Spider biodiversity patterns and their conservation in the Azorean archipelago, with descriptions of

34 Pages·2008·1.74 MB·English

SystematicsandBiodiversity6(2):249–282 Issued6June2008
doi:10.1017/S1477200008002648PrintedintheUnitedKingdom (cid:2)C TheNaturalHistoryMuseum
PauloA.V. Borges1∗ & Spider biodiversity patterns and their
Joerg Wunderlich2
1AzoreanBiodiversityGroup, conservation in the Azorean archipelago,
DepartamentodeCieˆncias
Agra´rias,CITA-A,Universidade
with descriptions of new species
dosAc¸ores.CampusdeAngra,
Terra-Cha˜;AngradoHero´ısmo–
9700-851–Terceira(Ac¸ores);
Portugal.
Email:[email protected]
2ObererHa¨uselbergweg24, Abstract In this contribution, we report on patterns of spider species diversity of
69493Hirschberg,Germany. the Azores, based on recently standardised sampling protocols in different hab-
Email:joergwunderlich@
itats of this geologically young and isolated volcanic archipelago. A total of 122
t-online.de
species is investigated, including eight new species, eight new records for the
submittedDecember2005
Azorean islands and 61 previously known species, with 131 new records for indi-
acceptedNovember2006
vidualislands.Biodiversitypatternsareinvestigated,namelypatternsofrangesize
distribution for endemics and non-endemics, habitat distribution patterns, island
similarity in species composition and the estimation of species richness for the
Azores.Newlydescribedspeciesare:Oonopidae–OrchestinafurcillataWunderlich;
Linyphiidae:Linyphiinae–PorrhommaborgesiWunderlich;Turinyphiacavernicola
Wunderlich;Linyphiidae:Micronetinae–AgynetadepigmentataWunderlich;Linyph-
iidae:Erigoninae–Acorigonegen.nov.withitstypespeciesAcorigonezebraneus
Wunderlich;Clubionidae–CheiracanthiumfloresenseWunderlich;Cheiracanthium
jorgeenseWunderlich;Salticidae–NeonacoreensisWunderlich.Othermajortaxo-
nomicchangesare:DiplocentriaacoreensisWunderlich,1992(Linyphiidae)istrans-
ferredtoAcorigone(comb.nov.),LeucognathaWunderlich1995(Tetragnathidae)is
notanendemicgenusoftheAzoresbutanAfricantaxonandsynonymouswithSan-
cusTullgren,1910;LeucognathaacoreensisWunderlich,1992istransferredtoSan-
cus.MiniciapicoensisWunderlich,1992isasynonymofM.floresensisWunderlich,
1992.Foreachspeciesadditionalinformationispresentedaboutitsknowndistribu-
tionintheislands,itscolonisationstatus,habitatoccurrenceandbiogeographical
origin.
Key words Araneae, Azores, biodiversity patterns, biogeography, cave species
endemic,islands,newtaxa,MacaronesianIslands,spiders
Introduction Duetotheabilityofmanyfamiliesofspiderstodisperse
over long distances using wind currents (‘ballooning’) these
Spiders (Araneae) are an important component of arthropod organismseasilycoloniseisolatedislandarchipelagoslikethe
faunas(Wise,1995),withtheirpredatorybehaviourbeing,for Azores and should have disproportionally higher species di-
instance, of great relevance for biological control in agroe- versity.However,spidersarenotaparticularlyattractivearth-
cosystems. Members of this order play an important role ropodgroupforhumans,andtheircurrentworldandAzorean
in most terrestrial foodwebs, may be very abundant in sev- taxonomicknowledgearefarfrombeingsatisfactory.Forin-
eral habitats and are among the most numerous arthropods stance,intheAzorestherateofnewspeciesrecordsandnew
from many samples in all kinds of habitats in the Azores speciesdescriptionindicatesthatonlyrecentlyareweachiev-
(Borges&Brown,2001,2004)andelsewhere(Basset,1991). ingasatisfactorypictureoftheAzoreanspiderdiversity(see
Moreover,despitetheimportanceofspidersinterrestrialeco- moredetailsbelow).
systems,inbothspeciesrichnessandabundance,thisarachnid The difficulty in spider biodiversity assessment in the
group is rarely considered in evaluating networks of protec- Azores seems to be related to the absence of historical
ted areas (but see Skerl, 1999; Cardoso, 2004; Borges et al., expeditions focusing only on this group of arthropods and
2005a). on the high richness and variability in microhabitats they
occupy. Historical investigations include the works of Denis
∗Correspondingauthor. (1964), that reported 70 species for the archipelago, and
249
250 PauloA.V.Borges&JoergWunderlich
Figure1 Mapofthestudiedregion,showingthenineislandsoftheAzores.
Wunderlich (1992), who listed 103 species and a few inde- andbiogeographicalorigin;(iii)toestimatespiderspeciesrich-
terminedtaxa.Specialsamplingprotocolsandastandardised nessintheAzores;and(iv)toplansomesuggestionsforthe
sampling of different habitats are urgently needed for the conservationofAzoreanspiderdiversity.
