NaturalistNotes Leech predation offrog spawn Introduction The predators ofAustralian anurans and their breeding activity in L. tasmaniensis. There larvae are well documented (Tyler 1976, 1994, were large persistent daytime choruses (> Littlejohn and Wainer 1978; Davies etal. 1979; 50 males) and numerous freshly deposited MorganandButtemer 1996,GillespieandHero foam nests around clumps ofaquatic vegeta- 1999). Bycontrast,little hasbeen publishedon tion. Most nests were aggregated amongst a m the sources ofpredation oftheir spawn. Tyler 9 2patchofSpikerushEleocharissphaecelata (1976, 1994) states that there are relativelyfew wheretheywereexposedto dappled sunlight predators of frog spawn and that ‘fish prob- orelse were completely shaded. A total of27 ably constitute the major predator. He notes nestswere located in this patch. The site was in particular that the foam nests ofthe genus visited over four consecutive days and nests Limnodynastes are probably most accessible inspected for the presence of leeches and to terrestrial insects because they tend to be other invertebrates on each occasion. Water located around the edges ofponds where they temperature approximately 10 cm below the are attached to peripheral vegetation, and that surface varied between 21-24°C at midday theyareoccasionallyeatenbyants.Membersof overthefourdays. the Australian frog genus Limnodynastes pro- Leeches were observed on the foam caps of duce floating foam-capped nests below which L. tasmaniensis nests on each day. All ofthe the egg mass resides (Parker 1940; Tyler and leechesappearedtobelongtothesamespecies Davies 1979; Roberts 1989). One member of andwereuniformblackincolourandapprox. mm this genus, the Spotted Marsh Frog Limnody- 50-60 in length. (Leeches were not able nastes tasmaniensis is a very common species tobeidentifiedtogenus(orspecies)levelow- , throughout much of south-eastern Australia ingtothelackofanappropriateidentification where it breeds in most months ofthe year in guide atthetime.) Theleecheswereobserved both temporary and permanent water bodies typically lying completely still on the foam and in awidevarietyofboth naturalandman- cap ofthe nests with the head and anterior made habitats (Barker et al. 1995; Hero et al bodyburieddown through thefoamcap into 1991; Littlejohn 2003). Herein I reportthepre- thegelatinouseggmassbelow.While mostof dation ofL. tasmaniensis spawn by leeches in theaffectednestscontainedasingleleech,on an ephemeral wetland near Melbourne some three nests there were two, and on one nest, 25 years ago and compare these observations three leeches. On three nests the surface of with a very similar report ofpredation docu- the foam caps had dried to a polystyrene- mentedbyBurginandSchell(2005)intheSyd- like consistency and leeches had attached neyarea. themselves to the side ofthe nestwhere they were just visible above the water line. Nests Observations aroundtheperipheryoftheaggregationwere 1. On 6 January 1987, following two days of mostaffectedbyleecheswhileonlyoneleech lhoecaavtyedraiinn,reamnsahnatlloRiwveerphReemderGalumwetEluacan-d was recorded on a nest near the ‘centre’. On lyptus camaldulensis woodland adjacent to the first day, three ofthe leeches (taken from nests outside ofthe aggregation) were eutha- the Darebin Creek in the north ofBundoora (37°69'S, 145°05'E) Victoria, was visited. The nised and foundtocontain numerous (> 10), swamp had been completely dry since about mostlyintactfrog’seggs. The incidence ofleeches on foam nests re- mid-December ofthe previous year but rain had refilled it and had stimulated a burst of mfeacitninegdafbaoirultyocnoen-stthainrtdovoefraltlhneefstosur(d3a0y-s3,7a%f;- Vol 130 (I) 2013 49 NaturalistNotes Table 1). Bythe fourth day, the eggs ofseven At all three localities the leeches found on nests had