l"'OLYTENY ATm SIZE VAEIATION IN fJLC'l'IC l'~J OHD
p,~mUDOC11LANUS
Susan 1'1. \'loods POLYTENY. AND SIZE VAlUATION IN 'J'l-IE COPEPOD, P31lJDOCALANU~,
li'ltol-'l 'J'~10 SEBI-IJlNDLOG1CED FIORDS TIl BAF'l·'DJ ISLAl.\fD.
by
Susan l-i. lrloods
A thesis submit.ted to the Facult;y of Gracluate ,Studies and Hesearch in partial fuli'illmcnt of the requirements for the derree of Master of Science.
Narine Scierces Centre, fI)cGill Univers it.~r , Hontreal. A prl,°1 19()'7'
(c) Susan M. Woods 1967 ii
TABLE OF.' CON'I'EN'rS
LIST OF 'l'ABLES · iii LIS'r OF FIGURF.1".l • • • • • • • • • • • • • • iv
INTHODUCTION • • • • • • • l
sM TEHIAU:: AND hETHODS. • • • * • • • • • • • • • 4 Samplinf; methods · • • 0 • • • • • 4 / DGtermination of volume ratios • • • • • • · • • • 8 0
Chromosome staining • • • • 0 • 6
Staining and c~rtophotometric analysis of nuclear DrfA · 0 ...... • ...... 6 EINlnONM11.J'I' . • • • • ?
General descr:i.ption of the environment .. .. • ...... 7
Environmental factors affGcting size ...... 0 • 7
'l'I-Œ LAlleE AND SIv~ALL FOlTI1S OF PSEUDOCALANUS ...... · Il
l'·;orphology .. • ...... • .. · Il
Body size ...... • .. .. • .. • . .. .. • .. Il
Egrr size ...... • ...... • • 20
Chromosomes ...... • 20
Polyteny and nuclear DNA content .. 0 • ...... 22
Effects of DNA ...... 0 .. • 24
Adaptive value of DHA .. .. • .. . 0 ...... • .. .. 26
Abundance of the polytene Psendocalanus • ...... 29
Polytene Pseudocalanus as a nevI species .. • ...... 32
• • • • • • • 0 .. • 33
AC ;~Nmj1EDGEr·ŒN'l'Ej • .. 35
DIBLIO~~EAPHY .. o 36 .. h!.l - iii -
LIST OF TABLES
TABLE PAGE
I. Results of photometrie measurements of DNA-Feulgen complex on nLlclei of five small and five large egGs corresponding to the 32 cell stane 0 •••••••• • • • • 25
II. Comparisons of sizes of the large and small forms of PseLldocalanLls from Ogac Lake, 1965 and \-Jint')n Ba;)r, 1964 • • 27
TII. Estimated nLlmbers per m? of cOl?epodite~; of the large form of Pseudocalan'1s in all available samples from the middle basin of Ogae Lake in 196.5 and from the outer basin of Hinton Bay (exeept for the collection on August 20 1Jh:i.eh l'las taI.en from the inner basin) in 1964. . . 30
IV. Estimated numbers per m? of copepodites of the large form of Pseudocalanus in tl';,:, middle basin of O(:;ac Lake in all
available samples from August of fOLlr Jrears ••••••• 0 31 - iv -
LIS~[' OF FIGURES
FIGURE PAGE
1. Nap showing location of Ogac Lake and Hinton Bay •• . . 2
2. Forms of Pseudocalanus • • • • • • • • • • • • • • • • • 12 3. Fifth lee: of adnlt males (wi th cephalothorax lengths) of
. Psel.ldocalanus • ~ • • • • • • 0 • • • • • • • • • • •• 13
l.1. First leg of adult, f'emales (with cephalothorax 1eneths) of Pseudocalanus • • • • • • • • • • • • • • • • • • •• 11.1
5. Size distribution of copepodite stages oP and ~ IV - VI inclusive from Geac Lake (August 6, 1965) éilld Hinton Day (August 15, 1962!) ••••• '. • • • • • • • • •• 15
6. Size distribution of copepodite stages l - III inclusive from Ogac Lalce (AUGust G, 1965) and Hinton Day (AuG;ust 15, 1961.~). • • • • • • a • • fi • • • • • • 0 • • • • • • •• 16
7. Size distribution of nauplius stages l - VI inclusive frOJn CJf;ac Lake (August 6, 1965) êmd Hint on Bay (August 15, 1964). • • • • • • • • • • • • • • • • • • • • • • • •• 17
8. Nauplius stage l hatched fJ:'om adult ~ ~ from Qrrac Lake Hi th nauplius cephalosome 1encth and femél1e ce~)balotborax 1ength • • • • • • • • • • • • • • • • • • • • • • • •• 19
9. Craphs cOlilparinL~ aciult fema1e cephalotlIorax 18n[I"L118 and diarnetero of the atktched egcs of Pseuclocalanus. • • •• 21
10. Aceto-orcein-stainecl haploid sets of me"taphasG chromo- somes fron fresh esrs •••• ...... 23 INTRODUC'l'ION
Seasonal size variation within local populations of the copepod
genus Pseudocalanus has recently been studied in relation to tempe rature
and food differences (Deevey, 1960; NcLaren, 1963, 1965b). Collections
taken from June l to October h during 1957 by I.A. 11cLaren trom Ogac
Lake, a warm semi-landlocked fj ord in Baffin Island, llOWeVGr, revealed
size variation lvithin a population of Pseudocalanus underroin~ similar
environmental influences. 'l'his situation was found later, in 1964,
to occur clea.rly in Pseudocalanus samples collected l'rom the semi
landlocked head of vlinton Day on the east coast of Baffin Island. The
posi tions of Ogac Lake at 62 0 52'N and 67°2l'l~ and Hil1'Lon Bay at
63°2L(' N and 64°39'1rJ are shoHn in Figure 1.
Previous collections taken from Ogac Lake in 1952 by an Expedition
arranged by r-i.J. Dunbar unc1er the auspices of the Ardic Institute of
North America and later samples collected there in 1962 and 1965 by
LA. ~;cLaren have been examined for the appearanee of these size forrns.
'l'he larger formt> bear e[';f'.s of a siGnificantly larger size than
thooe of the smaller forme No mention of such a lar[';e-e::med l'orm
oecurrint; els81iJhere has been found in the li terature. It -VIaS consider'ed
possible (l'lcLaren, 1965b) that these larGe animals Here ]lolyploid, but
this hypothesis Has not examined further at that tirne. Therefore a
comparative study of the size forms, their chromosomes, and their nuclear
DNA contents has been carr:ied out and is presented here.
The morphological i'eatures of both forms, excluc1ing size,
coincide Vii th the detailed description of PSGudocalanus gracilis by
Sars (1903). H01v8ver) i t is uncertain \Vhether the c;enus Pseudocalanlls
is cornprised of tbres distinct srecies, P. elongatus BeGek, - 2 -
6~-r ______~~~----~m---~--·,------~~~--r---~
64° - 1 ! _.------_/
.JZigure l l'~ap sho~ving location of Ogac Lake and Hinton Bay. - 3 - f.. gracilis Sars, and .E. mari or Sars (see llrodsky, 1950; Hiborg, 1954,
1955; Sars, 1903) or i-lhether the spccies described are actually synonymous l·rith ~. minutus (Kr~yer) as assumed by some authors (Jespersen,
1923; With, 1915; st~rmer, 1929; ,Narshall, 1949; Farran, 1951;
Fontaine, 1955; ~stvedt, 1955). For this reason, and also due to the appearance of the hHherto unknovm larr.:e-egged form, the animaIs discLlssed here will be referred ta only by the e;eneric name. - 4 -
MATERlAIS AND HETHODS
Sampling methods. The methods used in the collection 01'
Pseudocalanus vlore based essentially on those of ~jcLaren (YlS 1961). The
schedule of the hauls from vThich the various values were determined is
tabled in Appendix l. Some other samples referred to in the text, for
example from Frobisher Day and elsevlllere, were not collec'ted quanti tatively
and are not listed in Appendix 1. The material from 1957 and 1962 l'laS analysed by LA. f!jcLaren and made available for investigation hefe.
It can be seen that a vnriety of net sizes and meshes l'JaS used from year ta year. AlI the vertical hauls Hith the no. 6 nets lvere made from the anoxic depths (beloH 30 m.) ta the surface and thus can be assumed ta have sal:pled the "lh ole uater column. In aIl years, except 1952, these nets were hauled at a rate of approximately 0.5 m. pel' sec., ~vlüch allolvs estimates for numbers per m. 2 to be made (see belDlv).
Depending upon the allLlndance of the c0gepodi te stages in the complete haul, the counts of the stages uere assessed from either the
~vhole sample or a random subsample. EgL-bearine l'emales l"lere removed from the 1-1ho1e sample to avoid detaching the eggs in the act of sub t3amplinr;. 'l'he subsamples uere taken from thorough1y mixed samp1es, from Ivbich laré'e obstructing ore;anisms had Leon removed, by a 1ar8e bore suction pipette and the volumes measured in a graduatod cy1inder. The sizes of the subsaTf!p1es varied but they 1-101'0 usua1ly 10;~ or [';1'82..tor.
Counts 0:1 the naupliar s"l;ages vJel'e macle from random :':311Lsan~plcs of
10 - 20;,; Vlhich Here measnrecl in the above manner.
