Comparative susceptibility of conifers to knobcone pine dwarf mistletoe

Analysis of morphological characters of Arceuthobium apachecum and A. blumeri indicates there are several geographically consistent differences between these taxa, which supports their current classification at the specific level. Shoot height and perianth lobe number exhibited considerable geographic variation, and some morphological characters examined were continuous. Peak flowering and seed dispersal periods for these species differed slightly Altitudinal, seasonal, and latitudinal variations in flowering and seed dispersal were detected and may be responsible for the differences in phenology between these taxa.     

Genetic differentiation of rare and common varieties of Eriogonum shockleyi (Polygonaceae) in Idaho using ISSR variability

Idaho populations of Eriogonum shockleyi are divided taxonomically into 2 varieties: E. shockleyi var. packardae , which is endemic to Idaho, and the typical variety, which is widespread in the western United States. Recent morphological investigations of E. shockleyi in Idaho have identified potentially reliable morphological characters for field identification of the subspecific taxa. This paper investigates the genetic basis for the separation of the 2 varieties of E. shockleyi using inter simple-sequence repeats (ISSR) markers. Although we found some morphological differences between the populations that correlated with the 2 varieties, we identified no molecular markers in this study to distinguish between them. Morphological measurements obtained in the field indicate that although a population may have an overall average morphology that defines the variety, some individuals in nearly all populations have putative diagnostic characters that define the other variety. The morphological characters used to distinguish the 2 varieties are most likely the result of environmental variability and could result from differences in precipitation and soil water retention. Alternatively, high levels of outcrossing through pollen flow could be obscuring selection for morphological characters at particular sites.     

Partitioning phenotypic variation: genotypic,environmental and residual components from bryozoan skeletal morphology

Using morphometric studies of colonial (clonal) organisms such as Bryozoa grown as replicates in controlled laboratory experiments, phenotypic variation (hard part morphology) can be partitioned into its genotypic and environmental (ecophenotypic) components. The interaction between these, i.e. different genotypic responses to the same environmental change, can also be recognized. Palaeobiological studies are inherently constrained by species concepts based on morphotypes (preserved morphological phenotype). Uncertainties associated with fossil species concepts restrict the deductive resolution potential of fossil taxa in discussions of the broader biological questions of species evolution, ecology, biogeography and phylogeny. The relationship between species-level morphological variation and genetic variation in modern taxa is central to evaluating the viability of fossil morphotypes as biological species. Results from a preliminary study of three genotypes of Electra pilosa L., grown as replicate colonies in tanks comprising different microenvironmental conditions, allow for direct evaluation of morphospecies concepts. Numerical analyses (Cluster Analysis, Principal Component Analysis and Two-way ANOVA) of six morphometric characters demonstrated a strong Genotype control over zooid morphology and limited environmental (Tank) effects with minimal environmental differences among tanks. No significant Genotype by Tank (=environment) interactions were found for any characters. These results demonstrate that it is possible to quantify the extent to which a given trait is plastically expressed in different environments. The strong degree of correlation between morphology and genetics for this species is encouraging for the use of morphotypes as proxies for biological species.     

Ancestrular morphology in cyclostome bryozoans and the quest for phylogenetically informative skeletal characters

Cyclostomes are an ancient order of bryozoans with more than 500 living species. Traditionally, cyclostome taxonomy has depended almost entirely on characters of the calcareous skeletons of mature colonies. However, the taxonomic distribution of these characters is largely incongruent with well-supported molecular phylogenetic trees, implying the need for major revisions if cyclostome taxonomy is to reflect phylogeny. While far more taxa must be sequenced to ascertain their molecular relationships, there is also a need to discover morphological characters that can be used to support molecular clades, not least to allow these clades to be inferred among fossil cyclostomes for which molecular data will never be available. Here we survey the skeletal morphology of the first-formed part of the skeleton – the protoecium of the founding zooid (ancestrula) – in a variety of Recent and well-preserved fossil cyclostomes, motivated by the recent discovery of a morphologically disparate molecular clade that can be distinguished by protoecial characters. The distribution of pseudopores on the protoecium is shown to vary between species, with eight patterns recognizable, offering a new source of skeletal characters in both living and fossil taxa. However, the patterns seem not to be fully congruent with the cyclostome molecular tree and more data and analyses are required before these patterns can be used to recognize cyclostome clades.     

