Studies on the Cave- Spider Family Leptonetidae

The spider family Leptonetidae Simon, 1890 includes 17 genera and 213 species worldwide. They are broadly distributed in the Holarctic and typically associated with cool, moist habitats such as leaf litter, moss, rotting logs, and caves. The North American fauna is divided into two subfamilies, the Archoleptonetinae and Leptonetinae, with representatives in California through the Southern U.S. and Mexico. Five genera are currently recognized (Platnick, 2010), the most diverse of which is Neoleptoneta Brignoli, 1972 with a center of diversity in Texas where most species are known only from caves (Gertsch, 1974). Their restricted distributions and specialized biology have made them conservation priorities and two Texas species, Neoleptoneta microps (Gertsch, 1974) and N. myopica (Gertsch, 1974), are listed under the U.S. Endangered Species Act. The impetus for this study was a series of collections produced over the past thirty years which have dramatically increased the number of records for the family, including the discovery of several unknown sexes and new species. Additionally, detailed morphological study using scanning electron microscopy (SEM) has revealed a wealth of new characters many of which have implications for relationships within the family and among spiders as a whole. Lastly, fresh collections for several genera in Alabama, California, Mexico, and Texas have facilitated the use of molecular data to develop phylogenetic hypotheses within the family for the first time. The primary objective for the study is to revise the systematics of the North American genera, with particular emphasis on the taxonomy and relationships within the Archoleptonetinae and the Texas cave fauna. The study is divided into three chapters, the results of which are briefly summarized below. In the first chapter, a detailed morphological study of the genus Archoleptoneta revealed the presence of a cribellum an calamistrum representing the first cribellate member of the Leptonetidae. The morphology and relationships for the family are reviewed and the genus Darkoneta is described to include the ecribellate archoleptonetines. Three new species are also described from California, Mexico, and Guatemala. The second chapter uses molecular sequence variation from three genes to produce a phylogeny for the North American Leptonetidae, with emphasis on the relationships of Neoleptoneta Brignoli, 1972. The placement of two incertae sedis species, Leptoneta brunnea (Gertsch, 1974) and Leptoneta sandra (Gertsch, 1974) are also considered and four new genera are described. Morphological data are traced on the molecular phylogeny and patterns of cave evolution are discussed. The third chapter revises the taxonomy of the genus Tayshaneta, including the descriptions of ten new species from Texas. All Tayshaneta species are diagnosed and keyed, and comparative images using scanning electron and compound light microscopy are provided. Relationships among Tayshaneta are also discussed, including detailed descriptions of their morphology. Lastly, the karst faunal region (KFR) conservation strategy in Central Texas is evaluated using revised species distributions

Studies on the Cave- Spider Family Leptonetidae in North America

The spider family Leptonetidae Simon, 1890 includes 17 genera and 213 species worldwide. They are broadly distributed in the Holarctic and typically associated with cool, moist habitats such as leaf litter, moss, rotting logs, and caves. The North American fauna is divided into two subfamilies, the Archoleptonetinae and Leptonetinae, with representatives in California through the Southern U.S. and Mexico. Five genera are currently recognized (Platnick, 2010), the most diverse of which is Neoleptoneta Brignoli, 1972 with a center of diversity in Texas where most species are known only from caves (Gertsch, 1974). Their restricted distributions and specialized biology have made them conservation priorities and two Texas species, Neoleptoneta microps (Gertsch, 1974) and N. myopica (Gertsch, 1974), are listed under the U.S. Endangered Species Act. The impetus for this study was a series of collections produced over the past thirty years which have dramatically increased the number of records for the family, including the discovery of several unknown sexes and new species. Additionally, detailed morphological study using scanning electron microscopy (SEM) has revealed a wealth of new characters many of which have implications for relationships within the family and among spiders as a whole. Lastly, fresh collections for several genera in Alabama, California, Mexico, and Texas have facilitated the use of molecular data to develop phylogenetic hypotheses within the family for the first time. The primary objective for the study is to revise the systematics of the North American genera, with particular emphasis on the taxonomy and relationships within the Archoleptonetinae and the Texas cave fauna. The study is divided into three chapters, the results of which are briefly summarized below. In the first chapter, a detailed morphological study of the genus Archoleptoneta revealed the presence of a cribellum an calamistrum representing the first cribellate member of the Leptonetidae. The morphology and relationships for th

Studies on the Cave- Spider Family Leptonetidae in North America

The spider family Leptonetidae Simon, 1890 includes 17 genera and 213 species worldwide. They are broadly distributed in the Holarctic and typically associated with cool, moist habitats such as leaf litter, moss, rotting logs, and caves. The North American fauna is divided into two subfamilies, the Archoleptonetinae and Leptonetinae, with representatives in California through the Southern U.S. and Mexico. Five genera are currently recognized (Platnick, 2010), the most diverse of which is Neoleptoneta Brignoli, 1972 with a center of diversity in Texas where most species are known only from caves (Gertsch, 1974). Their restricted distributions and specialized biology have made them conservation priorities and two Texas species, Neoleptoneta microps (Gertsch, 1974) and N. myopica (Gertsch, 1974), are listed under the U.S. Endangered Species Act. The impetus for this study was a series of collections produced over the past thirty years which have dramatically increased the number of records for the family, including the discovery of several unknown sexes and new species. Additionally, detailed morphological study using scanning electron microscopy (SEM) has revealed a wealth of new characters many of which have implications for relationships within the family and among spiders as a whole. Lastly, fresh collections for several genera in Alabama, California, Mexico, and Texas have facilitated the use of molecular data to develop phylogenetic hypotheses within the family for the first time. The primary objective for the study is to revise the systematics of the North American genera, with particular emphasis on the taxonomy and relationships within the Archoleptonetinae and the Texas cave fauna. The study is divided into three chapters, the results of which are briefly summarized below. In the first chapter, a detailed morphological study of the genus Archoleptoneta revealed the presence of a cribellum an calamistrum representing the first cribellate member of the Leptonetidae. The morphology and relationships for th

