Spatial patterns of hybridization between bull trout, <Emphasis Type="Italic">Salvelinus confluentus</Emphasis>, and brook trout, <Emphasis Type="Italic">Salvelinus fontinalis</Emphasis> in an Oregon stream network

Hybridization with introduced species represents a serious threat to the persistence of many native fish populations. Brook trout (Salvelinus fontinalis) have been introduced extensively throughout the native range of bull trout (S. confluentus) and hybridization has been documented in several systems where they co-exist and is seen as a significant threat to the persistence of bull trout populations. We identified a group of diagnostic microsatellite loci to differentiate bull trout and brook trout and then used these loci to examine the spatial distribution of hybrids in the Malheur River basin, Oregon USA. In random samples of approximately 100 fish from each of three creeks we identified 181 brook trout, 112 bull trout and 14 hybrids. Although bull trout, brook trout and hybrids were found in all three creeks, they were not evenly distributed; brook trout were primarily found in the lower sections of the creeks, bull trout further upstream, and hybrids in the areas of the greatest overlap. One creek with a population of brook trout in a headwater lake provided an exception to this pattern; brook trout were found distributed throughout the creek downstream of the lake. Several post-F1 hybrids were identified suggesting that hybrids are reproducing in the Malher River Basin. Mitochondrial DNA analysis indicated that both female bull trout and brook trout are involved in hybridization events. Analysis of population structure suggested that brook trout have established multiple spawning populations within the Malheur system. Data presented in this study suggest that relative abundance of brook trout and habitat quality are important factors to consider when evaluating the threat of hybridization to bull trout populations.     

Daily temperature experience and selection by adfluvial bull trout (<Emphasis Type="Italic">Salvelinus confluentus</Emphasis>)

Bull trout (Salvelinus confluentus) are a thermally sensitive cold-water species with a threatened conservation status across much of North America. To improve our understanding of bull trout thermal ecology, we tagged more than 150 adults with temperature-sensing acoustic biotelemetry transmitters and monitored the animals in a British Columbia reservoir for two years. Thermal resource selection was estimated in open water from the summer to autumn as the system transitioned to isothermal conditions. On average, bull trout thermal history tracked seasonal changes and remained close to the optimum temperatures for growth and metabolism. As summer progressed, bull trout increasingly selected temperatures of 11–15 °C as they became less available within the water column. Selection indicated the movement to shallower waters where 11–15 °C temperatures existed. The results show that bull trout mainly occupy a narrow range of temperatures which suggests the importance of cold-water refuge for the species.     

Seasonal habitat selection by lake trout (<Emphasis Type="Italic">Salvelinus namaycush</Emphasis>) in a small Canadian shield lake: constraints imposed by winter conditions

The need for cold, well-oxygenated waters significantly reduces the habitat available for lake trout (Salvelinus namaycush) during stratification of small temperate lakes. We examined the spatial and pelagic distribution of lake trout over two consecutive summers and winters and tested whether winter increased habitat availability and access to littoral regions in a boreal shield lake in which pelagic prey fish are absent. In winter, lake trout had a narrowly defined pelagic distribution that was skewed to the upper 3 m of the water column and spatially situated in the central region of the lake. Individual core areas of use (50% Kernel utilization distributions) in winter were much reduced (75%) and spatially non-overlapping compared to summer areas, but activity levels were similar between seasons. Winter habitat selection is in contrast to observations from the stratified season, when lake trout were consistently located in much deeper waters (>6 m) and widely distributed throughout the lake. Winter distribution of lake trout appeared to be strongly influenced by ambient light levels; snow depth and day length accounted for up to 69% of the variation in daily median fish depth. More restricted habitat use during winter than summer was in contrast to our original prediction and illustrates that a different suite of factors influence lake trout distribution between these seasons.     

