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Sample records for alaskan threespine stickleback

  1. The evolution of antipredator behaviour following relaxed and reversed selection in Alaskan threespine stickleback fish

    PubMed Central

    Wund, Matthew A.; Baker, John A.; Golub, Justin L.; Foster, Susan A.

    2015-01-01

    Changing environments, whether through natural or anthropogenic causes, can lead to the loss of some selective pressures (‘relaxed selection’) and possibly even the reinstatement of selective agents not encountered for many generations (‘reversed selection’). We examined the outcome of relaxed and reversed selection in the adaptive radiation of the threespine stickleback fish, Gasterostues aculeatus L., in which isolated populations encounter a variety of predation regimes. Oceanic stickleback, which represent the ancestral founders of the freshwater radiation, encounter many piscivorous fish. Derived, freshwater populations, on the other hand, vary with respect to the presence of predators. Some populations encounter native salmonids, whereas others have not experienced predation by large fish in thousands of generations (relax-selected populations). Some relax-selected populations have had sport fish, including rainbow trout, Oncorhynchus mykiss, introduced within the past several decades (reverse-selected). We examined the behavioural responses of stickleback from three populations of each type to simulated attacks by trout and birds to determine whether relaxed and reversed selection has led to divergence in behaviour, and whether this divergence was predator specific. Fish from trout-free populations showed weak responses to trout, as predicted, but these responses were similar to those of oceanic (ancestral) populations. Fish from populations that co-occur with trout, whether native or introduced, showed elevated antipredator responses, indicating that in freshwater, trout predation selects for enhanced antipredator responses, which can evolve extremely rapidly. Comparison of laboratory-reared and wild-caught individuals suggests a combination of learned and genetic components to this variation. Responses to a model bird flyover were weakly linked to predation environment, indicating that the loss of predation by trout may partially influence the

  2. PERCHLORATE INDUCES HERMAPHRODITISM IN THREESPINE STICKLEBACKS

    PubMed Central

    Bernhardt, Richard R.; von Hippel, Frank A.; Cresko, William A.

    2011-01-01

    Recently, concern regarding perchlorate contamination has arisen in many contexts. Perchlorate has many military, commercial, and domestic applications, and it has been found in milk, drinking and irrigation water, and produce. Perchlorate is harmful at low levels, yet it remains unregulated in the United States while the U.S. Environmental Protection Agency attempts to establish acceptable exposure levels. The present study investigated potential reproductive effects on vertebrates using a model fish species, the threespine stickleback (Gasterosteus aculeatus). Sticklebacks were raised from syngamy through sexual maturity in untreated water and in three target concentrations of sodium perchlorate–treated water. Perchlorate was found to interfere with the expression of nuptial coloration, courtship behavior, and normal sexual development. Genetic testing revealed that some females were masculinized to the extent that they produced both sperm and eggs, and histological analysis showed that these individuals had intersexual gonads (ovotestes) containing both oocytes and cells undergoing spermatogenesis. In vitro fertilizations revealed that those gametes were capable of self- and cross-fertilization. However, crosses using sperm derived from genetic females died either during the blastula phase or near the onset of organogenesis. Sperm derived from genetic males produced viable fry when crossed with eggs derived from genetic females from all treatments. To our knowledge, the present study provides the first evidence that perchlorate produces androgenic effects and is capable of inducing functional hermaphroditism in a nonhermaphroditic vertebrate. PMID:16916028

  3. Intraguild predation drives evolutionary niche shift in threespine stickleback.

    PubMed

    Ingram, Travis; Svanbäck, Richard; Kraft, Nathan J B; Kratina, Pavel; Southcott, Laura; Schluter, Dolph

    2012-06-01

    Intraguild predation--competition and predation by the same antagonist--is widespread, but its evolutionary consequences are unknown. Intraguild prey may evolve antipredator defenses, superior competitive ability on shared resources, or the ability to use an alternative resource, any of which may alter the structure of the food web. We tested for evolutionary responses by threespine stickleback to a benthic intraguild predator, prickly sculpin. We used a comparative morphometric analysis to show that stickleback sympatric with sculpin are more armored and have more limnetic-like body shapes than allopatric stickleback. To test the ecological implications of this shift, we conducted a mesocosm experiment that varied sculpin presence and stickleback population of origin (from one sympatric and one allopatric lake). Predation by sculpin greatly increased the mortality of allopatric stickleback. In contrast, sculpin presence did not affect the mortality of sympatric stickleback, although they did have lower growth rates suggesting increased nonpredatory effects of sculpin. Consistent with their morphology, sympatric stickleback included more pelagic prey in their diets, leading to depletion of zooplankton in the mesocosms. These findings suggest that intraguild prey evolution has altered food web structure by reducing both predation by the intraguild predator and diet overlap between species.

