.A. Grant. and D.L. Kramer. 1993. Foraging movements in relation to niorpholo~r.u-atsr-colurnn use. and diet for recently ernerged brook trout (Sc~/i.~lir~rr.s_f~tlti~rc~lis)in sti1I-tvater pools. Can. J. Fish. Aquat. Sci. 5 1 : 268-279.

\IcLauglilin. R.L. and D.L.G. Xoakes. 1998. Going against the tlotv: an esaniination of thc propu1si1.e mot-sments made by Young brook trout in strearns. Can. J. Fish. Aquat. Sci. 55:S53-860,

\Ic.GIunry. M.J. 19S9. Fall trapnetting on the spawning grounds of lake trout and lake \vhitt'tisii in Lake Sinicoe. 1985-1988. Ontario Ministry of Natural Resources. Lake Siiiicoe Fislicrics Assessrnent Unit. Sutton West. Ontario. Report 1989-3. 5Sp.

.\Icrcer. J. 1998. Changes in the benthic invsrtsbrate community and the feediiig. grou-th anci PCB accuniulation in thres littoral zone tishes follow-ing a zebra musse1 invasion in Rics Lake. Ontrio. MSc. Thesis. Trent University. Peterborough. Ontario. 65p.

'Llichod. R.E. 1979. Evolution of iiîè histories in response to age-spscific mortality factors. Am. Xat. 1 13: 53 1-550. blinshall. G.W.. K.W. Cummins. R.C. Petersen. C.E. Cushing, D.A. Bruns. J.R. Sedell. and R.L. Vannote. 1985. Developments in strearn ecosystem theocy. Cm. J. Fish. Aquat. Sci. 43: 10-15- 1055. .LIinshall. G.W.. R.C. Petersen. K.W. Cummins. T.L. Bott, J.R. Sedell. C.E. Cushing. and R.L. L'annote. 1983. interbiome cornparison of stream ecosystem dynamics. Ecol. Monogr. 53 ( 1 1: 1-25. hlittclbach. G.G. 1984. Predation and rssourcè partitionincg in tu.0 sunfishes (Centratchidae). Ecology 65: 499-5 13. blittelbach. G.G. 1958. Competition among refùging siinfislies and effects of tish density on littoral zone invertebrates. Ecology. 69: 6 14-623.

ScK S..%. and G.R. Smith. 197s. iMuIti\.ariate analysis of hybrid tishss. Syst. Zool. 28: 1 76- 196.

Sicholls, K.H., M.F.P. Michalski. and Wm. Gibson. 1996. An experimental dcmonstration of rrophic interactions affecting \vater quality of Rice Lake. Ontario (Canada). H-cirobiologia. 3 19: 73-85.

Soltic. D.B. I9SS. Comparative grou-th and condition of northern stream-dwelling rock bas, .-fnrhluplir~s~-rryesrr-is (Ratineesque). Hydrobiologia 160: 199-206.

Soltic. D.B..and M.H..4. Keenleyside. 1957. Breeding ecolog. nsst characteristics. and ncst-site selsction of stream- and lake-dwrelling rock bass. .-lnzb/oplitesr-ripesrris (Ratinesque). Cm. J. Zool. 65: 379-390.

0hISR. 199 1. Rics Lake creel suney. Kan-artha Lakes Fislieriss Assessrnent Unit. Ontario blinistxy of Natural Resourcss. Lindsay. Ontario.

Osborne. L-L-. and .M.J. Wiley. 1992. Intluence of tributary spatial position on the structure of u-arrnn.ater tish communities. Can. J. Fish. Aquat. Sci. 49: 67 1-68 1.

Oscnbsrg. C.\V.. G.G. Mittelbach. and P.C. Wain~vright.1992. Two-stage lifc histories in tish: the interaction bstueeenjuvenile cornpetition and adult performance. Ecology. 73: 255-267.

Oscnberg. C.W.. E.E. Werner. G.G. Mittelbach. and D.J. Hall. 1988. Growth patterns in bl ucgi 1 l ( L c.yon1i.5-nrncr-uchir-us) and pumpkinseed (L.yibhosris) sunfish: environmental \.ariation and the importance of ontopwtic niche sliifts. Can. J. Fish. Aquat. Sci. 35: I7- 26.

Palmer. A.R. 1994. ExCalipcr version 2.00. Department of B iological Sciences. Lni~xrsityof Alberta. Edmonton. Alberta. Petriniouls. H.J. 1993. The life history and distribution of the Roanoke bass. -4nlbloplite.s cnijfi-otls Cops. in Virginia. Am. .Mid. Nat. 1 10: 338-353.