adequate inventory of spiders and other arthropod groups
in the Azores. This contribution is part of a larger study
Materials and methods
conductedsince1998intheAzoreanislands(ProjectBALA–
Biodiversity of the Arthropods of the Laurisilva of the
Azores) (see Borges et al., 2000a, 2005a) that aims to Areaofstudy:TheAzores
survey the Azorean arthropod fauna using standardised TheAzoreanIslandsarevolcanicinoriginbeinglocatedinthe
sampling protocols at different spatial scales covering most NorthAtlantic,roughlybetweenthecoordinates37◦to40◦N
protectedareasandnativeforestsinsevenofthenineAzorean latitudeand25◦to31◦Wlongitude(Fig.1).Thisarchipelago
islands. For this current contribution we use as a starting comprises nine main islands and some small islets and is
point the last list of Azorean spiders (Wunderlich, 1992), located at the triple junction between the African–Eurasian
and include data from recent field studies in pasturelands and North-American plates, emerging from the Azores Plat-
(Borges, 1999; Borges & Brown, 1999, 2001, 2004), cav- eau, a topographic and gravity high near the Mid Atlantic
ernicolous fauna (Borges & Orom´ı, in press), native forest ridge (MAR). The archipelago is situated over two tectonic
and grassland habitats (Borges et al., 2000b, 2005a), and plates: the westernmost islands of Flores and Corvo lie over
fruit orchards (Santos et al., 2005). The recently published theAmericanplateandareseparatedfromtheeasternislands
updatedlistofAzoreanfaunaandflora(Borgesetal.,2005b) by the Mid-Atlantic Ridge (MAR); the other seven main is-
also includes a revised list of Azorean spiders (Borges & lands are located in a large triangular plateau with a com-
Wunderlich,2005)thatisreproducedwithsomeupdatesand plicated structure known as ‘Azores Plateau’ (Nunes, 1999;
additionalinformation(e.g.newrecords,habitatdistribution, Franc¸a et al., 2003). The distance between the Azores and
biogeographical origin) in Appendix 1 (which is available the European mainland is about 1584km, calculated from
as “Supplementary data” on Cambridge Journals Online: CabodaRoca(themostwesterlypointoftheEuropeancon-
http://www.journals.cup.org/abstract_S1477200008002648) tinent). The nine islands are divided into three groups: the
andwillbethebasisofourbiodiversitypatternanalysis. occidental group of Corvo and Flores; the central group of
Studiesonislandbiodiversityandislandbiogeographical Faial,Pico,Graciosa,Sa˜oJorgeandTerceira;andtheoriental
patternsforspidersarescarceglobally(butseeBaert&Jocque´, groupofSa˜oMiguelandSantaMaria,plustheFormigasislets
1993; Real et al., 1999; Schoener et al., 2003). Therefore, (Fig. 1). The largest island is S. Miguel (757km2), and the
we are trying to make some headway by investigating some smallestisCorvo(17km2).S.Mariaisthesouthernmostisland
biodiversitypatternsintheAzoreanspiderfauna. (37◦N,25◦W),andFloresisthewesternmostone(31◦W).The
Thepurposesofthisworkare:(i)toupdateallthetax- mostnortherlyoneisCorvo(39,7◦N).Thedistancebetween
onomydataoftheAzoreanspiderfauna,describingnewtaxa, Corvo and Santa Maria, the islands farthest apart, is about
listingnewrecordsforindividualislandsandrevisingnomen- 615km. Corvo lies approximately at the same distance from
clature;(ii)toinvestigatesomebiodiversitypatternsconcern- the Iberian Peninsula and from Newfoundland. All the in-
ingdistributionbetweenislands,habitats,colonisationstatus formationconcerningthelongitude(long.),latitude(lat.),area,
Islandspiderdiversity 251
maximumaltitude,distancesfromthemainlandandgeological conservation management scheme, was launched covering
ageofeachislandaregiveninTableS1inSupplementaryMa- about13%oftheareaofAzoresislands.Selectedareaswere
terial. chosenbothfortheprotectionofselectedspeciesofbirds(Spe-
The acceptance of the Plate Tectonic Theory and the cial Protection Areas – SPAs; Portuguese ZPEs; n=15) and
confirmedvolcanicoriginoftheseislands,madetheAzoresa fortheprotectionofhabitatsand(non-bird)species(Special
totallyoceanicarchipelago.TheeasternpartofeveryAzorean AreasofConservation–SACs;PortugueseSICs;n=23).
island is geologically the oldest. This is a consequence of
theparticularseismovolcanicmechanismsofthisarchipelago
(Nunes,1999;Franc¸aetal.,2003). Spidersamplinganddatabases
Locatedatameanlatitudeof38◦30(cid:5) andsurroundedby Since1994spidersweresampledinastandardisedwayindif-
the Atlantic Ocean, the Azores enjoy the benefits of a mild ferenthabitats.Datafromsemi-naturalpasturesandintensive
andagreeableclimate.ThewarmGulfStreamisresponsible pastureswerecollectedonthreeislands(Terceira,PicoandS.
for quite similar temperatures at sea level in the southeast- Maria) in the years 1994 and 1995 by means of pitfall traps
ern as well as in the northwestern islands. The same can be anda‘Vortis’suctionsamplingmachine(seedetailsinBorges,
said of humidity levels in the different islands (Agostinho, 1999; Borges & Brown, 1999, 2001, 2004). The bulk of our
1966).Amarkedoceanicclimatewithlowthermalamplitude data comes from project BALA (Biodiversity of the Arthro-
andhighprecipitationandhumidityarecharacteristicofthis podsfromtheLaurisilvaoftheAzores),inwhichfrom1999
archipelago. to 2005 arthropods were collected by means of pitfall traps
Discovered by the Portuguese navigators in 1432, the inthenativeforestsofsevenislands(CorvoandGraciosaex-
Azores seem already to have been vaguely known, as indic- cluded)(seedetailsinBorgesetal.,2005a),butalsoinnatural
atedonoldermaps.ThepresentAzoreanlandscapehasbeen grasslandandsomeexotictreeplantations(Ecucalyptusspp.,
stronglymodifiedbyitshumaninhabitants,andonlyinsmall Acaciaspp.,PittosporumundulatumandCryptomeriajapon-
areas, where the soil or climate was too rough, have primit- ica)(Borgesetal.,unpubl.data).
iveconditionsremainedunchanged.Thepopulationexceeded Another habitat surveyed was the canopy of both nat-
300000inthe1960s,butnowadaysonlyabout260000people ive and endemic trees (see Ribeiro et al., 2005; also BALA
liveintheseislands(DREPA,1988).S.Miguel,Terceiraand project)andoffruitorchards(seeSantosetal.,2005;project
Faialarethemostdenselypopulatedislands. INTERFRUTA). In the case of project INTERFRUTA data
According to the recent list of Azorean vascular plants are only available for one island (Terceira). For the canopy
by Silva et al. (2005), there are 947 species and subspecies arthropodsamplingamodifiedbeatingtraywasused,which
(68 endemic; 7.2% of endemism) in the Azorean vascular consistedofaninvertedclothfunnelpyramid,1mwideand60
flora,butonlyaboutone28%ofthoseareindigenoustothe cmdeep(afterBasset,1999).Aplasticbagwasplacedatthe
archipelago.Therelativeimportanceofintroducedtaxabyset- tipwherearthropods,leavesandsmallbrancheswerecollec-
tlers is high in most plant groups. In fact, the percentage of ted.Foreachselectedplant,abranchwaschosenatrandom,
introducedspeciesisoneofthehighestinaworldwidecompar- thebeatingtrayplacedbeneathandthebranchhitfivetimes
ison,evenifoneconsidersexclusivelyoceanicislands(Silva withabeatingstick(formoredetailsseeRibeiroetal.,2005;
& Smith, 2004). The predominant native vegetation form is Santosetal.,2005).
