Western range extension for the black sandshell (Unionidae: Ligumia recta [Lamarck, 1819])

We report a population of the mussel the black sandshell ( Ligumia recta [Lamarck, 1819]) from the Carrot River in Saskatchewan, far north of the species’ known range in southern Manitoba and northwestern Ontario. Ligumia recta is reported to be declining substantially in its abundance and range, and this occurrence provides valuable information for the construction of a species status report in Canada.     

Distribution of Entocytheridae (Crustacea: Ostracoda) in the northern prairies of North America and reports of opportunistic clitellate annelids on crayfish hosts

Northern crayfish, Orconectes virilis (Hagen, 1870), were collected from 89 sites across Alberta, Saskatchewan, Manitoba, Montana, North Dakota, and Minnesota. The entocytherid ostracod Thermastrocythere riojai (Hoff, 1943) was found on O. virilis at 45 of the 89 sites, distributed primarily in the eastern and southern portion of the study area. These observations of T. riojai greatly extend the known range of the species. The widespread distribution of T. riojai suggests that the dearth of entocytherid records from other parts of Canada is a result of nontargeted sampling rather than true absence. In addition, we report on observations of 3 noteworthy associations of oligochaetes with their crayfish hosts. Se colectaron especímenes del acocil Orconectes virilis (Hagen, 1870) en 89 sitios a lo largo de Alberta, Saskatchewan, Manitoba, Montana, North Dakota y Minnesota. Encontramos el ostracódo entocitérido Thermastrocythere riojai (Hoff, 1943) en O. virilis en 45 de los 89 sitios, distribuidos principalmente en la parte sur y la parte este del área de estudio. Estas observaciones de T. riojai amplían considerablemente el área de distribución conocida de esta especie. La distribución extensa de T. riojai sugiere que la escasez de registros de entocitéridos en otras partes de Canadá es el resultado del muestreo inespecífico y no de una ausencia verdadera. Además, reportamos observaciones de 3 asociaciones sobresalientes entre los oligoquetos y los acociles huéspedes.     

New synonymy, new species, and taxonomic notes of North American Pityophthorus (Coleoptera: Scolytidae), Part III

New synonymies and new data affecting North American Pityophthorus are proposed as follows: chalcoensis Hopkins ( = herrerai Hopkins) and nigricans Blandford ( = chiapensi s Bright). Neotypes are designated for the following species described by Eichhoff: concentralis, cribripennis, infans, puchellus, and tuberculatus. New species are: carinatus (Canada), cavatus (Manitoba, Saskatchewan), euterpes (Mexico), hesperius (British Columbia), impexus (Mexico), intentus (Arizona), laticeps (Mexico), malleatus (Arizona), mesembria (Guatemala), montezumae (Mexico), scalptus (British Columbia, Colorado), trepidus (California), and vespertinus (Mexico).     

Survey of Wyoming crayfishes

Collections of crayfish by Wyoming Game and Fish Department biologists and University of Wyoming staff in 1985-1987 included five species: Pacifastacus gambelii , the only species found in the Snake River and Bear River drainages of western Wyoming; Orconectes neglectus neglectus , collected from one reservoir in the South Platte River drainage in southeastern Wyoming (its first reported occurrence in the state); O. immunis and O. virilis ,widespread east of the Continental Divide and in the Green River drainage of southwestern Wyoming; and Cambarus Diogenes Diogenes , collected from a tributary of the North Platte River in eastern Wyoming.     

