Pierre Paquin

The power and perils of 'molecular taxonomy': a case study of eyeless and endangered Cicurina (Araneae: Dictynidae) from Texas caves

Rapid development in karst‐rich regions of the US state of Texas has prompted the listing of four Cicurina species (Araneae, Dictynidae) as US Federally Endangered. A major constraint in the management of these taxa is the extreme rarity of adult specimens, which are required for accurate species identification. We report a first attempt at using mitochondrial DNA (mtDNA) sequences to accurately identify immature Cicurina specimens. This identification is founded on a phylogenetic framework that is anchored by identified adult and/or topotypic specimens. Analysis of ~1 kb of cytochrome oxidase subunit I (CO1) mtDNA data for over 100 samples results in a phylogenetic tree that includes a large number of distinctive, easily recognizable, tip clades. These tip clades almost always correspond to a priori species hypotheses, and show nonoverlapping patterns of sequence divergence, making it possible to place species names on a number of immature specimens. Three cases of inconsistency between recovered tip clades and a priori species hypotheses suggest possible introgression between cave‐dwelling Cicurina, or alternatively, species synonymy. Although species determination is not possible in these instances, the inconsistencies point to areas of taxonomic ambiguity that require further study. Our molecular phylogenetic sample is largest for the Federally Endangered C. madla. These data suggest that C. madla occurs in more than twice the number of caves as previously reported, and indicate the possible synonymy of C. madla with C. vespera, which is also Federally Endangered. Network analyses reveal considerable genetic divergence and structuring across caves in this species. Although the use of DNA sequences to identify previously ‘unidentifiable’ specimens illustrates the potential power of molecular data in taxonomy, many other aspects of the same dataset speak to the necessity of a balanced taxonomic approach.

The effects of preservatives and temperatures on arachnid DNA

We tested the effects of different preservatives and temperatures on the yield of spider and scorpion DNA useable for PCR amplification. Our experiment was designed to simulate conditions in the field and laboratory over a six-week time period, testing the preservatives RNAlater®, propylene glycol, and various ethanol concentrations. Three replicates of each preservation treatment were stored at five different temperature treatments; –80°C, –20°C, 2–4°C, 19–24°C, and 40°C. DNA was extracted and quality was assessed by electrophoresis on mini-gels, and by PCR amplification of high copy mitochondrial DNA fragments (cytochrome oxidase subunit I) and low copy nuclear DNA fragments (actin). Results show that RNAlater® and propylene glycol are significantly better than the other preservatives for high quality DNA preservation and that tissue is best stored at –80°C or –20°C. Storage in 95% ethanol is appropriate if specimens are stored at –20°C or –80°C. We believe our results can help guide biologists in choosing preservatives and temperatures for DNA-based research on arachnids, other arthropods and invertebrates in general.

Changes in soil macroarthropod communities in relation to forest maturation through three successional stages in the Canadian boreal forest

Abstract The edaphic macroarthropod communities of three sites representative of the forest succession in the Lake Duparquet region (situated in the southern part of the boreal forest, Abitibi, Quebec, Canada) were studied. A 47-year-old deciduous forest, a 144-year-old mixed forest, and a 231-year-old coniferous forest form a successional forest gradient with a vegetation composition that is a function of the time elapsed since the last forest fire. Along with forest succession, there is a reduction in macroarthropod community biodiversity. There is a negative gradient for mean total abundance (237–41 individuals), total richness (63–23 species), density (1792–661 individuals/m2), diversity (H′ = 1.478–1.007) and equitability (J = 0.821–0.739). These community changes affect saprophagous organisms more than predators. Certain species or taxa show preferences for a particular forest type, such as larval Diptera for the deciduous forest. A comparison of these results with the literature suggests an inverse preference as to habitat choice between microarthropods (Acarina and Collembola) and macroarthropods. From a conservation point of view, macroarthropod biodiversity will be favored by the protection of all forest types since each environment possesses a particular community structure and species.

Species status and conservation issues of New Zealand's endemic Latrodectus spider species (Araneae : Theridiidae)

New Zealand has two endemic widow spiders, Latrodectus katipo Powell, 1871 and L. atritus Urquhart, 1890. Both species face many conservation threats and are actively managed. The species status of the Latrodectus spiders of New Zealand was assessed using molecular (COI, ITS1, ITS2) and morphological methods and with cross-breeding experiments. Latrodectus katipo and L. atritus were not found to be reciprocally monophyletic for any of the gene regions or morphological traits. Other than colour, which is variable, there were no morphological characters that separated the two species, which cross-bred in the laboratory and produced fertile eggsacs. Colour variation is clinal over latitude and correlates significantly with mean annual temperature. We conclude that L. atritus is a junior synonym of L. katipo. An example of introgression from the Australian species L. hasseltii Thorell, 1870 was also detected and its conservation implications are discussed.