‘Laurisilva’,ahumidevergreenbroadleafandmicrophyllous Finally, cave fauna was investigated since 1987 in all
(hereaftershort-leaf)laureltypeforestthatoriginallycovered islands (except Corvo) using not only pitfall traps but also
mostofWesternEuropeduringtheTertiary(Dias,1996).Re- direct search (see details in Ashmole et al., 1996; Borges &
centstudies,however,supportamorerecentorigin,explained Orom´ı,1994,inpress).
by insular evolution from an ancestral herbaceous condition All data are organised in several databases, one for the
(Emerson,2002).Dominantendemictreesandshrubsinclude cave fauna, one for the pasture fauna, one for the fruit orch-
short-leafJuniperusbrevifolia(Seub.)Antoine(Cupressaceae) ard fauna and finally a large database for BALA data that
andEricaazoricaHochst.ExSeub.(Ericaceae),thebroadleaf includesbothpitfallandcanopysamples.Dataonnewrecords
species Ilex perado Ait. ssp. azorica (Loes.) Tutin (Aquifo- andtaxonomicnotesfrompasturesamplinghavealreadybeen
liaceae), Laurus azorica (Seub.) Franco (Lauraceae) and the published(seeBorgesetal.,1999),andthesameappliespar-
shrubVacciniumcylindraceumJ.E.Sm.(Ericaceae).Thistype tiallytocavefauna(Wunderlich,1992;Ashmoleetal.,1996;
of forest is characterised by reduced tree stature (usually up Borges&Orom´ı,1994,inpress).
to5m,rarelyreaching10m),shapedbytheshallowsoiland Thenewtaxaandrecordspresentedinthecurrentwork
sinuousterrain,whichisraiseduptotreetopsatsomepoints, come mainly from BALA project. All additional material
andloweredfivetosixmetresbelowatothers.Ahighcrown listed and reference to new records is indicated by a SITE
foliage density and thus low canopy openness, as well as a CODEthatiscomposedofseverallettersandnumbersasin-
particularly dense cover of moss and liverwort epiphytes is dicated previous to the list of Additional Material per taxon
typicaloftheseforests.Somebryophytesalsocoverleavesin in Table S2 (which is available as ‘Supplementary data’
higheraltitudehumidforests. on Cambridge Journals Online: http://www.journals.cup.org/
Inspiteofadominanceofnon-nativehabitatsintheseis- abstract_S1477200008002648).Forthegeographicallocation
lands(e.g.pastureland,fruitorchards,exotictreesplantations), oftransectswithinreserves(UTMcoordinates)seeTableS3
inthelasttenyearsNATURA2000,aEuropeanCommission inSupplementaryMaterial.
252 PauloA.V.Borges&JoergWunderlich
Dataanalysis grassland sampled with pitfalls and a Vortis machine
Spider species were classified in one of three colonisation (data available from three islands, Terceira, Pico and
categories: natives, endemics and introduced. Native species SantaMaria).
arrivedbylong-distancedispersaltotheAzoresandarealso (7) Pasture–epigeansoilandgrassandherbdwellingcom-
known in other archipelagoes and on the continental main- munities of intensively managed high altitude grassland
land.EndemicspeciesarethosethatoccuronlyintheAzores, sampledwithpitfallsandaVortismachine(dataavailable
as a result of either speciation events (neo-endemics) or ex- fromthreeislands,Terceira,PicoandSantaMaria).
tinctionofthemainlandpopulations(palaeo-endemics).Intro- (8) Fruit Orchards – canopy samples of four types of fruit
ducedspeciesarethosebelievedtobeinthearchipelagoasa orchard (bananas, orange trees, apple trees and peach
resultofhumanactivities,someofthembeingcosmopolitan trees) (data available only for one island, Terceira) (see
species. detailsonplantssampledinSantosetal.,2005).
Onewaytoexaminepatternsofdistributionistoplotthe
frequencyhistogramofspeciesdistributions,thatis,aspecies- Toevaluatethesimilaritybetweenland-usetypesinen-
range-sizedistribution(Gaston,1994).Totesttheoccurrence demic spider species composition we used hierarchical, ag-
ofmainlyrarespeciesor/andalsoalargeproportionofcom- glomerative cluster analysis. From among the various avail-
monspeciesweappliedtheTokeshi(1992)statisticaltestfor ablemethodswechosetheWardsmethod(with1–So¨rensen
bimodalitythatpermitsthecalculationoftheprobabilityun- similarity), also known as minimum variance or error sums
der the null hypothesis of the presence of larger numbers of ofsquaresclustering,inwhich,ineachiteration,allpossible
species in the two extreme classes (rare and common) (see pairsofgroupsarecomparedandthetwogroupschosenfor
Tokeshi,1992andBarretoetal.,2003formoredetails). fusion are those which will produce a group with the low-
In addition to the species distribution analysis we also estvariance(SoftwareCAP.-CommunityAnalysisPackagev.
analysed two other important components of rarity, namely 3.0;PiscesConservationLtd;www.pisces-conservation.com)
abundance and habitat affiliation. Taking into consideration (seeHenderson&Seaby,2004).
