Dispatch from the field: ecology of ground-web- building spiders with description of a new species (Araneae, Symphytognathidae)

Abstract Crassignathadanaugirangensis sp. n. (Araneae: Symphytognathidae) was discoveredduring a tropical ecology field course held at the Danau Girang Field Centre in Sabah,Malaysia.Ataxonomicdescriptionandaccompanyingecologicalstudywerecompletedascourseactivities.Toassesstheecologyofthisspecies,whichbelongstotheground-web-building spider community, three habitat types were surveyed: riparian forest, recentlyinundatedriverineforest,andoilpalmplantation.Crassignathadanaugirangensissp.n.isthemostabundantground-web-buildingspiderspeciesinriparianforest;itisrareorabsentfromtherecentlyinundatedforestandwasnotfoundinanearbyoilpalmplantation.Theavailabilityofthistaxonomicdescriptionmayhelpfacilitatetheaccumulationofdataaboutthis species and the role of inundated riverine forest in shaping invertebrate communities. Keywords Borneo,Crassignatha,disturbance,inundation,oilpalmplantation,riparianforest,riverineforest, tropical field course Introduction CrassignathaWunderlichisagenusofsix-eyedmicro-orbweavingspidersontheorderof1 mm in total body length. The genus was established to accommodate a single malespecimen collected at Fraser's Hill (Bukit Fraser in Malay), a forest reserve in Pahang,Malaysia (Wunderlich 1995). Miller et al. (2009) described eight additional species ofCrassignathacollectedinthecourseofasurveyoftheGaoligongshaninwesternYunnan,China.Onlyoneofthesespecieswasasingletonandmostspecieswereknownfrom7–20adultspecimens,suggestingthattheycanbeabundant.ButfewspecieswerecollectedatmorethanonelocalityandtherateofspeciesturnoverintheGaoligongshanappearedtobe on the order of 50–100 km.Studentsparticipatinginatwo-weektropicalecologyfieldcourseofferedbytheNaturalisBiodiversity Center and hosted by the Danau Girang Field Centre (DGFC) in Sabah,Malaysia, encountered a species ofCrassignathain the course of their studies. Withoutdoubt,undescribedarthropodspeciesaboundinthevicinityofanytropicalfieldstation,butbeingabletorecognizewhichspeciesarenewrequiresexpertiseandaccesstoliteratureand reference collections not often available in such remote places. In this case, thecorrespondingauthorwasabletodeterminethattheDanauGirangCrassignathawasnew,andsinceonlytwotaxonomicpapershavetreatedmembersofthisgenus,thecollectionofreferenceliteraturewassooncomplete.Studentsandlecturersparticipatinginthecourse,alongwithmembersofthefieldstationscientificstaff,resolvedtodescribethisspeciesandinvestigate its ecology using the resources available at the field station and submit theirresults in the form of a manuscript before the end of the course.