In arder to estimate the abundance of' copepodites of' the small and larr;e forms, the total numbers of aIder copepodites (stages IV to - 5 -
11/\ VI, or stage VI alone where these Here sufficiently common) liere
calculated for the no. 6 nets, since these are assumed to be 100;~
el'ficient in retainine; animaIs of this size. The estimates could then
easily be converted to numbers per m. 2 from the Imo1 (Appendix I). In order to estimate the abundance of younger stages (copepodites I - III), their numbers ,,18re calculated relative to those of older stages in samples from the no. 20 nets, wlüch are assumed to retain all stages vTith equal, but less than 100?; efficiency. 1'he one exception lias the determination of the abundance on August 3, 1965 in l!inton Bay. 'l'he estimate::; for aIl staces liere calculated from a no. 20 net as only the one co llection liaS talcen iihat day. Unfortunately, not ail the no. 20 nets l'mre hauled t'rom full depth, and some stages nlay Le clisproportionately represented e Uni' ortunately also, only samples from fine-mesh, no. Id net hauls are available t'rom 02:ac Lalce in 1952. Numbers are, therefore, caleulated assumine this net to be 100;~ efficient for aIl staees. It is possible that tbis efficiency was, in l'act, almost achieved in the phytoplankton-poor waters of August when the samples used here were collected. The cephalothorax lengths of the counted copepodites liere measured under a dissectin(~ nicroscope tlhile the cephalosome lene;ths of the naupliar stages and the e8[': diameters '\'lere measured under a compound microsc ope. 'l'he naupliar sta~~:es liere ident:ii'ied l'rom the dia[';rams by Ogilvie (1953). rehe egg diameters were deterrninecl l'rom the averac;e of the DIé1.ximum and minimum diameters of each erx, if it l'las not perfectly spherical. In order to compare the adult female cephalothorax lenc;'Lhs and the egg diameters, only those egc;s still attached to 'lhe females Nere measured. - 6 - Determination of volume ratios. The volume ratios of adult females and stage l copepodites were calculated by cubine mean cephalo t.horax lengths, assuming that the large and small forms "l'J'ere the same shape. The volumes of the small and large eggs vIere calculated from the mean diameters, ass uming the diameters to be those of two apheres. 'l'o estimate the volume ratio of t.he nuclei of the small and larf,e forms, ten adult females of each form 1iere stainec1 in haematoxylin ano sql1ashed in pe:cmount on separate slides. Like other organisms, cope pods exhibit somatic ploidy (Stich, 1962) and therefore only a single common type of nucleus - spherical and densely staining - HaG measured. The c1iameters of ten sl1ch nuclei in each ferr;ale "\Vere measured and the mean diameter of the tHO forms calculatec1. Again, assuminc the clial11Gters to be th 0[38 of ti.'ro spheres, the relative volul7'.8s "\·;rere calculated fI' Dm the p.Jean d iametel's. Chromosome st.aining. Incident.ally to studies by I.1\.. r'IcLaren on dcvelopment rate Di.' copepod e.(;(':s (NcLaren, 1966), fresh eggs Hore secured fo!' chromosome study. The egcs or carly embryos "VIere squashed in aceto-orcein st.ajn. The sql1ashes Here then covered and the slides sealed. Only the chromosomes of eggs at the metaphase staGe of division were used for comparison. Staining and cytophotometric analysis of nl1clear DN.~. Cytophoto rnetric analysis has been employed ta study the relative amount of nuclear DEA in ep;gs of the snlall and large forms. These lIere from formalin-preserved plankton samples ta1cen at Ot:ac Lake in 196.5. Ee:gs of each form t'18re trea'Gec1 concurrently ta avoid introduction of variants due to the staining procedure. The GfftS l'lere clefarmalinizecl by wasb inp; in clistilled lIater for 15 min. and soakinr~ in tHO 2LI hl'. changes - 7 - of 20% aqueous chloral bydrate. 'l'hey 1'1ere then 1fashed for 15 min. in distilled 1vater before staining (Lotho and Vaz Ferriera, ci ted by Davenport, 1960). The Feulgen reaction (de Tomasi, 1936) vlaS employed as a measure of relative amount of nuclea.!' DNA. The specificity and stoicbiometry of this reaction have been validated by Novü:off (1955), Stmvell (1946), DQdson (1946), :3wift (1953, 1955) and Leuchtenbert3er (1958). Follmv:i,ng deformalintzation, the eges were bydrated in 70~~ alcohol fol' 2 br., .5oïj alcohol for l hl'. and 30;'~ alcohol for l hr., then lœpt in distilled llater for 12 hl'. They Here rinsed in cold IN HCl for 2 mtn. and th en h~rdrolyzed in IN HGl for 9 win. at 600 c. Aftel' bydrolys:Ls, the eGUS i"lCre rinsed in colcl l1J HCl for 2 min. ffi1d 1iashed inthree 10 li'Ïn. changes of dis'Lilled Nater. The e~zs ',-Iere next tr'eated H:i,th ;.)chiff' 3 rear,ent, for 45 min. Several non-llydrolyzed 8[![:;S served as a control. The er,Œs tvGre removecl from the reagent and l'Iere transferred iihrough three 10 min. changee of sulphurous acid rinse. 'l'hey Here then Hashed in three 10 min. changes of distilled uater, dehydrated in ausolute alcohol for 10 min. and cleared in alcohol-:cylene (1:1). Squash pret)arations Di' these ev,[;s 1vere made and mounted in oj.l of refractive index (H.P. Cargille Inc.) to match the nuclear refractive index (small form, 1.580; large form, 1.592). Ic~easurements VIere made on Squasll preparations of the small and large e[[';8 each mounted on S8!)arate slides in oil of refractive index by a cytophotometer construded by Otto C. vJatzka Co. Ltcl. (]\'Iontreal). For the theol'ctical backgrolmd and cletails regardins equipment, the reader is referred to the orieinal rnpers (Caspersson, 1950; Siüft, 1950; Pollister, 1952; S1vift and Hasch, 1956; Pollister anù Ornstein, 19S5, 19.59; l'!endelsolm, 1958a). 'j'lle cytophotometric technique used l'JaS - 8 - the aperture me th od, and all measurements were by t.he tuo \mvelength !rethod (Ornstein, 1952; Patau, 1953). Absorption spect.rurn measurernents "J'ere tal=en 10 D1)l apart; the maxiplUm absorption at À ;;70m)l l..ras selected aa one I-Tavelength. 'l'he second uavelength "\las estimated b::r linear re(';re3sion (Garcia, 1962) and ul timate ly es tablis hed by trial éL.'1d error at À 500mp ~ S ubsequently , transmissions at À 570mp and À SOOTll)l Here Ilsed as a measure of amount of nuclear DNA per celle Duplicate readin~{s i·mre tal:en of 10 nuclei in fi 'le eggs eélch of the small and lar[':e forms at thE: 32 cell stage. The avex'at:e eX'Linction for cacil .field HélS ob-liained from Lendelsohn 1 s'l'ables (Nendelsobn, 19.58b). SincE: tl](3 en tire nucleu3 I-Tas included in the photometrie fielcl, the total af'lOunt of chroiilatopbore per nucleus vras estimated by pmltiplyin[; the averaf;e extinction by the area of thE: photometrie field (small, 523.0 Jl2; lal'f!e, 20E:.!.~.6 Jl2; Bee Table J:). - 9 - ENVIHONFENT General d~scription of the environment. Oc;ac Lake, its hydrography and its zooplanl,:ton have been descriuecl in detatl by HcLaren (FiS 1961, 1967). The lak8 lies at the head of Ney Harbour, an inlet on the south"lest shore of Frobisher Flay. It is divided into t.hree basins b~r shallo,i sills 'Vrith oxYeen a.bsent and H2S present belo"l 25 m. in the 101,)'8r basin, 30 m. j.n the midàle basjn, and 32.5 Trl. in the upper basin. 0 The suri'ace ,'raters are fresh and the salinity increases t.a 27 /00 at depth. 'l'he thresbold oi' the lako is so higb that only the hi[;hest tides from Frobisher Bay are able t.o fI o.'! j.nto the lali:c replenishin[; its salinity. 'l'h:r.oUi;hout tbe ;:rear OcacLake is mucb .."armer than the sea oui;side due t,1) :L'ts small ::;ize, its landlocked nature, and Li'}'; conservé.üion of radian:1i heatinf': b~r :L ts hir:;h ly stable \'Ta te.rs. ~,adiation causes considerable uarl1\in[; at de:)'lihs -Ga about 30 ln. Du:r.:i.nf. the 'I·rinter j:l, i3 jnsulatcd from heai; lODS by its ice and sno\'T cover. 'l'he l~ead of ~;j.nton Ba~.r, '\-Jhich is sitnélted on the soutlmest sh:Jl~c of LClbinson :3Duncl, is sirdlar ta O[';ac Lake in many Di' its physical aspect,s (r.;~Laren, 1967). It is divided into tHo basins Ly a 8ha1101'; sill. '.I.'he inncr bas:Ln is devoid of oxy[en at 31 m. as is 0 the outer basin at 32 ffi. Md tbe salinity increasec to 32 /00 at cle,')th. 