thatthesamplingeffortwasnotthesameforallinvestigated Thereisaneedtoestimatebiodiversityinordertocon-
habitats,weusedrelativeabundancewithineachhabitattoget serveasmuchaspossibleoftheremainingbiodiversity.How-
anestimateoftheabundanceofeachspecies.Thus,forapar- ever, some of the available techniques to extrapolate species
ticularhabitatwetotalledthenumberofspecimenscaptured numbershavemajorstatisticalproblems.Forinstance,oneof
for a species and than divided it by the total number of spe- themethods,‘extrapolationfromratesofscientifictaxonomic
cimenssampledofallspecies.Withthisprocedurewecould description’(seeDolphin&Quicke,2001;Cabrero-San˜udo&
rankspeciesfromabundant(common)toscarce(rare)within Lobo,2003),couldnotbeappliedtoourdatasincesampling
aparticularhabitat. effort was not constant through time in the Azores. Another
Concerninghabitats,inadditiontohabitataffiliationwe optionistheuseofthe‘geographicaldistributionofspeciesin
also investigated habitat frequency distribution of the spider betterknowntaxa’.Inthiscasetheratioofspeciesrichnessof
assemblageandtestedthehypothesisthatthereisagradientof thetargettaxonomicgrouptothatofawell-knowntaxoniscal-
endemicspeciesrichnesswithregardtohabitatdisturbance.In culatedinawell-knownarea,andlaterisappliedtotheglobal
ordertoinvestigatethesethreepatterns,weorganisedhabitats numberofspeciesofthewellstudiedtaxonintheareaofin-
inagradientofland-useconsideringeightdifferentland-uses terest(seeDolphin&Quicke,2001).Oneproblemassociated
(habitats)withdataonindividualislandspooled: with this method is related to the potential differential rates
ofspeciationofindicatortaxaindifferentgeographicalareas.
(1) Canopy–Laurel–canopyofnativeorendemicforesttrees In our study we examine beetles (Insecta, Coleoptera), but-
andshrubs(dataavailableforallislandsexceptCorvoand terfliesandmoths(Lepidoptera)aswell-knownrepresentative
Graciosa)(seedetailsonplantssampledinRibeiroetal., taxa,andtheCanariesasthebiogeographicalareaforcompar-
2005). ison.WeselectedtheCanaryIslands,becausetheybelongto
(2) Soil–Laurel – epigean soil communities of native forest the same biogeographical area as the Azores (Macaronesia),
sampledwithpitfalls(dataavailableforallislandsexcept andacomprehensivelistoftheirarthropodfaunaisavailable
CorvoandGraciosa). (Izquierdoetal.,2004).Theendemicnumberofspeciesforthe
(3) NaturalGrassland–epigeansoilcommunitiesofnative ColeopteraandLepidopteraoftheAzoreswasobtainedfrom
high altitude grassland sampled with pitfalls (data avail- therecentlistofAzoreanfaunaandflora(Borgesetal.,2005b,
ableforallislandsexceptCorvo,Faial,SantaMariaand c;Karsholt&Vieira,2005).Theratioestimatesforendemic
Graciosa). AraneaewithColeopteraandLepidopteraintheCanariesis,
(4) Caves–lavatubesandvolcanicpitscommunitiesbothat respectively,0.24and1.17.
entrances and deep inside (data available for all islands TohaveanindependentestimateforthepotentialAzorean
exceptCorvoandFlores). endemicspiderspeciesrichness,wealsoapplyanincidence-
(5) ExoticForest–epigeansoilcommunitiesofexoticforests based non-parametric estimator, Jackknife1 (see Colwell &
sampledwithpitfalls(dataavailableonlyforoneisland, Coddington,1994):S =S +a(n−1/n),whereS isthe
max obs obs
Terceira). numberofknownspecies,nisthenumberofsamples(n=9
(6) SN Pasture – epigean soil and grass and herb dwell- islandsinourcase)andathenumberofspeciesonlyfoundin
ing communities of semi-natural managed high altitude onesample(island)(theso-called‘uniques’).
Islandspiderdiversity 253
TheJackknife1estimatorwaschosen,becauseitiscon-
sidered the most robust with incidence (presence/absence
data) at larger scales (see Hortal et al., 2006). The estim-
ator was computed using the Software Species Diversity
and Richness version 3.0 (Pisces Conservation) (see Hende-
rson & Seaby, 2002). We also applied to the endemic spe-
cies dataset (see Appendix S1 in supplementary material
on Cambridge Journals Online: http://www.journals.cup.org/
abstract_S1477200008002648)anaccumulationcurvewithis-
landorderrandomised100timestoobtainameanspeciesac-
cumulation curve. The same number of 100 randomisations
werealsocomputedtoobtaintheJackknife1estimategener-
atingconfidenceintervalsfortheestimatedspeciesrichness.
All regression analyses were performed with ordinary
linearleast-squares(OLS)regression.Log10transformedgeo-
graphical variables and numbers of species were used for Figure2 OrchestinafurcillataWunderlichsp.nov.,Male;(a)
several reasons: (a) to overcome non-constant variance, and anteriorpartoftheprosomawitheyes;(b)labium,ventral
non-linearity of the data; (b) because higher r2 values were aspect(hairsarenotdrawn);(c)r.pedipalpus,retrolateral
aspect(onlyfewhairsaredrawn);(d)emboluswith
consistently obtained when using the log-log model; (c) the
conductorsofther.pedipalpus,proventralaspect;
residualsappearedtoshownopronouncedpatternsinthelog-
bar=0.05mminFig.d,0.1mmintheremainingFigs.
logmodel;and(d)thebiologicalandecologicalinterpretations
areavailablefromthefittedinterceptandslope.
allcongenerics.Bristlesarecompletelyabsent.Allmetatarsi
bearasingletrichobothrium,itspositiononI–IIin0.94,onIV
Results in0.55.–Opisthosomaoval,mostpartsarecoveredwithshort
hairsbutlonghairsarepresentaroundpedicelandspinnerets.–
Descriptionofnewspeciesandremarkson Pedipalpus: See above. The tibia bears two trichobothria. A
selectedtaxa tinythinandpointedstructureexistsventrallyontheembolar
OONOPIDAE furca.
Oonopidaearetinysix-eyedandfrequentlypalespiders;they
are easily overlooked. Only a single species of this family Ecology
hasbeenreportedfromtheAzores,OonopsdomesticusDal- Theonlyknownmalespecimenplusajuvenilespecimenwere
mas,1916,(seeWunderlich,1992,p.16).TheMediterranean collected in pitfall traps (with Ethylene Glycol) in a native
Orchestinapavesii(Simon,1873)isknownfromtheCanary forest dominated by the endemic tree Ilex perado Ait. ssp.
Islands.Anewspeciesofthisgenusisdescribedbelow. azorica(Loes.)Tutin(Aquifoliaceae)withthesoilcoveredby
theexoticandinvasiveplantHedychiumgardnerisheffardex
OrchestinafurcillataWunderlichsp.nov.(Fig.2)
Ker-Gawl.(Zingiberaceae).
