New systematic assignments in Gonyleptoidea (Arachnida, Opiliones, Laniatores)

As part of an ongoing revision of the family Gonyleptidae, we have identified many species that are synonyms of previously described species or misplaced in this family. This article summarizes these findings, adding previously unavailable information or correcting imprecise observations to justify the presented taxonomic changes. The following new familial or subfamilial assignments are proposed: Nemastygnus Roewer, 1929 and Taulisa Roewer, 1956 are transferred to Agoristenidae, Agoristeninae; Napostygnus Roewer, 1929 to Cranaidae; Ceropachylinus peruvianus Roewer, 1956 and Pirunipygus Roewer, 1936 are transferred to Gonyleptidae, Ampycinae; Gyndesops Roewer, 1943, Haversia Roewer, 1913 and Oxapampeus Roewer, 1963 are transferred to Gonyleptidae, Pachylinae. The following generic synonymies are proposed for the family Gonyleptidae: Acanthogonyleptes Mello-Leitão, 1922 = Centroleptes Roewer, 1943; Acrographinotus Roewer, 1929 = Unduavius Roewer, 1929; Gonyleptes Kirby, 1819 = Collonychium Bertkau, 1880; Mischonyx Bertkau, 1880 = Eugonyleptes Roewer, 1913 and Gonazula Roewer, 1930; Parampheres Roewer, 1913 = Metapachyloides Roewer, 1917; Pseudopucrolia Roewer, 1912 = Meteusarcus Roewer, 1913; Haversia Roewer, 1913 = Hoggellula Roewer, 1930. The following specific synonymies are proposed for the family Gonyleptidae: Acanthogonyleptes singularis (Mello-Leitão, 1935) = Centroleptes flavus Roewer, 1943, syn. n.; Geraeocormobius sylvarum Holmberg, 1887 = Discocyrtus serrifemur Roewer, 1943, syn. n.; Gonyleptellus bimaculatus (Sørensen, 1884) = Gonyleptes cancellatus Roewer,1917, syn. n.; Gonyleptes atrus Mello-Leitão, 1923 = Weyhia brieni Giltay, 1928, syn. n.; Gonyleptes fragilis Mello-Leitão, 1923 = Gonyleptes banana Kury, 2003, syn. n.; Gonyleptes horridus Kirby, 1819 = Collonychium bicuspidatum Bertkau, 1880, syn. n., Gonyleptes borgmeyeri Mello-Leitão, 1932, syn. n., Gonyleptes curvicornis Mello-Leitão, 1932, syn. n., Metagonyleptes hamatus Roewer, 1913, syn. n. and Paragonyleptes simoni Roewer, 1930, syn. n.; Gonyleptes pustulatus Sørensen, 1884 = Gonyleptes guttatus Roewer, 1917, syn. n.; Haversia defensa (Butler, 1876) = Sadocus vallentini Hogg, 1913, syn. n.; Liogonyleptoides minensis (Piza, 1946) = Currala bahiensis Soares, 1972, syn. n.; Megapachylus grandis Roewer, 1913 = Metapachyloides almeidai Soares & Soares, 1946, syn. n.; Mischonyx cuspidatus (Roewer, 1913) = Gonazula gibbosa Roewer, 1930 syn. n.; Mischonyx scaber (Kirby, 1819) = Xundarava holacantha Mello-Leitão, 1927, syn. n.; Parampheres tibialis Roewer, 1917 = Metapachyloides rugosus Roewer, 1917, syn. n.; Parapachyloides uncinatus (Sørensen, 1879) = Goyazella armata Mello-Leitão, 1931, syn. n.; Pseudopucrolia mutica (Perty, 1833) = Meteusarcus armatus Roewer, 1913, syn. n. The following new combinations are proposed: Acrographinotus ornatus (Roewer, 1929), comb. n. (ex Unduavius); Gonyleptellus bimaculatus (Sørensen, 1884),comb. n. (ex Gonyleptes);Gonyleptes perlatus (Mello-Leitão, 1935), comb. n. (exMoojenia);Mischonyx scaber (Kirby, 1819), comb. n. (ex Gonyleptes); and Neopachyloides peruvianus (Roewer, 1956), comb. n. (ex Ceropachylus). The following species of Gonyleptidae, Gonyleptinae are revalidated: Gonyleptes atrus Mello-Leitão, 1923 and Gonyleptes curvicornis (Roewer, 1913).     

