The species of Calineuria and Doroneuria (Plecoptera: Perlidae)

The genus Doroneuria is reviewed, and characters necessary for recognition of its two included species are figured. Doroneuria baumanni, sp. nov., is described for the male, female, and nymph, and a male holotype and female allotype are designated. Calineuria is removed from the synonymy of Doroneuria, and the genus is characterized in detail. Distributional data are presented for species in both genera.     

Hesperoperla hoguei, a new species of stonefly from California (Plecoptera: Perlidae)

A new species of Hesperoperla is named from northern California. The adult male and female, nymph, and egg are described and figured. Hesperoperla hoguei adds a second species to this previously monotypic genus.     

Home-range fidelity and use of historic habitat by adult Colorado pikeminnow ( Ptychocheilus lucius ) in the White River, Colorado and Utah

Twelve wild adult Colorado pikeminnow ( Ptychocheilus lucius ), captured in the tailwaters of Taylor Draw Dam on the White River, Colorado, were implanted with radio transmitters and their movement patterns monitored from 1992 to 1994. The spawning migration of these fish was extensive. In 1993, the only full year of the study, the fish migrated an average of 658 km from the White River to spawning sites in the Yampa or Green rivers and back to the White River. Eight of these fish were translocated in the river upstream of the dam in April 1993. These fish and the 4 others below the dam remained in the river until May 1993. All 12 had migrated down the White River to spawning sites in the Green and Yampa rivers by July 1993. The fish that were located above the dam successfully passed over the dam during their downstream migration. Seven fish migrated upstream toward the Yampa River Canyon spawning site and 5 migrated downstream toward the Green River Desolation/Gray Canyon spawning site. Five of 7 Yampa River fish were found at the spawning site. The other 2 were found 5-8 km downstream of the site. One of 5 Green River fish was found at the spawning site, the other 4 between 16 and 62 km upstream of the site. All fish migrated back to the White River by August 1993 and were found near the dam by October 1993. Two fish were recaptured and translocated above the dam in September 1993. Five fish were located below the dam and 2 above the dam in April 1994. By July 1994 seven of the same fish that had migrated toward the Yampa River in 1993 were found at the Yampa Canyon spawning site. At the same time, 3 of 5 fish that migrated toward the Green River in 1993 were found at the Desolation/Gray Canyon spawning site. This included 2 fish that had been found upstream of the site in 1993. The 12 fish traveled an average of 6 km d -1 (range: 4-10 km d -1 ) during the migration period from May through October 1993. Generally, fish moved faster to the spawning site than back from the site to the White River. These fish moved very little within their home ranges in the White River. Six fish tagged in 1992 moved only 0.1-2.3 km in the tailwater reach below Taylor Draw Dam from September 1992 through April 1993. All fish, after their spawning runs, had moved up to or near the dam by October 1993. These fish were not tracked again until April 1994. Their movement patterns in April 1994 were similar to those observed in April 1993. The greatest amount of fish movement in the White River was displayed by the 8 fish placed above Taylor Draw Dam in April 1993 and the 2 placed in Kenney Reservoir in September 1993. They moved 1.1-40.6 km in the river before and after their spawning migration in spring and autumn 1993. These spawning migrations suggest that adult Colorado pikeminnow in the White River were recruited from both Green and Yampa river spawning populations and were presumably imprinted to these respective spawning sites. Those fish placed above Taylor Draw Dam established home ranges in habitats previously occupied by Colorado pikeminnow before the dam was completed. They remained there until they migrated downstream during the spawning period. Although we did not study fish passage, our study demonstrates that adult Colorado pikeminnow will use habitat if access is provided. Translocation of wild adult fish into historic but unoccupied habitats may be a valuable recovery option.     

Gizzard shad ( Dorosoma cepedianum ) expansion and reproduction in the Upper Colorado River Basin

Gizzard shad ( Dorosoma cepedianum ) were introduced into the Colorado River Basin circa 1996 via an unintentional contaminated stocking. Gizzard shad were collected throughout much of the Upper Colorado River Basin in 2005, 2006, and 2007. These collections document a rapid range expansion of this introduced species and a threat to intact fisheries.     