Fish assemblage structure following impoundment of a Great Plains river

Understanding the upstream and downstream effect of impoundments on stream fish assemblages is important in managing fish populations and predicting the effects of future human activities on stream ecosystems. We used information collected over a 41-year period (1960-2001) to assess changes in fish assemblage structure resulting from impoundment of the Laramie River by Grayrocks Reservoir. Prior to impoundment (i.e., 1960-1979), fish assemblages were dominated by native catostomids and cyprinids. After impoundment several exotic species (e.g., smallmouth bass [ Micropterus dolomieu ], walleye [ Sander vitreus ; formerly Stizostedion vitreum ], yellow perch [ Perca flavescens ], brown trout [ Salmo trutta ]) were sampled from reaches upstream and downstream of the reservoir. Suckermouth minnows ( Phenacobius mirabilis ) were apparently extirpated, and hornyhead chubs ( Nocomis biguttatus ) and common shiners ( Luxilus cornutus ) became rare upstream of Grayrocks Reservoir. The lower Laramie River downstream from Grayrocks Reservoir near its mouth retains habitat characteristics similar to those prior to impoundment (e.g., shallow, braided channel morphology) and is the only downstream area where several sensitive species persist, including suckermouth minnows, hornyhead chubs, and bigmouth shiners ( Notropis dorsalis ). Grayrocks Reservoir serves as a source of exotic piscivores to both upstream and downstream reaches and has altered downstream habitat characteristics. These impacts have had a substantial influence on native fish assemblages. Our results suggest that upstream and downstream effects of impoundment on fish assemblage structure are similar and that downstream reaches which retain habitat characteristics similar to pre-impoundment conditions may serve as areas of refuge for native species.     

Population structure and ecological effects of the crayfish Pacifastacus leniusculus in Castle Lake, California

The recent appearance of the ""California crayfish,"" Pacifastacus leniusculus , in Castle Lake, California, and interest in its potential impacts on the lake ecosystem provided motivation for a study of the population structure and habitat use of this species and its effects on aquatic macrophytes. Mark-recapture studies indicated that the total number of adult (3 + yr or older) crayfish in the lake was ca 10,100 individuals, yielding an estimate of lakewide crayfish density in preferred crayfish habitats of 0.13 adults m -2 . Using mean body mass of individuals, we estimated that ambient biomass density was 5.9 g m -2 . Length-weight relationships determined for captured individuals were sex dependent, with males having greater body mass for a given carapace length. Length-frequency and weight-frequency diagrams indicated that P. leniusculus reaches larger sizes in Castle Lake than do populations of P. leniusculus in ultraoligotrophic Lake Tahoe. Population-wide, males were significantly larger in both carapace length and body mass than females. We also examined sex dependence of interhabitat differences in crayfish body size by comparing animals trapped in rocky areas with those from areas with macrophytes and soft sediments. No significant differences in overall body size were found between habitats, but a significant habitat-sex interaction term occurred because the sex-dependent size differences were more pronounced in sediment than in rocky areas. Exclosure and enclosure experiments indicated that crayfish had large but differential impacts on Castle Lake macrophyte species, as the abundance of two of the dominant species ( Chara sp., Potamogeton richardsonii ) declined in the presence of crayfish and, in one case, increased in exclosures. These effects occurred via both consumptive and nonconsumptive mechanisms. These studies indicate that and expanding population of P. leniusculus in Castle Lake may be producing sizable impacts on the littoral zone habitat.     

Distributions of two ectosymbionts,branchiobdellidans (Annelida: Clitellata) and scutariellids (Platyhelminthes: “Turbellaria”: Temnocephalida), on atyid shrimp (Arthropoda: Crustacea) in southeast China

Distribution of two ecologically similar but usually spatially separate ectosymbionts, branchiobdellidans (Annelida) and scutariellids (Platyhelminthes), on atyid shrimp (Neocaridina spp.) is reported from 18 localities in five Provinces of southeastern China. Prevalence was determined for the branchiobdellidan, Holtodrilus truncatus, found at seven locations, the scutariellid, Scutariella japonica, present at every site, and where cohabitation occurred. Both ectosymbionts showed a microhabitat predilection for the host's branchial chambers and instances of cohabitation occurred at all seven locations where H. truncatus were collected, although not on every shrimp. On-site observations of live hosts supporting both ectosymbionts showed that neither H. truncatus nor S. japonica reacted aggressively or defensively towards the other when in close proximity. Instances of imported Chinese Neocaridina spp. into central Honshu Island, Japan, almost certainly came from areas in southeast China identified in this study. These imported populations are predicted to spread northwards into the area where endemic Japanese branchiobdellidans occur.     