begun to hatch and most of the L. tasmaniensis nests appeared to be the same others were close to hatching (Gosner stages species. Theseleecheswereoccasionallycaught 20-25; DuellmanandTrueb 1986).Twonests indip-netsskimmedthroughwateraroundthe wereoccupiedbyleechesforuptothreecon- periphery of large ponds and swamps at the secutive days. Eight leeches closelyexamined sites, indicating their aquatic habit. While L. on the fourth day had noticeably distended tasmaniensis has frequently been observed to bodies,indicatingrecentfeeding. breed in small ephemeral ponds (n > 15), no Other arthropods located on the foam caps leeches were ever observed on nests deposited ofnests included (total number in parenthe- intheseponds.Leecheswereneverobservedas sis): ants (6), aquatic snails (5), spiders (4), ectoparasites ofL. tasmaniensis larvae oradult caterpillars (3), millipedes (2) and dipterans frogs at any ofthe sites, despite regular visits (8). As none of these arthropods appeared overmorethantenyears. to be feeding directly on the eggs, it is likely Discussion that these occurrences were quite incidental and represent fauna displaced by flooding The sanguivorous habit of many terrestrial (although see Discussion). The percentage and aquatic leeches is well known and leeches ofnests with other arthropods was consist- have been documented as ecto and endopara- ent over the three days they were recorded sitesofbothfrogsandtheirlarvae(Waite 1925; (14-16%;Table 1). Mann and Tyler 1963; Brockelman 1969; Tyler Inadditiontotheobservationsabove,Ihave 1976; Duellman and Trueb 1986; Sawyer 1986 since made very similar observations at two and references therein; McCallum etal. 2011). other(nearby) sites: By contrast the literature on leeches as mac- 2.Approximately3kmsouthoftheabovesite, rophagous predators of frog spawn, though beside the Darebin Creek in Bundoora, two relatively small, has been largely neglected or leeches were located on separate, recently omittedentirelyfrom consideration inreviews tdievpeolsyistmeadllL.epthaesmmeanriaelnspiosndnesftoslloinwinagrrealian- omfanbotahndleTercuheban1d98a6m;phGiobvieadnicbhio2l0o0g1y;(TDouleeldlo- in January. 2005;RomanoandDiCerbo2007).Arelatively 3. At Somerton (37°63’S, 144°95’E) near the recentliteraturereviewbyRomanoandDiCer- southernboundaryofCraigieburnGrasslands, bo (2007) found that anuran egg predation by four leeches were located separately on the leeches hadbeen documentedin some 20 spe- foamcapsoffreshlylaidL. tasmaniensisnests cies, representing 3.6% ofthe total number of partiallyconcealedbyPoasp.tussocksandde- anuran species in those regions where anuran posited in alargeephemeral pondwhich had leech predation occurred. That some leech beenfilledbyheavyraininNovember. species should consume frog spawn is curious Table 1. The frequency ofoccurrence ofleeches and other arthropods on 27 foam nests ofthe SpottedMarshFrogLimnodynastes tasmaniensismonitoredoverafourdayperiod. Day NumberofLeeches %ofnestswithLeeches %ofnestswith otherarthropods 1 11 30 15 2 15 37 16 3 16 37 14 4 10 33 - 50 TheVictorianNaturalist NaturalistNotes because it occurs in spite ofa clear adaptation preferencesoftheparticularspeciesofleechin- they have to piercing the skin of mammals volved. (Cargo 1960) and other vertebrates. Limnody- Burgin and Schell (2005) reported the leech nastes tasmaniensis is the only Australian frog Bassianobdellafusca feeding on L. tasmanien- species in which this kind of predation has sisfoam nests fromawetland near Sydney and beendocumentedtodate. most ofthe observations described above are The presence of leeches on L. tasmaniensis consistent with their work. For instance, the nests is unlikely to be the result of their dis- timing of the observations in both cases was placement due to flooding for two reasons: (i) summer (orlatespring),coincidingwith maxi- Ihad onlyeverlocatedthem inwaterandthus mum leech activity, and both sets ofobserva- theirpresenceonthetoporsidesoffoamnests tionsoccurredinlargeephemeralwaterbodies. above the water level (in many instances) is at OnenotablepointofdifferencewasthatBurgin oddswiththishabit,and(ii) inallinstancesthe and Schell (op. cit.) observed thatleeches con- headoftheleechwasprotrudingdownthrough sumed ova only in Gosner stages 1-14, which the foam cap into the egg mass, consistent meant that clutches were vulnerable to preda- with their being engaged in feeding. Even if tion onlyin the first24 hours followingovipo- the leeches were present on foam nests due to sition; observations in this work indicate that disturbance ofsome kind, the small sample of leechesremained onspawn clumps,apparently leeches found to have consumed frog spawn continuingtofeed,foruptofourdays.Itwould indicates opportunistic feedingwas occurring. beusefultoknowifthissameleechspecieswas The number ofleeches recorded on individual alsoresponsibleforpredation events described foam nests inthisworkmust,however,becon- in this work, and further, whether leeches are sidered an underestimate as only a few nests able toconsume largerand more developmen- were thoroughlyexamined forleeches residing tallyadvancedlarvae (i.e. Gosnerstages >14). amongsttheeggmassortheportionoftheegg Finally, Hakansson and Loman (2004) have massbelowthewater (andnonewerelocated). shownthatspawnlocatedinthecentreofcom- Theimpactthattheleecheshadonindividual munalaggregationsoftheCommon FrogRana nestswasnotapparentlyseveresincetheirpres- temporaria suffered markedly less leech pre- ence did not seem to affect the integrityofthe dation compared to those on the periphery. A nestsandtherelativelywarmconditionsmeant similarpattern ofleech predationwasnotedin that egg development was rapid, ensuring that thisworkand maybeworthyofmore detailed mosteggshatchedtoproducelarvae. examination. The occurrence ofdipterans on nests, while possibly incidental, is worthy ofcloser exami- References nation as the parasitisation of frog spawn by BaAruksetrraJl,iGarniFgrgogsG.C(SaunrdreTyyBleearttMyJ&(S1o9n9s5:)CAhiFpipeilndgGNuoirdteont,o dipteran larvaehasbeen documented to occur NSW) in various other anuran species (Bokermann BokermannWCA(1957) Frogeggsparasitizedbydipterous 1957; Tyler 1976; Villa et al. 1982; Menin and Brloacrvkaeel.mHaenrpWetYolo(g1i9c6a9)13,A2n31a-n2a3l2y.sisofdensityeffectsand Giaretta 2003). Furthermore six South Ameri- predation in Bufo americanus tadpoles. Ecology 50, 632- can leptodactylidae frog species (that produce Bu6r4g4i.nSandSchellCB(2005)Frogeggs:uniquefoodsource foam nests similar to L. tasmaniensis) were forthe leech Bassianobdellafusca. ActaZoologica Sinica found to suffer significant predation from dip- Ca5r1g,o3D49G-3(5139.60) Predationofeggsofthespottedsalaman-, teranlarvae(MeninandGiaretta2003). der, Ambystoma maculatum by the leech Macrobdella taIstmsaenieemnssirsemisariknabsloeu,th-geiavsetnerhnowAusctoramlimao,nanLd. DabdveyiceoAsrnatM.s,?CThWTyehlseearpVeMicaJtkoearniSadcniMeNnaacrteturi1an(l3,i)As,At191(691(-931)72,90)9.7.FrogsPreyedon the conspicuousness of black leeches on the Duellman EandTrueb L(1986) BiologyofAmphibians. contrasting white foam nests, that leech pre- Gil(lMecspGirea,w-GHRilla:ndNeHwerYoo,rkJ)-M (1999) Potential impacts of dation had not been reported until relatively introducedfishandfishtranslocationsonAustralianam- recently. This may indicate that leech preda- phibians. In Declines and Disappearances ofAustralian tion does not occur in all breeding situations, Ftrraolgisa,:Cpapn.be1r3r7a-)145. Ed A Campbell. (Environment Aus- or is limited by the distribution and/orhabitat Vol 130 (1)2013 51 NaturalistNotes