Life histories of stoneflies (Plecoptera) in the Rio Conejos of southern Colorado

Thirty-one stonefly species representing eight families were collected during the March 1987 to May 1990 study period. Genera represented by more than one species included Capnia, Utacapnia, Taenionema, Suwallia, Triznaka, Isogenoides, and Isoperla . Peak species richness was recorded on or near the summer solstice in 1988 and 1989. Climatic differences between years were reflected in nymphal development and emergence phenology of most species. New or important corroborative life history data are presented for 11 stonefly species of this assemblage. The hyporheic nymphal development of most cholroperlid species limited the number of early instars sampled and our capacity to interpret voltinism. Limited nymphal data suggested a univoltine-slow cycle for Plumiperla diversa (Frison). Adults of Suwallia pallidula (Banks) and S. wardi (Banks) were present for an extended summer period, but the bulk of their respective emergence times was temporally separated. Isogenoides zionensis Hanson, Pteronarcella badia (Hagen), and Pteronarcys californica Newport were all shown for the first time to have a 9-10 mo egg diapauses, and all three species have a semivoltine life cycle. Skwala Americana (Klápalek) and Isoperla fulva Claassen were further confirmed to have univoltine-slow cycles. Univoltine-fast and univoltine-slow life cycles are reported for the first time in I. phalerata and I. quinquepunctata , respectively. Regression analysis revealed that six of the eight abunduant species had extended emergence patterns (slopes of < 5%/d), while only two had synchronous patterns. Warmer spring and summer temperatures in 1989 increased the slopes for five of the eight species studied, but did not change their synchrony designation. Nine of 11 abundant species advanced their median emergence date in 1989 over 1988. This and the higher slope values are consistent with a hurried nymphal development and narrower emergence period due to the warmer thermal regime of 1989.     

Plecoptera and Trichoptera species distribution related to environmental characteristics of the metal-polluted Arkansas River, Colorado

The Upper Arkansas catchment has been polluted with heavy metals from mining for almost 140 yr. Adult Plecoptera and Trichoptera species distributions were recorded from 22 stations along 259 km of main river during 1984-85 so that these could be related to metal deposition and other environmental characteristics. Chemically or physically perturbed sites had poor species richness compared with adjacent sites. There was no sequential downstream increase in species numbers. Filter-feeders proportionally increased downstream as predators declined; these proportions were reset at a high-energy site before the trend resumed. Using canonical correspondence analysis, we found that species composition was most strongly related to changes in distance/altitude and to temperature, particularly after regulatory flows entered the river. The proportion of biological variation explained by river measurements indicated that collected adults were largely derived from the main Arkansas River. Species tolerant of high sedimentary metal concentrations were identified while some other species appeared to be sensitive. The study provides a disturbed-state reference for monitoring effects of remedial actions begun in 1991, and for comparisons with other Colorado rivers.     

Distribution, movements, and habitat use of razorback sucker ( Xyrauchen texanus ) in a lower Colorado River reservoir, Arizona-Nevada

Distribution, movements, and habitat use of 10 wild adult razorback suckers ( Xyrauchen texanus ) were examined in Lake Mohave, Arizona-Nevada, from November 1994 through July 1997. Movement rates (0.00-17.35 km d -1 ) and ranges ( x = 39 km) were similar to those for riverine populations. All study fish returned to spawning sites used in previous years, but they also visited other spawning areas. Spawning females were significantly ( P = 0.031) more active than males (480 vs. 87 m d -1 ) and moved substantial distances between spawning sites during peak reproduction (1-28 February). Fish became most active (m d -1 , km month -1 ) after spawning and moved to areas known to support higher algal production. Fish were typically within 50 m ( P 30.0 m). Adults were detected throughout the available thermal gradient (12°-30°C), but during summer typically had body temperatures between 18° and 22°C. Vertical movements within the water column showed no correlation with depth or time of day, but seasonal shifts suggest fish may regulate body temperature by seeking specific temperatures during reservoir stratification.     