  4. Life-history plasticity in female threespine stickleback

    PubMed Central

    Baker, J A; Wund, M A; Heins, D C; King, R W; Reyes, M L; Foster, S A

    2015-01-01

    The postglacial adaptive radiation of the threespine stickleback fish (Gasterosteus aculeatus) has been widely used to investigate the roles of both adaptive evolution and plasticity in behavioral and morphological divergence from the ancestral condition represented by present-day oceanic stickleback. These phenotypes tend to exhibit high levels of ecotypic differentiation. Population divergence in life history has also been well studied, but in contrast to behavior and morphology, the extent and importance of plasticity has been much less well studied. In this review, we summarize what is known about life-history plasticity in female threespine stickleback, considering four traits intimately associated with reproductive output: age/size at maturation, level of reproductive effort, egg size and clutch size. We envision life-history plasticity in an iterative, ontogenetic framework, in which females may express plasticity repeatedly across each of several time frames. We contrast the results of laboratory and field studies because, for most traits, these approaches give somewhat different answers. We provide ideas on what the cues might be for observed plasticity in each trait and, when possible, we inquire about the relative costs and benefits to expressed plasticity. We end with an example of how we think plasticity may play out in stickleback life history given what we know of plasticity in the ancestor. PMID:26286665

  5. Seasonal size distribution of three-spined stickleback in an intermittent/perennial stream system

    EPA Science Inventory

    To better understand patterns of habitat use by fish in an intermittent stream, we have been investigating the early life history of three-spined stickleback (Gasterosteus aculeatus). We collected three-spined stickleback and other fishes using dipnets, seines and minnow traps ...

  6. Sexual dimorphism in the feeding mechanism of threespine stickleback.

    PubMed

    McGee, Matthew D; Wainwright, Peter C

    2013-03-01

    Sexual dimorphism is common in nature and has the potential to increase intraspecific variation in performance and patterns of resource use. We sought to determine whether anadromous threespine stickleback, Gasterosteus aculeatus, exhibit sexual dimorphism in feeding kinematics. We filmed four males and four females consuming live prey in a total of 51 sequences filmed at 500 Hz, then tested for differences in cranial kinematics using a combination of principal component analysis and linear mixed models. We document, for the first time in fishes, divergence between males and females in both the timing of key movements and the magnitude of excursions reached by the hyoid, jaws and neurocranium during prey capture. Some of the largest differences are in jaw protrusion, with males exhibiting faster time to peak jaw protrusion but females exhibiting greater maximum jaw protrusion. Measurements of morphological jaw protrusion on cleared and stained specimens significantly predict jaw protrusion in kinematics. This morphological divergence could reflect ecological divergence between the sexes, or the demands of nest building and territory defense compromising male feeding performance. Remarkably, the morphological jaw protrusion divergence in anadromous males and females is similar to jaw protrusion divergence between ecomorphs in a benthic-limnetic species pair, with limnetics exhibiting female-like patterns of protrusion and benthics exhibiting male-like patterns. These results suggest that sexual dimorphism in feeding functional morphology exists in nature and may have played an important role in the radiation of threespine stickleback. PMID:23408802

  7. The evolutionary ecology of dwarfism in three-spined sticklebacks.

    PubMed

    MacColl, Andrew D C; El Nagar, Aliya; de Roij, Job

    2013-05-01

    1. Body size is a defining phenotypic trait, but the ecological causes of its evolution are poorly understood. Most studies have considered only a single putative causal agent and have failed to recognise that different environmental agents are often correlated. 2. Darwin suggested that although trait variation across populations is often associated with abiotic variation, evolution is more likely to be driven by biotic factors correlated with the abiotic variation. This hypothesis has received little explicit attention. 3. We use structural equation modelling to quantify the relative importance of abiotic (pH, metal concentrations) and biotic (competition, predation) factors in the evolution of body size in three-spined sticklebacks Gasterosteus aculeatus on the island of North Uist, Scotland. We combine phenotypic data from multiple isolated populations, detailed characterisation of their environment and a common garden experiment that establishes the genetic basis of size differences. 4. Three-spined sticklebacks on North Uist show almost unprecedented intraspecific evolution of body size that has taken place rapidly (<16,000 years). The smallest fish mature at only 7% of the mass of ancestral, anadromous fish. Dwarfism is associated with reduced abundance of a smaller competitor species, the nine-spined stickleback Pungitius pungitius, and with low pH indicative of poor resource conditions. Dwarfism also tends to occur where an important predator, the brown trout Salmo trutta, is also small. The abundance of P. pungitius and the size of S. trutta are themselves related to underlying abiotic environmental variation. 5. Despite the close association between abiotic and biotic factors across populations, our results support Darwin's hypothesis that biotic factors, associated with variation in the abiotic environment, are more important in explaining evolution than is abiotic variation per se. This study demonstrates the importance of considering the relationships