Differentiation of deep-water lake charr <Emphasis Type="Italic">Salvelinus namaycush</Emphasis> in North American lakes

Deep-water morphs of lake charr, Salvelinus namaycush, are found, with one exception, in four of the largest lakes in the world: lakes Superior and Mistassini (QC) and Great Bear and Slave lakes. This paper advances a hypothesis for resource polymorphisms involving two types of deep-water morph, one of which is characteristic of the humper and the other of the siscowet charrs of Lake Superior. My hypothesis states that, first, the humper, or a humper-like morph, diverged postglacially in sympatry from the ancestral common (shallow-water) lake charr and became a feeding specialist on Mysis relicta. Second, in at least two of the four lakes the siscowet, or a siscowet-like charr, diverged as a feeding specialist on postglacially derived forms of deep-water ciscoes. In Lake Superior a successional process may have resulted in dominance of the siscowet at the expense of the humper charr. I concur with a previous inference that the one occurrence of a deep-water charr in a small lake (the above exception) represents emigration from Lake Superior. I further infer that this event involved an early humper charr, which implies that this morphotype had differentiated in Lake Superior in less than 1,900 year. I suggest that innate differences in plasticity, breeding behavior and assortive mating, and philopatry account for why Arctic charr isolate readily in small lakes whereas lake charr do not. My hypothesis assumes divergence of deep-water morphs occurred postglacially, an idea consistent with genetic and biogeographical evidence.     

Environment-phenotype interactions: Influences of brackish-water rearing on lake trout (<Emphasis Type="Italic">Salvelinus namaycush</Emphasis>) physiology

Fertilization and development in salmonids occurs almost exclusively within freshwater environments (< 1 ppt). A less common life history strategy in this group of fishes is the brackish-water resident life history, where entire life cycles occur in brackish water (> 1 ppt). In the present study, we tested the hypothesis that differences in rearing environment (fresh or brackish water) results in significant differences in the ability of lake trout to ionoregulate when faced with a salinity challenge later in life. To test this, genetically similar lake trout were fertilized and raised at either 0 or 5 ppt saltwater. At approximately 240 days post hatch, lake trout from both rearing environments were acutely transferred to 20 ppt salt water or their respective rearing environments as a control. Individuals were sampled at time 0, 1, 7, and 14 days post transfer. Fish raised in 5 ppt transferred to 20 ppt saltwater had significantly higher gill Na⁺ K⁺-ATPase activity, gill Na⁺ K⁺-ATPase α1b expression, and lower plasma osmolality when compared to freshwater reared lake trout transferred to 20 ppt across various time points. Additionally, the 5 ppt control treatment had greater overall aerobic scope than 0 ppt control fish and those transferred from 0 ppt to 20 ppt. These data imply that populations exhibiting a brackish-water resident life history, as has been observed in Arctic Canada, may have an advantage over freshwater reared conspecifics when foraging in marine influenced environments and colonizing new locations in coastal regions.     

Evidence of repeated long-distance movements by lake charr <Emphasis Type="Italic">Salvelinus namaycush</Emphasis> in Lake Huron

Movements and dispersal distances of acoustically-tagged adult lake charr Salvelinus namaycush were estimated based on detections at acoustic receivers in Lake Huron during 2010–2014. Most lake charr were detected only at receivers proximate to their release location or were not detected at all, but 3–9% of tagged lake charr were detected at receivers located over 100 km from their release location. Several fish made extensive repeated migrations within the lake, some at the scale of the entire main basin. Our observations show that some lake charr individuals repeat a similar pattern each year of moving long distances, and some fish were observed to show annual fidelity to presumed foraging sites in the spring at a spatial scale of approximately 200 km. Our telemetry-based estimates were minimum estimates of dispersal, as the placement of receivers within Lake Huron was not optimal for detection of lake charr and did not cover the majority of the lake. Further study of long-distance movement in lake charr is necessary to fully understand the implications of this behavior to lake charr ecology, population dynamics, and management in the Great Lakes.     

Genetic clustering methods reveal bull trout (<Emphasis Type="Italic">Salvelinus confluentus</Emphasis>) fine-scale population structure as a spatially nested hierarchy

Many conservation genetics studies in fishes define populations based on capture location. In salmonid fishes, this traditional a priori designation is made by spawning stream, with subsequent post hoc approaches used to define units of conservation. In this study of bull trout from southwestern Alberta, we provide evidence that a model-based Bayesian genetic clustering method may provide a more parsimonious alternative to designating population structure and units of conservation in comparison to traditional methods. The clustering method captured a hierarchical model of population structure, in which seven local populations were nested within three genetic archipelagos. This was in contrast to using simple F _ST based approaches between thirteen a priori designated populations, which found significant differences for nearly every pairwise comparison. In addition, assignment tests results from Bayesian clustering revealed that movement may be common between sampling locations. These clustering methods are easy to use, intuitive and provide substantial information on populations of fish; this study provides an example of their utility for local fisheries management and conservation.     

