FROGLOG - Amphibian Specialist Group

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Population and Health of common toads across ag landsContinued from previous pageCaged tadpoles at agricultural siteshad MN in their erythrocytes, althoughthere was no significantdifferencewith respect to the controlgroup. Moreover, erythrocyteslysis was found in higher percentages(17.51%) in tadpoles caged atagricultural sites.Pesticides have the potential tocause dramatic variation in naturalcommunities (Relyea 2005),yet our knowledge of their effectson natural communities is limitedto cases in which pesticides havebeen intentionally or accidentallyapplied to natural sites with subsequentbiota surveys. Based inour results we can determine thattoads inhabiting agroecosystemsare at serious risk, based on evidenceindicating the response toexposure compromises health status.Indeed, we found anuran malformationsacross agricultural sitessuggesting a link with agrochemicalscontamination. Based on laboratoryevidence we propose thatB-sterases should be applied infield monitoring as biomarkers ofpesticide exposure to wildlife becausethe non-destructive natureof its analysis and the sensitivity ofwildlife to anti-ChE agrochemicals.These data represent the firstto indicate the response and healthstatus of toads across agriculturallands in Argentina. Extrapolationfrom the present study is easy, bythe use of representative species ofnative anuran commonly foundin agroecosystems. But, before definitiveconclusions can be drawnconcerning the unsuitability ofagricultural areas for anuran populations,long-term monitoringof population health are urgentlyneed.Acknowledgements: We thankvery especially to Dr. Juan CarlosSánchez-Hernández for his advicewith B-sterases techniques and logisticalsupport.References:ASIH, HL & SSAR. (2001).Guidelines for use of live amphibiansand reptiles in field research.http: //www.utexas.edu/depts/asih/herpcoll.htlm. Accessed on13/06/02Cabagna M.C., R.C. Lajmanovich,G. Stringhini, J.C.Sanchez-Hernandez & P.M. Peltzer.(2005). Hematological parametersof health status in thecommon toad Bufo arenarum inagroecosystems of Santa Fe Province,Argentina. App. Herpetol. 2(4): 373-380.Ellman L, K.D Courtey, V. Andreas& R.M. Featherstone. (1961).A new rapid colorimetric determinationof cholinesterase activity.Bioch. Pharm. 7: 88-95.Heyer, W.R., M.A. Donelly, R.W.McDiarmid, L.C. Hayek & M.S.Foster. (1994). (Eds.). Measuringand Monitoring Biological Diversity,Standard Methods for Amphibians.Smithsonian Institution Press,Washington DC.Lajmanovich R.C. (1995). Relacionestróficas de bufónidos (Anura:Bufonidae) en ambien tes del ríoParaná, Argentina. Alytes 13: 87-103.Meteyer C.U. (2000). Field guideto malformations of frogs and toadswith radiographic interpretations.Biological Science Report. USGS/BRD/BSR-2000-0005.Sanchez-Hernandez, J.C. & B.Moreno-Sanchez. (2002). Lizardcholinesterases as biomarkers ofpesticide exposure: enzymologicalcharacterization. Environ. Toxicol.Chem. 21: 2319-2325.Relyea R.A. (2005). The impactof insecticides and herbicides onthe biodiversity and productivityof aquatic communities. Ecol. Appl.15: 618-627Emails: paolapeltzer@hotmail.com; lajmanovich@hotmail.com;atademo@yahoo.comMore RESEARCHBatrachochytrium dendrobatidis infects Melanoprhyniscus moreirae (AnuraBufonidae) from an Atlantic Rainforest area (Itatiaia), southeastern BrazilMonique Van Slys, Thais Klaion Ferreira, Flavia Rachel Moreira Lamarão, Milton Ozório MoraesDeclines of amphibian populationsdriven by the chytridfungus Batrachochytrium dendrobatidisare a concern worldwide(Berger et al., 1999; Lips et al.,2005). Although there is evidencethat not all reported amphibian declinesare caused by the chytrid fungus(Daszak et al., 2005), the diseasechytridiomycosis has been linked to6species declines and extinctions onseveral continents (Weldon & duPrez 2004, Lips et al., 2006; Mendelsonet al., 2006; Schloegel et al.,2006).
