DNAbarcodinganddiversityofgroundwateroligochaetesinBenin(WestAfrica)PatrickMar?n1,MoïssouLagnika2,GontranSonet3andMoudachirouIbikounle2

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AbstractBackground:Groundwaterisamajorecosystemintermsofbiodiversity,endemismandrelictspecies.However,itsstygofauna,theobligategroundwaterfauna,remainstoooPenignored,althoughpresentonallcon?nents.Itsknowledgeisofpar?cularinterestforpublichealthasgroundwaterisalsothemaindrinkingwaterreservoironearth.Thisstudyaimstobuildagene?cdatabaseofgroundwateroligochaetesattheBeninesecountry,whichcanbeusedasareferenceforfuturestudiesbasedonDNAbarcoding.Itcomesinalargerframeworkusingthestygofaunaasanindicatorforwaterquality.Results:96wellsweresampledin2015and2016,andCOIbarcodeswereobtainedfrom126specimensofthegeneraAulophorus(Naididae)andHaplotaxis(Haplotaxidae),themaintwooligochaetecomponentsinBeninesewells.Moleculardataenabledaninteres?ngcomparisonbetweenbothgenera,intermsofspeciesdiversity,distribu?on,anddispersalcapaci?es.ThenumerousspecimensofthestygophileAulophorusprovedtoconsistof4species,widelydistributed,withlowintraspecificgene?cvariability,sugges?nganimportantdispersalcapacity.Incontrast,7poten?alspecieswereiden?fiedintherarestygobio?cHaplotaxis,eachofthembeingrestrictedtoonesta?on,withoneexcep?on,sothateachhydrogeographicbasincanbecharacterizedbyitsuniqueassemblageofHaplotaxisspecies.Significance:Thesefirstdatasuggestsaninteres?ngpoten?aluseofgroundwateroligochaetesforwatermanagementinBenin:(1)thepresenceofHaplotaxisisanindicatorofthephrea?coriginofwaterinwellsand,assuch,suggestsgoodwaterquality;(2)incontrast,thepresenceofAulophorusspeciesinawellgivesevidenceofpoorprotec?onofthela^eragainstexogenouselements,whichcanhaveanega?veimpactonwaterquality.

Groundwateristhemaindrinkingwaterreservoironearth,butalsoamajorecosystemintermsofbiologicaldiversity.Maintaininggroundwaterqualityandconservingitsbiodiversityareconverginggoalsbecausethehealthyfunc?oningofthesesystemsisa^estedbytheirlevelofbiodiversity.Groundwaterbiodiversitymustbedocumented,protectedandsustainablymanaged.Unfortunately,thesehabitatsares?ll“terraincognita”inAfrican,sub-Saharancountries.

Subterraneanaquiferhabitats:“terraincognita”

FIGURE2:Phylogene?crela?onshipsbetween23specimensofthestygobiontgenusHaplotaxis,basedonCOIsequences(maximumlikelihood),andloca?onofsta?onswithinthesub-watershedsoftheOuémébasin(Benin)fromwhichthespecimenswerestudied.Colourcodesareusedinordertomatchspecimensandsta?ons.

FIGURE1:Phylogene?crela?onshipsbetween43specimensofthestygophilegenusAulophorus,basedonCOIsequences(maximumlikelihood),andloca?onofsta?onswithinthesub-watershedsoftheOuémébasin(Benin)fromwhichthespecimenswerestudied.Colourcodesareusedinordertomatchspecimensandsta?ons.

pa^ernsofbiodiversitywithinthetwomainoligochaetecomponents.ThenumerousspecimensofthestygophileAulophorusprovedtoconsistofonly4species,withawidegeographicaldistribu?on.Incontrast,theobligategroundwater-dwelling(i.e.stygobiont)Haplotaxisgenusmayharbourupto7species,inspiteofitsrarityandrestricteddistribu?on,oPenlimitedtoonlyonesta?on.Itappearsthateachsub-watershedoftheOuéméhydrogeographicbasincanbecharacterizedbyitsownassemblageofHaplotaxisspecies.