Philipp. D.P.. J.M. Epifanio. and M.J. Jennings. 1993. Poinv'counterpoint: consenation censtics and current stocking practices - are they compatible'? Fislieriss. 1 S( 12): 13- 16. b

Pratt. T.C. 1998. The impact of predation on pumpkinseed (Lepolrris gibboslrs) life histov strritegies. MSc. Thesis. Trent University. Peterborough. Ontario. 64p.

Probst. \\'.E.. C.F. Rabsni. W.G. Covington. and R.E. -Mrineney. 1984. Resource use by strcarn-du-elling rock bass and smallmouth bass. Trans. Am. Fish. Soc. 1 13: 253-294.

Putrnan. J.H.. C.L. Pierce. and DM.Day. 1995. Rslationships behveen environmental \-ariablcs and sizs-specific growth rates of Illinois Stream tishes. Trans. Am. Fish. Soc. 124: 252-26 1.

Quiros. R.. and S. Cucti. 1989. The tishery of the lori-er Plata River basin: tish hanrest and limnology, p. 429-443. In D.P. Dodge [ed.] Proceedings of the international large river symposium. Can. Spec. Publ. Fish. Aquat. Sci. 106.

Regier. H.4. 1962. Validation of the scale method for estimatins age and growtli of bliisgills. Trans. Am. Fish. Soc. 91: 362-374.

Regier. H..L and K.H. Lotius. 1972. Ef'ects of tisheries esploitation on salmonid con~mutiitissin oligotrophic lakes. J. Fish- Res. B. Can. 29: 959-96s.

Rt.zriick. D.Y.. M.J. Butler IV. F.H. Rodd. and P. Ross. 1996- Litè history evolution in 6. Lrzuppiss (Poec-iliir rcricdura) Differential monality as a mechanism for naturai sclsction. E~.olution.50: 165 1 - 1660.

Robins. C.R.. R.V. Baile);, C.E. Bond, J.R. Brooker. E.A. Lachner. R.E. Lea. and W.B. Scott. 199 1. Common and scientitic names of tishes tiom the United States and Canada. 5th sdition. .c\nierican Fisheries Society Special Publication 20. Bethesda. Maryland.

Robinson. B.W.. and D.S. Wilson. 1995. Esperimentally induced morphological diversity in Trinidadian guppies (Poecilia r-eticrrk~ta).Copeia. 1995: 293-505.

Robinson B.W.. and D.S. Wilson. 1996. Genetic variation and ptienotypic plasticity in a trophically polymorpliic population of punipkinseed sunfish (Leponiis gibbostis). Evol. ECO(.10: 63 1-65?. Robinson. B.W.. D.S. Wilson. A.S. Margosian. and P.T. Lotito. 1993. Ecologicril and rnorphological di t'tèrentiation of pumpkinseed sunfish in lakes without bluegill suntish. E~.olutionaryEcoIo~g. 7: 45 1464.

Robinson. B.\V..D.S. Wilson. and G.O. Shea. 1996. Tnde-ot't's of ecological specialization: an intraspecific companson of pumpkinseed sunfish phenotypes. Ecology. 77: 170-17s.

Rotf. DA.1984. The evo1ution oflife history parameters in teleosts. Can. J. Fish. Xquat. Sci. 11: 989- 1000.

Rot'f. D-.A. 1992. The evolution of life histories: theory and analysis. Chapman & Hall. Sc\v l'ork. p. ,535.

Rosenbium. P.M.. TM. Brandt. K.B. Mayes. and P. Hutson. 1994. Annual cycles of eron-th and reproduction in hatchery-rerired Floridri Iargernoutli bass. Micropre~-us L .~c~//r~oi~/~.s-fI~~~~ic/~i~~~is.raissd on forage or pellsted diets. J. Fish Biol. 44: 1045- 1059.

Rossi. G.. and G. Preinazzi. 199 1. DeIay in Iake recovsry caused internai loadings. Wat. RCS. 25: 567-575.

Rjrder. G.L. and D. Scott- 1988. The applicability of the Ri\.er Continuum Concept to Xeiv Zealand streams. Vehr. Internat. Verein. Lirnnol. 23: 141 1 - 1435.

Rj-der. R..L and J. Pesendortèr. 1989. Larse rivers are more than flowing lakes: a con~par;iti\rsre\.is\v. p. 65-85. /II D.P. Dodge [ed.] Proceedings of the international large rilw synposium. Can, Spsc. Publ. Fish. .4quat. Sci. 106.

Schrit'kr. \\?..LI. 1974. Selection for optimal life histories: the effect of a,(7e structure. Ecolog. 55: 29 1-303.

Schlosser. I.J. 199 1. Stream fish ecolop: a landscape perspective. BioScience. 4 1 : 704- 712.