On the taxonomic status of Eriogonum robustum (Polygonaceae), a rare endemic in western Nevada

Evidence from the morphology, genetics, and biogeography of a rare endemic from western Nevada, Erigonum robustum , is presented to determine the most accurate taxonomic classification. Previous authors have classified E. robustrum Greene both as a species and as a variety E. lobbii Torrey & Gray. However, results of a morphometric comparison for 9 characters establish that significant morphological differentiation exists between E. robustum and E. lobbii . In addition, results of a genetic study using protein electrophoresis indicated that genetic differentiation may exist between these 2 taxa. Furthermore, the 2 taxa are geographically, ecologically, and reproductively isolated. Finally, the selective pressures that act on E. robustum in a narrowly restricted cold-desert environment are different from those that act on E. lobbii in subalpine environment. Thus, all available data support a species-level taxonomic classification for E. robustum .     

Identity of Mertensia oblongifolia (Nutt.) G. Don (Boraginaceae) and its allies in western North America

The current status of Mertensia oblongifolia (Nutt.) G. Don and its allied taxa is surveyed. On the bases of continuously coherent morphological characters and/or regionally correlated variations, more than 30 taxa, including species, subspecies, varieties, and 1 forma, previously considered different from M. oblongifolia , are now placed under synonymy of this species. Those taxa currently known as M. fusiformis Greene, M. bakeri Greene, and M. bakeri var. osterhoutii Williams are among the new synonyms. Typification, taxonomy, and morphological problems of M. oblongifolia are discussed.     

Progenesis as a principle in meiofauna evolution

The interstitial meiofaunal taxa may have evolved in very different ways, which are shortly discussed and schematically represented. Several taxa reveal the possibility of an evolutionary pathway by early maturation of larvae or juvenile stages of large size species with a pelago-benthic life-cycle. This presumed progenetic (= neotenic) evolution can be sustantiated in, for example, various Polychaeta and Crustacea by larval or juvenile morphological features. The progenetic origin of several of these taxa is also strongly supported by morphological series, of which species conforming well with typical larvae form the endpoint. The monophyletic origin of similar progenetic taxa, however, is only proved with difficulties. The theoretical available phylogenetic reconstructions for a series of progenetic taxa are discussed. It is emphasized that progenetic evolution is not regressive or degenerate but novel morphological features like derived reproductive organs are characteristic indications of the progenetic origin of a species. In general, progenesis may have a significant role in the evolution of higher taxa in the interstitial habitat.     

Seed dispersal, seed entrapment, and seedling recruitment in a temporally variable desert playa

Natural establishment of seedlings in desert playas with temporally variable precipitation hinges on many factors, including seed production, seed dispersal, seed entrapment, seed germination, and seedling survival. We investigated natural seed dispersal patterns and the effects of surface texture, wind barriers, resource availability (water and nutrients), and protection from herbivory on seedling establishment in a desert playa. We hypothesized that the seed rain would be consistent throughout the year and that seedling establishment would improve in resource-amended plots with barriers to wind dispersal. Contrary to our hypotheses, seed flux peaked seasonally during the winter, and fertilization had no consistent effect on seedling establishment. Seed availability for dispersal correlated with precipitation in the previous water year, whereas seedling recruitment was greatest when current-year precipitation during the spring germination and summer seedling growth periods was high. Gravel and barrier surface treatments contained more surviving seedlings than other surface treatments. Comparison with plots located outside of herbivore exclosures, however, showed that greater seedling presence in gravel plots may be due somewhat to protection from herbivory provided by the gravel, rather than simply to the greater seed-trapping quality of the gravel. With abundant seed availability, application of surface treatments, like coarse gravel, combined with increased seasonal water availability could lead to improved shrub establishment from seed in desert playas.     

Biochemical differentiation in the Idaho ground squirrel, Spermophilus brunneus (Rodenta: Scuridae)

Spermophilus brunneus is restricted to a 90 × 125-km area of west central Idaho, with two distinct (northern and southern) groups of populations within this limited range. Morphological differences in pelage length and coloration, external and cranial measurements, and bacula suggest that these groups are either very distinct subspecies or species. We used starch-gel electrophoresis to estimate the amount of genetic differentiation accompanying these morphological differences by assaying genetic variation at 31 loci in the two geographic groups. Fifteen loci were polymorphic (13 in the northern group, 12 in the southern), and mean heterozygosity (H) was high (12.3% northern and 10.8% southern). Nei's genetic distance (0.057) is in the range usually associated with subspecific differences. However, Jaccard's association coefficient (0.893) is about the same as that found between several ground squirrel taxa currently recognized as species. The high levels of heterozygosity suggest that S. brunneus is a neoendemic rather than a paleoendemic species.     