Material
HOLOTYPE Male: Azores, Sa˜o Miguel, Atalhada (Transect Relationships
2), August 1999, pitfall sample ET22 (P.A.V. Borges et al., AccordingtothestructuresoftheembolusO.arabicaDalmas,
leg.);depositedattheUniversityoftheAzores(‘ArrudaFur- 1916 from the Arabic Peninsula is most closely related; in
tado’Collection). arabicathepedipalpaltibiaismoreslenderandtheembolus
isshorter.
Diagnosis(male;femaleunknown)
Pedipalpus (Figs 2c, d): the tibia is the thickest article, the
Distribution
embolusislong,bentandfurcate.
Azores:Sa˜oMiguel.
Description(Male) TETRAGNATHIDAE
Measurements (in mm): Body length 1.0, prosoma: Length Tetragnathidae is a spider family characterised by the long
0.47, width 0.35, leg I: Femur 0.42, patella 0.12, tibia 0.38, chelicerae,representedintheAzoreswithfourspecies,three
metatarsus0.4,tarsus0.3,tibiaIV0.35,femurIV0.5,itswidth ofwhicharehumanintroductions.Theonlynativespeciesis
0.12. theendemicSancusacoreensis(Wunderlich,1992).
Colourpaleyellowbrownwithblacksurroundingsofthe
eyelenses. SancusTullgren,1910andLeucognathaacoreensis
Wunderlich,1992
Prosoma:Thoraxhigherthanthecaput,thoracalfissureabsent,
6largeeyes(Fig.2a),medianeyeslargest.Cheliceraeslender, According to Kuntner (pers. comm.), Leucognatha Wun-
labiumconcaveapically(Fig.2b).–Legs:sequenceoflength derlich, 1992 is a junior synonym of Sancus, and Leuco-
IV/I/II/III,fairlyslenderbutfemurIVstronglythickenedasin gnathaacoreensisWunderlich,1992fromtheAzoresmustbe
254 PauloA.V.Borges&JoergWunderlich
calledSancusacoreensis.Theonlyothercongenericspecies,
S.bilineatusTullgren,1910,occursinEastAfrica,atMount
Kenya.SancusacoreensisiswidelyspreadallovertheAzores,
mainlyinnativehabitats,buthasnotbeenreportedbyDenis
(1964)justlikemanyothercurrentlyknownendemicspecies.
Whileonecannotexcludethepossibilityofahistoricalhuman
introduction, this species may be considered as a genuinely
Azoreanendemicspecies.
Distribution
Azores: Flores, Faial, Pico, Terceira, Sa˜o Miguel and Santa
Maria(newtoSa˜oJorge).
LINYPHIIDAE
Linyphiidae are small spiders buiders of sheet webs. This is
the spider family most richly represented in the Azores; 36
speciesarereported,3speciesarereportedfromthesubfamily
Linyphiinae, 11 from Micronetinae and 22 from Erigoninae.
Wegivetwokeystoselectedtaxaofthisfamily.
Determination
In the small to tiny Erigoninae the number of leg bristles is
reduced:femora,tibialaterallyandmetatarsilackbristles,in
contrast to the Linyphiinae and most Micronetinae (in Mi-
croneta,andsomeAgynetaspeciesoftheMicronetinaealso,
femoralandmetatarsalbristles–insomespeciesevenlateral Figure3 PorrhommaborgesiWunderlichsp.nov.,Male:(a)position
tibialbristles–areabsentasintheErigoninae).Severalmale oftheeyes;(b)r.coxaI,retrolateralaspect.Notethefield
Erigoninae possess outgrowths or lobes of the prosoma; an ofstridulatoryfiles;(c)paracymbiumofther.pedipalpus,
epigynalscapusisabsentinthissubfamily. retrolateralaspect;(d)r.pedipalpus,prolateralaspect;
Female:(e)epigyne;(f)dorsalaspectofthevulva.
KeytotheAzoreangeneraofthesubfamiliesLinyphiinae
bar=0.2mminFig.a,0.1mmintheremainingFigs.
andMicronetinae:
1 Femoralbristlesabsent............................2 present, coxal files absent, paracymbium with at
– Femoralbristlespresent...........................4 least one tooth, epigyne with a large scapus as in
2(1) Metatarsi with a dorsal bristle. Fig.8c...............................Lepthyphantes
(T.cavernicola)..........................Turinyphia
– Metatarsalbristlesabsent..........................3
LINYPHIIDAE:LINYPHIINAE
3(2) Male:Tibiaofthepedipalpusapicallywithatransverse
PorrhommaSimon,1884
rowoflongandbristle-shapedhairs.Female:Epigynal
scapusnarrowposteriorly.(M.viaria).......Microneta This holarctic genus is new to the Azores and the Macar-
– Male: Pedipalpal tibia without such hairs. Female: onesian Islands. Numerous species of Porrhomma are cave
Scapuswideposteriorly..................Agynetas.l. dwellers; frequently they are weakly pigmented and possess
4(1) Male:Embolusverylongandthin,stronglysclerotised reduced eyes. P. borgesi sp. nov. is weakly pigmented and
(black).Female:Posteriorepigynalmarginwithanout- possesses reduced eyes but it is a forest dweller that occurs
growth(parmula),anteriorepigynaloutgrowth(scapus) alsoinavolcanicpit(seeFig.3a).TheepigeanP.pygmaeum
absent.(M.johnsoni)..................Microlinyphia (Blackwall,1834)isoneoftherarerspecieswhichhavelarge
– Male: Embolus wide, weakly sclerotised (transpar- eyes.ThestridulatoryfilesofcoxaI(usuallyweakeronII)is
ent). Female: Epigyne with a larger free opening anapomorphiccharacterofPorrhomma;suchfilesarestrongly
(Porrhomma) or with a large scapus as in Fig. 8c reducedorevenabsentinP.pygmaeum.Theabsence(loss)of
(Lepthyphantes)..................................5 stridulatorycheliceralfilesisanotherapomorphiccharacterof
5(4) Metatarsal bristles absent. Lateral cheliceral stridulat- thisgenus.
ory files absent but stridulatory files of coxa I present
(Fig. 3b). Male-pedipalpus (Fig. 3d): Paracymbium
PorrhommaborgesiWunderlichsp.nov.(Fig.3)
tooth-less.Female:Epigynewithadistinctfreeopening,
scapusabsent.(P.borgesi,aforestspiderwithsmalleyes, Derivationominis
Fig.3a).................................Porrhomma ThespeciesisnamedafterPauloBorgeswhodiscoveredthis
– Metatarsal bristles present. Lateral cheliceral files andmanyothernewspeciesintheAzores.