Estimating the young evolutionary age of marbled crayfish from museum samples

ABSTRACT

The obligately parthenogenetic, all-female marbled crayfish, Procambarus virginalis, is a triploid descendant of the similarly looking, sexually reproducing slough crayfish, Procambarus fallax, native to Florida and southern Georgia. We have earlier hypothesised that marbled crayfish may have originated from P. fallax only some 25 years ago, perhaps in captivity. In order to investigate the young evolutionary age hypothesis in more detail, I searched the P. fallax collection of the Smithsonian Institution Museum of Natural History (USNM, Washington, D.C.) for evidence of marbled crayfish before its detection in the German aquarium trade in 1995. In particular, I analysed the sex ratio of P. fallax and the frequency of pure female samples throughout its entire distribution range to detect potentially misidentified marbled crayfish among the P. fallax. If marbled crayfish had originated from P. fallax long ago, spread throughout Florida and Georgia and erroneously been sampled as P. fallax, then the sex ratio of the P. fallax in the collection should be significantly biased towards females and pure female samples should be much more frequent than in related Procambarus species. Comparison of P. fallax (n = 2299) with its closest relatives P. seminolae (n = 801) and P. leonensis (n = 150) revealed female proportions of 55.33%, 53.93% and 54.67%, respectively, which are not significantly different from each other. The average female proportion of the 14 Procambarus species investigated (8641 specimens) was 52.54 ± 7.54% (mean ± standard deviation). Moreover, pure female samples consisting of more than 3 specimens that could represent hidden marbled crayfish were not conspicuously more common in P. fallax (2.33%) than in all Procambarus species investigated (1.24 ± 1.79%). These data suggest that the P. fallax collection of the USNM consists of real, sexually reproducing P. fallax and does most likely not include hidden marbled crayfish, supporting the young evolutionary age hypothesis for marbled crayfish.     

Ranging behaviour of the invasive crayfish,Procambarus clarkii (Girard)

The spreading of the invasive crayfish Procambarus clarkii throughout the world is attributed to human introductions; however, the rapid and widespread diffusion of the species following its establishment is the result of its dispersal capabilities. This study aimed to provide further information for the comprehension of the invasive potential of this crayfish by underlining some aspects of its behavioural flexibility. Radio-telemetry was used to analyse locomotion, home-range faithfulness and dispersal of the species in an Italian irrigation ditch system. Space was used differently by the two sexes, females being more nomadic in their ranging behaviour probably due to their reproductive phase. In addition, an inter-individual variability was found in both speed of locomotion and dispersal pattern. By applying a simulation model, it was shown that (1) both sexes disperse, and (2) ranging behaviour is not the result of a passive dispersion, but that the occupancy of burrows may affect the rate of dispersion. Finally, an intra-individual variability is related to the occurrence of two spatial strategies within the same population.     

Inventory of Utah crayfish with notes on current distribution

Crayfish distribution and composition in Utah are poorly documented. Based upon limited collections, the native Pacifastacus gambelii is widespread and often abundant in the Bear and Weber river drainages and is occasionally represented in smaller tributaries to the Great Salt Lake and to the Raft River. Pacifastacus leniusculus was collected from Utah County and Procambarus clarkii from Tooele County; the origin of these populations is not known. The nonnative crayfish Orconectes virilis is currently abundant in the Virgin, Price, and Duchesne river basins and the Glen Canyon, Flaming Gorge, Deer Creek, and Starvation reservoirs; it is expanding in Huntington North, Scofield, and Willard reservoirs. Further work is required to develop a more complete inventory and monitor the impacts on aquatic ecosystems of expanding nonnative crayfish populations. Surreptitious stockings can be dealt with only if the public is made aware of the adverse consequences of ill-conceived introductions.     

Morphometrical characterization of the Austropotamobius pallipes species complex

Genetic studies have shown that the threatened crayfish Austropotamobius pallipes species complex is composed of two lineages (A. italicus and A. pallipes), both occurring in Italy. However, the issue surrounding their taxonomic status has not yet been solved even though the confused taxonomy may hamper attempts to conserve indigenous crayfish. The aim of this study was to develop methods for the morphometrical characterization of the A. pallipes species complex. Having analysed 18 morphometric variables on a total of 44 specimens of each lineage, we showed that the tip of the rostrum could be used to discriminate A. italicus and A. pallipes. Such discrimination was also obtained by analysing the size and shape of both the female spermatophoric plate and the male gonopods. These results confirm the potential to adopt morphometric studies to complement the genetic characterization of cryptic species.     