Diversity and dispersal history of the talitrids (Crustacea: Amphipoda: Talitridae) of Bermuda

Five taxa of talitrid amphipods were found in the archipelago of Bermuda, of which three were recorded there for the first time. Four of these are supralittoral wrack generalists: Platorchestia monodi BOLD:AAB3402, (a unique Molecular Operational Taxonomic Unit according to the Barcode Index Number system), a related species recognized by molecular methods, Platorchestia platensis BOLD:AAA2949, Mexorchestia carpenteri carpenteri BOLD:AAC1491 and Tethorchestia antillensis; and one a terrestrial leaf-litter generalist: Talitroides alluaudi. A key is provided to discriminate between the formally described talitrids of Bermuda. Dispersal mechanisms from the American continent to Bermuda were considered for all taxa based on species distributions along the North American Atlantic coast and also investigated by molecular methods, using genetic population differentiation and haplotype network analysis based on the barcode region of cytochrome c oxidase subunit I gene. For P. monodi BOLD:AAB3402 the genetic results suggest that some dispersal events occurred before human colonization of Bermuda but are equivocal about the source population and therefore the direction of dispersal. Some very recent synanthropic dispersal is possible with this species. For the other two species studied genetically, P. platensis BOLD:AAA2949 and M. c. carpenteri BOLD:AAC1491, the small population samples analysed support dispersal to Bermuda from the American mainland, before human occupation of Bermuda, although the available sample size was limited for these species. The available limited direct, non-genetic evidence supports synanthropic transport for Talitroides alluaudi. Platorchestia monodi BOLD:AAB3402 is found in the same wrack habitat as P. platensis BOLD:AAA2949 on Bermuda, apparently without interbreeding. No evidence was found that driftwood specialist talitrids had become established in Bermuda.     

A thousand and one wasps: a 28S rDNA and morphological phylogeny of the Ichneumonidae (Insecta: Hymenoptera) with an investigation into alignment parameter space and elision

Abstract

The internal phylogeny of the Ichneumonidae is investigated using parsimony analysis of a large data set including 1001 partial 28S ribosomal DNA sequences, 621 of which are newly reported, and a morphological data set of 162 characters scored variously at subfamily, tribe, genus group and genus levels and including only informative characters. The data set includes members of 630 named genera, representing all currently recognized subfamilies, all but four tribes and all but one of the taxa noted by Townes as being of uncertain placement. Sequences were aligned using clustal X, and a sensitivity analysis was performed varying gap-opening and gap-extension parameters. Alignments were appraised by reference to their ability to recover a range of traditional and morphologically recognized groups. Each alignment was analysed both independently and simultaneously with the morphological data set, and also with gap characters treated as both missing data and as informative. No single set of alignment parameters was found to be markedly better by this criterion, and different ranges of parameters led to the recovery of different recognized groups of taxa. Elision (combining all alignments into a single analysis) was therefore used, both with and without morphology and with both gap character treatments, to summarize the overall molecular signal. Analysis of the morphological matrix alone produced a number of results that are undoubtedly a consequence of convergence of morphological characters as the result of parallel evolution of similar life histories. Simultaneous analysis of the morphological data set with each of the 120 DNA alignments recovered most accepted subfamilies as monophyletic. Several currently recognized subfamilies are supported by most of the molecular analyses but some appear to be paraphyletic or polyphyletic. The Ctenopelmatinae are paraphyletic with respect to the Metopiinae. Robustly recovered results lead us to resurrect the Brachyscleromatinae to include Brachyschleroma and the Erythrodolius group of Phrudinae. The Neorhacodinae and the Phrudus group of Phrudinae are transferred to the Tersilochinae. Nonnus is transferred to the Nesomesochorinae. Hyperacmus is transferred to the Cylloceriinae. The major groupings of subfamilies that have recently been proposed (i.e. ichneumoniformes, pimpliformes and ophioniformes) were recovered as monophyletic, but their exact limits remain in question.     