  8. The evolutionary ecology of dwarfism in three-spined sticklebacks.

    PubMed

    MacColl, Andrew D C; El Nagar, Aliya; de Roij, Job

    2013-05-01

    1. Body size is a defining phenotypic trait, but the ecological causes of its evolution are poorly understood. Most studies have considered only a single putative causal agent and have failed to recognise that different environmental agents are often correlated. 2. Darwin suggested that although trait variation across populations is often associated with abiotic variation, evolution is more likely to be driven by biotic factors correlated with the abiotic variation. This hypothesis has received little explicit attention. 3. We use structural equation modelling to quantify the relative importance of abiotic (pH, metal concentrations) and biotic (competition, predation) factors in the evolution of body size in three-spined sticklebacks Gasterosteus aculeatus on the island of North Uist, Scotland. We combine phenotypic data from multiple isolated populations, detailed characterisation of their environment and a common garden experiment that establishes the genetic basis of size differences. 4. Three-spined sticklebacks on North Uist show almost unprecedented intraspecific evolution of body size that has taken place rapidly (<16,000 years). The smallest fish mature at only 7% of the mass of ancestral, anadromous fish. Dwarfism is associated with reduced abundance of a smaller competitor species, the nine-spined stickleback Pungitius pungitius, and with low pH indicative of poor resource conditions. Dwarfism also tends to occur where an important predator, the brown trout Salmo trutta, is also small. The abundance of P. pungitius and the size of S. trutta are themselves related to underlying abiotic environmental variation. 5. Despite the close association between abiotic and biotic factors across populations, our results support Darwin's hypothesis that biotic factors, associated with variation in the abiotic environment, are more important in explaining evolution than is abiotic variation per se. This study demonstrates the importance of considering the relationships

  9. Gene expression responses of threespine stickleback to salinity: implications for salt-sensitive hypertension.

    PubMed

    Wang, Gang; Yang, Ence; Smith, Kerri J; Zeng, Yong; Ji, Guoli; Connon, Richard; Fangue, Nann A; Cai, James J

    2014-01-01

    Despite recent success with genome-wide association studies (GWAS), identifying hypertension (HTN)-susceptibility loci in the general population remains difficult. Here, we present a novel strategy to address this challenge by studying salinity adaptation in the threespine stickleback, a fish species with diverse salt-handling ecotypes. We acclimated native freshwater (FW) and anadromous saltwater (SW) threespine sticklebacks to fresh, brackish, and sea water for 30 days, and applied RNA sequencing to determine the gene expression in fish kidneys. We identified 1844 salt-responsive genes that were differentially expressed between FW sticklebacks acclimated to different salinities and/or between SW and FW sticklebacks acclimated to full-strength sea water. Significant overlap between stickleback salt-responsive genes and human genes implicated in HTN was detected (P < 10(-7), hypergeometric test), suggesting a possible similarity in genetic mechanisms of salt handling between threespine sticklebacks and humans. The overlapping genes included a newly discovered HTN gene-MAP3K15, whose expression in FW stickleback kidneys decreases with salinity. These also included genes located in the GWAS loci such as AGTRAP-PLOD1 and CYP1A1-ULK3, which contain multiple potentially causative genes contributing to HTN susceptibility that need to be prioritized for study. Taken together, we show that stickleback salt-responsive genes provide valuable information facilitating the identification of human HTN genes. Thus, threespine sticklebacks may be used as a model, complementary to existing animal models, in human HTN research. PMID:25309574

  10. Gene expression responses of threespine stickleback to salinity: implications for salt-sensitive hypertension

    PubMed Central

    Wang, Gang; Yang, Ence; Smith, Kerri J.; Zeng, Yong; Ji, Guoli; Connon, Richard; Fangue, Nann A.; Cai, James J.

    2014-01-01

    Despite recent success with genome-wide association studies (GWAS), identifying hypertension (HTN)-susceptibility loci in the general population remains difficult. Here, we present a novel strategy to address this challenge by studying salinity adaptation in the threespine stickleback, a fish species with diverse salt-handling ecotypes. We acclimated native freshwater (FW) and anadromous saltwater (SW) threespine sticklebacks to fresh, brackish, and sea water for 30 days, and applied RNA sequencing to determine the gene expression in fish kidneys. We identified 1844 salt-responsive genes that were differentially expressed between FW sticklebacks acclimated to different salinities and/or between SW and FW sticklebacks acclimated to full-strength sea water. Significant overlap between stickleback salt-responsive genes and human genes implicated in HTN was detected (P < 10−7, hypergeometric test), suggesting a possible similarity in genetic mechanisms of salt handling between threespine sticklebacks and humans. The overlapping genes included a newly discovered HTN gene—MAP3K15, whose expression in FW stickleback kidneys decreases with salinity. These also included genes located in the GWAS loci such as AGTRAP-PLOD1 and CYP1A1-ULK3, which contain multiple potentially causative genes contributing to HTN susceptibility that need to be prioritized for study. Taken together, we show that stickleback salt-responsive genes provide valuable information facilitating the identification of human HTN genes. Thus, threespine sticklebacks may be used as a model, complementary to existing animal models, in human HTN research. PMID:25309574

  11. Reverse evolution of armor plates in the threespine stickleback.

    PubMed

    Kitano, Jun; Bolnick, Daniel I; Beauchamp, David A; Mazur, Michael M; Mori, Seiichi; Nakano, Takanori; Peichel, Catherine L