Sclioîkild. C.L.. S.P. Gloss. B.A. Plonski. and R.L. Spateholts. 1989. Production and cro\i-th eftkiency of brook trout ~Scr/i~c/irr~i~~fo~t~i~zu/is)in hvo Adirondack ~Mountain L (Sen-York) lakes following lirning. Can. I. Fish. Aquat. Sci. 46: 333-341.

Scott. \V.I3.. and E.J. Crossman. 1973. Frsshw-ater tishes of Canada. Fish. Res. Board Cm. Bull. 184. 966p. Sedcll. J.R.. J.E- Richey. and F.J. S\vanson. 1989. The river continuum concept: a basis tbr the sspected ecosystem behaviour of \-ery large rivers?. p. 19-55. Itz D.P.Dodge [ed.] Procsedings of the international large river sy-tnposium. Can. Spec- Publ. Fish. Aquat. Sci. 106-

Scip. D.E. 1995. An evaluation of stocking ~vaileyet'ingerlings in ten eastem Ontario lakss. 19S-l-93. Ontario %Iinistryof Naturai Resources. Southem Region Science & Technology Trmsfer Unit Technical Report TR-007. 83p.

Somsrs. K.M. 1986. Multivariate allometry and removal ofsize with principal compoiients rinrilysis. Syst. Zool. 35: 359-368.

Somers. K.M. 1989. Ailometry. isometry and shape in principal components analysis. Syst. Zool. 38: 16% 173.

Somers. K.M.. and R.H. Green. 1993. Seasonal patterns in trap catches of the craytïsh Ccrnlhcrr-rrs hr-roui and 01-conecres\vit-ili.s in six south-central Ontario lakss. Can. J. 2001. 71: 1136-1 145-

Stantield, L.. M. Jones. and M.Stoneman. 1996. Stream assessment protocol for southern Ontario. Ontario ~Ministryof Natuml Rssources. Great Lakes Salmonid Cnit. Picton. Ontario. 63p.

Stsrims. S.C.. and J.C. Koella. 19S6. The svolution of phenotypic plasticiry in life histo- traits: predictions of reaction noms for ags and size at maturity. Evolution. 30: 893-9 13.

Stonctrim. C.L.. and M.L. Jones. 1996. ri\ simple tnethod to classify stream thermal stnbility uith single obsenlations of daily maximum water and air temperatures. N. Amer. J. Fish. XIanage. 16: 725-737.

Strauss. R.E.. and F.L. Bookstein. I9S2. The truss: body forrn reconstmction in niorptiomstrics. Syst. Zool. 3 1 : I 13- 135.

S~vain.D-Pd. and L.B. Holtby. 1989. Difierences in morphology and beha\iour between ju\.eiii le coho salmon (Onc.o~-/z~~tlclr~r.~X-i.srlrc.h) rearins in Lake and in its tributary stream. Cm. J. Fisti. Aquat. Sci. 46: 1406- 14 14.

Tl-iorp. J.H. 1 991. The riverine productivity model: an heuristic viem- of carbon sources and orpnic processing in large river ecosystems. Oikos. 70: 305-3023.

L'annote. R.L.- G.W. ?VIinshall. K.W. Cummins. J.R- Sedell. and C.E. Cushing. 1980. The ri\-er continuum concept. Can. J. Fish. Aquat. Sci. 37: 130-137. Vollestad. C..k. and J.H. L' Abee-Lund. 1990. Geocpphic variation in Iife-history strritsgiss- of tëmale roach, Rzrtilris rirriltis (L.). J. Fish. Biol. 37: 853-864.

Liard. J.V.. and J.A. Stanford. 1983. The senal discontinuity concept of lotic ecosystenis. p. 29-42. /IZ T.D, Fontaine III. and S.iM. Bartell [sds.], D4vnamicsof lotic ecosystems. Ann Arbor Sci.

\Vebb. P.W. 1984. Body tom. loconiotion and foraging in aquatic \-enebrates. Amer. Zool. 24: 107- 120.

\l,'ebb. P.\V. 1988. Simple physical principies and vertebnte aquatic locon~otion.Amer. ZOO^. 18: 709-725.

\.'èbb. P. M'. 199 I . Composition and nieclianics of routine sw-imming of rainbo\v trout, OIIL~OI-II~-~IC~~~~~Sttq-kiss. Cm. J. Fish. Aquat. Sci. 48: 583-590. ii'hall. J.D. 1995. Rics Lake tropliic study. summer 1995 progess report. Ontario Ylinsitry of Saturd Resources and Trent University. Peterborough. Ontario. 27p.

LVilt.. 1. 1971. The rnacrophytes of the Kawanha Lakes - 1973, p. 69-82.1~The Kawartha Lukes management studÿ - water quality assessrnent i1972- 1976). Ontario Ministry of the Environment and Ontario Ministry of Xatural Resources. Toronto. Ontario.