'l'he ;,iaters are Harmer than t.hose oi' the bay outside due to thc sar,le causas 1Vlüch prevail in Of,ac l,é,]œ but 2,).'8 coolcr thm.... those of O:::élC Lake. Both O;?;ac Lokc élnd l)inton Bay are 8xtreHie eXaJi~plC:J of the i'j ord condition as c'le:Jcl'ibed L:'y Dunbar' (1950). Environmental factors a~';ecting size. Deevey (19(;0) Sl!Ol1Cd - 10 - that size of copepods Ü1 strone1y correlated vri.th temperatnre of the onviromnent and cstimateo amol.lnts of .food, but that the degree of dependence upon these factors varies Vlith the geosraphica1 aI'ea, ",nd espociallv the tempel'aturc J:'an[::F, of' the species oe:;.nc considered. j/cT..Iaren (1903) bas demomïl.ra"l:.od "l:.hat fol' 80me r;roups of poil:ilotherms, incluc1inc; calanoid copepods, size at any Stél.[<:8 of developmcnt is a lunction of tcmpsrature a10ne al th o11[:h lack of .t'ood ma;;,r t.h~mrt f'l'OlTth and developn:ent. 'l'he si.ze-temperature curve r:iv8n by llicVn'8n (196Sb) l'or Pseudoca1anus in the East,ern Canadien Arctic sbows Q raiïher siiGG)) , inverse size-tompera"l:.l1l'o relationsll:i.p. In trIO six f.';eocra~)hical area3 st.nc1 iE.cl Ly ~;cLar·3n (l96:.;b) only in tlle one locali ty of LOGh ;'.ltrivon HA.8 eg[~ size found to be nObativel;Jr correlated Hith temperaturo :.mc1 positively correlatecl HHh the mean female lenc;th. Even then, although the femalo lensth varied about 3S~·;, 8fT size varicd only 7:'.. CorrElations in othr:r locations \"lare not s:i.cnHicant. - 11 - 'l'lIE LJ\.RGE AND s}~ALL FORHS OF PSEUDOGALM,Tt.TS IV'orphrüoE-Y. As aforenlentjoned, "h..ro .t'orr,lS of Pseudocalanus 'Vlh:l.ch vary only in size éJre .round coexü;'cinr:: i.n both \)plC Lake (HcLaren, 196.5b) and \r{inton Bay (Fi2ur~ 2). The morpholoGical featuros arc similar to t;'ose attributed to f. :il'acilis by Sars (1903). The head of UlG adult copepodite j.s GJ.ii~h·U~r tapered. The firsi. leGs of the adult feJTJ8.1c are slilél.Jler T,han the othe"c J.efs and 1:cal' one lonr; aeta on the inner side of eaclj basipod. The basal seur.ents of the asyrnmetrical fifth pair 'Jf 16;;s ui tb3 aduH mo.le al'e approxinlately equal in length. The pointed tJorminal se'::;r::ent. of tho r::.ght lep;, wbich cunsists of t.hree segl:ients, is about equal in 1enC':t.h to the basipod. 'l'he left lee ~.s longer than the right ~nd, includiné~ the 1.);J.3i~od, consio"Ls of .L'ive segiilents. The ternlina1 Geg'lient of '0he 1eft 1er' 10 tipped l,'Tith a slender cpinu1e. 'l'he authors (nrodsky, 19.50; Sars, 1903) HliO ha.ve c1i.LferE:ntiated between the species/ Gwploy t11e firth pair of.' appenda[!:es in the adult male o.nd the J'irst pair in t!-;(~ adult lcmale as -LuC! of the principal distinguisltinc; fea'Lures of each GpE.:cies. 'l'he l'Elspective ap?endases sho~·ri.nz the similarj:ty ,)f t1;8 larn;E. and s;-I1<111 :~:)l'rns aro p~'GfJEmtcd in Figures 3 and 4. J:3ody size. AlI copepoditoG and nauplii cüntn:i.ned in c:oIliplete saTr:pl0's or subsamples col1ected ù'om ~'Vinton ;~a;y in 1964 and ()gac Lake in 196.5 l'Jere measured e i thel' for cephalothorax len8:1,h in tt-le case 01.' tCje copepodi tes Dl' lor cephalosome ::.6n[':1,h in the naupliar sta~~es. l'he frequencies and size cJistriLutions recorc.led from one collection ta\ësn trou Of~ac Lake on AUGust 6, 196, and one from l'linton Bay on Au~,;ust 15, 1961.( are presentecl in Figures S - 7. The frequencies s!1cnm for the - 12 - -- .... \ 1 1 1 1 1 1 1 1 r. 1 ., 1 1 1 1 [ 1 [ 1 ! - 1 '. ". - ... -. ---- _. --_ 1 1000)1 Forms of Pseudacalanus - upper: fram western Hudson St:cait middle: lare:e-egged form fram Ogac Lake IO'l-1er: dominant small farm from Oeac Lake w1-' b 100).1 a c ?igure .3 ?ii'th leg of adult rrlales (lJith cep:la.lot~02.·2.X lengths) of Pseudocalanus from a ) -\-:lèl.. t on -;:.;ay (1ar[e .!:orm~ = 1"00u/ • 3):Jl , b) -',illl"on . .1. DayT- ( sma11''' lOI'R - 007"7 .,)1),~ \ and c) ,iestern Hudson Strait (1097 .2p.) • .:':..ll are ta the same sca1e (abave). ri (,-1 r\ o C\! u 1.: ~, U) CI) ...... / ,.C: '" \1) t~:i '~{i ~) .~I ,-·1 o ~I ~j rt Cl o ,.\.:!+, ,----- 0 ,0 ,-1 CÙ .... :~ ~ ,C·: 0 r, ----- C, " , 0 ,:> ~p"\ 0 .',;) J ij\ N ..... -.. , ,.C: ,-1 ri (1) _j-'1 (\/ ~- •... TI r-I 0 ,/ ) ":J Il 'r·1 "i (0 '.- U) L'>.. , Î-' (J) ~ .j +') (L) ,·-1 () : ...) ,-1 (1.1 rl_1 c0 L-: ~ () q) Ccl Cl li.l 1 t"j j Ul " ',;J q) ..0 i:! '"'0 ::: i: ,~ r-1 ,1: ,,1 ~~ .... _"" Cf.) "c) f,: (\! ~ -. f~1 fl) CT; Q) r 1 ~: 1 ;n +" 1"' f ) V) (l r"" Cl ~~ '.r t~ ) .p , ·1 ~:. ; lI.) :r~ :: ~ ':J 0 lU Il) j., ':J r'l ·,-1·" ç' r~ (lI (,i 1 o - l.s - Ogac Lake Wlnton Bay 30 20 10 o~ __ 1300 700 BOO 900 1000 1100 1200 1300 Cephatolhorox Icnglh Ccphololhorox Icnglh loI Viel VI" A.. A. ~o:l+-~.--~~_L---~ ____ ~~.~~I~' __ -r__ ~ :j .~. . ... ~ou ïOO S'OO 900 lCioo UOO 1200 GOO 700 âoo 900 Kioo 1100 30 30 vV v9 20 20 10 1 Olt-__~~~~~ __-~~'LI~I~.~.~.~R~ ____ ~ ':.GOO "J'L,---. 700 800 ~..,...Jli"'I,JIIU;jA;JJl'.-A.'900 1000 1100 ~ 1200 700 000 900 lcioo liOO,2'00 1300 lJj~_~.~1lo011. u GOO 700 800 900 1000 lioo 1200 40 Iv9 30 20 10 IVd' IVd' ::Lt10 L L 1 ::l10 °500--~:-~00~~I'~ioo----~é~00~--9~'00----',~6u~~~I~O o 500 600 '''------'--''700 800 ~ 900 1000 1100 oize distribuT.ior! 01' cûpepodi te Cté1.g6S d'and ~ . IV - 'II incl'l;üve :'rorn Ot;ac Lako (All~:ust 6, 1965) and Iliinton ',l2.y (AUcust l~~, 1961.}). Hesults Ogac Lake Winlon Boy 70 • 60 50 r :il 30 20 10 ~." . 0 ,.. , 400 500 600 700 BOO 900 1000 Cephalalhara, lenQlh (v) C ephololhotOK lert9lh (v) 50 40 30 20 10 0 400 €OO BOO 900 1000 ~Size ,lis"tr:"LLutiol1 of co])epoc1He st.ages l - IE inclusive Îrom O[étC LélJ:::ê(AuBust 6, 1965) and (ünton Day (August 15, 1961-t). Hesults are deten1incd l'rom full volur:e of srunple. Ogac Lake Win ton Bay Ogac Lake Winton Bay 80 BQ 80 YI YI 70 70 70 60 60 50 50 C 40 Jl r~1" Lo ~30 20 10 ~ 2:1 oW. L ,~. o+~~J.J~~'~?~"~"Lr~,~~,~,-r~~ 2~O 260' 2~ 3CO XO 3':0 360 :;so 4(X) 240 260 260 300 320 340 360 380 400 CepMlos:me lenQlh (,u) Cepha lo!.ome lenQfh w) Cepholasome 1.~1h lu 1 C_tomo ~~ 1.1 50 50 1 'J 1-' =1 40 -..] :1 30 20 =1 20 ~ 10 ~ :i!220 2~O 260 , 280 300 320 3.;0" 360 380 60 60 60 N ri :~ 50 50 50 40 40 «l 40 30 30 30 30 20 20 20 20 !O 00"200" 220240 260 ~h"i, ~' &ï' <00 Z2a 240 ::sa ~j'igure 7 Size distribution of nauplius stages l - VI inclusive from Ogac Lake (August 6, 1965) and \Ji.:"'1t on Bay (August 15, 1964). Iiesults are ("letermined fror.t subsamples of 1/10 the volume of the sample. - le - copepodite stages represent the cor.·'pl-st.e s8.'Tlple l'r(,ile the frequencies of nauplj.ar stages 1·rere determined from a subsample of 1/10 volume of tae full haule î'he size ranCies (Fig. 5 - '1) of 0.11 stae;es from first nauplius to adults for both Ogac Lal;:e and Hinton Bay appear to be bimodal. The distribution of sizes obtained in t-vlO samples was tested for the 8ignificance of the difference betl·reen the tHO lIJeans (Utanley, 1963) and the difference was round to be si~nificant fOl' eacil stage (Appendix II). lJ.'he 5 ize distributions and frequencies obtainecl from the other samples col1ected during 1964 and 1965 are recorded as the mean and tl-lO standard errora for eaçh size mode for each staGe in Appendix III. 'l'hG animuls collected in hauls taken in Oeac Lake durinÉ; 1952, 19!)'l and 1962 also exhibit equally clear bimodality in their size distributions for some of the stages examined. They are Dot recol'ded here as ei ther the mea.surements were only taken for the copepodite stap;es or in sorne cases the measuremento vIere recordec1 only as the total numLer of animals occul'ring in each size Group. Collodions of livin~:' mate rial llere 11!élc1e a t Ogae "[Jwœ in 1965 by LA. I,.lcLaren, for tile purposo of studying embrfonic dGvelopwcmt rate of the large and small i'orms (Hc1élren, 1966). Hauplii of the 1a1'[;e and small forI1~, hatched at the <:lame temperat.ure (ca. ,OC), are shown in FiGure 8. Cl mrly, then, t{lO size di:fferenccs a1'e not. environment\llly induccd. It is intl'".restiï1:< to note t~:lat IJoth size :yrou)s appsarinf: in the i:d~1ton ;:58;)' collections 2"v(-)l'Z.Ce larCin' tbê.1n those in Urfac La1;:0. 