    2008-05-20

    Faced with sudden environmental changes, animals must either adapt to novel environments or go extinct. Thus, study of the mechanisms underlying rapid adaptation is crucial not only for the understanding of natural evolutionary processes but also for the understanding of human-induced evolutionary change, which is an increasingly important problem [1-8]. In the present study, we demonstrate that the frequency of completely plated threespine stickleback fish (Gasterosteus aculeatus) has increased in an urban freshwater lake (Lake Washington, Seattle, Washington) within the last 40 years. This is a dramatic example of "reverse evolution,"[9] because the general evolutionary trajectory is toward armor-plate reduction in freshwater sticklebacks [10]. On the basis of our genetic studies and simulations, we propose that the most likely cause of reverse evolution is increased selection for the completely plated morph, which we suggest could result from higher levels of trout predation after a sudden increase in water transparency during the early 1970s. Rapid evolution was facilitated by the existence of standing allelic variation in Ectodysplasin (Eda), the gene that underlies the major plate-morph locus [11]. The Lake Washington stickleback thus provides a novel example of reverse evolution, which is probably caused by a change in allele frequency at the major plate locus in response to a changing predation regime. PMID:18485710

  12. Genomic signatures of the plateless phenotype in the threespine stickleback.

    PubMed

    Mazzarella, Anna B; Boessenkool, Sanne; Østbye, Kjartan; Vøllestad, Leif Asbjørn; Trucchi, Emiliano

    2016-05-01

    Understanding the genetic basis of traits involved in adaptive divergence and speciation is one of the most fundamental objectives in evolutionary biology. Toward that end, we look for signatures of extreme plate loss in the genome of freshwater threespine sticklebacks (Gasterosteus aculeatus). Plateless stickleback have been found in only a few lakes and streams across the world; they represent the far extreme of a phenotypic continuum (plate number) that has been studied for years, although plateless individuals have not yet been the subject of much investigation. We use a dense single nucleotide polymorphism dataset made using RADseq to study fish from three freshwater populations containing plateless and low plated individuals, as well as fish from full plated marine populations. Analyses were performed using FastStructure, sliding windows F ST, Bayescan and latent factor mixed models to search for genomic differences between the low plated and plateless phenotypes both within and among the three lakes. At least 18 genomic regions which may contribute to within-morph plate number variation were detected in our low plated stickleback populations. We see no evidence of a selective sweep between low and plateless fish; rather reduction of plate number within the low plated morph seems to be polygenic. PMID:27096077

  13. Reverse Evolution of Armor Plates in the Threespine Stickleback

    USGS Publications Warehouse

    Kitano, J.; Bolnick, D.I.; Beauchamp, D.A.; Mazur, M.M.; Mori, S.; Nakano, T.; Peichel, C.L.

    2008-01-01

    Faced with sudden environmental changes, animals must either adapt to novel environments or go extinct. Thus, study of the mechanisms underlying rapid adaptation is crucial not??only for the understanding of natural evolutionary processes but also for the understanding of human-induced evolutionary change, which is an increasingly important problem [1-8]. In the present study, we demonstrate that the frequency of completely plated threespine stickleback fish (Gasterosteus aculeatus) has increased in an urban freshwater lake (Lake Washington, Seattle, Washington) within the last 40 years. This is a dramatic example of "reverse evolution," [9] because the general evolutionary trajectory is toward armor-plate reduction in freshwater sticklebacks [10]. On the basis of our genetic studies and simulations, we propose that the most likely cause of reverse evolution is increased selection for the completely plated morph, which we suggest could result from higher levels of trout predation after a sudden increase in water transparency during the early 1970s. Rapid evolution was facilitated by the existence of standing allelic variation in Ectodysplasin (Eda), the gene that underlies the major plate-morph locus [11]. The Lake Washington stickleback thus provides a novel example of reverse evolution, which is probably caused by a change in allele frequency at the major plate locus in response to a changing predation regime. ?? 2008 Elsevier Ltd. All rights reserved.

  14. Cryptic genetic variation and body size evolution in threespine stickleback.

    PubMed

    McGuigan, Katrina; Nishimura, Nicole; Currey, Mark; Hurwit, Dan; Cresko, William A

    2011-04-01

    The role of environment as a selective agent is well-established. Environment might also influence evolution by altering the expression of genetic variation associated with phenotypes under selection. Far less is known about this phenomenon, particularly its contribution to evolution in novel environments. We investigated how environment affected the evolvability of body size in the threespine stickleback (Gasterosteus aculeatus). Gasterosteus aculeatus is well suited to addressing this question due to the rapid evolution of smaller size in the numerous freshwater populations established following the colonization of new freshwater habitats by an oceanic ancestor. The repeated, rapid evolution of size following colonization contrasts with the general observation of low phenotypic variation in oceanic stickleback. We reared an oceanic population of stickleback under high and low salinity conditions, mimicking a key component of the ancestral environment, and freshwater colonization, respectively. There was low genetic variation for body size under high salinity, but this variance increased significantly when fish were reared under low salinity. We therefore conclude that oceanic populations harbor the standing genetic variation necessary for the evolution of body size, but that this variation only becomes available to selection upon colonization of a new habitat.