Opportunistic use of estuarine habitat by juvenile bull trout, <Emphasis Type="Italic">Salvelinus confluentus</Emphasis>, from the Elwha River before,during, and after dam removal

Estuaries are used by anadromous fishes, either as the definitive marine habitat or as transition habitat as they move to fully marine waters, and extent of estuary use may vary with habitat conditions and fish attributes. Bull trout (Salvelinus confluentus) are commonly fluvial or adfluvial, though anadromous populations also exist. However, little is known about estuary use, especially by juveniles of this threatened species. We sampled the estuaries of the Elwha River, where a spawning population exists, and the nearby Salt Creek, where none exists, to reveal seasonal timing of estuarine use by juvenile bull trout, size of those using the estuary, and possible use of the non-natal estuary. We captured juvenile bull trout (all ≥100 mm FL, most <300 mm) in the Elwha River estuary in all months except August, but primarily December through May. None was captured in Salt Creek’s estuary despite comparable sampling effort. We also evaluated how dam removal on the Elwha River influenced bull trout estuarine occupancy by sampling before, during, and after dam removal, because this process enlarged the estuary but also increased turbidity and sediment transport in the lower river. Catches were low before dam removal, increased during and immediately after removal, and returned to low levels in recent years, suggesting that juveniles temporarily sought refuge from conditions associated with dam removal. Our findings indicate juvenile bull trout occupy estuarine habitat opportunistically; this information may aid conservation efforts as anadromous populations occur elsewhere in rivers with estuaries altered by human development.     

New combinations and typifications in <Emphasis Type="Italic">Bistorta</Emphasis>, <Emphasis Type="Italic">Persicaria</Emphasis>, <Emphasis Type="Italic">Polygonum,</Emphasis> and <Emphasis Type="Italic">Rumex</Emphasis> (Polygonaceae)

New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora: Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii , Rumex densiflorus var. pycnanthus , R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage.     

Bio-resolution of glycidyl (<Emphasis Type="Italic">o</Emphasis>, <Emphasis Type="Italic">m</Emphasis>, <Emphasis Type="Italic">p</Emphasis>)-methylphenyl ethers by <Emphasis Type="Italic">Bacillus megaterium</Emphasis>

A newly isolated Bacillus megaterium with epoxide hydrolase activity resolved racemic glycidyl (o, m, p)-methylphenyl ethers to give enantiopure epoxides in 84–99% enantiomeric excess and with 21–73 enantiomeric ratios. The (S)-enantiomer was obtained from rac-glycidyl (o or m)-methylphenyl ether while the (R)-epoxides was obtained from glycidyl p-methylphenyl ether. The observations are explained at the level by enzyme-substrate docking studies.     

Phylogenetic analyses of <Emphasis Type="Italic">Uromyces viciae-fabae</Emphasis> and its varieties on <Emphasis Type="Italic">Vicia</Emphasis>, <Emphasis Type="Italic">Lathyrus</Emphasis>, and <Emphasis Type="Italic">Pisum</Emphasis> in Japan

A pea rust fungus, Uromyces viciae-fabae, has been classified into two varieties, var. viciae-fabae and var. orobi, based on differences in urediniospore wall thickness and putative host specificity in Japan. In principal component analyses, morphological features of urediniospores and teliospores of 94 rust specimens from Vicia, Lathyrus, and Pisum did not show definite host-specific morphological groups. In molecular analyses, 23 Uromyces specimens from Vicia, Lathyrus, and Pisum formed a single genetic clade based on D1/D2 and ITS regions. Four isolates of U. viciae-fabae from V. cracca and V. unijuga could infect and sporulate on P. sativum. These results suggest that U. viciae-fabae populations on different host plants are not biologically differentiated into groups that can be recognized as varieties.Contribution no. 184, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan     

