Freshwater Algae

48 Pages·2007·1.06 MB·English

Insthuteo f TerrestfiaEl cology
NATURALF NVF ONMENTH ESEARCCHO UNCIL
A beginner'gs uidet o
FreshwateAr lgae
llilarv Belche&r EricaS wale
CultureC entreo f Algaea nd Protozoa
Her Majestys Slaiion€ry Office
CultureC eite ot Agae and Frotozoa
0223 (c.mbrdqo)6 13/3
TheC uhureC oire ol A!ae and Prorozoa
s part of the lnslitul. ol Terestra Ecotogy,
(hi.h rs, c.mp,renr brdf ol th.
Nlural Envr o.mentF cse..chC oui. L
lntroduction
Thep urposeo f thisb ooklels to enableth osew ho would rke
1ol earnt o recognisseo m€ of the algaeo i freshwate1r0 m ake
a start.F romt he veryl argen umbero f differeftg cneraw e
haves elected1 10 of thosem ostl ikeLtvo be found,a n.lw e
haveiiu slraledo nespeciesb elonglngtoeach( A gerds.
pl.ra genera.s corgarabe w th thei amrlyn .me cI a person
'Wordswo(h'.
eg anda rpeciesp. ursis peclesi.s comparaeb
'W
with a firstn amee. g liani.)T hed rawingsa r€ n almost
everyc asem adef roml iv ng sp€clmens( exceptth oseo f dia
WI]ATA F€ ALGAE?
Aiga€ lnc udes uchd iverseg roupso f orllans mst hato ne m3y
" I n , "7 "1. e"4n qr.er I e c_1'nom^ 'I' o on i
that in the eary dayso f the developmenotJ ght microscopes.
and beforeth oseo i electronm icroscopetsh.e iri ull dLVertsy
couldn ol be detecledT- hec ellso f somea lgaea reo f bac-
lerials ize.io re xamplea,b out1 u m (1 nricromet=re 1 /100Om m)
or about0 00004i nsa crossO thersc ontaina vastn umbero f
cellsa ndc an be up to 50m (over1 5 0 feet)l ong.1 ore xampe ,
the afgesst eaweedsS omea lgaea r€ undotrbtedlpy a nts,
somed fier so litre frornb acleriath att heyc ouldb e mernbels
ol a speca l baclera l classs, omga rea nimalso r |nry show
cerian teaturebs otho f an malsa nd p ants Desp1 et hes€
faclsm osta gal 0roupsh av€ cerlainfe aturesr common.
I\,4icroscopalc g ae can be foLrnde verywheref,r om permanent
snowa ndi cet o desertsth, e oceans,a kesr, iversp, !ddLes,
rocksa nds orl.J usta st he 1reesg,r asseasn dh erbse veryone
is famrliawr th arel he ftrnrnb asiso f |ie on and.s o a qaea re
the basiso f thati n the seaa nd.I ndeedp. roclLrcaeb outt he
samea rnounot f organicm atlera ndo xyg€n asd o landp lants.
Althought hcre s nothn g in freshwatecro mparablwei th the
largets eaweedsth, esea gaes howa rangei n sizef romt he
smallesot f aboutT u m in diametetro trali ng folmso f more
HOWT O LOOKA T THEN4
To examinefr eshwetearl gaeth e equipmenrle quiredn eedn ot
be elaborateA. iew of the largerg enefac an be ,dentifiedb y a
handl ensa lone( magnlficatioonf sx 10 andx 20).b uia
m croscopew h ch magnf iesa r leastx 100 is generally
essentiaAl.t thiss taget herei s no needa t a I tor an o I
immersioonb tectivelt. wouldt aket oo muchs pacea. nd it
wouldn ot be verys atisfectortyo, explainin detailh ow to
mounta sampleo f algaeo n a qlasss lidea nd how actuayl
to !se a m croscooeF. ort hisa Je\/n rlnLileds emorstraiion
by someonee xperienceids fiore valuableth anp ageso l
description.
Algaeu suallyd ie andd ecayI airlyr apldlya flerc ollectionI.o
keept hemf resha s longa s possibled.o not overfI the con-
t€iner, alwaysle avea n air spacea nd keept he samplec ool.
Planklona lgaem avb e ealeob y assoca teda nrmals(s ucha s
Daphnia,t lrc watet flea) in a short time. li presentr n notice'
abe numbersth eys houd be strainedo ff immediatel(ya piece
of nylons tockingm akesa goods ieve).
Samplesm ayb e preservebdy addingi odines o utionw hlch,
howev€r,l urnsl he chloropa stb rovJi A saluraledso luiiono f
roor e r,ro olasr L^rr od,d6d rd walerc onb e oraporFob.u l
ordinaryti nclureo f iodinew ill do. lt is best1 0a ddi t froma
droppingb ottlau ntllt he wholei s of a palcb rownc olour.l t is
importantto ensureth att he speclmenb ortleo r tubeo f algae
is keptw ell stoppereads odinee vaporaterse adrly.
