A new genus and species of entocytherid ostracod (Ostracoda: Entocytheridae) from the John Day River Basin of Oregon, U.S.A., with a key to genera of the subfamily Entocytherinae

Zootaxa ◽  
2017 ◽  
Vol 4273 (4) ◽  
pp. 576 ◽  
Author(s):  
PATRICIA G. WEAVER ◽  
BRONWYN W. WILLIAMS
Keyword(s):  
Pacific Northwest ◽  
River Basin ◽  
New Genus ◽  
Targeted Sampling ◽  
The Pacific ◽  
John Day River ◽  
John Day ◽  
To Receive ◽  
Copulatory Complex ◽  
Insight Into

Targeted sampling efforts by the authors for the signal crayfish, Pacifastacus leniusculus, from its native range in the John Day River Basin, Oregon, U.S.A. yielded entocytherid ostracods with a male copulatory complex so clearly different from other entocytherines that a new genus, Aurumcythere gen. nov. is proposed to receive them. This newly proposed, apparently nonsclerotized, genus with hook and spur-like prominences of the posteroventral end of the peniferum is the first new genus of the subfamily Entocytherinae named since Hobbs & Peters described Aphelocythere (= Waltoncythere) in 1977. Aurumcythere gen. nov. represents only the second genus of entocytherid known from the Pacific Northwest. Lack of sclerotization in Aurumcythere gen. nov. provides new insight into poorly understood mating behaviors of entocytherid ostracods. 

Response of the Columbia River Fluvial System to Holocene Climatic Change

1992 ◽  
Vol 37 (1) ◽  
pp. 42-59 ◽  
Author(s):  
James C. Chatters ◽  
Karin A. Hoover
Keyword(s):  
Pacific Northwest ◽  
River Basin ◽  
Columbia River ◽  
River System ◽  
Climatic Conditions ◽  
Columbia River Basin ◽  
Fluvial System ◽  
Temperature And Precipitation ◽  
The Pacific ◽  
Floodplain Development

AbstractAn understanding of the response of a fluvial system to past climatic changes is useful for predicting its response to future shifts in temperature and precipitation. To determine the response of the Columbia River system to previous climatic conditions and transitions, a well-dated sequence of floodplain development in the Wells Reservoir region was compared with the paleoenvironmental history of the Columbia River Basin. Results of this comparison indicate that aggradation episodes, occurring approximately 9000-8000, 7000-6500, 4400-3900, and 2400-1800 yr B.P., coincided with climatic transitions that share certain characteristics. The inferred climates associated with aggradation had at least moderate rates of precipitation that occurred mainly in winter coupled with moderate winter temperatures. Such conditions would have resulted in the buildup of snowpacks and a high frequency of rain-on-snow events. The warming and precipitation increases predicted for the Pacific Northwest under most CO2-doubling scenarios are likely to repeat these conditions, which could increase the frequency of severe, sediment-laden floods in the Columbia River Basin.

scholarly journals Transmission Biology of Raspberry latent virus, the First Aphid-Borne Reovirus

2012 ◽  
Vol 102 (5) ◽  
pp. 547-553 ◽  
Author(s):  
Diego F. Quito-Avila ◽  
Danielle Lightle ◽  
Jana Lee ◽  
Robert R. Martin
Keyword(s):  
Pacific Northwest ◽  
New Genus ◽  
Phylogenetic Analyses ◽  
Virus Titer ◽  
Daily Basis ◽  
Latent Virus ◽  
Acquisition Period ◽  
The Pacific ◽  
Transmission Biology ◽  
Rice Ragged Stunt Virus

Raspberry latent virus (RpLV) is a newly characterized reovirus found in commercial raspberry fields in the Pacific Northwest (PNW). Thus far, all members of the plant reoviruses are transmitted in a replicative, persistent manner by several species of leafhoppers or planthoppers. After several failed attempts to transmit RpLV using leafhoppers, the large raspberry aphid, commonly found in the PNW, was tested as a vector of the virus. The virus was transmitted to new, healthy raspberry plants when inoculated with groups of at least 50 viruliferous aphids, suggesting that aphids are vectors of RpLV, albeit inefficient ones. Using absolute and relative quantification methods, it was shown that the virus titer in aphids continued to increase after the acquisition period even when aphids were serially transferred onto fresh, healthy plants on a daily basis. Transmission experiments determined that RpLV has a 6-day latent period in the aphid before it becomes transmissible; however, it was not transmitted transovarially to the next generation. To our knowledge, this is the first report of a plant reovirus transmitted by an aphid. Phylogenetic analyses showed that RpLV is related most closely to but distinct from Rice ragged stunt virus (RRSV), the type member of the genus Oryzavirus. Moreover, the conserved nucleotide termini of the genomic segments of RpLV did not match those of RRSV or other plant reoviruses, allowing us to suggest that RpLV is probably the type member of a new genus in the Reoviridae comprising aphid-transmitted reoviruses.

Predicting the impact of perturbations on salmon (Oncorhynchus spp.) communities: implications for monitoring

2004 ◽  
Vol 61 (7) ◽  
pp. 1166-1175 ◽  
Author(s):  
M R Arkoosh ◽  
L Johnson ◽  
P A Rossignol ◽  
T K Collier
Keyword(s):  
Pacific Northwest ◽  
Anthropogenic Factors ◽  
Valuable Insight ◽  
Community Members ◽  
Contaminant Exposure ◽  
Community Model ◽  
The Pacific ◽  
Chemical Contaminant ◽  
The Impact ◽  
Insight Into

Twenty-six salmon (Oncorhynchus spp.) stocks from the Pacific Northwest are listed as either threatened or endangered. A number of anthropogenic factors, likely including degradation of habitat by chemical contaminant exposure, have contributed to their decline. Techniques that can assess injury or judge the efficacy of regulatory actions on the recovery of this species are needed. We strive to understand why a population is changing by examining changes in their intrinsic birth rates, death rates, and (or) growth rates. However, salmon populations are influenced by other species in the community. To address this issue, we developed a parsimonious three-trophic-level community model consisting of prey, salmon, and parasites and examined the model's response to one anthropogenic factor (contaminant exposure) using qualitative analysis. This community model may not only provide valuable insight into salmon survival but also may broaden the approaches available to elucidate direct and indirect effects. We demonstrate analytically that some community members, possibly salmon themselves, might be ambiguous or unreliable variables to monitor. We also demonstrate that other species in the community, such as parasites, may be more sensitive than salmon in monitoring the influence of anthropogenic factors such as contaminants.

Sign in / Sign up

Export Citation Format

Share Document