'l'be GiGnificancc of tr1e di.:f' fer~Y1cG GetlIeen ti:w rr.eanG ,rns tes "Led (Ap)Jc:mài;( l'.') and in a s li;·'ht ma.i :Jrit.y ai:' 'L~\8 f,Ga,..::es Has .round ·co Le G ü"nificant. 0j.nc8 body size in i'seqclQGnJ...a.J.1J.ili 18 nei..;a·(;ively cJrrelated HUll tcr.11x~"'ature - 19 - ...... __ .... -._._-.... --- -- .... _. --... ~ .. --...... ---- ...... ''--..... ---.. -...... -..- ...... -.. -...... -- ...... _.... ·.. -1 1 Figur~ Nauplius stage l hatched from adult \!~ from Ogac Lake 'I-1ith nauplius cephalosome 1ength and female cephalothorax length. 1eft: lares form (nauplius = 168}l; ~ = 1069.4).-1.) right: small fOl~ (nauplius = 129.6p); ~ = 902.8}l) AlI are to the saroe scale (above). - 20 - (HcLaren, 1965b) the cooler waters of Hinton Bay (l\7cLaren, 1967) are efi'ec'i:.ing the increase in body size there. ~g size. In addition ta the variation in bod~r size of the two forms, the eggs born by the large form are conspicllDusly lareer than tllose of the small form. The menn diameters of sggs are plotted (Figure 9) a;:;ainst cepbalothorax length of the females beari.ng the eggs in l1auls l'rom i'Jinton Da.y in 196L, Oeac Lake in 1965, and from l?ro'oisher Bay in 1965. Î'1l0 distinct, size r..;roups appear in the lakes except for a few 1ar[;e forma beal'lng ep;iS's of btermediate size (1<'ig. 9 a,'b). NcLarer~ (1961, 196,b) has .round tnat sma11 nmlber's oi lar,?:e PS8uc1ocalanus enter O:;;ac 1.03.1(:12. at "Limes ol the llighest tides eut do not appear to survive lone and are presumaüly ill-adaptecl to the S !ldden env.Lronmental chancre. 'l'he lé.l.rf~er body size of tbese outside animaIs, Hhicb average one-tl1ird longer than the small fj ord form (NcLaren 1965b; see also Fig. 2), is due to t.he colder temperatures prevalent in Frobisher Bay. It is probable, therefore, t.ho3.t the larp;e 8pecimens bearing small er;gs hael :cecently come j.nto the lak83 from outsiôe. IlltG:t'8:Jtinr~1;v, their cgr_~s are cOlliparable i~ size 1-/11;h those from L"robioher I;ay (c.f. Figure 9 a,b, -vrj.-th FiGUre 9c). If the cgf;:S vlOre, in l'act, ~rodnc8d in the 1mrl11er 1.vaters of the fj o:ccls, this implies tnat ef3r~ size is a fllnction of female size as snch, and not t.emperatures at t.he til'le of spamüng. Cb:comosowes. It seom3 clear that neithe:;:' food nor tempe:cature could C2use the sj.ze bimodalism of tbe i!ldigenolls populat.ions oi' Pseudo calanus in the tHO lanclloc1ced fj ords a~ the3e anilr;als are experiencing the 3a;118 environmcnta1 ini'luenc8[). It \Vas considered possible (l'TcLare!'., 1965h) that the lar[~e forms cou1d be polyploids as hael been eliscovered in Calan us [inmarchicnp - 21 2UO..------. 200------' 180 180 .: 1 • 1 • 160 160 " '. 1...... ;.: ." .... !40 .3 140 '" ~ ~ ~ TI !20 -e 120 ~ w ICO 100 a b 80 700 800 900 1000 1i00IcuOl-:S00 1400 80700 800 900 1000 1100 1200 1300 1400 Cephalolhorax lenglh (u) Cephalothorax lenglh (u) 2(~r_------. ISU 10' :3 140 ~ ~ ü 128 0> rJ> W 100 c 80 7()!.' 0,:;0 ~'uO /000 1100 1200 '-~Oll 140U Cephalalharax lenljlh (u) ;:r'~'lt!~!S CJ:!jl.l~),r·irl:;· odu l-t.· .~~'··;rl;;J.IC' G(-l P11D lO·C .. ll{)l:r~·: 1en!j:i,hs O;'jc: rJÜ.l!i:ct,f.'r;' Qi.' t,"le u.Lt.:l.CI1Nl C~';~:3 of PscuJJc~~lar.lls ù.'or:) a) \'Ji~ttün 15a;; - 1~}01~, ;~) \)S~l.C L::~lœ - 19ô:;, cù:.(l c) I-'rlJbü,h8r - hG:-;. - 22 - (Ha.rding and Marshall, 195,; l-18,rsha1l anc1 Orr, 1955). Aceto-orcein squash preparations of fresh (~[!,gs revca1ed that the large forms in O~ac Lake possess t.he nonnal calanoicl chromosome complement of n=16 (I~arshall and Orr, 19~:~;) as do the s n:all forms (Fi~;ure 10). 'l't'1D ef?;s only Di' one of the large ferilales 'rJel'G discovr:red to have a chromosome complement of n=17 (Figure lOb). Accordinr; to Da~vson (1962) this is causcd O;ir the phenol1lenon referred to as non-clis,jul1ction vThore pa.irs of chromosomes J~ail to scparate at meiosis. The chromosomes of the larGe form, hou8vor, Kere not.:i,cealJly 1areer tllan those of tlle sMlll form tlnd a180 lOJ'f,er than tlJOse i'ound in fresh m.-'1terial collectcd in Frobi:.ober :.lay, l'L~1.'l'., I-laliîax, H,,~., and Iii11pol't, Scotland. J.~orr:1alj.n prcservod materialvlas available for staining from l ..Jinton ~ln;v but the dov81opTr'ent of the err,bryos Has too advanc8à ta n1101'1 a dctailed pic-Lure of the chromosomes. Polytèny and nnc1ear DNA contont. It is an acceptable theory (Hughes-Scbrader and Scl1l'D.cler, 1956) that an important factor :in the detC'rm:i,na'tton of cnromosorr.e oize is the OGcurrence of polyteny, in vThich a chromosome endoreplieates simultaneous1y a nur.1ber of tirnes and, instead of. separating, the cla.ughter strands remain t.ogether formiD[; a many- threaded po1ytenic cable (Hers1::ouitz, 1962; Altenburg, 1957; Hazia, 1961). Darlington (195Ci) has stated that "the chromosome is a nucleo- protein ...... • probably based on units consistinf, of poly- peptide cliains ta 'ilhiclJ are attached double columns ai' polymerised nucleotidc8 fOl'minr; desoxyribose nucleic aeid" and'tllat "it seems safe ta assume tbat miA is ordinarily restricted to the chromosomes" (Darlinrrton, 1955). Therefore, as chromosome size in:::reases 1.n.th ascending levels of polyteny, the nuclear mTA content inereases proportionally (see !luGhes-Schrader cmd Sehrader, 1956; I(urniclc and HerslcoHitz, 1952; 2-.J" - ,\-.: ~~; (,) uJ () .,.-1 (1) (1-1 ,.U ..J." >-< ('\ (~ ! t&~\ r,..: ~'.: ' ;. _1 ~, i··:.~ u - 1-, o (\J -~-: r-l .-.... C, _, '(j <.'.. o '"l , .1 li) ,-.... ,,) Ü 0 (':; rtj .~ ~") ,r< ~ ,,) :, ~ 1 ('j ~l (") +.:, ~. l"_1 ;:! () (--1 ;~ [n (--1 ': .. ~ ;:.: ('I-l +.) N o l'J -J :"""1 c'" ! l, :r) ~~ ·;~1 1 _;_1 (1J rl'~ CJ -:J, r-~ (,j CJ o o ''0 n "r j "CJ () o r;:! ,'~ • U ,-,1 r~J r-·I C: 'Il [.. ': ré '1j o C,-l UJ '.' c) .. , ., ~ ~ï~"j ~j? 'r': ~--' Il I~; r.,1 () s:-: ',-i GJ r-! , r--,. C) ~, ... o (IJ ',ù u 1 -1 • ~'I o -!-:. L -1 cj -p 0 -- ~~ , ___ , ~ti .:; :j ) - 24 - Swift and Hasch, 1954). Since the DNA content in the resting nücleus remains constant (Darlington, 1955) a cytophotometric analysis, as described in Materials and Nethods, was carried out on the 'Feillgen-stained interphase nuclei of the small and large forms. Although the Feulgen test cannot by itself establish the absolute amount of nuclear DNA, if the differences in DNA content are sufficientl;}; large the test does suppl;r accurate estimates of the relative amounts (Leuchtenberger, 1954; J..,.;~T.ri ... __ f'+ .."..Lo 1950) • 'rhe r8presen tative absorption spectrum for the Feulgen-DNA complex is presented in Appendix V, plotted as per cent of maximum extinction (from t.he averaee absorption spectrum for each form - see Appendix VI). versus l'Javeleneth 'ta facilitate comparison. The average absorption spectra \V'ere calculated fro};} the abs orption s pectrum measurements talœn for each of the eggs of both forms. 'l'he' average ex-Linction values for each series of photometric measurements viere analysed by the Chi 2 test (~3nedecor, 1956; Duncan, 1959) and lV'ere found to have a normal distribution (Appenûix VII). l'he results of the photometric analysis sllOvl that the ratio of the relative amount of DNA per nucleus in the large form to the small form is approximately 7:1 ('l'abl~ I), and this f,eems safely attributable to polyteny. Effects of DNA. Commoner (196LI) has demonstrated that in bacteria the cellular DIJA content i8 directly rela.ted to the cell volume and in various vertebrate erythrocytes the relationship i8 directly proportional. Hirsky and Ris (1950) also state that "in general •••• the greater tq.e DNA content, the larger the cell". ]!'urthermore, since over-all cell size i8 generally inversely rela'ted to the metabolic rate, a species' characteristic rate of oxidative metabolism is inversely related to the - 25 - TABLE l Results of photometrie measurements of DNA-Feulgen complex on nuelei of five small and five large eggs eorresponding to the 32 cell stage. Amount of ehromatophore is determined as an average of duplicate readings of ten nuclei each per egg. Avera~e Extj.nction Photomet2'ic Area Total Amount (jî _ 6) (p. ) Chromatophore Small .122 +_ .025 523.0 63.8 .138 +_ .021 72.2 .1l~1 : .036 73.7 .115 +_ 0012 60.2 .146 ~ .016 76.4 Amount DNAI + Nucleus .132 - .022 69.0 + Large • 2!