The female genitalia of Gonioctena,subgenus Spartoxena (Coleoptera: Chrysomelidae)

The taxonomy of the eight species of Gonioctena Chevrolat belonging to the subgenus Spartoxena Motschulsky is mostly based on male genitalia due to the unsuitability of external characters (i.e. coloration patterns) for identification. In order to provide similar diagnostic characters for both genders, the female genitalia of the eight species are described and illustrated. Considering the lack of spermathecae within the genus, the shapes of tergite 8, and sternites 8 and 9 have been explored as possible diagnostic characters. These structures present marked differences between taxa and simultaneously stability among individuals of each species, and thus they are very useful for taxonomic purposes. A key to the females of the subgenus Spartoxena is provided, and figures of tergite 9, and sternites 8 and 9 of each species are included.     

Morphology and spatial constraints in a dorso‐ventrally flattened skull,with a revised species description of Platyallabes tihoni (Poll, 1944)

This study details the morphology of Platyallabes tihoni (Poll, ) as part of a complete revision of the anguilliform clariids. The overall body form of air‐breathing clariids ranges from fusiform to anguilliform genera (Boulenger ; Pellegrin ). Although P. tihoni has the typical external morphological features of other elongate clariids, this study shows that it occupies an intermediate position between fusiform and anguilliform taxa with regards to its cranial and postcranial morphology. The main morphological similarities of anguilliform species are a narrow skull roof with a high level of interdigitation between the bones, the reduced canal bones, a connection between the neurocranium and suspensorium via several processes, an extended tooth patch on the lower jaw, and the hypertrophied jaw muscle complex. Shared features typical for the fusiform species are a low coronoid process on the lower jaw and the posteroventral orientation of the opercular process on the hyomandibula. Platyallabes tihoni shows a series of unique features: an anterior fontanel situated entirely between the frontals, two tooth plates on the prevomer, a reduced height of the suspensorium, the absence of an anterior bony plate on the hyomandibula, a horizontal position of the sphenotic and pterotic, and a toothed entopterygoid. Many of these unique characters are linked to the spatial constraints associated with an extremely flattened skull in this species.     

Recovery and germinability of native seed fed to cattle

Using livestock as seed dispersal agents may be an effective method for increasing species diversity on degraded and previously seeded rangelands. We quantified seed passage and recovery rates, and post-passage germinability of Wyoming big sagebrush ( Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young), bottlebrush squirreltail ( Elymus elymoides [Raf.] Swezey), and gooseberry globemallow ( Sphaeralcea grossulariaefolia [H. & A.] Rydb.) by feeding Holstein heifers seeds of each species at 3 levels (15,000; 30,000; and 60,000 seeds) over a period of 3 weeks. One-kg fecal samples were collected 1, 2, 3, and 4 days after seed ingestion. Undamaged seeds were extracted from the samples and tested for germinability. Globemallow had the highest percentage of recovered, undamaged seed, followed by squirreltail and sagebrush. Globemallow and sagebrush seed passage was highest on Day 1, after which seed numbers dropped sharply. Squirreltail passage and recovery were more consistent through time, with higher seed recovery at lower seed feeding levels. Post-passage germinability was highest for squirreltail and globemallow on Day 1. Sagebrush germination was negligible. Differences in physical seed properties (size, shape, and seed coat) likely influenced interspecies variation in passage, recovery, and germinability. Globemallow and squirreltail seeds may be suited for livestock dispersal, but sagebrush seeds are not.     

Cryptic and non-cryptic diversity in New Guinea ground snakes of the genus Stegonotus Duméril,Bibron and Duméril, 1854: a description of four new species (Squamata: Colubridae)

ABSTRACT

The island of New Guinea has been identified as biologically megadiverse but many taxa are still poorly known. This is especially the case for many of the island’s snakes, which by their very nature can be difficult to collect and study. Here we examine the phylogenetic and phylogeographic structure of a poorly studied snake genus, Stegonotus, focusing on the species of New Guinea; until now, Stegonotus has never been examined using modern phylogenetic methods. Using molecular data from 49 individuals representing eight of the ten described species, and including all New Guinea taxa, we estimate a multilocus phylogeny and examine population structure to help identify undescribed taxa. We use morphological data from the corresponding museum vouchered specimens (where available) and also examine additional specimens for taxa not included in the molecular data set to determine morphological differences among putative taxa. We find molecular evidence for four new species of Stegonotus, both morphologically obvious and cryptic, and describe them herein. The recognition of these four species indicates that Stegonotus diversity has been previously underestimated and also suggests that there are likely additional undescribed taxa within the genus. These four taxa increase the number of described species by 40% and further confirm New Guinea as the centre of diversity for the genus.