  15. The genomics of ecological vicariance in threespine stickleback fish

    PubMed Central

    Roesti, Marius; Kueng, Benjamin; Moser, Dario; Berner, Daniel

    2015-01-01

    Populations occurring in similar habitats and displaying similar phenotypes are increasingly used to explore parallel evolution at the molecular level. This generally ignores the possibility that parallel evolution can be mimicked by the fragmentation of an ancestral population followed by genetic exchange with ecologically different populations. Here we demonstrate such an ecological vicariance scenario in multiple stream populations of threespine stickleback fish divergent from a single adjacent lake population. On the basis of demographic and population genomic analyses, we infer the initial spread of a stream-adapted ancestor followed by the emergence of a lake-adapted population, that selective sweeps have occurred mainly in the lake population, that adaptive lake–stream divergence is maintained in the face of gene flow from the lake into the streams, and that this divergence involves major inversion polymorphisms also important to marine-freshwater stickleback divergence. Overall, our study highlights the need for a robust understanding of the demographic and selective history in evolutionary investigations. PMID:26556609

  16. Developmental timing of perchlorate exposure alters threespine stickleback dermal bone

    PubMed Central

    Furin, Christoff G.; von Hippel, Frank A.; Postlethwait, John; Buck, C. Loren; Cresko, William A.; O’Hara, Todd M.

    2015-01-01

    Adequate levels of thyroid hormone are critical during development and metamorphosis, and for maintaining metabolic homeostasis. Perchlorate, a common contaminant of water sources, inhibits thyroid function in vertebrates. We utilized threespine stickleback (Gasterosteus aculeatus) to determine if timing of perchlorate exposure during development impacts adult dermal skeletal phenotypes. Fish were exposed to water contaminated with perchlorate (30 mg/L or 100 mg/L) beginning at 0, 3, 7, 14, 21, 42, 154 or 305 days post fertilization until sexual maturity at one year of age. A reciprocal treatment moved stickleback from contaminated to clean water on the same schedule providing for different stages of initial exposure and different treatment durations. Perchlorate exposure caused concentration-dependent significant differences in growth for some bony traits. Continuous exposure initiated within the first 21 days post fertilization had the greatest effects on skeletal traits. Exposure to perchlorate at this early stage can result in small traits or abnormal skeletal morphology of adult fish which could affect predator avoidance and survival. PMID:25753171

  17. Three-spined stickleback seasonal size and length-at-age distribution in an intermittent/perennial stream system

    EPA Science Inventory

    We examined the early life history of three-spined stickleback (Gasterosteus aculeatus) to better understand fish habitat patterns in an intermittent stream. We collected three-spined stickleback and other fishes using dipnets, seines and minnow traps during the summer 2010 low-...

  18. Genomics of Rapid Incipient Speciation in Sympatric Threespine Stickleback

    PubMed Central

    Marques, David A.; Lucek, Kay; Meier, Joana I.; Mwaiko, Salome; Wagner, Catherine E.; Excoffier, Laurent; Seehausen, Ole

    2016-01-01

    Ecological speciation is the process by which reproductively isolated populations emerge as a consequence of divergent natural or ecologically-mediated sexual selection. Most genomic studies of ecological speciation have investigated allopatric populations, making it difficult to infer reproductive isolation. The few studies on sympatric ecotypes have focused on advanced stages of the speciation process after thousands of generations of divergence. As a consequence, we still do not know what genomic signatures of the early onset of ecological speciation look like. Here, we examined genomic differentiation among migratory lake and resident stream ecotypes of threespine stickleback reproducing in sympatry in one stream, and in parapatry in another stream. Importantly, these ecotypes started diverging less than 150 years ago. We obtained 34,756 SNPs with restriction-site associated DNA sequencing and identified genomic islands of differentiation using a Hidden Markov Model approach. Consistent with incipient ecological speciation, we found significant genomic differentiation between ecotypes both in sympatry and parapatry. Of 19 islands of differentiation resisting gene flow in sympatry, all were also differentiated in parapatry and were thus likely driven by divergent selection among habitats. These islands clustered in quantitative trait loci controlling divergent traits among the ecotypes, many of them concentrated in one region with low to intermediate recombination. Our findings suggest that adaptive genomic differentiation at many genetic loci can arise and persist in sympatry at the very early stage of ecotype divergence, and that the genomic architecture of adaptation may facilitate this. PMID:26925837

  19. Genetic Architecture of Conspicuous Red Ornaments in Female Threespine Stickleback

    PubMed Central

    Yong, Lengxob; Peichel, Catherine L.; McKinnon, Jeffrey S.

    2015-01-01

    Explaining the presence of conspicuous female ornaments that take the form of male-typical traits has been a longstanding challenge in evolutionary biology. Such female ornaments have been proposed to evolve via both adaptive and nonadaptive evolutionary processes. Determining the genetic underpinnings of female ornaments is important for elucidating the mechanisms by which such female traits arise and persist in natural populations, but detailed information about their genetic basis is still scarce. In this study, we investigated the genetic architecture of two ornaments, the orange-red throat and pelvic spine, in the threespine stickleback (Gasterosteus aculeatus). Throat coloration is male-specific in ancestral marine populations but has evolved in females in some derived stream populations, whereas sexual dimorphism in pelvic spine coloration is variable among populations. We find that ornaments share a common genetic architecture between the sexes. At least three independent genomic regions contribute to red throat coloration, and harbor candidate genes related to pigment production and pigment cell differentiation. One of these regions is also associated with spine coloration, indicating that both ornaments might be mediated partly via pleiotropic genetic mechanisms. PMID:26715094

