REVISION AND CLADISTIC ANALYSIS OF THE ERIGONINE SPIDER GENUS SISICOTTUS (ARANEAE, LINYPHIIDAE, ERIGONINAE)
Jeremy A. Miller: Department of Biological Sciences, The George Washington University, Washington, D.C., 20052, and Department of Entomology, National Museum of Natural History, NHB-105, Smithsonian Institution, Washington, D.C. 20560 USA
ABSTRACT. The erigonine spider genus Sisicottus is revised for the first time. Cladistic analysis of Sisiconus suggests the following hypothesis of interspecific relationships: ((S. montigenus, S. quoylei) (S. panopeus (S. montanus (S. crossoclavis (S. cynthiae (S. orites (S. nesides, S. acnigmaticus))))))). The monophyly of the genus is unambiguously supported by six putative synapomorphies: a terminal embolic hook. a suprategular membrane projecting apically from the distal suprategular apophysis, copulatory ducts that originate on the ectal side of the spermathecae, imbricated stridulatory striae, the presence of two dorsal macrosetae on tibia III, and the absence of a trichobothrium on metatarsus IV. Evidence for the monophyly of each Sisicottus species is discussed. A taxonomic key, diagnoses, descriptions, quantitative character values, illustrations, locality records, natural history information, and distribution maps are presented for the nine recognized species. Five new species are described: S. quoylei, S. panopeus, S. crossoclavis, S. cynthuae. and S. aenigmaticus. Typhochrestus uintanus (NEW COMBINATION) is formally transferred out of Sisicottus.
The Journal of Arachnology 27:553-603
RADIATION OF THE GENUS DYSDERA (ARANEAE, DYSDERIDAE) IN THE CANARY ISLANDS: THE ISLAND OF TENERIFE
Miquel A. Arnedo and Carles Ribera: Departament de Biologia Animal, Universitat de Barcelona, Avinguda Diagonal 645, E-08028 Barcelona, Spain
ABSTRACT. An overwhelming number of endemic species belonging to the spider genus Dysdera have been reported from the oceanic archipelago of the Canary Islands. A complete taxonomic revision is currently being performed in order to assess the extent of this species' radiation, as well as to supply enough data to place it in a phylogenetic framework. The present article is devoted to the Dysdera species inhabiting the island of Tenerife. A total of 22 species is recognized in Tenerife, including the cosmopolitan Dysdera crocota C.L. Koch 1839. Two new species are described: Dysdera guayota new species and Dysdera hernandezi new species. Ten new synonymies are reported: D. moquinalensis Wunderlich 1991 and D. vilaflorensis Wunderlich 1991 = D. brevispina Wunderlich 1991; D. medinae Wunderlich 1991 = D. cribellata Simon 1883; D. inacquuscapillata Wunderlich 1991 = D. crocota; D. pergrada Wunderlich 1991, D. pseudopergrada Wunderlich 1991, D. tabaibacnsis Wunderlich 1991, D. teideensis Wunderlich 1991 and D. teneriffensis Strand 1908 = D. macra Simon 1883; D. obscuripes Wunderlich 1991 = D. propinqua Ribera, Ferrandez & Blasco 1985. Sixteen species are redescribed: D. ambulotenta Ribera, Ferrandez & Blasco 1985; D. brevisetoe Wunderlich 1991, D. brevispina Wunderlich 1991; D. chioensis Wunderlich 1991; D. cribellata Simon 1883; D. curvisetoe Wunderlich 1987; D. esquiveli Ribera & Blasco 1986; D. gibbifera Wunderlich 1991; D. gollumi Ribera & Arnedo 1994; D. Iabradacnsis Wunderlich 1991; D. macra Simon 1883; D. minutissima Wunderlich 1991; D. montanetensis Wunderlich 1991; D. propinqua Ribera, Ferrandez & Blasco 1985; D. ungulmmanis Ribera, Ferrandez & Blasco 1985 and D. volcania Ribera, Ferrandez & Blasco 1985. The females of four species: D. brevisetne, D. brevispina, D. minutissima and D. montanetensis are described for the first time. Females formerly assigned to both D. gibbifera and D. volcania are considered to be incorrect identifications. A neotype is designated for D. macra. The presence of D. rugichelis Simon 1907 in Tenerife is considered to be doubtful. Ecological and distributional patterns of the species are discussed.
The Journal of Arachnology 27:604-662
ANTERIOR MEDIAN EYES OF LYCOSA TARENTULA (ARANEAE, LYCOSIDAE) DETECT POLARIZED LIGHT: BEHAVIORAL EXPERIMENTS AND ELECTRORETINOGRAPHIC ANALYSIS
J. Ortega-Escobar: Faculty
of Psychology, Univ. Authnoma, 28049 -Madrid, Spain
A. Munoz-Cuevas: Laboratoire de Zoologie (Arthropodes), M.N.H.N.-C.N.R.S., 61 Rue Buffon, 75231-Paris Cedex 05, France
ABSTRACT. We studied solar light cues that may be used by Lycosa tarentula (Linnaeus 1758) (Araneae, Lycosidae) for homing. Experiments performed under clear skies, under overcast skies, and under clear skies as seen through a plastic sheet (which changed the polarization from linear to elliptical), allowed us to discover which attributes of daylight were used by the spiders during orientation and homing. We found that patterns of linearly polarized light in the natural sky were sufficient to allow accurate homing by the spiders. The homing behavior of individuals having the anterior median eyes (AME) or all other eyes blinded allowed us to determine that AME were responsible for the reception of polarized light. Electroretinography of all eyes confirmed that only the anterior median eyes were differentially sensitive to the orientation of polarization in linearly polarized light.
The Journal of Arachnology 27:663-671
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