GovedichFR(2001)AReferenceGuidetotheEcologyandTax- ParkerHW(1940)TheAustralasianfrogsofthefamilyLep- oofnAoumsytroaflaFsrieashawnadteOrceaanndiaT.er(rCesotorpiearlaLteievceheRses(EeuahricrhuCdeinnterae) RotmodaanctoylAidaaned.NDoiviCteartbeosZAoRol(o2g0i0c7a)eL42e,ec1h-1p0r6e.dationonAm- forFreshwaterEcology,IdentificationGuideNo.35:Thur- phibianeggs.ActaZoologicalSinica53,750-754. goona,NSW) SawyerRT(1986)LeechBiologyandBehavior.VolumesI,II HatkhaenCsosomnmPonanFdroLgoRmaannatJe(m2p0o0r4a)riCao-mEmgugntaelmpsepraawtnuirenganidn Tol&edIoII,.L(FCl(a2r0e0n5d)oPnrPerdeastsi:oOnxoffojrudv)enileandadultanuransby HeprroedJaMt,ioLnicttolnesjeoqhunenMcesa.ndEtMhaorlaongtyel1l1i0,G66(51-969810).Frogwatch itnolvoegritceablraRteevsi:ecwusr3r6e,nt39k5n-o4w0l0e.dgeandperspectives.Herpe- FieldGuideto VictorianFrogs.(DepartmentofConserva- TylerMJ(1976)Frogs(Collins:Sydney) tion&Environment:Melbourne) TylerMJ(1994)AustralianFrogs-anaturalhistory. (Reed LitHtalnejdobhnooMkJN(o2.006.3)2Ferdong.s(oUfniTvaesrmsaintiyao.fFTaasumnaanioaf:TaHsombaanrita), TylBeorokMsJ:CahnadtsDwaovoide,sNMSW()1979) Foam nest constructionby LittlejohnMJandWainerJW(1978)Carabidbeetlepreying AustralianLeptodactylidFrogs(Amphibia,Anura,Lepto- MaonnnfrKogHs.aTnhdeTVyilcetrorMiaJn(N1a9t6u3ra)liLsete9c5h,e2s5a1s-2e5n2d.oparasitesof VildlaactJy,lMidcaDei).arJmouirdnaRlWofaHenrdpeGtaollloagrydo13J,M50(91-958120).Arthropod McfCroagls.luNmatuMrLe,(LMoonsdeorn)W1E9,7,W1h2e24e-l1e2r25B.A and Trauth SE p5r7e7d-a5t8o9r.sofleptodactylidfrogfoamnests.Brenesia19/20, (2011) Amphibian infestation and host size preference WaiteER(1925)FieldnotesonsomeAustralianreptilesand bytheleechPlacobdellapicta(Verrill, 1872) (Hirudinida: abatrachian. Records oftheSouthAustralian Museum 3, Rhynchobdellida: Glossiphoniidae) from the Eastern 17-32. MeOnzianrkMs,aUnSdA.GiaHreertpteatoAlAog(y2N0o0t3e)sP4r,ed1a4t7i-o1n51o.nfoamnestsof leptodactylinefrogs(Anura:Leptodactylidae)bylarvaeof Beckeriellaniger(Diptera:Ephydridae).JournalofZoology (London)261 239-243. GrantSTurner MorganLAand,ButtemerWA(1996)Predationbythenon- 103SettlementRoad nativefishGambusiaholbrookionsmallLitoriaaureaand Bundoora,Victoria3083 L.dentatatadpoles.AustralianZoologist30(2),143-149. OneHundredandTwenty-twoYearsAgo NotesOnThePlanarianWormsObtainedOnTheUpperWellington. BYARTHURDENDY 1. Geoplana howitti, species nova.—Unfortunatelyonlyasinglespecimenofthiswormwasfound,butit isawellmarkedandverybeautifulspecies. Thegroundcolourofthedorsalsurfaceisyellowishwhite.In themiddlelinethereisafairlybroadbandofthegroundcolour,andoneachsideofthisastripeofabout equalwidthofdarkpurplishbrown,thenaratherbroaderbandofgroundcolourthicklyfleckedwithdark purplishbrownandedgedontheoutsidebyafinelineofthesame.Outsidethisisaverynarrowmargin ofgroundcolour.Allthedarkbands uniteateachend.Theventralsurfaceispaleyellowishwhiteorgrey, withnomarkings. — 2.Geoplanalucasi,Dendy. Thisisaremarkableandveryrareplanarian,ofunusuallylargesize,andwith blackandwhitemarkings. Itwashithertoknownonlyfromthreespecimensfoundonthetopofthecoast rangesintheCroajingolongdistrict,ontheoccasionoftheClub'sexpeditiontothatlocality,anddescribed (from spirit specimens only) bymeinthe "Transactionsofthe Royal SocietyofVictoria." Onlyasingle specimenwasfound. 3. Geoplanaquadrangulata,Dendy.—Asmallvarietyofthisremarkablespecieswasfound inabundance. HithertoithasonlybeenrecordedfromMacedon,andinverysmallnumbers. — 4. Geoplanafrosti, Spencer. This species was recently discovered on the Clubs expedition to the Yarra Falls, and is described by Professor Spencer in the “Transactions ofthe Royal Society ofVictoria.” We obtainedonesmallspecimen. 5. Geoplanaalba,Dendy.—Weobtainedseveralfineexamplesofthiscommonplanarian. — 6. Geoplanasulplmrea,FletcherandHamilton. Thisspecieswascommon. FromThe VictorianNaturalist VIII, pp.43-44,June-July, 1891 , 52 TheVictorianNaturalist