  20. Partially repeatable genetic basis of benthic adaptation in threespine sticklebacks.

    PubMed

    Erickson, Priscilla A; Glazer, Andrew M; Killingbeck, Emily E; Agoglia, Rachel M; Baek, Jiyeon; Carsanaro, Sara M; Lee, Anthony M; Cleves, Phillip A; Schluter, Dolph; Miller, Craig T

    2016-04-01

    The extent to which convergent adaptation to similar ecological niches occurs by a predictable genetic basis remains a fundamental question in biology. Threespine stickleback fish have undergone an adaptive radiation in which ancestral oceanic populations repeatedly colonized and adapted to freshwater habitats. In multiple lakes in British Columbia, two different freshwater ecotypes have evolved: a deep-bodied benthic form adapted to forage near the lake substrate, and a narrow-bodied limnetic form adapted to forage in open water. Here, we use genome-wide linkage mapping in marine × benthic F2 genetic crosses to test the extent of shared genomic regions underlying benthic adaptation in three benthic populations. We identify at least 100 Quantitative Trait Loci (QTL) harboring genes influencing skeletal morphology. The majority of QTL (57%) are unique to one cross. However, four genomic regions affecting eight craniofacial and armor phenotypes are found in all three benthic populations. We find that QTL are clustered in the genome and overlapping QTL regions are enriched for genomic signatures of natural selection. These findings suggest that benthic adaptation has occurred via both parallel and nonparallel genetic changes. PMID:26947264

  1. Ecological causes of morphological evolution in the three-spined stickleback

    PubMed Central

    Spence, Rowena; Wootton, Robert J; Barber, Iain; Przybylski, Mirosław; Smith, Carl

    2013-01-01

    The central assumption of evolutionary theory is that natural selection drives the adaptation of populations to local environmental conditions, resulting in the evolution of adaptive phenotypes. The three-spined stickleback (Gasterosteus aculeatus) displays remarkable phenotypic variation, offering an unusually tractable model for understanding the ecological mechanisms underpinning adaptive evolutionary change. Using populations on North Uist, Scotland we investigated the role of predation pressure and calcium limitation on the adaptive evolution of stickleback morphology and behavior. Dissolved calcium was a significant predictor of plate and spine morph, while predator abundance was not. Stickleback latency to emerge from a refuge varied with morph, with populations with highly reduced plates and spines and high predation risk less bold. Our findings support strong directional selection in three-spined stickleback evolution, driven by multiple selective agents. PMID:23789080

  2. Introduction and spread of the threespine stickleback (Gasterosteus aculeatus) in Lakes Huron and Michigan

    USGS Publications Warehouse

    Stedman, Ralph M.; Bowen, Charles A.

    1985-01-01

    The threespine stickleback (Gasterosteus aculeatus) was not known to occur in the Great Lakes above Niagara Falls until 1980, when it was collected in South Bay, Manitoulin Island, in the Lake Huron basin. By 1984 this species had been found in tributaries of Lakes Huron and Michigan, and in the open waters of both lakes. All specimens identified were the completely plated morph that is most prevalent in fresh water along the east coast of North America. The status of this species in Lakes Huron and Michigan appears to be “Possibly Established.” If threespine stickleback increase in abundance they may eventually provide additional forage for large salmonids.

  3. Geography of the circadian gene clock and photoperiodic response in western North American populations of the threespine stickleback Gasterosteus aculeatus

    PubMed Central

    O’Brien, C.; Unruh, L.; Zimmerman, C.; Bradshaw, W. E.; Holzapfel, C. M.; Cresko, W. A.

    2014-01-01

    The gene clock is a core component of the daily circadian oscillator in flies and mammals. This gene gained renewed interest over a decade ago when the C-terminus of the Clock protein was found to include polyglutamine repeat domains (PolyQ). Since that time, several studies have used variation in PolyQ as a proxy for variation in circadian function. Furthermore, conjectures were made about the possible role of this variation in photoperiodic control of seasonal timing in birds and fishes, generally with questionable results. Herein, we use controlled laboratory experiments to show that Oregon and Alaskan threespine stickleback, collected from populations that differ by 18° of latitude, show no significant variation in length of the polyglutamine domain of clock, or in photoperiodic response within or between latitudes despite the fact that male and female sticklebacks are photoperiodic at both latitudes. Hence, we urge caution when interpreting variation in the PolyQ domain of the clock gene in the context of seasonal activities or in relationship to photoperiodism along geographical gradients. PMID:23464546

  4. Evolution of Schooling Behavior in Threespine Sticklebacks Is Shaped by the Eda Gene.

    PubMed

    Greenwood, Anna K; Mills, Margaret G; Wark, Abigail R; Archambeault, Sophie L; Peichel, Catherine L

    2016-06-01

    Despite longstanding interest in the genetic mechanisms that underlie behavioral evolution, very few genes that underlie naturally occurring variation in behavior between individuals or species are known, particularly in vertebrates. Here, we build on our previous forward genetic mapping experiments and use transgenic approaches to identify Ectodysplasin as a gene that causes differences in schooling behavior between wild populations of threespine stickleback (Gasterosteus aculeatus) fish. This work provides rare insight into the proximate mechanisms that have shaped the evolution of vertebrate behavior.