Floral development and systematic position of <Emphasis Type="Italic">Arillastrum</Emphasis>, <Emphasis Type="Italic">Allosyncarpia</Emphasis>, <Emphasis Type="Italic">Stockwellia</Emphasis> and <Emphasis Type="Italic">Eucalyptopsis</Emphasis> (Myrtaceae)

We have investigated the floral ontogeny of Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis (of the eucalypt group, Myrtaceae) using scanning electron microscopy and light microscopy. Several critical characters for establishing relationships between these genera and to the eucalypts have been determined. The absence of compound petaline primordia in Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis excludes these taxa from the eucalypt clade. Post-anthesis circumscissile abscission of the hypanthium above the ovary in Stockwellia, Eucalyptopsis and Allosyncarpia is evidence that these three taxa form a monophyletic group; undifferentiated perianth parts and elongated fusiform buds are characters that unite Stockwellia and Eucalyptopsis as sister taxa. No floral characters clearly associate Arillastrum with either the eucalypt clade or the clade of Stockwellia, Eucalyptopsis and Allosyncarpia.We gratefully acknowledge Clyde Dunlop and Bob Harwood (Northern Territory Herbarium) for collecting specimens of Allosyncarpia, and Bruce Gray (Atherton) for collecting specimens of Stockwellia. The Australian National Herbarium (CANB) kindly lent herbarium specimens of Eucalyptopsis for examination. This research was supported by a University of Melbourne Research Development Grant to Andrew Drinnan.     

<Emphasis Type="Italic">KRAS</Emphasis>, <Emphasis Type="Italic">BRAF</Emphasis>, <Emphasis Type="Italic">EGFR</Emphasis> and <Emphasis Type="Italic">HER2</Emphasis> gene status in a Spanish population of colorectal cancer

To evaluate the KRAS, BRAF, EGFR, and HER2 gene status in colorectal cancer by novel techniques and evaluate whether anti-HER2 therapies could be offered in the treatment of these patients. There are conflicting data on the prevalence of BRAF mutations and EGFR and HER2 gene amplification in colorectal KRAS wild type patients. In our study we tried to evaluate these expressions and their relationship to future treatment assays. Clinical–pathological data and paraffin-embedded specimens were collected from 186 patients who underwent colorectal resections at General Yagüe Hospital in Burgos, Spain. KRAS and BRAF status was analyzed by real-time PCR in all patients. EGFR and HER2/NEU gene amplification was detected using fluorescent in situ hybridisation technique (FISH) in 38 KRAS and BRAF wild type patients. KRAS mutations were present in 48% of the colorectal cancer patients. BRAF mutations were present in 6.25% of the KRAS wild type patients. EGFR and HER2 gene amplification was observed in 5.3% and 26.3%, respectively, of KRAS and BRAF wild type colorectal cancer patients. HER2, but not EGFR gene amplification, was frequently observed in KRAS and BRAF wild type colorectal cancer patients. These data indicate that HER2 amplification could be one of the genes to be considered in the therapeutic management of colorectal cancer.     

Lake trout (<Emphasis Type="Italic">Salvelinus namaycush</Emphasis>) spawning behaviour: the evolution of a new female strategy

A video camera inside an underwater housing was used to record the spawning activities of lake trout, Salvelinus namaycush, in Kushog Lake, Ontario (Canada). Contrary to the commonly accepted belief describing lake trout as the only salmonine to spawn exclusively at night, the recordings were taken during the day. Lake trout spawning behaviour is described in detail and compared with other salmonine species. The loss of female “nest-building” and assumption of a novel itinerant strategy during which females travel across the breeding grounds accompanied by a group of males, is considered to be an important change in the evolution of the lake trout’s unique mode of spawning.     

A new methanol assimilating yeast, <Emphasis Type="Italic">Ogataea</Emphasis><Emphasis Type="Italic">parapolymorpha</Emphasis>, the ascosporic state of <Emphasis Type="Italic">Candida</Emphasis><Emphasis Type="Italic">parapolymorpha</Emphasis>

Ogataea parapolymorpha sp. n. (NRRL YB-1982, CBS 12304, type strain), the ascosporic state of Candida parapolymorpha, is described. The species appears homothallic, assimilates methanol as is typical of most Ogataea species and forms hat-shaped ascospores in asci that become deliquescent. O. parapolymorpha is closely related to Ogataea angusta and Ogataea polymorpha. The three species can be resolved from gene sequence analyses but are unresolved from fermentation and growth reactions that are typically used for yeast identification. On the basis of multiple isolates, O. angusta is known only from California, USA, in association with Drosophila and Aulacigaster flies, O. parapolymorpha is predominantly associated with insect frass from trees in the eastern USA but O. polymorpha has been isolated from various substrates in the USA, Brazil, Spain and Costa Rica.     