Range extension and ecological information for Orconectes virilis (Hagen 1870) (Decapoda: Cambaridae) in Idaho, USA

We report the 1st record of the crayfish Orconectes virilis (Hagen 1870) from Idaho and the Pacific Northwest, USA. We also provide an updated checklist of recent Idaho crayfishes, which now includes 2 families (Astacidae and Cambaridae), 3 genera ( Pacifasticus, Orconectes , and Procambarus ), and 7 species and subspecies ( Pacifasticus connectus (Faxon 1914), P. gambelii (Girard 1852), P. leniusculus leniusculus (Dana 1852), P. leniusculus klamathensis (Stimpson 1857), P. leniusculus trowbridgii (Stimpson 1857), O. virilis , and Procambarus clarkii (Girard 1852). Native crayfish were not found at the O. virilis collection sites. The localities where O. virilis was found were characterized by low-gradient streams impacted by fine sediment. Aquatic invertebrates found in association with O. virilis tended to be the more pollution-tolerant taxa.     

Notes on three varieties of Astragalus lentiginosus (Leguminosae)

A taxonomic review of the Astragalus lentiginosus complex in Utah indicates that the epithet var. albiflorus, antecedes and therefore should replace var. diphysus. The range of var. vitreus has been extended to include Kane and Garfield cos., Utah, and var. fremontii has now been identified from the state.     

Cambarus loughmani,a new species of crayfish (Decapoda: Cambaridae) endemic to the pre-glacial Teays River Valley in West Virginia,USA

ABSTRACT

A new species of crayfish, Cambarus loughmani sp. nov., is described from the preglacial Teays River Valley of Cabell, Kanawha, Lincoln, Mason, and Putnam counties, West Virginia. The species was previously considered to be part of the Cambarus dubius complex. Loughman et al. restricted C. dubius to an orange colour morph found in central and northern portions of the Allegheny Mountains and Appalachian Plateau in central West Virginia, western Maryland, and south-central Pennsylvania. The new species described herein can be distinguished from all other members of Cambarus Erichson, 1846 by a double row of cristiform tubercles on the palm, an open areola with two rows of punctations, and a consistent blue colouration.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:5BC7C861-038E-457C-80F3-ED7A66E10D73     

Bird use of riparian vegetation along the Truckee River, Califonia and Nevada

The Truckee River in California and Nevada is subject to diverse water regimes and a corresponding variety of flow rates. Original riparian vegetation has been altered by these variable flow rates and by a variety of human uses resulting in loss of native riparian vegetation from its historic extent. We conducted bird surveys along the Truckee River during spring 193 to (1) determine relationships between birds and the present vegetation; (2) determine the importance of different vegetation types to sensitive bird species that have declined recently in the western United States due to competition from exotic plant species, cowbird ( Molothrus ater ) parasitism, reduction in nesting habitat, or other unidentified reasons; and (3) establish a monitoring program and collect baseline data for future comparisons. The most frequently detected bird species throughout the study was the Brown-headed Cowbird. The greatest number of bird species (98 of 116) was found in the native mixed willow ( Salix spp.) riparian scrub vegetation type. We recommend protecting the remaining native riparian vegetation types for bird habitat along the Truckee River.     

Leeches of the Snake River in Idaho and Oregon: paleodrainage implications of Mooreobdella microstoma

Leech species of the mid-Snake River of Idaho and Oregon are described, and the distribution of the extant leech Mooreobdella microstoma Moore in the Snake River paleodrainage is delineated. Samples were collected from aquatic surveys in the Snake River using suction dredging by the Idaho Power Company and U.S. Bureau of Reclamation between 1995 and 2006. Supplementing these surveys, opportunities were provided for leech identification in water-quality analyses in Arizona and Wyoming and in other surveys in California, Oregon, Washington, and Idaho. Eight species of leeches were found in the Snake River surveys. Erpobdella parva Moore was the most widely distributed species, occurring both above and below Shoshone Falls. Mooreobdella microstoma was widely distributed below Shoshone Falls. Other leech species were rare, although Helobdella stagnalis Linnaeus was very common above and less common below Shoshone Falls, a natural barrier to the anadromous fish. Mooreobdella microstoma is an extant species that links the Snake River to the lower Colorado River by various paleodrainages. It probably colonized the Snake River by upstream movement, whereas Erpobdella parva likely colonized this river by downstream movement.     