\Vile. 1.. and G. Hitchin. 1976. PhysicaI-chernicd limnology of the Krt~varthaLakes ( 1972 and 1976). p. 9-35. Itl The Kauvartha Lakss ivrtter management study - water quaiity assessrnent ( 1972- 1976). Ontario .Ministry of the Environment and Ontario ~Ministryof Saturd Rssources. Toronto. Ontario.

\Vinans. G..A. 19S4. blultivariate morphometric ~ariabilityin Pacitic salmon: technical demonstation. Cm. J. Fish. Aquat. Sci. 4 1 : 1 150-1 159. .-\PPENDIS I

1IE.-\SS .-\NDST-ANDARD ERRORS FOR MORPHOLOGICAL V.4RIABLES Appendix 1. Means and standard errors of unadjusted morphological variables for pumpkinseed fernales.

Indian River Rice - Unvegetated Rice - Vegetated

Pectoral Length Pectoral Width Pelvic Length Pelvic Width Anal Fin Depth Dorsal Fin Depth Predorsal Prepelvic Prepectoral Body Depth Preanal ant. Pelvic-ant.Anal ant. Dorsal-ant.Anal Dorsal Fin Base Anal Fin Base ant.Anal-post.Dorsal Depth ant-Peduncle Peduncle (Dorsal Plane) Peduncle (Ventral Plane) Depth post.Peduncle Peduncle Truss Interorbital Width @ Pect. Insertion Width @ant.Peduncle Horizontal Gape Appendix 1 (cont). Means and standard errors of unadjusted morphological variables for pumpkinseed males.

lndian River Rice - Unvegetated Rice - Vegetated

Pectoral Length Pectoral Width Pelvic Length Pelvic Width Anal Fin Depth Dorsal Fin Depth Predorsal Prepelvic Prepectoral Body Depth Preanal ant.Pelvic-ant.Anal ant. Dorsal-ant.Anal Dorsal Fin Base Anal Fin Base ant.Ana1-post.Dorsal Depth ant.Peduncle Peduncle (Dorsal Plane) Peduncle (Ventral Plane) Depth post.Peduncle Peduncle Truss Interorbital Width @ fect. Insertion Width @ant.Peduncle Horizontal Gape Appendix 1 (cont). Means and standard ertors of unadjusted morphological variables for rock bass fernales.

lndian River Rice Lake Eels Creek Stony Lake

Pectoral Length Pectoral Width Pelvic Length Pelvic Width Anal Fin Depth Dorsal Fin Depth Predorsal Prepelvic Prepectoral Body Depth Preanaf ant-Pelvic-ant.Anal ant.Dorsal-ant.Anal Dorsal Fin Base Anal Fin Base ant.Anal-post.Dorsal Depth ant-Peduncle Peduncle (Dorsal Plane) Peduncle (Ventral Plane) Depth post.Peduncle Peduncle Truss Interorbital Width @ Pect. Insertion Width @ant.Peduncle Horizontal Gape Appendix 1 (cont). Means and standard errors of unadjusted morphological variables for rock bass males.

lndian River Rice Lake Eels Creek Stony Lake

Pectoral Length Pectoral Width Pelvic Length Pelvic Width Anal Fin Depth Dorsal Fin Depth Predorsal Prepelvic Prepectoral Body Depth Preanal ant.Pelvic-ant.Anal ant.Dorsal-ant.Anal Dorsal Fin Base Anal Fin Base ant-Anal-post.Dorsal Depth ant. Peduncle Peduncle (Dorsal Plane) Peduncle (Ventral Plane) Depth post-Peduncle Peduncle Truss interorbital Width @ Pect. Insertion Width @ ant.Peduncle Horizontal Gape APPEXDIX 2

PCA AND DFA LOriDlKGS Appendix 2. PCA loadings for pumpkinseed femsles (from the residuals analysis).