~1 _ .030 20SJ-/.6 502.4 + .233 - .029 485.7 .279 +_ .030 581.6 .202 +- .026 421.1 .238 ~ .012 496.1 Amount DNAI Nucleus .239 +_ .035 498.2 - 26 - ) DNA content. These relationships have also been discussed by McLaren (1965a), Ycas, Sugita, and Bensam (1965), and Stebbins (1966). In addition, it was found that nuclear volume is positively related to the length of the mitotic cycle (Van't Hoff and Sparrovl, cited by Stebbins, 1966). Therefore, an increase in the amount of DNA results in an increase in t,he cell volume but a decrease in the metabolic and division rates. Since copepods slJOvT determinate grDwth and probably determinate cell number (IvIcLaren, 1965b) an increase in the amoun'~ of DNA would be expected to increase the size and to reduce the development rate of the entire animal. The relative volumes of the adult females of the t1\''O fj ord forms 1 the staGe l copepodites (Table II). The ratios of these volumes were approxirnately 3:1 as shawn also by r-lcLaren (1965h). Therefore, since the relative nuclear DNA contents of the t"lfO forms of Pseudocalanus are in the proportion of 7 :1, the DlJA content j,s directly related to the cell volume but the relationship is not proportional. ,rvIcJ-:"aren (1965b) investiga"ted the development rates from field samples of the small and large forms in Ogac Lake and s hOlfed that the mean rate in the small form was signjJ'icantly greater at O.Ü2 stages per day than in the large form at 0.28 stages per day. Later (NcLaren, 1966) he "l'laS able ta 8hol1 experimentally that egEs of the small form develop about 1.7 times as fast at any temperature. Thus, as a con:3equence of polyteny, the nuclear DNA contents of the larGe form have increasec1, cansing an increase in cell volume and therefore body size, and a decrease in development rate. Ac1aptive value of pOlyteEZ. It is a reasonable assumption that the croater :,he amount ot' DNA, the more complex the or[~anism, and - 27 - TABLE II Comparisons of sizes of the large and small forms of Pseudocalanus from Ogac Lake, 1965 and Winton Bay, 1964. Values are means and t'VlO standard errors. Large form Sma11 form Volume ()l) (JI) ratio Ogac Lake - Egg diameter 158.71 ! 0.70 110.23 ! 0.19 2.98 Nucleus dinmeter 5.19 +_ 0.07 3.53 ! 0.03 3.16 ~ cephalothorax length 1089.37 ! 3.97 851.12 ! 0.89 2.10 stage l copepodite length 532.40 :!: 1.33 362.0L~ ! 0.94 3.18 \'linton Day - Ef,f, diameter 162.46 :!: 0.60 116.04 :!: 0.32 2.74 Nucleus cliameter 5.04 :!: 0.04 3.54 :!: O.Otl 2.77 ~ cephalothorax 1ength 1159.27 :!: b.39 8L~0. 77 :!: 0.69 2.62 Stage l copepodite length ~;5ô.oo '!: 0.83 398 .L~l :!: 0.35 2.75 - 28 - consequently the greater the variation passible in its adaptability (HerskovTitz, 1962; Stebbins, 1966). However, tbis can only be a long term value, and the polytenic Pseudocalanus does not appear to diffar in ways unrelated to size. In the inner basin of Ogac L3ke three broods of the small form of Pseudocalanus are produced during the year (McLaren, NS 1961). However, on~ the first brood survives as it is spawned during the phytoplankton bloom; the numbers of the second brood decrease sharply and the third brood (actuall,y the first of a second generation) completely disappears due largely to the depleted food conditions. The reproductive cycle in the middle basin is similar to tha'jj in the upper basin vlith the slo\-1 growth of the first brood, the attentuation of the second brood and the obliteration of the third. The pattern in the outer basin diCfers froTrl that of the other basins as only tl'TO broods are spawned and both 'of these may survive due to the maintenance of the, Chaetoceros s upply. Therefore, in Ogac Lalce ti'TO generations of the small form are produced in a year in the outer basin Hhile the reproductive cycles in the middle and inner basins are essentially unnual but Hi th two abortive broods beine produced. The reproductive cycle of Pseudocalanus minutus in orc1inary arc tic Haters is usuall;)r annual (Digby, 1954; Ussine, 193[\; Fontaine, 1955; yfstvedt, 1955) and, as aforementioned, the normal arctic Pseudocalanus are of a much greater size than.the small form in the tvJO landlocked fj ords. 'l'hus, as a result of the unusuall,v warm l'1aters in the f,i orc1s the size of P. minutus is f.,;reatly reduced and ,the development rate increased. The larger size and the reduced development rate of the polytene animals may, therefore, represent "an evoluM.onary attempt to resiiore - 29 - normal size and development rates for these high latitudes" (rvIcLaren, Woods, and Shea, 1966), perhaps "r.ith less "lmstage" of reproductive products on abortive broods •. Abundance of the polytene Pseudocalanus. Estimates of the numbers pel' m. 2 of copepodites of the large form of Pseudocalanus appearing in aIl available samples collected from the middle basin of Ogac Lake in 1965 and from Hinton Bay in 1964 are presented in Table III. Collections from one day only, August 6, were avaUable from Ogac Lake. The small form in these samples appears to be approximately three times as numerous as the large forme On August 7, 1964 in Winton Bay the large form lms one-fifth as nU!TIer;)us as the small forme It :night thus be considered that the laree form is relatively more abundant in Ogac Lake than it is in 'iV1nton Bay. HOIi8Ver, on August 3, 1964 in Î'/inton Bay the large form outnumbered the sw~ll form by about 3:1 vmile on August 15 the sooll form Has only twice as abundant as the large forme The small form also ou tnumbered the large f orrn approxilila'tely 5: l and 4: l on August 20 and August 28 respectively. If the estimates for the vJinton Bay collections are totalled the ratio of the number of large forms to the number of sw~ll forms is 1:3 as it is in the August 6, 1965 collection from Ogac Lalœ. 'l'herefore, since there is such a variation in the ratios of the relative abundance of the small and large forms it is felt that further investigation is necessary before a conclusion can be reached as to lJhether the large form is consistently more abtmdant in one fj ord than in the other. 'l'he variation in the abundance of the lc.1.rge form during a thirteen year peri ad I·TaS calculated from collections talcen from the middle basin of Ogac Lake in 1952, 19~~7, 1962, and 1965 ('rab le IV). In 1952 the large TABLE III Esti':lê..ted numbers per m? of copepodites of the large fom of Pseudocalanus in aIl available samples from the middle basin of Ogac Leke in 1965 and from the outer basin of ~J:inton Bay (except the collection on August 20 Hhich uas taken from the inner basin) in 19640 Calculated as discussed in text. Locality Nurrbers per m? of copepodites of large fOIm Total copepodites per m? and date T II III IV V adult ~ large form SIllE.ll form \..J.) Ogac La...l{e - 0 August 6 1330 1870 2730 2350 1130 710 10,170 27,840 Uinton Bay - August ...