Batrachochytrium dendrobatidis infects M. moreirae from an Atlantic rainforest, brazilContinued from previous pageIn Brazil, reported declines ofamphibian populations comemainly from the Atlantic Rainforest,and also from the Cerrado(Heyer et al., 1981; Weygoldt,1989, Guix et al., 1998, Eterovicket al., 2005). B. dendrobatidis hasalready been reported from severalspecies in the Atlantic Rainforest,from Rio Grande do Sul (southernmoststate) to Pernambuco (northeastern)(Toledo et al., 2006, Carnavalet al., 2006). However, thereis not enough data to link B. dendrobatidisto amphibian declines inBrazil.Melanophryniscus moreirae is asmall bufonid (mean adult bodysize < 20mm) found in the ItatiaiaPlateau and in the SerraFina, southeast Brazil, alwaysabove 2,000 m (Bokerman, 1967;Marques et al, 2006). These toadsare diurnal, and breed in shallowpuddles from September to December(Bokerman, 1967; Starret,1967; Guido-Castro, 2006).M. moreirae has been reported as‘declining’ by Guix et al. (1998),but no systematic monitoring ofthis endemic toad has been carriedout.Herein we report the occurrenceof B. dendrobatidis infecting thetoad M. moreirae using Real timePCR.The study was carried out on theItatiaia Plateau in the Itatiaia NationalPark (PNI), located 44º34’to 44º42’ W, and 22º16’ to 22º28’S, southeast of Brazil. Field workwas carried out in spring 2006(October and November) as part ofa monitoring program. Fifty adultmales were captured between 09hand 16h in individual new plasticbags, in which they were measuredfor snout-urostyle length(SUL) with a calipers (precision =0.1mm). We firmly ran one swab(Medical Wire & Equipment Co.)in different parts of the frog’s body(Kriger et al., 2006). All animalswere released after sampling.We analyzed swabs using quantitative(real-time) PCR techniques(Boyle et al. 2004, Krigeret al., 2006). We classified eachsample as positive or negative forinfection with Batrachochytriumdendrobatidis. Our estimates ofthe number of zoospores representthe mean value of B. dendrobatidisgenome equivalentsdetected in the three runs of thePCR analysis.Two individuals (SUL =24.9mm and 26.1mm) were infectedwith B. dendrobatidis, correspondingto a prevalence (sensuBush et al., 1997) of 4%. Thenumbers of zoospore equivalentswere low in both individuals (1.4and 1.5 zoospore equivalents, respectively).No evident clinical orabnormal signs were observed inthese frogs.This is the first report of B. dendrobatidisin M. moreirae and thefirst for the genus. Even thoughthe prevalence and severity of infectionwere low, this result suggestsprecautionary measures betaken considering the restrictedgeographic range of M. moreirae.Monitoring of M. moreirae aswell as the possible evolution ofthe pathogen in this populationshould contribute to our currentunderstanding of the dynamics ofthis disease and to accurately determinethe impact of B. dendrobatidison this endemic species.Acknowledgements.We thank CNPq and Biodiversitasfor fundings. D. Boyle fromCSIRO, Australia, provided thestandards. We appreciate the financialsupport provided by RANA forone of the authors (TKF) to attendthe workshop on chytrid investigation.ReferencesBerger L, Speare R, Hyatt AD(1999) Chytrid fungi and amphibiandeclines: overview, implicationsand future directions. In: CampbellA (ed) Declines and disappearancesof Australian frogs. EnvironmentAustralia: Canberra, p 23-33.Boyle, DG, Boyle DB, OlsenV, Morgan JAT, Hyatt AD (2004)Rapid quantitative detection ofchytridiomycosis (Batrachochytriumdendrobatidis) in amphibiansamples using real-time TaqmanPCR assay. Dis. Aquat. Org.60:141-148.Bokermann, WCA (1967) Observaçõessobre Melanophryniscusmoreirae (Mir. Rib.) (Amphibia -Brachycephalidae). An. Acad. Bras.Cienc. 39(2):301-306.Bush AO, Lafferty KD, Lotz JM,Shostak AW (1997) Parasitologymeets ecology on its ows terms:Margolis et al revisited. J Parasitol83(4): 575-583.Carnaval, ACOQ, PuschendorfR, Peixoto, OL, Verdade, VK, Rodrigues,MT (2006) Amphibianchytrid Fungus Broadly distributedin the Brazilian Atlantic Rain Forest.EcoHealth, 2006:1-8.Daszak P, Scott DE, FaggioniC, Kilpatrick AM, Gibbons JW,Porter D (2005) Amphibian pop-7
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