FROGLOG - Amphibian Specialist Group

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ASG Global NetworkWe are pleased to announcethat the complete ASGGlobal Network of Regional andNational Chairs is posted at www.amphibians.org. We are very gratefulto all those who have accepted aposition as Chair or Co-Chair andlook forward to working with all ofyou. One of the aims of the ASG isto catalyze conservation actions byforging partnerships and collaboration- we hope that by havingpoints of contact in each Regionof the world, we will facilitatecommunication among conservationistsand researchers. Pleasecontact the appropriate regionalChair regarding any amphibianwork that you are undertaking orplanning in your region.Seed Grant ReportsReports and publications from previous DAPTF Seed GrantsRecipients of former DAPTFSeed Grants are generally expectedto publish the results oftheir projects in refereed journals,or as articles in Froglog. They arealso required to send reports, sothat their results can be madeavailable to ASG members. Belowis a report that has been receivedrecently. Anyone wanting a copyof it should contact the author inthe first instance; if you cannotreach the author, please contactTim Halliday - t.r.halliday@open.ac.uk.Muhammad Iqbal Setiadi, BenEvans, Amir Hamidy, Zainal AbidinYusufpati & Dwi Susanto.(2006) Speciation and DistributionPatterns of <strong>Amphibian</strong>s andReptiles in Halmahera, Indonesia.(setiadmi@mcmaster.ca)J. Susanne Hauswaldt, JessikaFüssel, Claudio Angelini, DiethardTautz, Sebastian Steinfartz. (2006)Population genetics of the endangeredSpectacled Salamander, Salamandrinaperspicillata and S. terdigitata.(sebastian.steinfartz@unibielefeld.de)• The following papers report worksupported by former DAPTF SeedGrants:Alemu, I. J. B., Cazabon, N. M. E.,Dempewolf, L., Hailey, A., Lehtinen,R. M., Mannette, R. P., Naranjit,K., & Roach, A. C. J. (2007) Ecologicalobservations on the criticallyendangered Tobago endemic frogMannophryne olmonae. AppliedHerpetol: 4; 377-386. (Grants toAdrian Hailey et al., 2005, funded byChester Zoo.)(adrian.hailey@sta.uwi.edu)Population and Health of Common Toads AcrossAgricultural Lands: Implications in Worldwide DeclinesPaola M. Peltzer, Rafael C. Lajmanovich, Andrés M. Attademo, Mariana Cabagna, Gabriela Fiorenza, CelinaM. Junges and Agustín BassóEmerging evidence indicatesthat loss of habitat as a resultof agricultural development maybe contributing to reductions inanuran diversity in some locations.Although, this vertebrate group iscommonly used in laboratory toxicitytests, few field studies haveproduced evidence a significantrelationship between agriculturalactivities and amphibian responses.The overall goal of this researchwas to determine the diversity andhealth of toad populations on agriculturallands of Entre Ríos Province(Argentina). The three selectedspecies in this study (Chaunusfernandezae, C. arenarum, and C.schneideri) are widely distributedin Argentina and have relativelysmall home ranges (Lajmanovich1995), making them excellent bioindicatorsof contamination at alocal scale.The Primary Objectives of thisstudy were: a) estimate the diversityand composition of toads in soybeancropland; b) determine the extent ofcholinesterase activity in commonadult toads of agricultural sites; c)establish hematological parametersof adults, and d) detect genotoxic effectsof pesticide in erythrocytes oftadpoles.We studied agricultural sites in the4
Population and Health of common toads across ag landsContinued from previous pageMid-west region of Entre Ríos Province.It presents the biggest expansionof agricultural lands and fragmentationof the landscape. Tensoybean fields and two control siteswere sampled for larvae and adultsduring breeding events (coincidentwith period of soybean cultivation).During the day, surveys were conductedto detect anuran egg massesand tadpoles, while night surveysincluded active searches to detectnon-calling anurans and listeningfor calling male anurans, followingthe guide by Heyer et al. (1994).Individual adults were transportedin buckets to Ecotoxicology Lab ofFBCB-UNL for laboratory analysis.Each individual was anesthetized usingthe guide by ASIH et al. (2001),sexed, measured for snout-ventlength (SVL; to nearest mm) with acaliper and mass (g) with a balance.Adult malformations were analyzedfollowing the descriptionsdetailed in the field guide to malformationsof frogs and toads (Meteyer,2000). To take representativesamples and comparable data weused adult of three bufonid speciesfor this parameter. Samples of blood(ca. 300-500 µL) were extracted inanesthetized adult animals by cardiacpuncture using a small heparinizedneedle, previously locating the heartvia palpation. The anurans then werereleased in the same sites in whichthey were captured. Plasma BChEactivity was determined colorimetricallyby the method of Ellman etal. (1961) with some modifications(Sánchez-Hernández & Moreno Sánchez,2002). Hematocrit, hemoglobinconcentration, mean of cell hemoglobin,mean cell volume, meancell hemoglobin concentrations,red blood cell, and white blood cellwere determined for each toad speciesfollowing the protocols of Cabagnaet al. (2005).For micronuclei (MN) testswe conducted field experimentswith Scinax nasicus (Anura, Hylidae)tadpoles caged in agriculturalponds, because this species is notgregarius and is larger than Chaunustadpoles. Three replicates ofeach in situ chamber (ten tadpolesof similar Gosner developmentstage (st. 37) were located in eachpond under plant shade). Samplesof blood was extracted in anesthetizedtadpoles by cardiac puncture.Two peripheral blood smearsfor each tadpole were prepared onclean slides, fixed and stained bythe May-Grunwald-Giemsa method.The MN frequency was determinedin 1,000 erythrocytes fromeach tadpole using 1,000 X magnification.Other alterations of theerythrocytes were also registered.Relative abundance.The most common toad speciesobserved was Chaunus fernandezae,recorded in 65% of the total pondssampled surrounded by or withinsoybean croplands, followed by C.schneideri (21%) and C. arenarum(14%). Tadpoles and eggs in jellystrand were recorded for the threetoad species in reference sites, butevidence of reproduction was onlyobserved for C. fernandezae in pondssampled surrounded by sor withinsoybean croplands. The proportionof males and females of C. fernandezaedid not differed signifcantlyamong pond samples (agriculturalsites and controls). The proportionof sexes of C. arenarum and C. schneiderivaried significantly amongagricultural ponds and referenccesites, being biased towards malesin the former.We found upper eye-lid (n = 1),hindlimb (n = 3), and forelimb (n= 3) malformations in toad specimens(total specimens review n =124) collected across agriculturalsites of the Mid-west Entre RíosProvince. Moreover, similar malformationswere recorded in othernative species (Leptodactylus ocellatus,L. chaquensis, L. gracilis, Physalaemusbiligonigerus) that commonlyoccur in agroecosystemsalongside the three study species.Cholinesterase analysis and haematologicalanalysis:The mean values of plasma BChEactivity varied from 1 µmol min-1ml-1 (C. schneideri at agriculturalsites) to 17.31 µmol min-1ml-1(C. fernandezae at references sites).BChE activity was statisticallylower in the amphibians collectedfrom the agricultural sites thanthose from the reference site (KStest for the three species P < 0.05).Moreover, the differences in theactivity of BChE were significantamong the three study species (P< 0.05). In addition, the increasein plasma BChE was inverselyproportional to the body weight ofthe three anurans (r = - 0.85; P 0.01), in all caseslower values in agricultural siteswere recorded for each haematologicalparameter.The erythrocystes of caged tadpoles in natural sites were oblongovalshaped with centric nuclei.5
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