  5. Development of a bioenergetics model for the threespine stickleback Gasterosteus aculeatus

    USGS Publications Warehouse

    Hovel, Rachel A.; Beauchamp, David A.; Hansen, Adam G.; Sorel, Mark H.

    2016-01-01

    The Threespine Stickleback Gasterosteus aculeatus is widely distributed across northern hemisphere ecosystems, has ecological influence as an abundant planktivore, and is commonly used as a model organism, but the species lacks a comprehensive model to describe bioenergetic performance in response to varying environmental or ecological conditions. This study parameterized a bioenergetics model for the Threespine Stickleback using laboratory measurements to determine mass- and temperature-dependent functions for maximum consumption and routine respiration costs. Maximum consumption experiments were conducted across a range of temperatures from 7.5°C to 23.0°C and a range of fish weights from 0.5 to 4.5 g. Respiration experiments were conducted across a range of temperatures from 8°C to 28°C. Model sensitivity was consistent with other comparable models in that the mass-dependent parameters for maximum consumption were the most sensitive. Growth estimates based on the Threespine Stickleback bioenergetics model suggested that 22°C is the optimal temperature for growth when food is not limiting. The bioenergetics model performed well when used to predict independent, paired measures of consumption and growth observed from a separate wild population of Threespine Sticklebacks. Predicted values for consumption and growth (expressed as percent body weight per day) only deviated from observed values by 2.0%. Our model should provide insight into the physiological performance of this species across a range of environmental conditions and be useful for quantifying the trophic impact of this species in food webs containing other ecologically or economically important species.

  6. Dissection and Flat-mounting of the Threespine Stickleback Branchial Skeleton.

    PubMed

    Ellis, Nicholas A; Miller, Craig T

    2016-05-07

    The posterior pharyngeal segments of the vertebrate head give rise to the branchial skeleton, the primary site of food processing in fish. The morphology of the fish branchial skeleton is matched to a species' diet. Threespine stickleback fish (Gasterosteus aculeatus) have emerged as a model system to study the genetic and developmental basis of evolved differences in a variety of traits. Marine populations of sticklebacks have repeatedly colonized countless new freshwater lakes and creeks. Adaptation to the new diet in these freshwater environments likely underlies a series of craniofacial changes that have evolved repeatedly in independently derived freshwater populations. These include three major patterning changes to the branchial skeleton: reductions in the number and length of gill raker bones, increases in pharyngeal tooth number, and increased branchial bone lengths. Here we describe a detailed protocol to dissect and flat-mount the internal branchial skeleton in threespine stickleback fish. Dissection of the entire three-dimensional branchial skeleton and mounting it flat into a largely two-dimensional prep allows for the easy visualization and quantification of branchial skeleton morphology. This dissection method is inexpensive, fast, relatively easy, and applicable to a wide variety of fish species. In sticklebacks, this efficient method allows the quantification of skeletal morphology in genetic crosses to map genomic regions controlling craniofacial patterning.

  7. Population Genomics of Parallel Adaptation in Threespine Stickleback using Sequenced RAD Tags

    PubMed Central

    Etter, Paul D.; Stiffler, Nicholas; Johnson, Eric A.; Cresko, William A.

    2010-01-01

    Next-generation sequencing technology provides novel opportunities for gathering genome-scale sequence data in natural populations, laying the empirical foundation for the evolving field of population genomics. Here we conducted a genome scan of nucleotide diversity and differentiation in natural populations of threespine stickleback (Gasterosteus aculeatus). We used Illumina-sequenced RAD tags to identify and type over 45,000 single nucleotide polymorphisms (SNPs) in each of 100 individuals from two oceanic and three freshwater populations. Overall estimates of genetic diversity and differentiation among populations confirm the biogeographic hypothesis that large panmictic oceanic populations have repeatedly given rise to phenotypically divergent freshwater populations. Genomic regions exhibiting signatures of both balancing and divergent selection were remarkably consistent across multiple, independently derived populations, indicating that replicate parallel phenotypic evolution in stickleback may be occurring through extensive, parallel genetic evolution at a genome-wide scale. Some of these genomic regions co-localize with previously identified QTL for stickleback phenotypic variation identified using laboratory mapping crosses. In addition, we have identified several novel regions showing parallel differentiation across independent populations. Annotation of these regions revealed numerous genes that are candidates for stickleback phenotypic evolution and will form the basis of future genetic analyses in this and other organisms. This study represents the first high-density SNP–based genome scan of genetic diversity and differentiation for populations of threespine stickleback in the wild. These data illustrate the complementary nature of laboratory crosses and population genomic scans by confirming the adaptive significance of previously identified genomic regions, elucidating the particular evolutionary and demographic history of such regions in natural

  8. Variation in Lateral Plate Quality in Threespine Stickleback from Fresh, Brackish and Marine Water: A Micro-Computed Tomography Study

    PubMed Central

    Reseland, Janne E.; Østbye, Kjartan; Haugen, Håvard J.; Vøllestad, Leif A.