Diatoms of the Middle Fork of the Salmon River drainage, with notes on their relative abundance and distribution

A total of 145 species of diatoms was collected from 13 sites in the Middle Fork of the Salmon River drainage, Idaho, USA. Achnanthes minutissima was the prevalent species with an importance index of 19.25. Cluster analysis revealed 2 main site groupings, sites above the entrance of Loon Creek and sites below. The entrance of Loon Creek (6th order) increases the Middle Fork of the Salmon River to a 7th order stream. Shannon-Weiner diversity values were generally high.        

Zoogeographic affinities of the stoneflies (Plecoptera) of the Raft River Mountains, Utah

We examined faunal affinities of the Raft River Mountains using stoneflies (Plecoptera) as indicators. This island-like mountain range is isolated from other major mountain ranges in the Intermountain West by low-elevation, arid regions. Thirty-seven species were recorded from collections from 19 sites in the Raft River Mountains. Cluster analysis demonstrated the Raft River Mountain stonefly assemblage to be most similar to faunas of the Sawtooth and Wasatch mountains, and quite different from that of the Sierra Nevada. An analysis of the distribution patterns of each species, on a family-by-family basis, showed that the Raft River Mountains fauna consists mostly of species widespread in western North America. Most families were represented by at least 1 species whose distribution supports faunal affinities with regions to the north and west. Logistic regression of 6 long-distance dispersal factors against stonefly presence-absence data did not support long-distance dispersal as a viable means of colonization for the Raft River Mountains. This suggest that stonefly distribution patterns may be attributed to expansion and subsequent vicariance of suitable stonefly habitats during Pleistocene climatic oscillations.     

Aquatic invertebrate fauna of a northern prairie stream: range extensions and water quality characteristics

The benthic macroinvertebrate fauna of southern Saskatchewan, Canada, has received little attention relative to other regions of western North America. Therefore, little is known of the related aquatic ecosystem health and biogeography of regional aquatic insects. Here we present the results of an aquatic macroinvertebrate survey for the Pipestone Creek watershed in southeastern Saskatchewan. We qualitatively sampled aquatic macroinvertebrates in 5 sites on 4 dates through spring, summer, and fall 2006. Sampling produced 294 taxa of macroinvertebrates including 25 provincial range extensions to the southeast corner of the province. Presence/absence data of taxa grouped the sites into lentic and lotic sites. However, the relative proportions of the taxa varied greatly among sites, with no 2 sites having a community similarity greater than 50%. Functional feeding group analyses separated the sites into collector-dominated and scraper/grazer-dominated sites. However, the taxonomic make-up of the feeding groups varied among sites and also among dates. A modified Hilsenhoff Biotic Index of the site communities indicated that all were influenced by organic pollution. Results of this study suggest that although the watershed is enormously diverse, its biological communities are likely influenced by organic pollution. Further, range expansions of species found here, such as the stonefly Perlesta placida , have implications for invasion pathways and post-glaciation species islands in a prairie landscape.     

Distribution, abundance, and genetic population structure of Wood River sculpin, Cottus leiopomus

The Wood River sculpin Cottus leiopomus is endemic to the Wood River Basin in central Idaho and is a nongame species of concern because of its limited distribution. However, status and genetic population structure, 2 factors often central to the conservation and management of species of concern, have not been assessed for this species. We used backpack electrofishers to survey streams that were small enough (i.e., a priori to contain, possibly contain, or not contain the sculpin, respectively. Native redband trout Oncorhynchus mykiss gairdneri were present at 21 study sites, including 18 of the 20 sites that contained Wood River sculpin. Sixty-one study sites (60%) were dry or had too little water to contain any fish. We estimated that a minimum of 1.36 million Wood River sculpin (≥20 mm total length) currently reside in the basin. The presence of Wood River sculpin was positively associated with stream width:depth ratio and percent cobble/boulder substrate and negatively associated with stream gradient. Mitochondrial DNA haplotype differences were observed between and within the 3 major river subbasins supporting sculpin, with the most striking differences observed between populations in the Camas Creek subbasin and the other 2 subbasins, among which no haplotypes were shared, suggesting relatively long-term isolation. Our results suggest that the Wood River sculpin remains relatively widespread and abundant within its endemic range, despite obvious changes in historical stream connectivity caused by irrigation diversions and other chronic habitat alterations.