www.zoobank.org/urn:lsid:zoobank.org:pub:9E21390E-3FD4-40EB-9442-31BC92A76B4F     

Effectiveness of the seed wing of Pinus flexilis in wind dispersal

Limber pine ( Pinus flexilis James) seeds are usually wingless but occasionally have short, stubby wings. To determine the effectiveness of these wings in slowing seed descent, rates of fall were determined before and after wing removal. A similar experiment was conducted with seeds of Himalayan blue pine ( P. griffithii McClelland), a white pine with typically long seed wings. The short wings of limber pine seeds were found to influence rate of seed fall far less than the wings of Himalayan blue pine. This is consistent with evidence suggesting that limber pine seeds are not effectively dispersed by wind but are dependent for dispersal on Clark's Nutcracker ( Nucifraga columbiana ).        

A description of the song of Chorthippus cazurroi (Orthoptera: Acrididae) with notes on its taxonomic position and distribution

The highly characteristic calling and courtship songs of Chorthippus cazurroi are described for the first time and are used, together with a number of morphological characters, as a basis for discussing the differences between this species and C. pullus, C. pulloides, C. nevadensis and Omocestus llorenteae, with which it has been or might be confused. Despite the superficial resemblance between cazurroi and these species, clear and reliable characters are described for distinguishing it from all of them. The distribution of cazurroi is also discussed and it is suggested that its inclusion in the Libro Rojo de los Ortópteros Ibéricos as extinct or in danger is, as the authors of that work suspected, unduly pessimistic. A lectotype is designed from the type material of C. cazurroi.     

Sibling species in the marine pollution indicator genus Pontonema Leidy (Nematoda: Oncholaimidae), with a description of P. mediterranea sp. nov.

Species of the marine nematode genus Pontonema have been found to dominate the macrobenthos under abnormally high conditions of particulate organic enrichment. Populations from organically enriched habitats in six localities (Kiel fjord, Germany; the Garroch Head sewage-sludge dump ground in the Firth of Clyde, Scotland; Cornelian Bay, N.E. England; the Tyne estuary, N.E. England; Sete, N.W. Mediterranean, France; Blanes Bay, N.W. Mediterranean, Spain) have been compared. Multivariate analyses of 16 morphometric characters in males, and 13 in females, shows that each population is significantly different morphologically from every other population. However, there is morphological overlap between the populations, and it is considered pragmatic to recognize three species in this group, based on a few stable morphological characters: P. vulgare (Bastian, 1865) from the Baltic, P. alaeospicula Bett and Moore 1988 from the UK sites, and P. mediterranea sp. nov. from the Mediterranean. P. mediterranea sp. nov. is described. The species were not found to have established sympatry in this study, unlike many other opportunistic taxa from organically enriched habitats, and the significance of this is discussed.     

Phlox longifolia Nutt. (Polemoniaceae) complex of North America

Over 1,000 herbarium specimens including 24 type specimens were examined in an attempt to achieve a clearer understanding of the Phlox longifolia complex. Four variables were measured for each specimen and the data were statistically analyzed by discriminant analysis. Using a previously published system of classification for the complex, approximately 73 percent of the measured variation among the specimens was accounted for by that system. The clustering patterns produced in this first analysis indicated that a more conservative approach would be advisable. The formulation and subsequent application of a modified system produced a grouping of specimens that accounted for 95 percent of the measured variation for the four morphological characters considered. From four species and seven subspecies previously recognized, one species with five varieties is proposed. The typification of Phlox longifolia Nutt. and other related taxa is resolved.        

Morphological variation of Eucyclops elegans (Herrick, 1884) (Copepoda: Cyclopoida) in the Americas and comments on records of Eucyclops conrowae Reid, 1992

Based on an examination of material from different areas of the American continent, we evaluate the morphological variations of Eucyclops elegans (Herrick, 1884) with an emphasis on characters used in the current taxonomy of the genus. Eucyclops elegans is clearly a member of the serrulatus group. Differences in both female and male specimens from North America and South America and the lack of records in southern Mexico and Central America suggest that it is possible that this nominal species contains at least two taxa. Characters such as the ornamentation of the antennal basis and coxa of P4 are described for the tropical species E. conrowae Reid, 1992. This species is clearly not a member of the serrulatus group and differences with respect to the type specimens indicate that records of E. conrowae in Mexico do not correspond to this taxon and should be reassigned to other species.