Observations on the early life history stages of Notaden bennettii in the Chinchilla area of southern Queensland

3 Pages·1995·0.6 MB·

by  M Sharman

6
OBSERVATIONS ONTHEEARLY LIFEHISTORY STAGES OFNOTADEN
BEsWNETTlIINTHECHINCHILLA AREA OFSOUTHERN QUEENSLAND
M. SHARMARLWILLIAMSON& D.S.L.RAMSEY
Sharman, MM Williamson, I. & Ramsey, D.S.L. 1995 1201: Observationsontheearly life
historystagesofNotadenbennettiiintheChinchillaareaofsouthernQueensland. Memoirs
oftheQueenslandMuseum38(2):667-669. Brisbane. ISSN007^-8835.
Eggs, larvae and metamorphs ofNotaden bennettii were observed in natural pooh in the
ChinchillaarMea,southeastQueenslandbetweenFebruaryandMarch1994.Theobservations
suggestthat bennettiihassomeinterestingbehaQviouralandmorphologicalcharacteristics
thaiareabsentorrareinotherAustraliananurans. Notadenbennettii,lifehistory,southeast
Queensland.
M Shannon* I Williamson&D.&L RaJnsey,SchoolofLifeScience\QueenslandUniversirv
ofTechnofaw GPOBox2434, Brisbane. Qld400l Australia; 27September1995,
y
Notadenbennettiiisacommonfrogfoundover massesa2-3cmwidebandofvegetation(mainly
a large area of inland eastern Australia (Cogger, dead Cypressneedles) was found around the pe-
1992). Howeverthereis little informationon the rimeter of the egg mass (Fig. 1). The remaining
We
early life history stagesofthisspecies. report twomasseshadonlysmallamountsofvegetation
here on observations of the eggs, larvae and around theirperimeters. Because egg layingwas
metamorphs of N. bennettii made in the Chin- not observed it is not clear whether each mass
chillaareaofsouthern Queensland. represents one clutch, and if adults placed the
Observations were made at a site within the vegetation around the egg mass or ifvegetation
BuxakulaStateForest,approximately40kmnorth accumulatedaround theegg mass as it drifted in
ofChinchillainsouthernQueensland.Vegetation the pool. However, the small interval between
in the area is mainly open woodland dominated observing amplexus and resulting egg masses
by whitecypress(Callitrisglauca).Observations (<12h)and theconsistentarrangementofvegeta-
were made in situ, or on live individuals trans- tion suggest that the vegetation was placed
ported to the laboratory. Descriptive terminol- around the egg mass, perhaps to act as a barrier
ogy for tadpoles follows Altig (1970) and the againstegg predators.
stagingsystemusedisfromGosner(1960).Mea- Embryosin naturalpoolshadhatched by 1200
surements oftadpoles were made to the nearest on February 17 (approximately 60h). Embryo*
0.5mm under a dissecting microscope, and transportedtothelaboratoryhadreachedstage 1
metamorphs were measured using dial calipers.
Water temperatures were recorded with maxi-
mum-minimumthermometers.
A numberofpermanent and temporary water
bodies were monitored for calling males, eggs,
larvae and metamorphs approximately once per
week from November 1994 to March 1995.
Notaden bennettiiwereheard calling onJanuary
30, February 8andFebruary 14. Amplexedpairs
werelocated on February 14 following 70mmof
rain in the previous 48 hours. Amplexus was
pelvic and pairs were seen in shallow temporary
pools (10-20cm deep). Egg laying was no* ob-
served, but 15 egg masses were noted in four
separatepoolsthefollowingmorning, Each mass
was oval in shape and measured approximately
10x6cm. Masseswerefreefloating,possiblydue
toanumberofairbubblesdistributedthroughout
Ibe mass, andcontainedapproximately 500eggs FIG. 1.Typicalegg massofNotadenbennettii Masses
in individualjelly capsules. In 13 of the 15 egg measuredapproximately 10x6cm.
'.** MEMOIRS OFTHEQUEENSLANDMUSEUM
distinctdark posteriorsectionintadpolesbeyond
stage36(Fig.2).Darktailtips,withadjacentlight
areas, may function to misdirect the attack of
&
predators (Altig Channing, 1993), especially
odonate naiads (Caldwell. 1982). Many tadpoles