A REVISION OF THE SPIDER GENUS CALILEPTONETA PLATNICK (ARANEAE, LEPTONETIDAE), WITH NOTES ON MORPHOLOGY, NATURAL HISTORY AND BIOGEOGRAPHY

Volume: 32Start Page: 231End Page: 26

Madagascar. Contributions to the study of the biodiversity of Madagascar. Number 1. A monograph of the migid trap door spiders of Madagascar and review of the world genera (Araneae, Mygalomorphae, Migidae)

Volume: 151Start Page: 7End Page: 12

An extraordinary new family of spiders from caves in the Pacific Northwest (Araneae, Trogloraptoridae, new family)

The new spider genus and species Trogloraptor marchingtoni Griswold, Audisio & Ledford is described as the type of the new family Trogloraptoridae. The oblique membranous division of the basal segment of the anterior lateral spinnerets of Trogloraptor suggests that this haplogyne family is the sister group of the other Dysderoidea (Dysderidae, Oonopidae, Orsolobidae and Segestriidae). Trogloraptor is known only from caves and old growth forest understory in the Klamath-Siskiyou region of Oregon and California

Systematics, conservation and morphology of the spider genus Tayshaneta (Araneae, Leptonetidae) in Central Texas Caves

The spider genus Tayshaneta is revised based on results from a three gene phylogenetic analysis (Ledford et al. 2011) and a comprehensive morphological survey using scanning electron (SEM) and compound light microscopy. The morphology and relationships within Tayshaneta are discussed and five species-groups are supported by phylogenetic analyses: the anopica group, the coeca group, the myopica group, the microps group and the sandersi group. Short branch lengths within Tayshaneta contrast sharply with the remaining North American genera and are viewed as evidence for a relatively recent radiation of species. Variation in troglomorphic morphology is discussed and compared to patterns found in other Texas cave invertebrates. Several species previously known as single cave endemics have wider ranges than expected, suggesting that some caves are not isolated habitats but instead form part of interconnected karst networks. Distribution maps are compared with karst faunal regions (KFR’s) in Central Texas and the implications for the conservation and recovery of Tayshaneta species are discussed. Ten new species are described: T. archambaulti sp. n., T. emeraldae sp. n., T. fawcetti sp. n., T. grubbsi sp. n., T. madla sp. n., T. oconnorae sp. n., T. sandersi sp. n., T. sprousei sp. n., T. vidrio sp. n. and T. whitei sp. n. The males for three species, T. anopica (Gertsch, 1974), T. devia (Gertsch, 1974) and T. microps (Gertsch, 1974) are described for the first time. Tayshaneta furtiva (Gertsch, 1974) and T. uvaldea (Gertsch, 1974) are declared nomina dubia as the female holotypes are not diagnosable and efforts to locate specimens at the type localities were unsuccessful. All Tayshaneta species are thoroughly illustrated, diagnosed and keyed. Distribution maps are also provided highlighting areas of taxonomic ambiguity in need of additional sampling

A re-consideration of the taxonomic status of Nebria lacustris Casey (Coleoptera, Carabidae, Nebriini) based on multiple datasets – a single species or a species complex?

This study gathered evidence from principal component analysis (PCA) of morphometric data and molecular analyses of nucleotide sequence data for four nuclear genes (28S, TpI, CAD1, and Wg) and two mitochondrial genes (COI and 16S), using parsimony, maximum likelihood, and Bayesian methods. This evidence was combined with morphological and chorological data to re-evaluate the taxonomic status of Nebria lacustris Casey sensu lato. PCA demonstrated that both body size and one conspicuous aspect of pronotal shape vary simultaneously with elevation, latitude, and longitude and served to distinguish populations from the southern Appalachian highlands, south of the French Broad, from all other populations. Molecular analyses revealed surprisingly low overall genetic diversity within N. lacustris sensu lato, with only 0.39% of 4605 bp varied in the concatenated dataset. Evaluation of patterns observed in morphological and genetic variation and distribution led to the following taxonomic conclusions: (1) Nebria lacustris Casey and Nebria bellorum Kavanaugh should be considered distinct species, which is a NEW STATUS for N. bellorum. (2) No other distinct taxonomic subunits could be distinguished with the evidence at hand, but samples from northeastern Iowa, in part of the region known as the “Driftless Zone”, have unique genetic markers for two genes that hint at descent from a local population surviving at least the last glacial advance. (3) No morphometric or molecular evidence supports taxonomic distinction between lowland populations on the shores of Lake Champlain and upland populations in the adjacent Green Mountains of Vermont, despite evident size and pronotal shape differences between many of their members