Conventional and ultrastructural analyses of the chromosomes of Discocyrtus pectinifemur (Opiliones, Laniatores, Gonyleptidae)

Among the Opiliones, species of the suborders Cyphophthalmi, Eupnoi, Dyspnoi and Laniatores have shown very diverse diploid chromosome numbers. However, only certain Eupnoi species exhibit XY/XX and ZZ/ZW sex chromosome systems. Considering the scarcity of karyotypical information and the absence of structurally identifiable sex chromosomes in the suborder Laniatores, we decided to analyse the chromosomes and bivalents of Discocyrtus pectinifemur (Gonyleptidae) to identify possible sex differences. Testicular cells examined under light microscopy showed a high diploid number, 2 n  = 88, meta/submetacentric chromosome morphology and a nucleolar organizer region on pair 35. Prophase I microspreading observed in transmission electron microscopy exhibited 44 synaptonemal complexes with similar electron density and thickness. The total and regular synapsis between the chromosomes of the bivalents was also noted in pachytene nuclei. Male mitotic and meiotic chromosomes revealed no distinct characteristic that could be related to the occurrence of heteromorphic sex chromosomes. Evolutionary trends of chromosome differentiation in the four suborders of Opiliones are discussed here.     

Genetic diversification without obvious genitalic morphological divergence in harvestmen (Opiliones, Laniatores, Sclerobunus robustus) from montane sky islands of western North America

The southern Rocky Mountains and adjacent Intermontane Plateau Highlands region of western North America is a geographically diverse area with an active geologic history. Given the topological complexity and extensive geologic activity, organisms inhabiting this region are expected to show some degree of morphological and genetic divergence, especially populations found on the southern montane 'sky islands' of this region. Here we examine the phylogeographic history and diversification of a montane forest inhabiting harvestmen, Sclerobunus robustus, using a combination of genetic and morphological data. Divergence time estimates indicate that much of the diversification within and between major groups S. robustus predate the Pleistocene glacial cycles. The most widespread subspecies, Sclerobunus robustus robustus, is recovered as six genetically distinct, geographically cohesive mitochondrial phylogroups. Gene tree data for a single nuclear gene reveals congruent, albeit slightly more conservative, patterns of genetic divergence. Despite high levels of genetic divergence throughout their distribution, phylogroups show extreme conservation in somatic and reproductive morphology. This uncoupling of morphological and genetic differentiation may be due to morphological conservatism associated with a conserved microhabitat preference. Based on these data, it is obvious that S. robustus has undergone some level of cryptic diversification.     

Comparative study of the morphology of the gland opening area among Grassatores harvestmen (Arachnida,Opiliones, Laniatores)