Pearson Product-Moment Correlation Variation Accounted for bv Each Axis Axis 1 Axis 2 Axis 3 Axis 4 -Axis 1 -Axis 2 -Axis 3 --Axis 4 Total 96 Pectoral Length 0.û4ld 0.1381 0.6502 0.2775 0.0092 0.1027 2.2770 0.414ô 2.8û37 Pectorcl Width -0.1 120 4.3575 0.5460 0.3985 0.0831 0.8470 1 .9758 1 .O520 3.9578 Pelvic Lenoth 0.1299 0.0015 0.2211 0.5422 0.0607 O.GO00 0.1758 1.W 1.2931 Pelvic Width 0.0091 -0.3388 O. 1068 0.4678 0.000p 0.5480 0.0545 1 .O459 1.6494 Anal Fin Depth 0.- -0.5242 -0.1020 0.1884 0.6779 1 .a77 0.0609 0.2077 2.5543 Dorsal Fin Depth 0.3456 -0.5844 -0.3357 0.3196 0.7716 2.2061 0.81 73 0.6597 4.4547 Predorsal -0.0055 0.0997 -0.1226 0.0552 0.0000 0.0078 0.01 18 0.0024 0.0220 Prepelvic 0.5467 -0.1669 -0.1619 -0.1254 0.3719 0.0347 0.0326 0.0196 0.4587 Prepectoral 0.3191 0.0903 0.0267 4.0567 0.1510 0.0121 0.001 1 0.0048 0.1689 Body Depth 0.0765 4.5668 -0.3089 0.0224 0.0087 0.4433 O. 1414 0.0007 0.5942 Preanaf 0.0765 -0.0080 -0.461 1 -0.2îO7 OXû37 0.m O. 1281 0.0294 0.1612 cnt.Pelvic-cn: A~al -0.~716-0.- am3 -O.= 1.3967 0.0276 1 A961 0.2682 3.1888 snt.Dorscl-ant.Anal 0.0683 -0.4220 -0.3317 -0.0642 0.W 0.1 742 0.1076 O.W 0.2903 Corsal Fin aase 0.1019 0.3365 0.2100 0.3272 0.0130 0.1430 0.0605 O. 1352 0.3517 Anal Fin Base 0.0566 0.3912 0.2543 0.4554 0.0105 0.4993 0.21 09 0.6765 1.3971 ant.Anof-post.Dorsal -0.1051 -0.5293 0.1042 -0.0355 0.01 73 0.4351 0.0169 0.0020 0.4712 Cepth ant.Peduncle -0.2894 -0.5982 0.0775 -0.31 78 0.3427 1 A638 0.0246 0.4 131 2.2443 Peduncle (Dorsal Plane) -0.3540 -0.2922 0.1222 -0.4413 0.71 10 0.4844 0.0847 1 .IO51 2.3853 Peduncle (Ventral Plane) -0.2295 -0.6202 0.3382 -0.31 16 0.3231 2.3586 0.7013 0.5954 3.9786 Depth post.P&uncle -0.351 8 0.1381 0.471 1 0.2544 0.3856 0.0594 0.6916 0.2017 1.3383 Pedunc!~Truss -0.3335 -0.4480 0.5244 -0.1702 0.3710 0.6697 0.9172 0.0967 2.0546 Interorbital -0.2475 -0.1987 -0.1026 0.2140 0.2146 0.1383 0.0368 0.1603 O 5501 WidthGPect. Insertion -0.5272 -0.1475 -0.0702 0.1 1 28 ;. 1007 0.0862 0.0195 0.W 1.2568 WidthSant.Peduncle -0.5627 0.2772 0.2077 -0.1580 2.561 1 0.6217 0.3490 0.2020 3.7338 Horizontal Gape -0.6421 -0.0142 -0.3636 0.5439 4.3186 0.0021 1.3845 3.0982 8.8034

Shaded cells indicate that the variable is highly correlated to the Axis at -0.50>r>0.50 Appendix 2 (cont). PCA loadings for pumpkinseed males (from the residuals analysis).

Pearson Product-Moment Correlation 9'0 Variation Accounted for bv Each Axis Axis 1 Axis 2 Axis 1 Axis 2 Total 96 Pecroral Length 0.2 1 70 0.3048 0.2806 0.5536 0.8343 Pectoral Width -0.3380 -0.0890 0.8376 0.0586 O .8963 Pelvic Length -0.3777 -0.0438 0.5û74 0.0076 0.5750 Pelvic Width -0.4076 0.0656 0.8782 0.0228 0.9010 Anal Fin Depth -0.9662 -0.2002 6.0436 O.2594 6.3031 Dcrsal Fin Deprh -0.5 193 0 .CM63 1.9275 0.0 153 1.9427 Predorsal 0.0277 O. 1341 0.0007 0.0150 0.01 63 Prepelvic -0.1O98 -0.0 1 a 0.0166 0.0003 0.0169 Prepectoral -0.0 lm 3.1 715 0.0002 0.0483 0.0484 Body ûepth 3.7862 O. i 704 0.0569 0.0470 0.iW Preanal 4.0959 0.0375 0.006 1 0.0009 0.007 1 ont .Pelvic-ant.Anal 0 .O054 0.0 1O3 0.0002 0.0007 0.0009 ant.Dorsal-ant.Anal -0.2232 0.3052 0.0539 O. 1 008 O. 1547 Dorsal Fin Base -0.0732 0.2996 0.0075 0.1254 O. 1329 Anal Fin Base -0.2850 0.31 14 0.2930 0.3500 0.643 1 anr.Anal-post.Dorsal -0.23 18 0.1312 0.0923 0.0296 0.1219 Depth ant.Peduncle 0.0238 0.0 185 0.0026 0.00 15 0.0041 Peduncle (Dorsal Plane) 0.3301 4.6343 0.684 1 2.5258 3.2099 Peduncle (Ventral Plane) 0.229 1 -0.6966 0.3560 3-2914 3 Depth post.Peduncle 0.2048 0.3085 0.1445 0.328 1 0.4727 Peduncle Truss 0.6013 -0.3745 1.33M 0.5 1 78 1.8521 In terorbital O. 1261 0.3648 0.06 16 0.5 156 0.5772 Width3Pecr. Insertion 0.1254 0.4522 0.0688 0.8958 0.9646 Wid?hiC3ant.Peduncle 0.2303 O. 1024 OS 123 0.0939 0.6062 Honzontal Gape 0.1976 0.5550 0.4525 3.5685 0.021 1