Islandspiderdiversity 255
Material (bothhaveapalaearcticdistributionandareepigeicspecies)
HOLOTYPE Male: Azores, Terceira, Miste´rios Negros B arethemoststronglyrelatedspecies.IncontrasttoP.borgesi
(Transect 8), September 1997, pitfall sample ET12 (Alvaro bothhavestronglyreducedstridulatoryfilesofthecocaI-II.P.
Vitorino&P.A.V.Borges,leg.);samelocality,butJune1997, pygmaeumhaslargeeyesandiswellpigmented,itspedipalpal
1maleparatype(AlvaroVitorino&P.A.V.Borges,leg.);La- structures are identic, the vulva is different; in P. pallidus,
goa do Pinheiro (Transect 10), August 1999, pitfall sample whichalsohasapalecolourandreducedeyes,theembolusis
TU09, 1 female paratype (Catarina Melo & P.A.V. Borges, lessbentandthevulvaisverysimilar.
leg.);CaldeiradaSerradeSantaBa´rbara(Transect60),July
2001,pitfallsampleTU19,1femaleparatype(P.A.V.Borges Distribution
etal.,leg.);AlgardoCarva˜o,25thNovember1999,1subad. Azores:Terceira,PicoandSa˜oMiguel.
male paratype (Fernando Pereira & P.A.V. Borges, leg.). All
materialisdepositedattheUniversityoftheAzores(‘Arruda TurinyphiaVanHelsdingen,1982
Furtado’Collection).
Reviseddiagnosis
Diagnosis
Leg bristles: Femoral and patellar ones absent, tibia I with
Pale spiders, eyes distinctly reduced (Fig. 3a), position of
lateralanddorsalbutwithoutventralones,usuallyallmetatarsi
the trichobothrium on metatarsus I in 0.4, femoral bristles:
withadorsalbristle(accordingtoSchenkel,1938itisabsent
I-II bear a dorsal one, I an additional prolateral one. Male-
inT.maderiana),thoracalfissurestronglyreducedtoabsent.
pedipalpus (Figs. 3c–d) as in P. pygmaeum, embolus fairly
Bulbussmall,lamellacharacteristicaabsent,embolussickle-
bentandslender,velumindistinct,tipoftheembolusnearto
shaped,epigynesimple,withanunfoldedscapus.
thedorsalapophysis.
Description Typespecies
Measurements (in mm): Body length 1.7–1.8 (2.0 in the fe- LinyphiaclairiSimon,1884.
male),prosoma:length0.9–0.95,width0.6–0.65,largestdia-
meterofanposteriormedianeye0.02,legI:femur0.65,patella Relationships
0.22,tibia0.65,metatarsus0.55,tarsus0.42,tibiaIV0.7. AmemberoftheLinyphiinae.InPlesiophantesHeimer,1981,
Colouryellowtolightbrown,withoutdarkenings.–Pro- which JW (see also Wunderlich, 1987) regarded as a senior
soma:caputfairlyconvex,withfewhairs,thoracalfissurein- synonymofTurinyphia,abristleoffemurI,abasalhookof
distinct,eyes(Fig.3a)smalltotiny,widelyspaced,posterior the chelicerae and a lamella characteristica are present, and
medianslargest,lensesoftheanteriormedianeyesabsentor theembolusismoreslender(seeWunderlich,1995,p.413).
almost absent. Chelicerae fairly large, stridulatory files ab- InFrontiphantesWunderlich,1987(Madeira)alongthoracal
sent,anteriormarginwith3,posteriormarginwith5teeth.– fissureandaprolateralbristleoffemurIarepresent.
Legs only fairly long, IV longest, stridulatory files of coxa I
(Fig. 3b) well developed. Bristles long, all tibiae bear 2 Distribution
dorsally,Ianadditionaldistal-lateralpair,IIasingledistally- Palaearctic: Southern Europe (T. clairi (Simon, 1884)),
retrolaterally;femora:seeabove;metatarsibristle-less.Tricho- Madeira (T. maderiana (Schenkel, 1938)) and Azores (T.
bothriumabsentonmetatarsusIV,itspositiononmetatarsusI cavernicola Wunderlich sp. nov.); Japan: T. yunohamensis
in0.4.–Opisthosomaoval.–Malepedipalpus(Figs.3c–d)as (Bo¨senberg&Strand,1906).Turinyphiaspecies–likeFron-
inP.pygmaeum(seeabove),patellawithathindorsalbristle. tiphantes and Plesiophantes – may well be relict taxa and
Epigyne (Fig. 3e) with a well visible vulva structures, width palaeoendemics;mostspeciessurvivedinmountainareas,sev-
of the opening almost 0.1 mm. Vulva (Fig. 3f) (very similar eralspeciessurvivedonislands.
to P. pallens) with large introducing ducts which are touch-
ing medially and widely separated primary and secondary
TurinyphiacavernicolaWunderlichsp.nov.(Fig.4)
receptacula.
Material
Ecology
Mostspecimenswerecollectedbymeansofpitfalltraps,loc-
HOLOTYPE, male and 3 juv. paratypes: Azores, Terceira,
ateddeepinsideveryhumidlaurelforestsonTerceira,Picoand
Algar do Carva˜o, 25th November 1999 (F. Pereira & P.A.V.
Sa˜oMiguel.Onespecimenwascapturedinavolcanicpit(Al-
Borgesleg.);samelocalitybut19–25November1999,5juv.
gardoCarva˜oatTerceira).Inmostsitestheterrainisbasaltic,
paratypes(F.Pereira&P.A.V.Borgesleg.);samelocalitybut
withasystemofcracksanddeepholesandtheforestflooris
10–16August1999,1juv.paratype(F.Pereira&P.A.V.Borges
coveredbyadensecarpetofmossesandfernswithlittlelight
leg.);samelocalitybut29December1999to5January2000,
reachingtheground.However,somespecimenswerealsocol-
5juv.paratypes(F.Pereira&P.A.V.Borgesleg.).Allmaterial
lectedinhighaltitudenaturalgrasslandandinaCryptomeria
isdepositedattheUniversityoftheAzores(‘ArrudaFurtado’
japonicaplantationinTerceira.