Arachnids of the order Opiliones (harvestmen), which includes around 6000 specìes, have a pair of scent glands that open at the sides of the body, producing substances used as defence. Several types of behavioural, morphological and chemical defensive mechanisms have been identified in the order as a whole, although some of these tactics were restricted to particular groups. Only around 60 species have been studied from this perspective so far, more than half of which belong to the largest harvestman family within the order Laniatores, the Gonyleptidae, and have only recently been studied in an evolutionary perspective, showing the usefulness of defensive characters in taxonomy and evolutionary biology. Within Laniatores, the Grassatores clade includes the Gonyleptidae and 20 additional families, mostly poorly or not previously studied. We describe the morphology of the structures involved in fluid displacement during chemical defence in 15 of these families (data on two additional families are available from the literature) and discuss the evolution of such traits based on an available phylogenetic hypothesis of relationships within Grassatores, using the representatives of Triaenonychidae (a non‐Grassatores family of Laniatores) for comparison. We conclude that most non‐gonyleptoid Grassatores share (maybe plesiomorphically) a series of characteristics, mostly strongly different from what is observed within the gonyleptoids, and that smaller groups seem to share diagnostic features related to chemical defence, as is the case of stygnids, cosmetids and triaenonychines, and especially of manaosbiids and cranaids, whose defensive morphologies largely resemble those of derived gonyleptids. The following main synapomorphies were detected: (a) Grassatores: the presence of a deep and well‐defined descending channel; (b) Samooidea+Zalmoxoidea+Assamioidea+Gonyleptoidea: lateral pegs along the lateral channel; (c) Samooidea+Zalmoxoidea: deep channels forming an H on the dorsal scute; (d) Gonyleptoidea: ozopore cutting dorsally (reversing in Agoristenidae and Stygnidae to a laterally placed oval ozopore), a wide and smooth lateral channel, reversing to a lateral channel whose bottom is covered with either small plates (Agoristenidae) or high tubercles (Stygnidae), and apophyses of coxa II close to or covering the ozopore.     

Hidden Mediterranean diversity: Assessing species taxa by molecular phylogeny within the opilionid family Trogulidae (Arachnida,Opiliones)

This is the first comprehensive study to evaluate the relationships between the western palearctic harvestman families Dicranolasmatidae, Trogulidae and Nemastomatidae with focus on the phylogeny and systematics of Trogulidae, using combined sequence data of the nuclear 28S rRNA and the mitochondrial cytochrome b gene. Bayesian analysis and Maximum parsimony do not reliably resolve Dicranolasma as distinct family but place it on a similar phylogenetic level as several lineages of Trogulidae. Nemastomatidae and Trogulidae turned out to be monophyletic, as did genera Anelasmocephalus and Trogulus within the Trogulidae. The genera Calathocratus, Platybessobius and Trogulocratus each appeared para or polyphyletic, respectively and are synonymized with Calathocratus. The monotypic genus Kofiniotis is well supported. We show molecular data to be in general concordance with taxa characterized by morphology. Molecular data are especially useful to calibrate morphological characters for systematic purposes within homogeneous taxa. In the majority of closely related valid species we show the lowest level of genetic distance to be not lower than 5%. By this threshold in terms of traditionally accepted species the estimated number of species turns out to be 1.5–2.4 times higher than previously believed. With respect to European fauna cryptic diversity in Trogulidae is obviously extraordinarily high and hitherto largely underestimated.     

A comparative analysis of the chemical nature of defensive secretions of Gonyleptidae (Arachnida: Opiliones: Laniatores)

The arachnids of the order Opiliones (harvestmen) produce substances used in defense. In the present paper, we analyzed 22 species of Gonyleptidae to explore the use of defensive substances in taxonomy and evolutionary biology. Thirty-seven different compounds were detected, 18 of which were preliminarily identified. These compounds were mapped onto a phylogenetic tree showing the relationships within the Gonyleptidae. Data from Cosmetidae were used as an outgroup. Five ketones and six alkyl phenols were reported for the first time in harvestmen.     

A new monster from southwest Oregon forests: Cryptomaster behemoth sp. n. (Opiliones,Laniatores, Travunioidea)

The monotypic genus Cryptomaster Briggs, 1969 was described based on individuals from a single locality in southwestern Oregon. The described species Cryptomaster leviathan Briggs, 1969 was named for its large body size compared to most travunioid Laniatores. However, as the generic name suggests, Cryptomaster are notoriously difficult to find, and few subsequent collections have been recorded for this genus. Here, we increase sampling of Cryptomaster to 15 localities, extending their known range from the Coast Range northeast to the western Cascade Mountains of southern Oregon. Phylogenetic analyses of mitochondrial and nuclear DNA sequence data reveal deep phylogenetic breaks consistent with independently evolving lineages. We use discovery and validation species delimitation approaches to generate and test species hypotheses, including a coalescent species delimitation method to test multi-species hypotheses. For delimited species, we use light microscopy and SEM to discover diagnostic morphological characters. Although Cryptomaster has a small geographic distribution, this taxon is consistent with other short-range endemics in having deep phylogenetic breaks indicative of species level divergences. Herein we describe Cryptomaster behemoth sp. n., and provide morphological diagnostic characters for identifying Cryptomaster leviathan and Cryptomaster behemoth.     