Shaded cells indicate that the variable is highly correlated to the Axis at -0.50>~0.50 Appendix 2 (cont). PCA loadings for rock bass females (from the rcsiduals analysis).

Pearson Product-Moment Correlation Oh Variation Accounted for by Each Axis ----Axis 1 Axis 2 Axis 3 Axis 4 -Axis 1 -Axis 2 -Axis 3 --Axis 4 Total % Pectorci Length 0.1312 0.5050 0.3284 0.3121 0.0802 1.1907 0.5027 0.4541 2.2278 P~crorclWidth 0.006i 0.4609 0.0747 0.5007 0.0002 1.0670 0.0281 1.2594 2.3547 Pelvic Lengrh 0.4369 0.3057 0.0082 0.3606 0.ô42û 0.3145 0.0002 0.3904 1.3471 Pelvic Width 0.4828 0.0537 0.2834 0.3426 1 S2û1 0.0188 0.5240 0.7656 2.8285 Anal Fin Deprti 0.6512 0.2348 0.1737 0.338 2.7838 0.361 9 0.1980 0.82ô3 4.1699 Dorsal Fin Depth 0.6668 0.0238 -0.0767 0.1234 2.5123 0.0032 0.0333 0.0861 2.ô3.49 Predorsal 0.0726 -0.0470 0.0870 0.0363 0.0027 0.001 1 0.0039 0.0007 0.0085 Prepeivic 0.0100 0.1 191 0.1104 -0.1745 0.000'1 0.0102 0.0087 0.0219 0.0409 Prepectoral 0.2843 0.2215 0.0392 -0.0358 0.0755 0.W 0.0014 O.OC12 0.1240 Sody Dapth 0.6206 -0.439a 0.1739 -0.0022 0.7W 0.3842 0.06û2 0.0000 1.2108 Prsanai -0.4734 -0.2014 0.3742 0.3695 0.2005 0.0363 0.1253 0.0043 0.3663 cnt Pelvic-cct Anal -O.- -0.3976 0.671 O. 1309 2.2219 1.2242 1.6193 0.1329 5.1983 ant.Dorso1-anr.Anal 0.491 1 -0.4548 0.2033 0.0017 0.4997 0.4280 0.08% O.GO00 1 .O139 Dorsal fin Base 0.7491 0.3089 -0.0079 -0.0978 0.0177 0.0760 0.0076 0.0076 0.1090 Anal Fin Base 0.6143 0.1W -0.2310 -0.2835 1.0110 0.0!577 0.1441 0.2153 1.4281 ant.Anal-post.Donoi 0.7753 -0.1384 -0.0253 -0.0682 0.9394 0.0300 0.0010 0.0073 0.9778 Depth ont.Peduncle 0.40c10 -0.4386 -0.0198 0.1681 0.5248 0.6185 0.0013 0.0909 1.2355 Peduncle (Dorsal Plane) 5A750 -0.1017 -0.3M2 0.4146 1.3920 0.0639 0.8186 1 .W 3.339 Peduncle (Ventral Plane) -0.3441 4.3652 -0.4847 0.5094 0.8724 0.9825 1.7306 1.91 16 5.4970 Deprh pos:.Peduncle 0.3733 O. 1940 -0.0148 0.0850 0.2953 0.0798 0.0005 0.0153 0.309 Peduncie Truss -0.1882 4.2223 -0.31 24 0.3897 0.0726 O. 1012 0.1999 0.31 11 0.6847 Interorbital 0.5919 -0.4744 -0.4105 -0,0614 3.3149 2.12% 1.5943 0.0357 7.07a8 WidthGPect. Insertion 0.093 4.0649 0.2666 -0.1347 0.0371 1.8329 0.2898 0.0740 2.2038 [email protected] -0.2297 -0.5201 0.3546 0.1582 0.3W 1 .a685 0.8686 0.1 728 3.2743 Horizontal Gape 0.4773 -0.521 6 0.2588 0.1 187 1.5879 1.8970 0.- 0.0982 4.û498

Shaded ceils indicate that the variable is highly correlated to the Axis at -0.50>~0.50 Appendix 2 (cont). PCA loadings for rock bas$ males (from the residuals analysis).