Winter ecology of Arctic charr (<Emphasis Type="Italic">Salvelinus alpinus</Emphasis>) and brown trout (<Emphasis Type="Italic">Salmo trutta</Emphasis>) in a subarctic lake,Norway

We studied habitat choice, diet, food consumption and somatic growth of Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) during the ice-covered winter period of a subarctic lake in northern Norway. Both Arctic charr and brown trout predominantly used the littoral zone during winter time. Despite very cold winter conditions (water temperature <1°C) and poor light conditions, both fish species fed continuously during the ice-covered period, although at a much lower rate than during the summer season. No somatic growth could be detected during the ice-covered winter period and the condition factor of both species significantly declined, suggesting that the winter feeding rates were similar to or below the maintenance requirements. Also, the species richness and diversity of ingested prey largely decreased from summer to winter for both fish species. The winter diet of Arctic charr <20 cm was dominated by benthic insect larvae, chironomids in particular, and Gammarus lacustris, but zooplankton was also important in December. G. lacustris was the dominant prey of charr >20 cm. The winter diet of brown trout <20 cm was dominated by insect larvae, whereas large-sized trout mainly was piscivorous, feeding on juvenile Arctic charr. Piscivorous feeding behaviour of trout was in contrast rarely seen during the summer months when their encounter with potential fish prey was rare as the small-sized charr mainly inhabited the profundal. The study demonstrated large differences in the ecology and interactions of Arctic charr and brown trout between the winter and summer seasons.     

Redescriptions of the Indo-Pacific atherinid fishes <Emphasis Type="Italic">Atherinomorus forskalii</Emphasis>, <Emphasis Type="Italic">Atherinomorus lacunosus</Emphasis>, and <Emphasis Type="Italic">Atherinomorus pinguis</Emphasis>

The Indo-Pacific marine atherinid fishes Atherinomorus forskalii (Rüppell, 1838), Atherinomorus lacunosus (Forster, 1801), and Atherinomorus pinguis (Lacepède, 1803) are redescribed as valid species based on the types and non-type specimens collected throughout the Indo-Pacific. They are similar to each other chiefly in having a wide midlateral band (almost the same or greater than the midlateral scale width), large mouth (posterior tip of upper jaw reaching to or beyond a vertical through anterior margin of pupil), and no distinct tubercle at the posterior end of the dentary. All three species are distinguishable from congeners by those characters. The three species have long been confused with each other or synonymized erroneously as a single species. Atherinomorus forskalii, known from the Red Sea and eastern Mediterranean, differs from Atherinomorus lacunosus and Atherinomorus pinguis in having conspicuous, large endopterygoid teeth, forming obvious tooth ridges. Atherinomorus lacunosus, widely distributed in almost the entire Indo-Pacific, from East Africa to Tonga, north to southern Japan, and south to northern Australia, differs from Atherinomorus pinguis in having a wider midlateral band (the lower margin reaching to almost the center of the fourth scale row at level of the anal fin origin vs. the lower margin reaching to the ventral end of the third scale row in Atherinomorus pinguis) and more numerous midlateral scales (40–44 vs. 38–41 in Atherinomorus pinguis). Atherina morrisi Jordan and Starks, 1906, Hepsetia pinguis mineri Nichols and Roemhild, 1951, Pranesus capricornensis Woodland, 1961, Pranesus maculatus Taylor, 1964, and Pranesus pinguis ruppelli Smith, 1965, are regarded as junior synonyms of Atherinomorus lacunosus. Atherinomorus pinguis is also widely distributed in the Indo-West Pacific, from East Africa to northern Australia and north to southern Japan. Atherina pectoralis Valenciennes, 1835, is considered a junior synonym of Atherinomorus pinguis. Supplementary material to this paper is available in electronic format at