from natural pools had tail damage consistent
withattackbyodonates,andodonateswerecom
mon in pools with N. bennettii,
Inthe field tadpoles were noted in the shallow
FIG. 2. Lateral view of a stage 37 Notaden bennettii waterat theedge ofpoolsat all times oftheday,
tadpole. Scalebar= 10mm. Rseiczexnftrloymmlelt.aOtmoor1p4h.o9smemd(imnediavnid=ua1l2s.7r,anng=ed18)i.n
Metamorphs were noted nearpools from Febru-
after approximately 36 hours* and stage 20 after
approximately 60 hours. Temperature was not ary28toMarch 14.Thelengthofthelarvalperiod
c2o0n°traonldle3d0d°uCriSntgatgheis2p6etraidodp,olbeustrraannggeeddibneltewnegetnh pinoonlasturwailthpotnaddspoilsedsifoffickulntotwondeatgeermdirnieedbebceafuosree
individualsmetamorphosed. Watertemperatures
ftarionmed7.w5asto3I8O..0Ommmm,(aatndstmagaex4i0m).umAlesntgatghe a3t7- ilnartvhaeesienapnooelxsperrainmgeendtaflrpoomnd19r°eatcohe3d6°mCe.taSmoomre-
tadpole is illustrated in Fig. 2. Ratios of body phosis in 50 days (temperature range 19° to
proportionswerebody length:totallength=0.42 36°C). However, egg and larval period may be
a(nnd=2b0o)d,yboddeyptwhidttohb;obdoydywildetnhgt=h=0.06.163((nn== 1100)), afsrosghsowrteraesf2i8rstthoe3a0rddcaaylsliinfge(gJgasnuwaerrye3l0a)iadnwdhtehne
Eyes were dorsal and the mouth was orientated metamorphs emerging from those eggs were the
ventrally.Therewerethreeupperandthreelower ones noted on February 28.
rows of labial teeth with the formula 3(2-3)/3, Metamorphs were active during the day and
with the A2 gap being narrow and the A3 gap appeared to bask in sunny positions on the damp
wide (Fig. 3). Marginal papillae had an anterior substrate.The meatant,Iridomyrmexpurpureus,
gap. The anus was median and the spiracle was was seen preying on some metamorphs. Other
sinistral, located ventrolaterally and orientated anuranspecies,notedaseithercallingmalesoras
posteriorly. Tadpoles between stages 27 and 38 larvae, that used the same water bodies as N.
generally hadasmaltpalespotmid-dorsally.The bennettii were Litoria albogutiatus, L.fallax, L
typical N. bennettii back pattern became evident latopalmata, L. peronii, L rubella, Cyclorana
atstage37to38.A darkenedposteriortailsection cultripet, Umnodynastes omatus, L lasmanien-
developed from a slight difference in the distri- sis, L terraereginae, Crmia parinsignifera and
bution of dark pigment at stages 27 to 30, to a Uperoleatugosa.
Slater& Main (1963) described the tadpole of
Notaden nichollsi, However, information on the
life history ofthe genus Notaden is limited. The
observationspresentedheresuggestthatNotaden
bennettii has some interesting behavioural (egg
layingbehaviour)and morphological (tail colour
pattern) characteristics that are absent or rare in
otherAustralian anurans.
Observationsweremadeduringfieldworkcon-
ducted for the CSIRO - ANZECC Cane Toad
Research Committee as partofa grant to I, Wil-
liamson Steve Richards and Glen Ingram pro-
vided useful comments.
LITERATURECITED
FIG. 3. The oral disc ofa stage 37 Notadenbennettii ALTIG.R1970.Akeytothetadpolesofthecontinental
tadpole Scalebar= 1mm. United Stales and Canada. Herpetological 26:
80-207.
1
NOTADENBENNETTH 669
ALTIG,R.&CHANNING,A. 1993.Hypothesis:func- GOSNER, K.L. 1960. A simplified table for staging
tional significanceofscalerandpatternofanuran anuran embroys and larvae with notes on their
tadpoles. HerpetologicalJournal 3: 73-75.
CALDmWoErpLhLi,smJ.iPn.A1c9r8i2s.tDaidsproulpetsivienr:eastpaoilnssecatloerdipfofleyr-- SLATiEdRen,tiPf.ic&atMioAnI.NH,erAp.eRt.ol1o9g6ic3a.N1o6t,e1s8o3n-t9h0e.biology
entialpredation.CanadianJournalofZoology60: of Notaden nichollsi Parker (Anura:
2818-2827.
COGGAEusRt,ralHi.a'G.3r1d9E9d2.n.'(RAepHtil&esAanWd RAemepdh:ibSyidannesy)o.f L8:ep1t6o3d-a1ct6y6l.idae). Western Australian Naturalist