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.     

Growth and reproduction of the flannelmouth sucker, Catostomus latipinnis, in the Upper Colorado River Basin, 1975-76

Growth rates estimated using the scale annuli of flannelmouth sucker, Catostomus latipinnis , did not differ between fish collected from the Gunnison and Colorado rivers, and the Green and Yampa rivers. However, body condition and fecundity were significantly greater in the former population. Age of first maturity for male and female fish from all rivers was IV; and most fish were mature by age VII. The smallest mature female collected was 405 mm, and the smallest mature male was 391 mm total length. Fecundity ranged from 4,000 ova in fish 450 mm long to 40,000 ova in a 500-mm fish: mean ovum diameter was 2.39 mm. Ripe male flannelmouth suckers were collected from early April through June; ripe females were collected from both study areas during May and early June. &nbsp;&nbsp;&nbsp;     

Esox lucius (Esocidae) and Stizostedion vitreum (Percidae) in the Green River basin, Colorado and Utah

Northern pike, Esox lucius , stocked in the Yampa River in 1977, invaded the mainstream Green River by 1981 and subsequently increased in range and abundance. The speed of this invasion is indicated by two recaptured pike that moved 78 and 110 km, respectively, downstream in about one year. Pike stomachs (n = 123) were usually empty (54.5%), but some contained fish (43%) and nonfish items (2.4%). Red shiner, Notropis lutrensis , and fathead minnow, Pimephales promelas , predominated among the 12 fish species eaten. Walleye, Stizostedion vitreum , presumably introduced to the Green River drainage in the 1960s, was widely distributed but low in abundance. Most of 61 adult walleye stomachs contained food (60.7%) ; of 6 fish species eaten, channel catfish, lctalurus punctatus , and fathead minnow were most frequently consumed. Northern pike and walleye were captured in habitats occupied by endangered Colorado River fishes, particularly Colorado squawfish, Ptychocheilus lucius . Predation on endangered fishes was not detected, but northern pike and walleye consumed at least three other native fishes. The northern pike may pose a threat to endangered fishes due to its population expansion, piscivory, and resource sharing. Diets of northern pike and walleye species should be further evaluated if their abundance increases.     

Changes in riparian vegetation along the Colorado River and Rio Grande, Colorado

Changes in vegetation including area occupied, canopy cover, and maturity class of cottonwoods ( Populus spp.) within lower-elevation zones of the Colorado River and Rio Grande in Colorado were monitored over 25- and 27-year intervals, respectively, using photo-interpretative methods. Estimated loss of cottonwoods along the Colorado River was 2ha/km (-17.5%), and remaining stands had become more open and older. Cottonwoods along the Rio Grande increased 1.6 ha/km (9.3%) with minor canopy cover and maturity class changes. Area occupied by shrubs and river channel changed little along the Colorado River, but declined along the Rio Grande. Loss of hay meadow occurred along both rivers, whereas developed land increased along the Colorado River and farmland increased along the Rio Grande. Wildlife habitats along the Colorado deteriorated much more rapidly than those along the Rio Grande during monitored intervals.     

Chironomidae (Diptera) of the Colorado River, Grand Canyon, Arizona, USA, I: systematics and ecology

We describe the chironomid midge fauna of the Colorado River between Glen Canyon Dam and Lake Mead, Arizona. This depauperate fauna, consisting of 38 species, is dominated by euryecious Nearctic or Holarctic orthocladine taxa. In addition, a small Neotropical faunal component is represented by Polypedilum obelos Sublette & Sasa and Rheotanytarsus hamatus Sublette & Sasa. The following new synonyms are given: Protenthes riparius Malloch 1915 with Tanypus bellus Loew 1866 [= Procladius (Psilotanypus) bellus (Loew)]; Cricotopus olivetus Boesel 1983 with Cricotopus (Circotopus) annulator (Goetghebuer) 1927; Cricotopus edurus Sublette & Sublette 1971 with Orthocladius infuscatus Malloch 1915 [= Cricotopus (Cricotopus) infuscatus (Malloch)]. The following new species are described: Cricotopus (Cricotopus) blinni Sublette, Cricotopus (Cricotopus) hermanni Sublette, Metriocnemus stevensi Sublette, and Cladotanytarsus marki Sublette. We discuss the distribution and ecology of each chironomid species in this large, regulated, aridlands river.     