Pearson Product-Moment Correlation O/, Variation Accounted for by Each Axis ----Axis 1 Axis 2 Axis 3 Axis 4 -----Axis 1 Axis 2 Axis 3 Axis 4 Total Oh Pecioral Lengrh 0.4339 0.3863 0.2213 0.1879 0.6713 0.532û O. 174 0.12M 1.5039 Pectoral Width 0.2162 0.2725 O. 1428 O. 1 107 0.2304 0.W O. 1005 O.OC>Od 0.7573 Pelvic Length 0.6745 0.1859 0.0223 0.1951 1.8106 0.1376 0.0020 0.1515 2.1017 Pelvic Width 0.m -0.0771 0.0341 0.0469 1.6572 0.0350 0.0069 0.0130 1.7121 Anal Fin Depth 0.6265 O.2ûû8 0.M 0.1875 2.7655 0.2839 1.5220 0.2478 4.8193 Dors01 Fin Depth 0.5503 -0.0531 0.3681 0.4593 2.0231 0.0188 0.9051 1.4094 4.3564 Preaorsal 0.0452 0.0452 0.0246 0.0370 0.0009 0.0009 0.0003 0.0006 0.0027 Prepelvic 0.3319 0.0378 -0.1053 -0.0212 0.0710 0.0009 0.0072 0.0003 0.0794 Prepectoral 0.381â 0.1320 4.1288 -0.1 123 0.1516 0.0181 0.0173 0.0131 0.2001 6odv Depth 0.3153 4.6778 0.1486 -0.1597 0.1730 0.7901 0.0380 0.0443 1.0549 Pranal -0.2723 -0.1983 -O. 14Q7 0.6356 0.0619 0.0328 0 O187 0.3371 0.4504 cn: Peivic-ant.Anal -0.&92 -0.3438 4.1018 0.7032 1.7944 0.0632 0.0844 4.0308 6.8728 ant.Dorsal-ant.Ana1 0.2384 4.6831 0.0859 4.0483 0.1014 0.8321 0.0132 0.0042 0.9508 Dorsal Fin Base O. 1 X34 0.0243 -0.221 1 -0.3215 0.0094 0.0004 0.0318 0.0673 0.1089 Anal Fin Base 0.4310 4.0897 -0.0001 -0.2974 0.3797 0.0165 0.0166 0.1807 0.5934 ont Anal-post.Doncl 0.4023 -0.5590 0.1288 -0.3515 0.2543 0.4909 0.0260 0.1941 0.9653 Depth ant.Peduncle -0.0415 -0.5140 0.4623 -0.2021 0.0069 1 .O557 0.8541 0.1631 2.0799 Peduncle (Dorsal Plane) 4.5988 0.41O8 0.4756 0.0167 2.9146 1.3715 1.8387 0.0023 6.1270 Peduncle (Ventral Plane) -0.4291 0.2587 0.6380 -0.1374 1 .a325 0.5207 3.1668 0.1469 5.266ô Depth post.Pedunc1e 0.1676 0.0303 0.1 162 -0.0118 0.0572 0.0019 0.0274 0.0003 0.- Peduncie Truss 4.3771 -0.07C9 0.5658 -0.2020 0.4190 0.01-48 0.9430 O. 1202 1.4969 Inrerorbital 0.M24 -0.2740 0.1330 -0.4413 1.1702 0.4489 O. 1058 1.1646 2.8896 'NidtnGPect. Insertion -0.201 1 -0.6685 -0.0240 -0.0835 0.2668 1.7489 0.0023 0.0273 2.0452 [email protected] -0.4279 -0.4314 0.091 9 -0.08 13 1.2505 1.2707 0.0576 0.0451 2.6230 Horizontal Gape 0.1462 -0.6728 0.4677 0. 1 137 0.1433 3.3379 1.6131 0.0953 5.1914

Shaded cells indicate that the variable is highly correlated to the Axis at -0.50>r>0.50 Appendix 2 (cont). DFA loadings for pumpkinseed females and males (from the residuals analysis) given as Canonical root pooled with group correlations.