Review of the genus Plistobunus Pocock, 1903, with description of a new species from Hainan Island, China (Opiliones, Laniatores, Epedanidae)

The genus Plistobunus Pocock, 1903 and its type species Plistobunus rapax Pocock, 1903 are redescribed based on the type material deposited in the British Museum of Natural History (BMNH), London. In addition, a new Plistobunus species from Hainan Island is described and illustrated of Plistobunus columnariussp. n. The new species is diagnosed by having a row of 12 setiferous tubercles on anterior margin of carapace, and the femur of pedipalpus ventrally with 13 setiferous tubercles in male.     

A new Tithaeus species from Hainan Island, China (Arachnida, Opiliones, Laniatores, Epedanidae), with a key to the Chinese species

A new species of the harvestmen Tithaeus calyptratussp. n. (Epedanidae, Opiliones) from Hainan Island (China) is diagnosed, described and illustrated. A key to the two Chinese species of Tithaeus is provided.     

Integrative Taxonomy and Species Delimitation in Harvestmen: A Revision of the Western North American Genus Sclerobunus (Opiliones: Laniatores: Travunioidea)

Alpha taxonomy, and specifically the delimitation of species, is becoming increasingly objective and integrative. The use of coalescent-based methods applied to genetic data is providing new tools for the discovery and delimitation of species. Here, we use an integrative approach via a combination of discovery-based multivariate morphological analyses to detect potential new species. These potential species are then used as a priori species in hypothesis-driven validation analyses with genetic data. This research focuses on the harvestmen genus Sclerobunus found throughout the mountainous regions of western North America. Based on our analyses, we conduct a revision of Sclerobunus resulting in synonymy of Cyptobunus with Sclerobunus including transfer of S. cavicolenscomb. nov. and elevation of both subspecies of S. ungulatus: S. ungulatuscomb. nov. and S. madhousensiscomb. nov., stat. nov. The three subspecies of S. robustus are elevated, S. robustus, S. glorietusstat. nov., and S. idahoensisstat. nov. Additionally, five new species of Sclerobunus are described from New Mexico and Colorado, including S. jemezsp. nov., S. klomaxsp. nov., S. skywalkerisp. nov., S. speoventussp. nov., and S. steinmannisp. nov. Several of the newly described species are single-cave endemics, and our findings suggest that further exploration of western North American cave habitats will likely yield additional new species.     

A new apameine genus and species from the southern Appalachian Mountains,USA (Lepidoptera,Noctuidae, Noctuinae)

Cherokeeagen. n. is proposed for a rarely collected apameine moth species from the southern Appalachian Mountains, C. attakullakullasp. n. It is recorded from foothills and lower montane habitats of North Carolina and Georgia where hill cane, Arundinaria appalachiana Triplett, Weakley & L.G. Clark is found. Adults and their genitalia are figured and a mtDNA barcode sequence is given.     