The fundamental importance of taxonomy in conservation biology: the case of the eyeless Cicurina bandida (Araneae : Dictynidae) of central Texas, including new synonyms and the description of the male of the species

Three eyeless species belonging to the spider genus Cicurina Menge are known from five caves located south of Austin, Travis County (Texas, United States). Because adult female cave-dwelling Cicurina are not common, and adult males rarely collected, these species were described from a very small sample of individuals (nine females). Recent collections have allowed the examination of a larger series of specimens, providing an opportunity to assess intraspecific variability. This has resulted in the synonymy of C. cueva Gertsch and C. reyesi Gertsch with Cicurina bandida Gertsch. The synonymy is supported by both female and male morphology; the male of the species is described for the first time. Cicurina bandida is now known from ~20 caves, restricted to a 10 km × 30 km area. Cicurina cueva was proposed to be listed as an endangered species. Because of the special conservation status of troglobitic Cicurina, modifications of the original species hypothesis are fertile grounds for confrontation between conservationists and proponents of development. Taxonomy is a dynamic science that progresses by proposing new scientific hypotheses and this conflicts with conservation principles that are embedded in a static framework. The criteria used to assign species a particular conservation status should be based on the best available evidence, and not limited by political considerations. Long-term conservation goals can only be achieved when based on a robust taxonomy, which is still largely unavailable for most Texas cave arthropods.

Hydrologic evolution of the Edwards Aquifer recharge zone (Balcones fault zone) as recorded in the DNA of eyeless Cicurina cave spiders, south-central Texas

The Balcones Escarpment of south-central Texas is the eroded topographic expression of an en echelon fault zone where Cretaceous carbonates have been modified by karst processes influenced by structural and stratigraphic controls. While the modern confined Edwards Aquifer flows through cavernous voids at the base of the escarpment, air-filled caves perched in the escarpment are relicts of paleoaquifer hydrology. The structural geology of the Balcones Escarpment and the phylogeography of its endemic cave spiders provide mutually informative frameworks from which to establish relative dates for the activation of discrete groundwater recharge areas. The mitochondrial genetic variability of troglobitic spiders is correlated with the structural elements of the Balcones fault zone in and around the San Antonio relay ramp. Older (basal) genetic lineages occur in structurally high, mature karst terrains, while the younger (derived) lineages occur in structurally low, emergent karst terrains. Based on mitochondrial deoxyribonucleic acid (mtDNA) data, Cicurina diversity is interpreted as the product of the progressive availability of vadose zone habitat as discrete recharge areas have developed.

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

Abstract 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: Tayshaneta archambaulti sp. n., Tayshaneta emeraldae sp. n., Tayshaneta fawcetti sp. n., Tayshaneta grubbsi sp. n., Tayshaneta madla sp. n., Tayshaneta oconnorae sp. n., Tayshaneta sandersi sp. n., Tayshaneta sprousei sp. n., Tayshaneta vidrio sp. n. and Tayshaneta whitei sp. n. The males for three species, Tayshaneta anopica (Gertsch, 1974), Tayshaneta devia (Gertsch, 1974) and Tayshaneta microps (Gertsch, 1974) are described for the first time. Tayshaneta furtiva (Gertsch, 1974) and Tayshaneta 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.

Systematics of the spider genus Neoleptoneta Brignoli, 1972 (Araneae:Leptonetidae) with a discussion of the morphology and relationships for the North American Leptonetidae