Occurrence of native Colorado River cutthroat trout ( Oncorhynchus clarki pleuriticus ) in the Escalante River drainage, Utah

Field surveys were conducted during 1997 and 1998 documenting the distribution and abundance of Colorado River cutthroat trout ( Oncorhynchus clarki pleuriticus ) in Escalante River tributaries. This documented occurrence of native trout in the Escalante River drainage of southern Utah represents an expansion of the known historic range of this subspecies as reported before the 1990s. We found 5 populations of native trout ranging in biomass from 3.0 to 104.2 kg ha -1 and occupying 13.2 km of stream of 130 km of estimated historic habitat. Current distribution and abundance of Colorado River cutthroat trout were compared to early introductions of nonnative trout stocked for sport fishing purposes. Native cutthroat trout have been displaced by nonnative cutthroat trout ( O. c. bouveri ), rainbow trout ( O. mykiss ), brook trout ( Salvelinus fontinalis ), and brown trout ( Salmo trutta ) except where they were isolated by physical or biological barriers. Displacement may have been more extensive except for the remoteness of the drainage and relatively recent introductions of nonnative trout. These conditions limited the overall amount of the drainage stocked, numbers of nonnative trout stocked, and time over which stocking occurred. Discoveries of native trout populations within the Escalante River drainage have allowed expanded conservation of this subspecies by adding new populations to what was known to exist and by increasing the known natural range of this fish.     

Chironomidae (Diptera) of the Colorado River, Grand Canyon, Arizona, USA, II: factors influencing distribution

Biogeographic, flow regulation (water clarity and temperature), and temporal influences affect the composition of the chironomid midge assemblage in the Colorado River between Glen Canyon Dam and Lake Mead. This assemblage is dominated by euryecious Nearctic and Holarctic orthocladine taxa (23 of 38 total species, total weighted relative abundance [WRA] = 0.972) and includes a minor Neotropical component. Chironomid species richness increases over distance downstream from the dam, and dominance shifts across 3 turbidity segments. Eleven species occur in the cold-stenothermic Clearwater (CW) segment between the dam and the 1st perennial tributary (the Paria River, 26 km from the dam). Chironomid diversity increases from 18 to 24 species in the variably turbid (VT) and usually turbid (UT) segments downstream, respectively. Total Cricotopus spp. WRA is negatively correlated with distance (turbidity), white total Chironominae WRA shows the opposite pattern. In contrast to chironomid diversity, species density decreases from 0.42 species/km in the CW segment to 0.19 and 0.08 species/km in the VT and UT segments, respectively. Seasonal dominance shifts slightly from orthocladine Eukiefferiella spp. in winter (WRA = 0.101) to Cricotopus spp. (WRA = 0.165) in summer. Total WRA is lowest in spring (0.191). The assemblage is depauperate compared with other western rivers and has changed over post-dam time.     

Emergence, attack densities, and host relationships for the Douglas-fir beetle ( Dendroctonus pseudotsugae Hopkins) in Northern Colorado

Douglas-fir beetle-infested Douglas-fir trees were partially caged to determine the emergence period and beetle production. Beetles began emerging in April, but emergence peaked between 10 and 26 June. In 1987 and 1988 beetle emergence averaged 20 or more per sq. ft. of bark. Annual growth of the infested trees showed a decline prior to the beetle outbreak followed by an increase during the outbreak.     

North American stoneflies (Plecoptera): systematics, distribution, and taxonomic references

A list of 537 Nearctic stonefly species is provided and distributions of all species are given by U.S. state and Canadian province. The list includes a bibliography of systematic and biogeographic papers published since the Zwick (1973) catalogue.