Glaciation effects on the phylogeographic structure of Oligoryzomys longicaudatus (Rodentia: Sigmodontinae) in the southern Andes

The long-tailed pygmy rice rat Oligoryzomys longicaudatus (Sigmodontinae), the major reservoir of Hantavirus in Chile and Patagonian Argentina, is widely distributed in the Mediterranean, Temperate and Patagonian Forests of Chile, as well as in adjacent areas in southern Argentina. We used molecular data to evaluate the effects of the last glacial event on the phylogeographic structure of this species. We examined if historical Pleistocene events had affected genetic variation and spatial distribution of this species along its distributional range. We sampled 223 individuals representing 47 localities along the species range, and sequenced the hypervariable domain I of the mtDNA control region. Aligned sequences were analyzed using haplotype network, bayesian population structure and demographic analyses. Analysis of population structure and the haplotype network inferred three genetic clusters along the distribution of O. longicaudatus that mostly agreed with the three major ecogeographic regions in Chile: Mediterranean, Temperate Forests and Patagonian Forests. Bayesian Skyline Plots showed constant population sizes through time in all three clusters followed by an increase after and during the Last Glacial Maximum (LGM; between 26,000-13,000 years ago). Neutrality tests and the "g" parameter also suggest that populations of O. longicaudatus experienced demographic expansion across the species entire range. Past climate shifts have influenced population structure and lineage variation of O. longicaudatus. This species remained in refugia areas during Pleistocene times in southern Temperate Forests (and adjacent areas in Patagonia). From these refugia, O. longicaudatus experienced demographic expansions into Patagonian Forests and central Mediterranean Chile using glacial retreats.     

Biogeographical variation in the harvestman Mitopus morio (Opiliones, Arachnida)

The taxonomic status of three forms of the harvestman Mitopus morio in Britain have been examined. These have been identified by previous workers as a small, upland M, morio cinerascens , a larger, lowland M. morio morio , and a northern M. morio borealis. In this paper, the delimitation of trinomials has been found to be inappropriate for M. morio. since all three forms have been shown to lie at different points on a continuum of phenotypic variation within the species M. morio. It is suggested that this phenotypic variation is mediated by the variation in temperature regimes between different localities.     

Restricted movement by mottled sculpin (pisces: cottidae) in a southern Appalachian stream

1. We used direct observation and mark‐recapture techniques to quantify movements by mottled sculpins (Cottus bairdi) in a 1 km segment of Shope Fork in western North Carolina. Our objectives were to: (i) quantify the overall rate of sculpin movement, (ii) assess variation in movement among years, individuals, and sculpin size classes, (iii) relate movement to variation in stream flow and population size structure, and (iv) quantify relationships between movement and individual growth rates. 2. Movements were very restricted: median and mean movement distances for all sculpin size classes over a 45 day period were 1.3 and 4.4 m respectively. Nevertheless, there was a high degree of intrapopulation and temporal variation in sculpin movement. Movement of juveniles increased with discharge and with the density of large adults. Movement by small and large adults was not influenced by stream flow, but large adults where more mobile when their own density was high. Finally, there were differences in the growth rates of mobile and sedentary sculpins. Mobile juveniles grew faster than sedentary individuals under conditions of low flow and high density of large adults, whereas adults exhibited the opposite pattern. 3. Our results support the hypothesis that juvenile movement and growth is influenced by both intraspecific interactions with adults and stream flow. In contrast, adult movement appears to be influenced by competitive interactions among residents for suitable space. The relationship between movement and growth may provide a negative feedback mechanism regulating mottled sculpin populations in this system.     

Patch selection by mottled sculpin (Pisces: Cottidae) in a southern Appalachian stream

1. We examined the effects of prey abundance on patch selection by a benthic fish, the mottled sculpin ( Cottus bairdi ), in a fourth order, southern Appalachian stream (North Carolina, U.S.A.). This habitat is a mosaic of small (i.e. < 0.5 m²), relatively discrete patches.
2. Patches were characterized in terms of physical habitat variables, detritus (coarse particulate organic matter, CPOM) and macroinvertebrate abundance (number and biomass). We quantified patch selection by comparing the characteristics of patches utilized by sculpin with those of locally available patches. Locally available patches were selected using a constrained random sampling design (i.e. randomly selected within a 2 m radius from each fish). We also examined the relationship between macroinvertebrate abundance, CPOM and the physical characteristics of available patches.
3. Patches selected by sculpin contained significantly higher macroinvertebrate abundances (both number and biomass) than locally available patches in five out of six seasonal samples. Sculpin also occupied patches with significantly higher amounts of CPOM in three out of five seasonal samples. Patches utilized by sculpin, however, could not be consistently differentiated from locally available patches on the basis of physical variables. In addition, macroinvertebrate abundance was not consistently related to physical habitat variables or CPOM during the course of the study.
4. Our results suggest that sculpin are able to assess patch quality on the basis of prey abundance and select patches that potentially maximize energy gain. This behaviour may produce an increase in individual fitness, especially when prey distributions are not consistently related to habitat variables. Quantifying patch use in relation to prey abundance may help elucidate the causal factors determining habitat use by benthic fishes in other lotic systems.     