Females Males Root 1 Root 2 Root 1 Root 2 Pectoral Length 0.29 13 0.0635 -0.3762 -0.0550 Pectoral Width 0.1 183 0.3045 -0.001 5 0.1 749 Pelvic Length 0.1 41 9 0.1 180 0.0461 0.2264 Pelvic Width 0.01 81 0.1 527 0.0943 -0.0569 Anal Fin Depth -0.3664 0.1 61 2 0.2275 0.2329 Dorsal Fin Depth -0.2693 0.1 200 0.2089 O. 1O63 Predorsal 0.0230 O. 1377 -0.0439 0.1352 Prepelvic -0-3591 0-0546 O. 1422 -0.0671 Prepectoral -0.0826 -0.2035 -0.1 O47 -0.0835 Body Depth -0.4374 0.0002 0.1 743 -0.1 041 Preanal -0-1 324 0.1388 0.1 477' 0.271 2 ant. Pelvic-ant-Anal 0.0072 -0.01 92 O. 1329 -0.0253 an t. Dorsal-ant.Anal -0.2794 -0.0096 O. 1307 0.1631 Dorsal Fin Base O. 1874 -0.01 40 -0.1 526 -0.0207 Anal Fin Base 0.1 851 0.0999 -0.0989 O. 1859 ant.Anal-post.Dorsal -0.2523 -0.1 140 0.1418 -0.0 138 Depth ant.Peduncle -0.2574 -0.281 3 O. 1538 -0.3998 Peduncle (Dorsal Plane) -0.0289 -0.3329 0.031 3 -0.0777 Peduncle (Ventral Plane) -0.0262 -0.0607 0.0997 -0.081 9 Depth post.Peduncle 0.3020 -0.0741 -0.1619 -0.1 789 Peduncle Truss 0.1 106 -0.2243 -0.0981 -0.4072 Interorbital 0.0203 0.0629 -0.1 628 0.1 O32 Width @ Pect. Insertion O. 1403 0.0288 -0.1 360 -0.0384 Width @ ant.Peduncle 0.251 2 -0.2875 -0-0986 -0.0564 Horizontal Gape 0.061 4 -0.1567 -0.1 133 -0.2502

Shaded cells indicate that the variable is highly correlated to the Root at -0-30>h0.30 Appendix 2 (cont). DFA loadings for rock bass females and males (from the residuals analysis) given as Canonical root poaled within grobp conelations.

Females -Males Root 1 Root 2 Root 3 Root 1 Root 2 Root 3 Pectoral Length -0.0014 -0.1721 0.5409 0.2202 -0.1 342 0.5321 Pectoral Width -0.0854 -0.2781 0.1 354 0.0943 -0.1492 0.0036 Pelvic Length O. 1 208 -0.2496 -0.0576 0.2522 0.021 3 -0.0781 Pelvic Width 0.1 621 -0.2537 -0.1 780 O. 1 850 0.1 173 -0.3298 Anal Fin Depth O .2922 -0.2077 0.1217 0.2038 0.1 710 0.1 644 Dorsal Fin Depth 0.291 7 -0.0769 O. 1 559 0.0704 0.2468 0.2496 Predorsal 0.0577 0.1 61 3 -0.0320 -0.1226 0.1 098 -0.0621 Prepelvic 0.01 12 -0.1277 O. 1 744 0.2482 0.01 22 -0.0915 Prepectoral 0.08 1 6 -0.3453 -0.0718 0.31 80 -0.0692 -0.2063 Body Depth 0.5995 -0.1061 -0.2251 0.2558 0 A887 -0.0393 Preanal -0-1 1 89 O. 1095 0.0462 -0.1533 0.0288 -0.0971 ant.Pelvic-ant.Anal -0.0909 0.2840 -0.0398 -0.3291 0.0693 -0.1121 ant.Dorsa1-ant.Anal 0.4699 -0.1470 -0.0448 0.21 69 0.4566 0.0751 Dorsal Fin Base -0.1122 -0.1987 0.0894 O. 1 528 -0.2203 0.0253 Anal Fin Base 0.2366 -0.2954 -0.1760 0.2743 0.1 543 -0.0806 ant.Anal-post.Dorsa1 0.5905 -0.3229 O-1285 0.3777 0.5600 0.0571 Depth ant-Peduncle 0.4552 0.3036 0.1 679 -0.0925 0.4533 0.2 1 07 Peduncle (Dorsal Plane) -0.1742 O. 1 709 -0.1 555 -0.2897 -0.2188 0.3577 Peduncle (Ventral Plane) -0.0136 0.3035 0.0460 -0.1734 0.0799 O. 1 888 Depth post-Peduncle 0.1 296 -0.3654 -0.0902 0.0484 -0.1555 0.0962 Peduncle Truss 0.0276 O. 1047 0.1495 -0.1926 0.0841 0.4460 Interorbital 0.3678 0.0484 -0.3544 0.0960 0.2652 -0.2609 Width @ Pect. Insertion 0.1 609 0.2263 -0.3907 -0.1321 O. 1 749 -0.0479 Width @ ant.Peduncle -0.0020 O. 1683 -0.0451 -0.0628 0.0158 0.0969 Horizontal Gape 0.3397 0.2833 0.0065 -0.0871 0.5565 0.0233

* Shaded cells indicate that the variable is highly correlated to the Root at -0.30>~0.30