Collection).
Relationships
Accordingtothechaetotaxyaswellastherelativelyshortlegs, Derivationominis
P.pygmaeum(Blackwall,1834)andP.pallidusJackson,1913 Thespeciesisnamedafteritspreferredcavernicoloushabitat.
256 PauloA.V.Borges&JoergWunderlich
Figure5 Turinyphiamaderiana(Schenkel,1938)fromMadeira,
Male,embolusandconductor(distally)ofther.
pedipalpus,ventralaspect;bar=0.05mm.
Distribution
Figure4 TurinyphiacavernicolaWunderlichsp.nov.,Male;(a) Azores:Terceira.
patellaandtibiaofther.pedipalpus,dorsalaspect;(b–c)
LINYPHIIDAE:MICRONETINAE
paracymbiumofther.pedipalpus,retrodorsaland
retrolateralaspect;(d)embolusofther.pedipalpus, AgynetaHull,1911
ventralaspect;bar=0.05mminFig.d,0.1mminthe
WeregardAgynetainawidesense,includingMeionetaHull,
remainingFigs.
1920. The intraspecific body colour is very variable in this
genus. Four species of this genus were reported earlier from
Diagnosis(male;femaleunknown)
theAzores,afifthspeciesisdescribedbelow.
Pale spiders with long legs and large eyes. Male pedipalpus
KeytotheAzoreanspeciesofAgyneta:
(Fig4):tibiawithasingletrichobothriumonly,paracymbium
withatooth-shapeddistalhook,embolusbasallywide. 1 Position of the trichobothrium on metatarsus I near
the end of the article, in c. 0.9. A widely spread
Description(male) species...................................A.decora
Measurements (in mm): Body length 2.0, prosoma: length – Position of the trichobothrium on metatarsus I in the
0.95,width0.85,legI:femur1.8,patella0.35,tibia1.7,meta- basalhalf........................................2
tarsus1.75,tarsus1.05,tibiaIV1.5. 2(1) GenitalorgansasinFig.6,cymbiumnotelevated....A.
Colour of prosoma and legs pale, yellow, sternum and depigmentatasp.nov.
opisthosoma(moredistinctdistally)mediumgrey;blackpig- – Genital organs different, cymbium elevated (e.g.
ment around the eye lenses. – Thoracal fissure absent, eyes Fig.7)...........................................3
large,posteriorrowrecurved,posteriormedianeyesseparated 3(2) Male: lamella characteristica wide, dorsally strongly
by 0.4 diameters. Chelicerae slender and slightly diverging, convex. Female: pedipalpus: femur and patella light in
lateralfilesfairlydistinct,anteriormarginwith3largeteeth, contrast to the black tarsus and tibia. A widespread
posterior margin smooth. – Legs long and slender; bristles species..................................A.rurestris
thin,femora,patellaeandtarsibristle-less,tibiaewith2dorsal – Male: Lamella characteristica more slender. Female:
bristles,Iwithanadditionaldistalpair,II–IVbeararetrolat- pedipalpusunicoloured............................4
eral one in the distal half. Trichobothrium on metatarsus IV 4(3) Male:basalcymbialoutgrowthundivided,lamellachar-
absent, its position on metatarsus I in 0.15. – Opisthosoma acteristica fairly slender, apically claw-shaped. Fe-
slender,coveredwithshorthairs.–Malepedipalpus(Fig.4; male: epigynal scapus wider than long. A widespread
seeabove)patellashort,withalongerbristle,tibiafairlyshort, species...............................A.fuscipalpis
withasingletrichobothrium. – Male:basalcymbialoutgrowthbilobed(Fig.7),lamella
characteristica slender, apically not claw-shaped. Fe-
Ecology male:epigynalscapusaswideaslong(seeWunderlich,
Allspecimensareknownfromasinglevolcanicpit,Algardo 1992:Figs.376,378)......................A.rugosa
Carva˜oinTerceira.Thespeciesbuildswebsacrosssmallholes
Agyneta(Meioneta)depigmentataWunderlichsp.nov.
involcanicbasalticrock.
(Fig.6)
Relationships Material
InT.maderianaandT.clairithetibiaofthemalepedipalpus HOLOTYPE,maleand3juv.paratypes:Azores,Flores,Morro
bear3trichobothria;inT.clairithepedipalpaltibiaislonger Alto Este (Transect 8) July 1999, pifall sample T29 (Clara
than the cymbium, in T. maderiana metatarsal bristles are Gaspar&P.A.V.Borgesleg.);samelocalityanddatebutpifall
absent,inbothspeciestheparacymbiumiselongatedbasally. sampleT27,1femaleparatype(ClaraGaspar&P.A.V.Borges
EmbolusofT.maderiana:Fig.5. leg.);RibeiradaFazenda(Transect4)July1999,pitfallsample
Islandspiderdiversity 257
Figure7 AgynetarugosaWunderlich1992,Male:(a)tibiaand
cymbiumofther.pedipalpus,dorsalaspect;(b)cymbium
ofther.pedipalpus,prolateralaspect;bar=0.1mm.
Figure6 AgynetadepigmentataWunderlichsp.nov.,Male:(a)tibia
Ecology
ofther.pedipalpus,dorsalaspect;(b)cymbiumofther.
pedipalpus,prolateralaspect;(c)lamellacharacteristicaof ThespidersliveinnativeJuniperusbrevifoliaforestwiththe
ther.pedipalpus,retrolateral-ventralaspect;(d)female, soil covered with dense Sphagnum spp. mire, in the higher
epigyne;bar=0.1mm. altitude central plateau of Flores island. It is also common
in high altitude natural grassland dominated by native and
TU03, 2 females paratypes (Clara Gaspar & P.A.V. Borges
endemicvascularplantsandalsobryophytes.
leg.);samelocalityanddate,butpitfallsampleET10,1male
withoutopisthosomaparatypeand3juveniles(ClaraGaspar&
Distribution
P.A.V.Borgesleg.);samelocalityanddate,butpitfallsample
Azores:Flores.
TU11, 1 female paratype and 5 juveniles (Clara Gaspar &
P.A.V.Borgesleg.).AllmaterialisdepositedattheUniversity
AgynetarugosaWunderlich,1992(Fig.7)
oftheAzores(‘ArrudaFurtado’Collection).