NQTESO NT I]ED RAWINGS
Indicationo f s zeso f the algaed rawnl s difliculta st hisv aries
so muchb elweens peciese.v eno f the sameg enus( fori n
srance,. e It ol Chlorcganiun ta.ge Irc'r] 5 15 L'm n length
lat C. euchbrunt b 25orn Iar C. maxtmum).) twould be
misleadrg to showt,h e srzeo { eachs peciesil lusrf6teds.o we
haves taleda rangec overingth e wholeg enus.
Thes tudentis stronglya dvs edr o drawm icroscocp objects
whenevepr ossibleT.h erei s no necessry to'be ablet o draw'
to do this.W hatm aiiefss havingy ouro wn recordo f what
the thingl ookedI ke,t o helpy ou to remembetr andt o
Lrndersianrtds s hapel ils surprisinhgo \1,tryin1g0 d raw
it makeso fa lookm uchh arderro seew hat ihe atgai s realty
like.A lways labeli he d.awing with the name( f Itte akJai l
knowna nda ddt he datea ndr hep lacew here I wasr ouno.
CLASFSI CATION
To hep findl he way in morea dvancedp ubr catron(ss ee
page4 6).t he algaei ncludedh erea rea rrangedn thelrm ajor
groupingsb elow:
Greena lgae( Chlorophyceaein),c luding:
Swimmingc els andc o onies( Volvocales()n, os.1-14)
Non motilec ellsa ndc olonles(C hlorococcales),
(nos.15-33)
F lamentouasl gae( of variousfa ml ies).n os3 4-50)
Desmd s (Conjugae s in paft),( nos.5'1-59)
Yellowg reena lgae( Xanthophyceae(n),o s.60-63)
Goldeny e ow algae{ Chrysophyceae(n).o s.64-68)
Distoms( Bacillariophycea(en)o. s.69-85)
Cryptophycea(en,o .86)
Dinofa gela tes( Dinophyceae()n, os.878, 8)
Euglcnoifdla ge ates( Euglenophyceae(n),o s.8S-91)
Beda lgae( Rhodophyceae()n.o s.92-95)
Blue-greean g ae (l\,lyxophyceoare C yanophyceae).
(nos9 7-110)
lsee the diapran apposhe)
Lnt he centreo i the ce I
Binary vegetativdei vrso n of a free-livingce l intot wo
equa ands eparaldea ughtecr e ls
lhe co oureds tructurein p Enrc e lsw hich
absorbsI g ht Lrsedn photosynthesiussi ual,
!lreeno r brolvn,o ccasronalrley do r blLre-green
Cyst restings taoew ilh thickw a . fonnedf rome
srngLcce
rsed of a plantw hichl rows on rnother.b ut not
/,rirp ikes lrucllresu sedb Vc els lor swlmmn g
bul diffc u t 10s eeu nlesss tainedb y iodinee tc;
'f
h€nce a!,eal tcs'-ce s swimmingb y flagella.
ln.b. flageuLln s slngua r. plura f/agel/a)
hslf shello f a di.tom-see noteo r diatoms
iol!oh,inqn o.68
seen oteo n dratomsa ndl abel edd iagram
colourlessst ructurwe h ch containsh ereditary
lyrnga gainstlh e wall of a c€ll
co eclrvele rmf c'ra n nralsa nd plaflsw hicl_
lLoali n walei and arec arriedp assv elyb y
a coloure sss tructurca ssociatewd th the ch oro
plasta ndc oncerfedw jth starchfo r.nallon
the Inears tr!.lurez longi be canlreo , somed ia
lom frustLers seel abee d diagram
Signoid oi an e ongatedS -shapel.i k€ Gylrslgra no.80
Srellate staas hapedm, ainy us€d oJc h oroplasts
Stiae th€ stripel iken rarkrngosI a diaromf rLstule
seen oteo n dralomsa nd abelled.l agram
Diagrammatsict ructureo f somea lgae
ALGALF LAGELLATE
Flagellun
Contractilvea cuole
Eyes pot
Nucleus
Chloroplast
FILAIIE NTOUS FiLA[4ENTOUS
GBE€N ALGA BLUE.GREEN
ALGA
Chloroplast
Ceilwall
vegetatlve
DIATOM
Striae
view
1-GJrdle
Baphe
Chlorophyce:a Ger eena lgae
Greens wirnmingc els lsee alsoE uglenaa ndP hacus)
Chlamydonanas.A very big genuso f round.o val or cylin,
clricacl els whichs wimw ith two flagellao i equall englh.