A phylogenetic analysis of the spider genus Neoleptoneta Brignoli, 1972 is presented based on molecular sequence variation from three genes (mitochondrial cytochrome c oxidase subunit I, nuclear histone H3 and nuclear 28S rDNA) and including exemplars for all North American leptonetid genera except the ecribellate archoleptonetine Darkoneta. Analysis of concatenated data and independent genes using Bayesian, maximum likelihood and parsimony methods failed to recover Neoleptoneta as monophyletic. The genera Archoleptoneta, Appaleptoneta and Calileptoneta are monophyletic and a sister group relationship is supported between Appaleptoneta and Calileptoneta. Morphological data based on a survey of leptonetid genera using scanning electron and compound light microscopy are discussed and traced on the molecular phylogeny. Images for each North American leptonetine genus are provided, including comparison with Asian and European outgroups. Images of the incertae sedis species Leptoneta brunnea Gertsch, 1974 and Leptoneta sandra Gertsch, 1974 are provided and their generic placement is re-evaluated. Ancestral state reconstruction is used to assess patterns of cave evolution and shows that most species are descended from troglophilic ancestors and that troglobites have evolved at least nine times independently within the North American Leptonetidae. Neoleptoneta is relimited to include seven species restricted to central Mexico including N. bonita (Gertsch, 1974), N. capilla (Gertsch, 1971), N. delicata (Gertsch, 1971), N. limpida (Gertsch, 1974), N. rainesi (Gertsch, 1971) and N. reclusa (Gertsch, 1971) and to include Leptoneta brunnea, giving the new combination N. brunnea (Gertsch, 1974). The remaining species described in Neoleptoneta are placed in three new genera: (1) Chisoneta, gen. nov. from south-western Texas and Nuevo Leon, Mexico, including the four species C. chisosea (Gertsch, 1974), C. isolata (Gertsch, 1971), C. modica (Gertsch, 1974) and C. pecki (Gertsch, 1971), new combinations; (2) Ozarkia, gen. nov. from Arizona and New Mexico north-east to Arkansas, Alabama and Georgia, including the nine species O. alabama (Gertsch, 1974), O. apachea (Gertsch, 1974), O. archeri (Gertsch, 1974), O. arkansa (Gertsch, 1974), O. blanda (Gertsch, 1974), O. georgia (Gertsch, 1974), O. ivei (Gertsch, 1974), O. novaegalleciae (Brignoli, 1979) and O. serena (Gertsch, 1974), new combinations; and (3) Tayshaneta, gen. nov. from Texas south to Coahuila, Mexico, with the eleven species T. anopica (Gertsch, 1974), T. bullis (Cokendolpher, 2004), T. coeca (Chamberlin & Ivie, 1942), T. concinna (Gertsch, 1974), T. devia (Gertsch, 1974), T. furtiva (Gertsch, 1974), T. microps (Gertsch, 1974), T. myopica (Gertsch, 1974), T. paraconcinna (Cokendolpher & Reddell, 2001), T. uvaldea (Gertsch, 1974) and T. valverdae (Gertsch, 1974), new combinations. Leptoneta sandra Gertsch, 1974 cannot be placed in any North American, European or Asian genus and is thus transferred to the new genus Montanineta, gen. nov., giving the new combination Montanineta sandra (Gertsch, 1974).

Influence of phenobarbital pretreatment on methoxyflurane and sodium fluoride nephropathy in Fischer 344 rats

Abstract Adult male Fischer 344 rats were used to investigate the effect of phenobarbital on methoxyflurane- and sodium fluoride-induced nephropathy. Pretreatment consisted of the ip administration of phenobarbital sodium at a dose of 50 mg/kg/day for 5 days; control animals were given saline. Pretreated animals were exposed to anesthetic concentrations of methoxyflurane during a period of 2 or 4 hr, whereas other pretreated animals were exposed only to oxygen, the methoxyflurane carrier gas. For comparative purposes, other pretreated animals received sodium fluoride in saline at doses of 0, 4.2 and 8.4 mg/300g. The results show that phenobarbital pretreatment enhances the nephrotoxicity of methoxy-flurance as evidenced by a significant interaction between phenobarbital and methoxyflurane on plasma concentrations of sodium and potassium, urinary volume, urinary excretion of urea, and urinary concentration test. In contrast, the nephrotoxicity of sodium fluoride was not affected by phenobarbital. These results provide good evidence that the urinary concentration test is a reliable monitor of the potentiating effect of phenobarbital on methoxyflurane nephrotoxicity.

ON THE DISTRIBUTION AND PHENOLOGY OF ARGYRODES FICTILIUM (ARANEAE, THERIDIIDAE) AT ITS NORTHERN LIMIT OF NORTH AMERICA

Abstract Argyrodes fictilium is a rarely collected species whose northern range was thought to be southern Canada. Recent collections in the eastern boreal forests of Québec extend its distribution range to the north and suggest that A. fictilium might be found anywhere within the boreal forest tree limit. Mature males collected in May indicate a summer-stenochronous type of phenology.