~ 3150 30 10 310 1750 2~O 5,490 1,620 August 7 1240 110 60 10 100 450 1,970 9,650 August 15 500 460 70 60 150 50 1,290 2,310 August 20 240 110 40 110 420 100 1,020 5,370 August 28 90 2500 2040 180 890 500 6,200 26,880 TABLE Dl Estimated numbers per m? of copepodites of the large f0rill of Pseudocalanus in the illiddle basin of Oeac Lruce in all available s~TJples froill August of four years. Calculated as discussed in texte Date Numbers per m? of copepodites of large form Total copepodites per m? l II III IV V adult !? large form snall form \..v 1952 ~;-August 7 10 70 50 80 60 20 290 10,120 1-' August 12 10 30 50 10 100 6,380 1957 August 3 630 400 1400 2,430 98,600 August 17 180 1550 260 200 2,090 50,800 August 31 150 120 270 28,000 1962 August 10 0 251,600 August 22 22C 220 880 1,320 129,200 1965 August 6 1330 1870 2780 2350 1130 710 10~170 27,840 .:<- estirnates probably too 101-T since on1y less efficient fine-mesh net used - 32 - form .vas outnumbered by the small fOIm on August 7 by about 35:1 éU1d on August 12 by 64:1. The ratios varied in 1957 from 24:1 (small to large) on August 17 to 104:1 on August 31. No large forms were collected in hauls on August la in 1962 but on August 22 the ratio was approximatel.v ninety-cight small to one large forme As m8ntioned above, the large forros on August 6, 196.5 were one-third as numerous as the small forms. Therefore, the marked variations from year to year in relative abundance of the small and large forms may be taken as evidence that they are differentially adapted to the environment, but whether or not the large form is better adapted (i.e., increasing at the expense of the small form) cannot be said on present evidence. Polytene Pseudocalanus as a ne1-1 species. Hughes-~chrader (1951, 1953) demonstra"Led that in the n;orphologica1ly similar species 01' the mantid genus Liturgousa the amount of nuclear DNA cou1d oe employed as a species constant in considerinc; ;Lnterspecific relationships. Evidence presented by Hirsky and Ris (19)49, 1950), Ris and r'Iirsky (19LI9), and Sl-rift (1950) also supports the hypothesis tha t the nuclear DNA content is a constant chal'acteristic of a species. On this baais the polytene form of Pseudocalanus could be considered as a new species. HOIvever, as the taxonorl\'! of the genus Pseudocalanus is still indefini te, i t is fel t that further examination of the taxonomy is necessary before the status of the polytene form can be deciàeù. Further, it is quite possible that the polytene form has arisen independently from the ordinary form in OEac Lake and "V"linton Bay. This obviously raises conceptual difficulties for systenatic analysis. - 33 - 1. A brief description of Ogac Lake and Hinton Bay is given in order to show the similarity' in the physical features of the t.va landlocked f.:i ords. l'he Haters in vlin'hon Bay are cooler than the lVaters in Ogac Lake but tbe temperat.ures in both fjords are mu ch warmer than those present in the waters outside. 2. The morphological features of the adults of the t'-lO size forms of Pseudocalanus alJPcaring in the fjords are discussed and are found to te close tu those of P. gracilis Sars. They do not appear to dUfer JDorphologically from the ordinary arc tic forms outside the f,j ords. 3. Collections taken from Ogac Lake in 196.5 and lvinton Day in 1961., are examined for the 1ength dist.ributions of the naupliar and c opepodite staGes. Bimodality is s ie:nificantly apparent in a1l stages. noth forms in l:Jinton Bay al"e larger as a result of colder tempe ratures there. 4. 'l'he larGer form is shol-ln to bear eggs l-J'tJ:Ï.ch are conspicuous ly larger than those of the small forme A l'eH lar[e individuals in the tHO 1'.i orcls are observecl ta bear small euss. 1'hes8 are attributed to the larger outside animaIs Vll'lich enter durine; the highest tides, tut lVhicrl are not able ta survive in the fjord conditions. 5. Chror,Iosome stains revcal trJat bath size forllls possess the sarne number of chromosomes (n=16) tbU3 eliminating pol.yploidy as the causativo factor in tlie sü;e variation. Hm'lever, the chromosomes - 34 - of the large form are notably larger than those of the small forme 6. The relative nuolearDNA oontents of the two forma were determined by a oytophotometrio ana~sis and the large form is shown to oontain about seven times as muoh DNA as the small forme Therefore, it is oonoluded that polyteny is effeoting the bimodality of size distributions. 7. A brief aocount is given of the effeots of variation in the amount of DNA. The sevenfold increase, in DNA has been ·shown to decrease the developmentrate of the large forro in addition to being the source of its increase in oell size and therefore body size. 8. Reasons for this adaptation are discussed and it is suggested that 'the increased oell size and decreased development rate are an attempt to restore the "normal" arctio size and development rate to a high latitude location oontaining extraordinarily warro waters. 9. The relative abundance of the large form in the two fjords i8 estimated but it i6 concluded that further investigation is necessary in order to determine whether the large fom is consistently more abund~t in one fjord than in the other. From , J collections tak~ from Ogac Lake over a thirteen year period it appears that the large form has varied considerably in abundance in relation to the small forro from year to year. 10. The classification of the polytene form as a new species is considered but it is concluded that further examination of the taxonomy of Pseudocalanus is necessary before its definite status can be decided. - 35 - l am indebted to a number of individuals for their assistance during the course of this study. l lüsh to aclmowledge my sincere gratitude and appreciation to Dr. I.A. HcLaren, v1ho suggested this pro,iect, for making his collections available for investigation and for his patient attention, and also to Dr. H.,T. Dunbar for his assistance. l am most grateful to Dr. J.H. Shea, JI'. of the Department of Anatomy for his instruction and continuous encJuragement during the cytophotometric analysis. The interest shmm in this study by Jvlrs. D.C. Eaclellan and ber assistance in the preparation of the thesis are particularly aclcn01'lledged. My gratitude is also due to H:tss Susan Davis for the typine of the thesis. 1'-1i8S Irene Turnbull of the Department of Geneties and br. H. l';cCandlish of the Department of Zoology kindly provided the cherücals required for the staining procedures. The financial support for this research l'las supplied through funds reeeived L'rom the IJational Eesearch Council. - 36 - BIBL IOGRAP HY Altenburg, E. 1957 (revisod edition). Genetics. Henry Holt and Company, New York. 496 pp. Brodsky, K.H. 1950. Copepoda, Calanoida, of the far eastern waters of the D.S.S.R. and Polar Basin. Classification of thefauna of the U.S.SJt. Publ. 2001. Inst. (Acad. Sci.) U.;:î.G.H. 35:109 -114. Caspersson, '1'.0. 1950. Cell grouth and cel1 function: a cytochemical study. l'J.H. Norton and Company, New' York. 185 pp. Commoner, 13. 1964.' Dl'JA and the cllemistr;r of inberitance. Amer. Scient. 52CJ) :365 - 38S. Darlington, C.D. 1955. '.L'he chromosome as a ptlY"sico-chemical entity. Nature 176 (h491~) :1139 - 1144. 1958. Evolution of p,enetj.c systems. Oliver and Boyd, Edinburgh and London. 265 pp. Davenport, H.A. 1960. Histological and histochemical technics. W.B. Saunders, London and Philadelphia. 392 pp. Dm-ISDn, G .T;i.P. 1962. An introduction to the cytogenetics of polyploids. Oxford Press. Deevey, CI.B. 1960. Relative effects of temperature and food on seasonal variations in leneth of marine copepods in some eastern American and l'18stern European Hat.crso Bull. Dingham oceanogr. Coll. 17(2):55-06. - 37 - de 'romasi, J .A. 1936. Improving the technic of the Feulgen stain. Stain Tech. 11(4) :137 - lLlh. Digby, P.S.B. 1954. The biology of the marine planktonic copepods of Scoresby Sound, East Greenland. J. Anim. Ecol. 23(2): 298 - 338. DOdson, E.O. 19h6. Some evidence for the specificity of the Feulgen reaction. Stain Tech. 21(3):103 - 105. Dunbar, H.,J • 1958. Physical ocean o~raphic resll 1 ts of the "Calanus Il expedi tions in Ungava Bay, Frobisher Bay, Cumberland ~;ound, Hudson Strait, and Northern Hudson Bay, 1949 - 1955. J. Fisl:!':- Hes. Bd. 0Qn. 15(2) :155 - 201. Duncan, A.J. 1959 (revi..sed edition). Quality control and industrial statistics. Ilichard D. I nn.n , Inc. 9!16 pp. F'arran, G.P., revised by \'J. Vervoort. 1951. Copepoda. Conseil International pour l'Exploration de la l-ler. Zoop1ankton sheet 37, h pp. Fontaine, N. 1955. The planlcLonic copepods (Calanoida, Cyclopoida, Honstrilloida) of Ungava Bay, with special reference to the biology of Pseudocalanus minutus and Calanus finmarchicus. ,J. Fish. Res. Bd. Cano 12(6) :B58 - 398. Uarcia, A.N. 1962. studies on DNA in leucocytes and related cells of mal'1n:als. lIOn the Feu1gen reaction and tNo-uave1ength microspectro-photometry. Histochemie 3:178 - 19h. - 38 - Harding, J .P. and S.N. Narshall. 