Material
Azores:Faial,Cabec¸odoFogo(Transect2),September1999,
Derivationominis
Pitfall sample TU03; 1 male (P.A.V. Borges et al. leg.). De-
Thespeciesnameisbasedonitspale(depigmented)colour.
positedattheUniversityoftheAzores(‘ArrudaFurtado’Col-
Diagnosis lection).
Pale(depigmented)spiders,positionofthetrichobothriumon
metatarsusIinc.0.4.Male:pedipalpus(Figs.6a–c):nocym- Remarks
bial outgrowth, bulbus small, lamella characteristica three- (1) In contrast to the type material, the colour of the speci-
pointed. Female: epigyne small, as in Fig. 6d, only slightly men from Faial is pale light grey, and a light spot above the
protruding. spinneretsisabsent.(2)Malepedipalpaltibiaandcymbium:
seeFigs.7a–b.(3)Thespeciesmaybemorecloselyrelatedto
Description EuropeanthantoNorthAmericanspecies.
Measurements (in mm): body length: male 1.1, female 1.7;
prosoma(male,female):Length0.65,width0.55,legI(male): Ecology
femur0.65,patella0.2,tibia0.68,metatarsus0.53,tarsus0.42, CollectedinapitfalltrapwithTURQUINattractantinasec-
tibiaIV0.7;female:tibiaI0.68,tibiaIV0.7. ondaryJuniperusbrevifolia–Ericaazoricanativeforest.
Colourpale(depigmented),eyeregion,sternumandopis-
thosoma ventrally dark grey, female pedipalpus yellow. Pro- Distribution
soma with an indistinct thoracal fissure, eyes large, as in A. Azores:Sa˜oMiguelandFaial(newtoFaial).
rugosa Wunderlich, 1992. Male chelicerae diverging but not
excavatedmedially;anteriormarginwith4–6teeth,posterior Lepthyphantes(Palliduphantes)cf.schmitziKulczynski,
marginwithfewsmallteeth.Femalepedipalpusslender.Legs 1899(Fig.8)
slender,bristlesasinA.rugosaexcepttheretrodistaloneon
Material
metatarsusIVwhichisabsent.Trichobothriumonmetatarsus
Ac¸ores:Flores,nearSantaCruz,2femaleJWleg.inVII,coll.
IVabsent,itspositiononmetatarsusIin0.4–0.43.Malepedip-
JW.
alpus (Figs. 6a–c): cymbial outgrowth absent, paracymbium
toothless,bulbussmall,lamellacharacteristicathree-pointed.
Remark
Epigyne as in Fig. 6d, scapus small, fairly wide and only
slightlyprotruding. The determination of the Azorean specimens is unsure (see
Wunderlich, 1992, p. 22). JW does not want to exclude the
Relationships possibilitythatthesefemalesaremembersofanasyetundes-
IntheEuropeanA.(Meioneta)mollis(O.Pickard-Cambridge) cribedendemicAzoreanspecies.Epigyneinthreeaspects:see
thelamellaandtheepigynalscapusareslender/narrow. Figs8a–c.
258 PauloA.V.Borges&JoergWunderlich
Figure9 Diplocentriabidentata(Emerton,1882)(Linyphiidae:
Erigoninae)fromEurope,leftlungcover(L)with
stridulatoryfilesandastridulatorytoothontheleftIVcoxa
(Z)similartotheAzoreangenusAcorigoneWunderlich
gen.nov.TakenfromWiehle(1960,fig.787).
Relationships
AccordingtothegenitalstructuresErigoneAudouin(cosmo-
political)andEperigoneCrosby&Bishop(NearcticRegion)
maybemostcloselyrelated.Inthesegenerastridulatoryfiles
ofthelungcoversareabsent,theclypeusislong,denticlesof
theprosomalmargin,thecheliceraeandthepedipalpalfemur
areusuallypresentatleastinErigone,andthereisusuallya
pedipalpalpatellaroutgrowthinErigone.InDiplocentriaHull
Figure8 Lepthyphantes?schmitziKulczynski,1899,Female, –inwhichstridulatoryfilesarepresentonthelungcovers(Fig.
epigyne,ventral(a)posterior(b)andlateralaspect(c); 9)asinAcorigone–theshapeoftheparacymbiumandthebul-
bar=0.2mm. busstructuresarequitedifferenttoAcorigone;apparentlytheir
coxal-opisthosomalstridulatoryorgansevolvedconvergently.
Distribution
Distribution
Azores,allislandsexceptCorvo(newtoSa˜oJorgeandSanta
Azores.
Maria).
AcorigonezebraneusWunderlichsp.nov.(Fig.10)
LINYPHIIDAE:ERIGONINAE
Material
AcorigoneWunderlichgen.nov
HOLOTYPE male: Azores, Sa˜o Jorge, Topo (Transect 12),
Diagnosis August2000,pitfallsampleTU05(P.A.V.Borgesetal.,leg.);
MalewithastridulatoryorganbetweencoxaeIVandlungcov- samelocalityanddate,butpitfallsampleTU25,1femalepara-
ersasinDiplocentriaHull,1911(similartoFig.9).Prosoma type(P.A.V.Borgesetal.,leg.).DepositedattheUniversityof
low(clypeusshort),cheliceraelarge,anteriormarginwithlong theAzores(‘ArrudaFurtado’Collection).
teeth(Fig.10b).Sequenceofthetibialbristles2/2/2/1.Tricho-
bothrium on metatarsus IV present (A. zebraneus sp. nov.) Derivationominis
orabsent(A.acoreensis,newcombination).Malepedipalpus Thespeciesisnamedbasedonmarkingsoftheopisthosoma,
(Figs 10c–f): tibia with a ventral apophysis, cymbium with displaying a distinct yellow dorsal pattern with dark grey
distal bristles, embolus short. The epigyne (Figs 10g–j) is a stripes.
wideplate.
Diagnosis
Typespecies Prosomal length 0.7–0.75 mm, trichobothrium present on
Acorigone zebraneus gen. nov. et sp. nov. Further species: metatarsus IV, its position on metatarsus I in 0.9, male-
Acorigoneacoreensis(Wunderlich,1992). pedipalpusasinFigs10c–f,epigyneasinFigs10g–j.