Patch selection by mottled sculpin (Pisces: Cottidae) in a southern Appalachian stream

1. We examined the effects of prey abundance on patch selection by a benthic fish, the mottled sculpin ( Cottus bairdi ), in a fourth order, southern Appalachian stream (North Carolina, U.S.A.). This habitat is a mosaic of small (i.e. < 0.5 m²), relatively discrete patches.
2. Patches were characterized in terms of physical habitat variables, detritus (coarse particulate organic matter, CPOM) and macroinvertebrate abundance (number and biomass). We quantified patch selection by comparing the characteristics of patches utilized by sculpin with those of locally available patches. Locally available patches were selected using a constrained random sampling design (i.e. randomly selected within a 2 m radius from each fish). We also examined the relationship between macroinvertebrate abundance, CPOM and the physical characteristics of available patches.
3. Patches selected by sculpin contained significantly higher macroinvertebrate abundances (both number and biomass) than locally available patches in five out of six seasonal samples. Sculpin also occupied patches with significantly higher amounts of CPOM in three out of five seasonal samples. Patches utilized by sculpin, however, could not be consistently differentiated from locally available patches on the basis of physical variables. In addition, macroinvertebrate abundance was not consistently related to physical habitat variables or CPOM during the course of the study.
4. Our results suggest that sculpin are able to assess patch quality on the basis of prey abundance and select patches that potentially maximize energy gain. This behaviour may produce an increase in individual fitness, especially when prey distributions are not consistently related to habitat variables. Quantifying patch use in relation to prey abundance may help elucidate the causal factors determining habitat use by benthic fishes in other lotic systems.     

External ultrastructure of sensory organs in the subfamily lrumuinae (Arachnida, Opiliones, Assamiidae)

The external ultrastructure of sensory organs in edaphic reprerentatives of the subfamily Irumuinae is described. The types of receptor are either bristle-shaped or bulbiform. The bristle-shaped receptors occur on the ventral side of the coxae and displace sensory hairs there. The bulbiform ones are distributed over the scute and on proximal joints (femur, trochanter) of legs. These structures are considered as adaptations to the soil environment.     

Ancient phylogeographic divergence in southeastern Australia among populations of the widespread common froglet, Crinia signifera

Geographic patterns of species diversity in southeast Australia have been attributed to changes in Pleistocene climate, but related phylogeographic patterns and processes are relatively understudied. 12S and 16S mitochondrial DNA sequences in Crinia signifera populations were used to infer historical patterns and processes in southeast Australia. Phylogenetic analysis identified three geographically restricted ancient lineages and several geographically restricted sub-clades. Present-day features that may prevent gene flow are absent between these geographic regions. Divergence among the three lineages corresponds to a late Miocene origin, approximately 9 million years ago (mya). The geographic breaks among the lineages are consistent with Miocene-Pliocene uplift in the Great Dividing Range and elevated sea levels in East Gippsland. Divergence among sub-clades in Victoria and South Australia is estimated to be within the early Pliocene, whereas sub-clades in New South Wales are estimated to have diverged near the Plio-Pleistocene boundary, approximately 2 mya. Geographic limits of sub-clades are consistent with geographic variation in advertisement calls, but are inconsistent with phylogeographic limits previously identified in other southeastern species.