1955. 'l'riploid nauplii of Calanus finmarchicuso Nature 175 (Llhh7) :175. Herskowitz, I.H. 1962 (second edition). Genetics. Little, Brown and Company, 13oston and Toronto. 554 pp. Hughes-Schrader, S. 1951. The desoxyriLonucleic acid content of the nucleus as a cytotaxonomj.c character- in mantids (Orthoptera:Hf:1.ntoidea). Biol. Bull. 100:178 - 187. 1953. 'l'he nuclear content of desoxyribose nucleic acid and interspecHic relationships in the mantid renus Liturcousa (Ort.hoptera:Fantoidea). Chromosoma 5:5hh - 55ir. and F. Schrader. 1950. Polyteny as a factor in the chromosomal evolution of the Pentatomini (Hemiptera). CbrOl,lOsoma e:135 - 151. Jespersen, P. 1923. Dr. 'l'hor;.ld ï;Julîf 1 s plankton-collect:Lons in the vmters Hest of Greenland. r'~etazon. Den. II Thule Ekspedition 'Jil Gr~nL.1.nds Nordkyst 1916 - lB. Nr. h:121 - 123. Kurnick, N .LI. and LH. Herskmvitz. 1952. 'l'he estimation of polyteny in Drosophila salivary E!land nuclei based on determination of clesoxyribonucleic acid content. J. cell. comp. Physiol. 36:281 - 299. LeucbtenberGcr, C. 19:JLr. CrHical evaluat.ion of Feulgen microspectro photorr:etry for estimating amount of DI'JA in cell nllclei. Science 120: 1022 - 1023. - 39 - Leuchtenberger, C. 1958. Quantitative determination of DNA in cells by Feulgen microspectrophotometry. p. 219 - 278, v.l. In: J.F. Danielli (ed.), General cytochelllical methods. Academie Press, New York and London. Narshall, S .N. 1949. ·On the biology of the small copepods in Loch Striven. ,J. Nar. biol. Ass. U.K. 28:45 - 122. ------and A.P. Orr. 1955. The bioloGY of a marine copepod, Calanus finmarchicus (Gunnerus). Oliver and Boye'!, Edinburgh and London. 18H pp. hazia., D. 1961. Hitosis and the pb;)rsiology of cell division. p. 77 - 1112, \' .3. In: 13rachot al1d .Cdrsky (eds.), The cell. Acaderrlic Press, Heu Yorl~ and London. l'IcLaren, I.A. 1961. 'l'he hydrography and zoop1,mkton of Ogac Lake, a land10cked fiord on Baffin Islanrl. Fisheries Hesearch Board of Canada l'"anuscript Heport Series (Bi01oc:ical). No. 709. 167 pp. 1963. EffeL:ts of tempe rature on f;ro'{lth of zooplanlcton, and the adapi',ive value of vertical migration. J. li'ish. lies. l!d. Cano 20:685 - 727. 1965a. Temperature and frog eGgs: a recJnsideration of metatolic control. J. gcn. Pl1;\rs .ioI. hEJ : 1071 - 1079. 1965b. [30me relationships betH'Jen temperature and eu.:: size, body size, àeveloprnent rate, and fecundity, of the copepod, Pseudoc:alanus. Limnol. (: ûceanor:r. 10:528 - :;38. IJ)cLaren, I.A. 1966. PredictinG development rate of copepod eggs. Diol. J3u:1.l. 131:1.~::;7 - 1.\651. 1967. P'oysical émd cllemica1 characteristics of Ogac Lake, a lanc110ckecl fiord on Baffin Island. J. Fish. ltes. Bd. Can. 21.(. In press. ------,G.:N. \~oods, and ,J.h. ,shen, Jr. 1966. pol;}rteny: a source of cr;fptic speciation among copepods. 0cience 1.53 (J7h4) : 161(1 - 16h2. IJleJ1l1elo olm, r'i.L. 19':;[; a • 'fbe t~vo-ua ve1ength meth od of micros pectro- 1.)11 Ot.OrdC.otr'J. J: :1~ micl'ospectropli otometer Md tes ts on mode 1 s,lrs teIl's. IT. bioph:\rs. hlochem. C~rtol. h :h07 - 411.1. 1~)5éJ1J. rrhe t~-JO-"Wavc length rneth oel of rr,icrospediro pl1otometry. IJ::A set Df tables to facilHate ca1cu1.ations. IT. bioph;rs. biochem. Oytol. 1.1 :)ü5 - ü2h. j/I:i.r3ky, 1l.1~. f.mcl H. His. 19h9. \rariable and constant CO;~lponents oi' chromoson:es. iJa"Lu1'e IG3(Üll.II:l):666 - 667. 19.~O. 'l'he clesoxyribonucleic acid content of animal ceHs and Hs evolutionary significance. J. r;en. Physiol. 3h:L151 - ).162. NOllikoff, 11..11. 1955. l1j.stochernica1 and cytochemical staining ïflethocJs. p. n -11, chapt. 2. In: L.C. 1"81101's (ed.)., Analytical cytolOLY, first edition. i.·1CC'rral-J Hill, NevfYork. - hl - Or;ilvie, II.S. 1953. Copepod nauplii (1). Conseil International pour l'Exploration de la Her. Zooplankton shed, 50, h pp. Ornstein, L. 1952. 'l'he clistributional error in microspectrophotometry. Lab. Invest. 1:250 - 265. ~stvedt, O.-,T. 195~~. Zooplémld,on investigattons from Viea,ther Ship r'l in the Norwegian Sea, 19h8 - 19h9. HvalràcJ. SIcr. l'Jo. 40, 93 pp. Pa'Gau, 1\. 19:;3. Absorption miurophotornetr;;r of' irrec;ulal'-shaped objects. Chromos oma 5: J),! l - 362. pollister, A.I,j. 1952. l!;ierospectro~)hotometry of c:ells by visible U[ht. Lab. Invest. 1:231 - 2119. and L. Ornstein. 19:;~. Cytopbotomutrir: analysis in t.he visible S)Y:~ctrnTI1. -;;>. 3 - 71, chapt. 1. In: H.G. )';e110rs (ed.), Analyticnl cytolo[:y, first edit.ion. l-lcGraH Hill, 1')81-7 York. 1959. The photometrie ehemieal analy~:;is of celhi. p. h31 - 518. In: hellors (ec1.), Ana1yticnl c,'rLolog;y, second edition. hcGravr Hill, IJeH Yorh:. his, H. and A.B. Uirsky. 19L19. Quan'Litative eytocbe~f1ical deterrnination of desoxyribonucleic acid \Vith the Feulgcn nucleal r'eact.ion. ~f. con. Pllysiol. 33: 125 - 11.!6. Sars, G.0. 1903. An account of the Crustacea of Ho:nray. Copepoda (Calan'Jicla). Christiania and Copenhagen. 1'11 pp. - 42 - Snedecor, G.W. 1956 (fifth edHion). Statistic::al methods. Io.. m Stata University Press, Ames. 53Lr pp. ;:Jtanley, ,J. 1963. 'l'he essence of biometry. NcGill University Press, Nontrcal. lL~7 pp. stebbins, G.L. 1966. Chromos omal variation and evolution. Science 152(3728):lh63 - ll169. Stich, H.F. 1962. Variations of the desox,yribonucleic acid (DNA) content in embr~ronal cells of Cyclops strenllus. E.,xp. Cell. Res. 2~:136 - 143. St~rmer, L. 1929. Gopepods from the "Nichael Sars" expedition, 1921,. Happ. Gons. Exp1or. 1"er. ;;6(7):1- ~7. Stowell; Ti.B. 1946. 'l'he specificity of the Feul,~en l'oaction for thymonucleic acic1. ;)t~in Tech. 21:137 - lhû. ;')uift., Il.E. 19:;0. 'l'he clesoxyribose l1ucleic acid content Di' animal nucl€i. Pllysiol. Y.o/H. 23(3) :169 - 1913. 1953. Quantitative aspects of nuclear 1l11c1eoproteins. Internat.. Ftev. Cytol. 2:1 - 76. 1955. Cyt.ocher:lica1 techniques for nucleic acids. p. 51 - 92, v.II. In: E. Chargaff and tT.N. Davidson (eds.), 'l'he nucleic acids. Academic Press, Nell York and London. and R.E. Hasch. 195h. l'ïucleoproteins in Drosophi1a polytene c:b'omosomes. J. lIistochem. a. Cytochem. 2 :456 - ü5Ll. - 43 - b /' Swift, H. and E.N. Rasch. 1956. Nicrospectrophotometry wii!h visible light. p. 354 - 400, v.3. In: G. Oster and A.W. Pollister (eds.), Physical techniques in bioloBica1 research. Academie Press. NeH' York and London. Ussing, H.H. 1938. The bioloBY of some important planlcton animaIs in the f.ioroo of East Greenland. Hedd. Gr~nland 100(7):1 ~ 108. Hiborg, K.F. 195).).. Investigations on zooplankton in. eoastal and offshore waters of i1Testern and north-lv0stern Norway with special rci'erence to the copepods. }?iskeridir. Skr. I-Iavunders~k. 11(1):1 - 2h6. 1955. Zooplankton i:l relation to the hydrography in the NOr"~Teeian Sea. Fiskeridir. Skr. Havundersj6'lc. II(h):1 - 66. v/Hl!, C. 1:715. Copepoda l Calc.noida A:~phaskandria. The Danish Ingolf expedition 3(4). 260 pp. Yeas, H., N. Sugita and A. Bensam. 1965. A model of cell size regulation. J. theor. Biol. 9:4hü - ü70. - 44 - Appendix l Table of routine vertical plankton hauls from Ogac Lake and Winton Bay used in tbis study. Location Date DeEth Mesb size Net diameter Yr. Time Day Jllonth m. \rJ'inton Bay 1964 7 8 35-0 6 1/2 m. 15 8 32-0 6 1/2 m. 15 8 32-0 6 1 ft. 20 8 35-0 6 1/2 m. 23 (3 33-0 6 1/2 ID. 3 [3 30-0 20 1 ft. 7 8 35-0 20 1 ft. 15 II 32-0 20 1/2 m. 20 u() 35-0 20 1 ft. 28 B 33-0 20 1 ft. Oeac Lake 1952 11120 7 ô 40-0 18 1/3 m. (al1 from the middle basin) 0950 12 S 30-0 18 1/3 m. 1957 3 8 35-0 6 1 ft. 17 [l 35-0 6 1 ft. 31 8 35-0 6 1 ft. 3 8 35-0 20 1 ft. 17 8 20-0 20 1 ft. 31 8 20-0 20 1 ft. 1962 10 8 35-0 26 1/2 l'I1. 22 8 35-0 6 1/2 m. 10 [3 35-0 20 1 ft. 22 ô 3;;-0 20 1 ft. 1965 6 8 3.5-0 6 1 ft. 6 8 35-0 20 1 ft. - h5 - ApEendix II Table of mean cephalosome lengths of the naupliar stages and of mean cephalothorax leneths of the copepodite stages of Pseudocalanus and T test value5 to 7erif.r the bimodality of the length distribution. Values are expressed as mean and tiVO standard errors. Date Stage Smal1 Large T test Difference ()J ) ()l) value be bTe en means lVinton Bay 3/B/64 Naup.I 131.52! 