Physocyclus

Abstract: -Three species of the spider genus Physocyclus (P. californicus, P. enaulus, P. sp.) were karyotyped using an air-drying, Giemsa staining method. All chromosomes were meta centric, with males being 2n = 15 (N = 7 + XO) and females being 2n = 16. The karyotyping method resulted in slide preparations which were countable five years post-fixing. Members of the spider family Pholcidae are known cytologically by only four species. In each case, only males have been examined, and XO and X1X20 sex determination mechanisms have been illustrated or reported (Sharma et al., 1959; Cokendolpher and Brown, 1985). Of these four species, reliable chromosome counts are available for only two species. Previous researchers have noted the difficulty in properly preparing pholcid chromosomes for accurate counting (Painter, 1914; Su zuki, 1954). It is the purpose of this publication to record the karyotypes of two additional species including the first female karyotypes of two species. Additionally, data is provided on the stability of chromosome preparations made by an air-drying method. MATERIALS AND METHODS An adult male of Physocyclus californicus Chamberlin and Gertsch (9.5 km N Santa Isabella, San Diego Co., CA) and adult males and females of P. enaulus Crosby (Brackettville, Kinney Co., TX) and P. sp. (Lubbock, Lubbock Co., TX) were collected and returned to the laboratory. All specimens were dipped in a 0.005% colchicine/ Ringer's solution and held for 24 hours to accumulate meiotic and mitotic meta phases. Two males of P. sp. were karyotyped without colchicine treatment to ascertain effects of the drug on chromosomes (see Smith, 1965; Sharma and Sharma, 1972). Testis and ovary preparations were air-dried and stained with Giemsa following the procedure outlined by Cokendolpher and Brown (1985). Preparations were not cover slipped and were maintained at room temperatures. RESULTS AND DISCUSSION Chromosome preparations of a male P. californicus, two male P. enaulus, and four male P. sp. reveal 2n = 15, with n = 7 + XO (Figs. 1-4). These counts are based on 15, 14, and 31 nuclei, respectively, for the three species. Many meiotic nuclei were observed with 7:8 segregation with the X chromosome showing positive het eropycnosis (Fig. 1). During diakinesis the X's are isopycnotic (Fig. 2). Chromosome preparations of two P. enaulus (nine nuclei) and three female P. sp. (15 nuclei) reveal 2n = 16. The sex chromosomes are indistinguishable from auto This content downloaded from 157.55.39.117 on Fri, 15 Jul 2016 06:27:46 UTC All use subject to http://about.jstor.org/terms 476 JOURNAL OF THE NEW YORK ENTOMOLOGICAL SOCIETY Vol. 97(4)

Abstract: Recent studies on the pholcid fauna of Central America have elevated the number of known Costa Rican species from 11 to 28 in only two years. The present paper summarizes the scattered literature and adds two new species as well as three undescribed species, bringing the total number. to 33 species representing seven genera. An illustrated key is presented. An annotated list surnmarizes the information available about taxonomy, morphology and natural history of all known Costa Rican pholcids. The two new species·are Anopsicus tico n.sp. from the Central Valley, and Physocyclus guanacaste n.sp. from the Santa Rosa National Park, Guanacaste. The male of Metagonia hondura Huber, 1997 is described and illustrated for fue first time. Old pholcid records. from Costa Rica are discussed, and types of unsufficiently well described species are redescribed, including all previously known Costa Rican Anopsicus species (A. chiriqui Gertsch, 1982; A. concinnus Gertsch, 1982 ; A facetus Gertsch, 1 982; A. turrialba Gertsch, 1982) as well as Metagonia osa Gertsch, 1986 and M. selva Gertsch, 1986. New localities are given for twelv.e species; of these, four are new for Costa Rica: Anopsicus chiriqui Gertsch, 1982; ' Coryssocneinis' viridescens Kraus, 1955; Physocyclus globosus (TacZanowski, 1873); and Smeringopus pallidus (Blackwall, 1858). The genera Coryssocnemis Simon, 1893 and Smeringopus Simon, 1890 are new for Costa Rica. It is argued that carefully directed· collecting in certain areas and habitatS will probably lead to a further considerable increase in known species.

Abstract: With 30 species and a natural distribution in North America, 28 confined to Mexico, Physocyclus Simon 1893 is the most diverse genus within the pholcid spider subfamily Arteminae. This paper provides the first phylogenetic test of the genus's monophyly through a cladistic analysis of 54 morphological characters using equal and implied weighting. The equally weighted analysis found 12 most parsimonious trees, whereas the analysis with implied weights varying the concavity values (K 5 6-10) found five or six most parsimonious trees. The monophyly of the genus Physocyclus is supported by three synaphomorphies: 1) the paired ventral apophysis on the anterior part of the epigynum; 2) the lateral constraints in the middle part of the epigynum; and 3) the arc of the uterus, with a single sclerotized projection on the anterior part. The genus Physocyclus contains two clades treated as species groups: the globosus group, with 11 species, and the dugesi group with 19 species. The species relationships within the globosus group were better resolved than those in the dugesi group. The globosus group has a biogeographical distribution pattern in the Mesoamerican and Mexican Mountain biotic components, whereas the dugesi group has a distribution pattern in the Mesoamerican and Continental Nearctic biotic components. Given the complex biogeography in Mexico, apparently a large-scale vicariant event separated the two major clades within the genus Physocyclus.