T, "." rr"/ J. 1"/ rot ba a D. .a-o:cj. bLt a rpd pya 5po- .
lsuallyp resentT. hew all is smootfa ndi hin.C etlsc an be
trom2 5 to 50sm or morei n engrh,mosllyb2 0 (wlthout
ncludn g the flagela.a s in al rneasuremenints t hisb ookleO.
FoLrnidn everyk indo f aquarich abt at.s pecieso i thisg enus
ar€ the mostl ikeiyg reens wimmingc e s to be encounlefed.
Chlarcgoniun.I hls has r,NaI agellaI ke Chlamydomonas
but s spindle-shapeUdn. liket he srnna rlys hapedt/ g/era
(89) il doesn ot changej1 s{ orm 5 50gmt ong( l rare
speciesre ache2s 50tm). andi ound n pondsa ndr ivers.
BBchionanas. Relaledb Chlamydamorasb ut has a po nted
tarla ndf o!r ateralo besw h ch sticko ut of the bodyl ike
frfs. Sometlmefso undi n bird-bathas nctln poolsn eari he
sea.1 0-50Uml ong.
PteromanasL. ike Chlanydarnonasb ut with a longltud nal
wing on eachs ideo f the bodyI ke an e m f.u t. Revov esa s
rl swrmsi.s 10-25urnl ong.a ndl ivesr n pondsa nd slow
rlvers4 b, a ce ltn transverssee ction
Haenatococcus.C els ova . 10-30um tong.c onlents
separatefdro mt he wa by a clears pacec rossedb y rada l
lhreadsT. heg reenc hloroplasist somelirnensr askedb y red
' i loL'6do il Tr e dan 6 oop ,td onso f .-i<o rgarr ' oclL'r I g
in bird-bathsw. et ho ows in rockst,h e depressronIns m !n
halec oversa ndo rhers ma temporsrwy aterb odiesm avb e
ertnebr ngntg reeno r rustyr €d.
Loban)onasC. ellsl ike Chlamydonanas,3 2Esm long. with
ll obedo r wavyo ut n€. Occlrs n pldd es.p ondse tc.€s
doesr hes m larr rplosraurorw, hr.h ssquare
Phacotus.C els ike Chlamydomonasl. O 20um rong.a no
iound rn similapr aces.b ul eachi s enclosedrn a wal
resembin g rwo watchg lassefs t tingt ogethers,o metimes
lnrna ndt ransparenbtu t moreo itent hicka nds cutprurecl.
Pytan)imanaCs.e llso valo r strawberry-shape5d,Z. bUml ong,
w lh foLrfr ageliaw hicha risef roma prta rt he rronte no.
Antefiore dgeo f the chloraplasdte €p y divid€d inrof our or
€rqht lobes,g vingt he celta stripeda ppearancTeh. eres no
wall.3 ndt he ce I divd esb y binaryf issicnp. onds.p !ddtes

Chlorophyce:a Ger eena lgae
Greens wimmingc olonies
Pyrcbotrys.P eat-shapeds wimmingc e ls b-25um lonq.
looseiya ltgfeqatetdo {orma co ony.I n hoofp rinlsa ndo ther
puddlcsft chi n organicm alterW. ill somelimeasp pearif
mud andw atert romt heses icftt o standt ogethewr th a
pieceo f a driedp ea.T hes imilaPr ascrer,?haa so nly4 cells
insteado f 8 of 16.
'10
Eudatina.Ihes 'r.,arlo undc ells.5-15uml ong.o ccura t the
surfaceo f a globularc olony up to 20Os m across S€veral
specieso,n ec ommoni n puddlesp, onds,la kesa nd rrvers.
11 Pandarha. D)tfercf tam Eudozra tn that the cellsi it c osely
logelharw itho!1a lafgec enirasl paceC ommonin puddles.
pondsl,a kesanrdi versC. els8 -20urno ng,cooniesupto
50 um diameter.
12 GorlumC. onsistosf squarefl,a t.f ouro r 16 cel edc olonies
!p to 100uma crossC. ells5 -25Umlo ng.C ommoinn
puddlesp.o ndsl,a kesa nds lowr ivers.
13 Stepha na spha eft- f he coloniesa rec haracterisriccl ear
globesL rpt o 60uma crossc ontsininge ightl argec ettst ike
thoseo i Haerlalo..rsa fiangedln af equaiorianln g.T he
glober evov esa s it swimst hrought he water.F oundp ar
ticularlyrn water-fillesdo lulionh ollowso f lrrnesronreo cKs.
l/o/yoxC. oloniesv jsibc to the unaidede ve( up to I mm
across)c.o ntan rngh undredos f cells.F oundi n pudde s,
ponds.a kesa nds low rvers.F ora n articled ealjngw irltt his
andt he previoufso ur generas.e eJ ane,F .W ., 1949.F amous
plan$: 1, Volvax,N ew Bialagy,6, S7-99.