1.51 Naup.II HIS' .92: 0.69 ... ~ Naup.III lü5.0ll::' 0.02 239.52:12.50 h.347 s" Naup.IV 227.76::' 1.25 291. 12Z1B • ell 3.355 s Naup.V 260.130'!:- 2.35 346.32Z 6.82 Il.81-1.5 s Naup.VI 259.92"!:. 6.79 3)6.G4:!: 2.6h 13.276 s Cop.I h21.59:' h.B3 556.B3:!: 1.52 26.706 s Cop~II 505.aSLI5.80 63U.25:!:10.35 7.oh9 s Cop.III 585.12i: 6.56 Cop.IV 0" 715.5J~lI9.82 976.35:!:12.35 5.081 s Cop.IV~ 629.97:!:17.94 927.36:!: 7.94 15.157 s Cop.V ~ 703.00-n + 0.00 107 4 .33-+ 6 • 97 53.160 s Cop.V'? 793.50::'55.3LI 1082.61:!: 6.28 5.190 s Cop.VIa" 663. 78:!.:15.25 JD35.00:!.: 0.00 2LI.3hl s Cop. VI ~ 818.34: 8.35 1O[39.51:!.:13.66 16.937 s - 46 - Date Stage Small Large T test Difference (p) (p) value betl-leen means ~'linton Bay l'Taup.I 7/8/64 134.16: 0.82 --- + Haup.II 146.16_ 0.79 174.00: 6.00 }~ .600 s Haup.III 183.84: 0.86 226.08: 1.27 27.535 s + Naup.IV 224.64~ 1.27 264.00_ 0.00 30.992 s Naup.V 261.12_+ 1. 73 Haup.VI 275.28: 1.3h 374.40:' 8.42 11.625 s Cop.I Lllh.69: 3.38 563. 73'~ 2.ô3 330811 5 Cop.II 4135.07:' 6.49 669.99~15.80 10.826 s Cop.TII 576 .8h~12 .L19 812.8 i':2[l. oD 7.679 5 + Cop. IV Cop.V ri' 718.98:'18.42 1101.93:17.94 14.894 s Cop.V 9 731. 40_ +4 1. L10 1109.52~ -1-..10. 2tJ:) El.B67 s Cop.Vld' 675.51:' 6.!.19 CopoVICf o5 0.0[3- + 2.69 ilS'8 .;Jl_~ -1- 2. 50 83.972 s ~~ • • n' t 5=SJ.['"DJ.1 J.can Appendix III Table of mean cephalosome lengths of the naupliar stages and of mean cephalothorax lengths of the copepodite stages of Pseudocalanus as determined from vertical plankton hauls from Winton Bay and Ogac Lake in 1964 and 1965 respectively. The values are expressed as mean and two standard errors. Date and location 1-Iinton 15/8/64 l'linton 20/8/64 ~{inton 28/8/64 Ogac 6/8/65 SIP..a.ll Large Small Large Small Large Small Large Stage (p.) (JI) (JI) (p.) (JI) (JI) (p.) (JI) + . + Naup.I 133.68:!: 1.29 131.04± 1.80 187.20-+ 0.00 137.52-+ 1.80 170.40-14.40 127.44-1.10 + + + Naup.II 144.96:!: 0.65 14"0.00- ~ + 0.09-, 148.32- 0.86 142.56-0.60 208.80-16.80 1 . + + + ~ Naup.III 185.28! 0.46 220.0st 3.41 183.36- 0.69 214.80- 3.60 185.7rt. 0.69 204.00~ 0.00 176.64~0.46 243.12- 2.47 -.J Naup.IV 227.52:': 0.46 292.8~ 8.42 226.80~ 1.01 270.72:': 8.26 226.80: 0.69 264.00: 0.00 217.92:2.47 304.80: 0.00 + Naup.V 264.72! 0.69 333.60-12.14 264.48-+ 1.22 302.40: 0.00 262.32-+ 0.94 324.72-18.07+ 241.2o!:2.74 349.20: 1.20 + Naup.VI 275.76! 2.38 333.6ot 0.00 266.88- 2.09 267.3~ 3.52 348.00-+ 0.00 249.3~2.30 346.80: 2.86 + + Cop.I 407.79- 1.45 571.37- 2.55 389.85- 1.73 522.3J!11.79 396.7~ 0.62 527 .8~14.35 365.70:2.42 534.7.s! 2.07 + Cop.II 497.49! 2.89 698.97:!: 3.73 472.65- 4.89 623.7~13.52 479.5 Je::! .... - 1.31 709.32: 2.35 451.2~1.79 667.23: 2.42 + Cop.III 583.05! 6.07 822.48:::15.39 538.20- 4.07 763.83-32.43+ 552.69-+ 2.00 844.5~ 2.69 538.20:1.45 812.1~ 2.14 + + .... + Cop.IV 0" 632.04:':10.14 1010.8~15.53 616.17- 4.97 1009.47-16.49 611.34: 3.04 952.89:16.84 609.96':'2.69 903.21- 3.38 + + + + . Cop.IV~ 623.76-18.56 1099.17-29.95 594.78-11.45 993.60:19.94 618.24:': 4.76 1014.30:21.67 621.00:.:2.00 907.35- 5.24 .... + + + ., + + + Cop.V cl" 645.15!.39.26 n07.4':19.25 703.00_ 9.59 1105.38-10.28 678.27- 3.52 L113.6~11.59 682.41-3.11 1012.92- 9.32 + + Cop.'f ~ 815.58!l8.15 il19.87~20.29 665.85- 3.45 1139.19-21.87 721.74: 7.04 1128.1s! 6.90 718.98~3.52 JD38.4S: 7.04 + + / + + + + Cop.VI ~ 705.18:' 6.69 1083.9~26. 77 688.62- 7.52 ll46.09-12.69 093.45- 7.66 1101.93-28.91 676.20-3.86 986.01-10.97 + + + + Cop. VI ~ 81i5.59: 2.17 Jl78.38:!: 3.55 839.·,.r 3.31 1144.71-17.80 848.01: 3.66 1188.87~16.84 850.77-2.54 1092.72- 5.80 Appendix ri Table of mean cephalosome lengths of the naupliar stages and of mean cephalothorax lengths of the copepodite stages of both the small and large forros from hauls from Winton Bay (August 7, 1964) and Ogac Lake (August 6, 196,) and the T test values and significance for the difference between these means. The values for the mean lengths are mean and tl-TO standard errors with the 1:: f value in parentheses. Stage Winton Small Ogac small T test Difference ~-linton large Ogac large T test Difference ()l) ()l) value between (p.) (p.) value between means means Haup.I 134.1ôt. 0.82(7) 127.44±1.10(16) 4.897 sI Naup.II 146.16t 0.79(27) 142.,6t0.60(4,) 3.629 s 174.00! 6.00(1) 208.8Qt16.80(2) 1.950 ns 1 ~ Naup.III 183.84± 0.86(92) 176.64±0.46(168) 7.382 s 226.08± 1.27(5) 243.12t 2.47(4) 6.133 s 0:> Naup.IV 224.64± 1.27(47) 217.92±2.47(,4) 2.419 ns2 264.00!: 0.00(1) 304.8ot. 0.00(2) Naup.V 261.1zt 1.73(18) 241.2ût2.74(3l) 6.148 s 349.2ot. 1.20(2) Naup. VI 27, .28"t 1. 34( 6) 249. 36t.2 .30(17) 9.737 s 374.4at. 8.42(3) 346.8ot. 2.86(4) 3.103 s Cop.I 414.6~ 3.38(29) 365.7~2.42(162) Il.784 s ,63.7Y- 2.83(88) 534.75~ 2.07(41) 8.265 s Cop.II 48,.07: 6.49(13) 4,1.26~1.79(94) ,.022 s 669.99:.15.56(8) 667.2~ 2.42(66) 0.172 ns Cop.III 576.84~12.49(5) 538.2~1.4'(136) 3.073 s 812.87..2[3.08(4) 812.1~ 2.14(97) 0.024 ns ns Cop.IV~ 621.00:12.28(4) 609.96t2.69(59) 0.878 903.21~ 3.38(39) -- Cop.IV~ 658.9~31.0'(2) 621.0~2.00(88) 1.219 ns 979.8c7.. 0.00(1) 907.3~ 5.24(44) 13.826 s Cop.V ~ 718.9B:18.42(5) 682.41~3.11(60) 1.958 ns 1101.9;':'17.94(3) 1012.9~ 9.32(16) 4.402 s Cop.V'? 731.40t 41.40(2) 718.9Bt3.52(76) 0.298 ns 1109.,2tl0.28(4) 1038.45t 7.04(24) 5.703 s Cop.VI d" 675.51t 6.49(20) 676.2cf-3.86(28) 0.091 ns 986.01tl0.97(9) Cop. VI ~ 8S0.0st 2.69(360) 8'O.77"t2.,4(416) 0.186 ns 1158.51t 2.50(20) 1092.7~ 5.80(50) 10.409 s 1 s = significant difference. 2 ns = non-significant difference. ~ -, 1*'1)· .. ·• '-0,., 'c._~ te" & '4 ttt"'"",.'"cf"'t&ràt'tt)kd«il:ff "St,r1n1"€,,,,, C2i"tirii't:'rf&aSifntW ..:= }niiirl'itii'*î?f:rii~1 n" . ~.. 2& - 49 - 100 80 c 0 -+- u .f; -+- 60 >< a> E ::J E 40 >< a E '+- 0 20 -+- c a> u lo- a> 0... 0 450 500 550 600 650 Wavelength (m}J) Appendix V Representative· aLsorption spectruli1for mUI.-PeulLen con:üex displayinc; maximum absorption at 570 r.p expl'cs,:;c;c1 as p:Cl'cent of maximum extinction versus 112'lelc.'D[;,th. - 50 - Appendix VI Values for representative absorption spectruJll de"liermined by expressine the mean extinction values at the wavelengths as percentage of the mean extinction value at ).. 570m}l. \vavelength PeI' cent of max:l.mum extinction E450-650jEb Av L E450-650jEb Av S He an 450 ])4.82 16.76 15~79 460 17.58 19.92 18.75 470 22.41 21.1+7 21.94 LiSO 27.93 2Li .L19 26.21 Li90 3.5086 32.77 3LI031 LI95 hO.OO 38.61 39.30 .500 46 • .55 42.88 44.71 .505 51.37 49.91 50.611 510 57.93 56.24 .57.08 520 68.96 67.49 68.22 .530 79 • .31 75.82 77 •.56 5!lo 8.5.86 83.18 84 • .52 .5.50 92 .)~1 90.69 91..55 560 97 •.58 96.32 96.95 .56.5 98.96 98.86 98.91 570 100.00 100.00 100.00 575 99.31 98.70 99.00 580 97 • .58 9h.37 95.97 590 87.2h 80.85 8l.J.OI.I - 51 - vlavelength Per cent of maximum extinction E450-650/Eb Av L Eh50-650/Eb Av S Mean 600 68.62 59.[31 614.21 610 44.13 36.93 11 0 .53 620 25.51 19.63 22.57 630 13.44 9.62 11.53 640 8.27 6.38 7.]2 650 5.51 4.21 4.86 1 1 L . ; 1 1 !EEendix VII Chi2 test for the extinction values of the nuclear DNA both for the small eggs and the large eggs to test the hypothesis of normal distribution. Upper Limit of Limits in Relative Relative Absolute Actual F-f (F-f)2 (F-f) 2 class interval standardized frequency frequency theoretical frequency f units from of interval frequency X x=X-X Z (X-X)/ér --to Z (f) (F) Lar~ .19 " -.049 -1.40 .0808 .0808 4.0 4 0 0 0.000: .22 -.019 -0.54 .2946 .2138 10.7 7 3.7 13.69 1.279 1 \n .25 .011 0.31 .6217 .• 3271 16.4 16 .4 .16 0.009 1\) 1 .28 .041 1.17 .8790 .2573 l2.9 16 3~1 9.61 0.744 OC> 00 1.0000 .1210 6.1 .1. .9 .81 0.132 50.1 50 2.i64 Small .10 -.032 -1.45 .0735 .0735 3.7 5 1.3 1.69 0.456 ".12 -.012 -0.54 .2946 .2211 Il.1 li .1 .01 0.000 .14 .008 0.36 .6406 .3460 17.3 13 4.3 18.49 1.068 .16 .028 1.27 .8980 .2574 12.9 15 2.1 4.41 0.341 1.0000 .0102 5.1 6 .9 .81 0.158 , 50.1 50 2.023 2 X (j L (F-f)2 Chi • (n.2) Decision f 0 05 Large .239 .035 2.164 5.99 Accept (normal distrib.) Small .132 .021 2.023 5.99 Accept (normal distrib.)