Anunexpectedoligochaetediversity

0829101-Delaya bureschi

LM56_COI_ISH

LM55__COI_ISH

LM71_COI_BEN047LM53_COI_BEN031

LM52_COI_BEN031LM54_COI_BEN031

LM47_COI_BEN031

LM51__COI_BEN031LM70_COI_BVS016

LM64_COI_BEN003LM48_COI_BEN003

LM08_COI_BEN003

LM69_COI_BEN072LM57_COI_ISH

100

94

LM67_COI_ISH

84

LM50_COI_BEN008

LM49_COI_BEN008

LM18_COI_BEN008100

LM63_COI_BEN031

LM62_COI_BEN031LM61_COI_BEN031

LM60_COI_BEN031

100

LM68_COI_BEN072

100

100

PhyML ln(L)=-3048.4 658 sites GTR 100 replic. 4 rate classes 0.05

Thisprojectsuggestsaninteres?ngpoten?aluseforwatermanagementinBenin,asitseemspossiblethateachundergroundbasincanbecharacterizedbyitsownassemblageofspecies.Bysamplingthewaterfromwellswecouldalsotellwhichbasinithascomefrom,helpingusmapundergroundwaterways.Theprojectcouldeventuallybeexpandedtotherestofthecountry,providingacompletereferenceforthewholeofBenin.

BiodiversityandwatermanagementinBenin

Affilia?ons1  RoyalBelgianIns7tuteofNaturalSciences,O.D.Taxonomy&Phylogeny,29rueVau7er,1000Brussels,Belgium.

2  Universitéd’Abomey-Calavi,DépartementdeZoologie,LaboratoiredeParasitologieetd’Ecologieparasitaire,FacultédesSciencesetTechniques,01BP526,Cotonou,Benin

3  JEMU,RoyalBelgianIns7tuteofNaturalSciences,29rueVau7er,1000Brussels,Belgium

JQ519897.1_Chaetogaster_diaphanusAF534839.1_Dero_vaga

LM144_COI_BEN087LM114_COI_BEN087LM109_COI_BEN080LM108_COI_BEN080LM101_COI_BEN079LM101-1-COI_BEN079LM113_COI_BEN087LM110_COI_BEN080LM152_COI_BEN091

KP204260.1_Dero_furcataHQ691221.1_Dero_furcataAF534837.1_Dero_furcata

LM93_COI_BEN074LM97_COI_BEN075LM94_COI_BEN074

89

LM27_COI_BEN015LM25_COI_BEN015LM82_COI_BEN068LM83_COI_BEN068LM84_COI_BEN068LM89_COI_BEN060LM95_COI_BEN075LM141_COI_BVS20LM140_COI_BVS2098

100

LM128_COI_BVS02LM127_COI_BVS01LM126_COI_BVS01

88

100

LM106_COI_BEN092LM125_COI_BEN091

LM124_COI_BEN091LM151_COI_BEN091

LM79_BEN082LM105_COI_BEN092LM104_COI_BEN086LM81_COI_BEN082LM111_COI_BEN067

LM37_COI_BEN023LM121_COI_081

LM115_COI_BEN08771

100

100

LM99_COI_BEN078LM120_COI_BEN081LM117_COI_BEN089

LM01_COI_BEN001LM02_COI_BEN001LM100_COI_BEN078LM118_COI_BEN08872

85

100

AF534835.1_Dero_digitataAF534836.1_Dero_digitata

AF534838.1_Dero_obtusaLM153_COI_BEN077

100

94LM98_COI_BEN078

95

98

LM91_COI_BEN052LM90_COI_BEN052LM92_COI_BEN052LM92-1_COI_BEN05283

100

PhyML ln(L)=-3306.4 658 sites GTR 100 replic. 4 rate classes 0.02

FundingSources/Acknowledgements

Abiodiversityinventoryofabout100BeninesewellsinthelargeOuémébasin,throughDNAbarcoding,hasrevealedcontras?ng