    2016-01-01

    Introduction It is important to understand the drivers leading to adaptive phenotypic diversity within and among species. The threespine stickleback (Gasterosteus aculeatus) has become a model system for investigating the genetic and phenotypic responses during repeated colonization of fresh waters from the original marine habitat. During the freshwater colonization process there has been a recurrent and parallel reduction in the number of lateral bone plates, making it a suitable system for studying adaptability and parallel evolution. Objective The aim of this study was to investigate an alternative evolutionary path of lateral plate reduction, where lateral plates are reduced in size rather than number. Materials and Methods A total of 72 threespine stickleback individuals from freshwater (n = 54), brackish water (n = 27) and marine water (n = 9) were analysed using microcomputed tomography (μCT) to determine variation in size, thickness and structure of the lateral plates. Furthermore, whole-body bone volume, and bone volume, bone surface and porosity of lateral plate number 4 were quantified in all specimens from each environment. Results The results showed a significant difference in plate size (area and volume) among populations, where threespine stickleback from polymorphic freshwater and brackish water populations displayed lateral plates reduced in size (area and volume) compared to marine stickleback Conclusions Reduction of lateral plates in threespine stickleback in fresh and brackish water occurs by both plate loss and reduction in plate size (area and volume). PMID:27764140

  9. Association patterns and shoal fidelity in the three-spined stickleback.

    PubMed Central

    Ward, Ashley J W; Botham, Marc S; Hoare, Daniel J; James, Richard; Broom, Mark; Godin, Jean-Guy J; Krause, Jens

    2002-01-01

    We investigated pairwise association patterns and shoal fidelity in free-ranging, individual three-spine sticklebacks (Gasterosteus aculeatus) by capturing entire shoals of sticklebacks and tagging each shoal member with a unique individual mark before releasing the shoal at the point of capture. We recaptured tagged fishes in the study area on five subsequent days, noting their identity, their location and the individuals with which they were associated. Stable partner associations between fishes were observed which might provide the basis for shoal fidelity via social networks. These results suggest the potential for the kinds of inter-individual association patterns assumed by models of predator inspection and 'tit-for-tat' behaviours in free-ranging fishes. PMID:12495488

  10. Timing of Infections in the Threespine Stickleback (Gasterosteus aculeatus) by Schistocephalus solidus in Alaska.

    PubMed

    Heins, D C; Eidam, D M; Baker, J A

    2016-04-01

    This study provides direct evidence for the timing of infections by Schistocephalus solidus in the threespine stickleback (Gasterosteus aculeatus) of south-central Alaska. Young-of-the-year fish in Cheney Lake were infected during their first summer within a few months after hatching in May-June. Infections appear to continue under ice cover on the lake during the subsequent fall and winter. Few, if any, 1-yr-old fish seemed to be infected for the first time, although 1-yr-old hosts with established parasites apparently acquired additional infections.

  11. Timing of Infections in the Threespine Stickleback (Gasterosteus aculeatus) by Schistocephalus solidus in Alaska.

    PubMed

    Heins, D C; Eidam, D M; Baker, J A

    2016-04-01

    This study provides direct evidence for the timing of infections by Schistocephalus solidus in the threespine stickleback (Gasterosteus aculeatus) of south-central Alaska. Young-of-the-year fish in Cheney Lake were infected during their first summer within a few months after hatching in May-June. Infections appear to continue under ice cover on the lake during the subsequent fall and winter. Few, if any, 1-yr-old fish seemed to be infected for the first time, although 1-yr-old hosts with established parasites apparently acquired additional infections. PMID:26654283

  12. Perchlorate Exposure Reduces Primordial Germ Cell Number in Female Threespine Stickleback.

    PubMed

    Petersen, Ann M; Earp, Nathanial C; Redmond, Mandy E; Postlethwait, John H; von Hippel, Frank A; Buck, C Loren; Cresko, William A

    2016-01-01

    Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown to affect primordial sexual differentiation in the aquatic model fishes zebrafish and threespine stickleback, but the mechanism has been unclear. Stickleback exposed to perchlorate from fertilization have increased androgen levels in the embryo and disrupted reproductive morphologies as adults, suggesting that perchlorate could disrupt the earliest stages of primordial sexual differentiation when primordial germ cells (PGCs) begin to form the gonad. Female stickleback have three to four times the number of PGCs as males during the first weeks of development. We hypothesized that perchlorate exposure affects primordial sexual differentiation by reducing the number of germ cells in the gonad during an important window of stickleback sex determination at 14-18 days post fertilization (dpf). We tested this hypothesis by quantifying the number of PGCs at 16 dpf in control and 100 mg/L perchlorate-treated male and female stickleback. Perchlorate exposure from the time of fertilization resulted in significantly reduced PGC number only in genotypic females, suggesting that the masculinizing effects of perchlorate observed in adult stickleback may result from early changes to the number of PGCs at a time critical for sex determination. To our knowledge, this is the first evidence of a connection between an endocrine disruptor and reduction in PGC number prior to the first meiosis during sex determination. These findings suggest that a mode of action of perchlorate on adult reproductive phenotypes in vertebrates, including humans, such as altered fecundity and sex reversal or intersex gonads, may stem from early changes to germ cell development. PMID:27383240

  13. Perchlorate Exposure Reduces Primordial Germ Cell Number in Female Threespine Stickleback

    PubMed Central

    Petersen, Ann M.; Earp, Nathanial C.; Redmond, Mandy E.; Postlethwait, John H.; von Hippel, Frank A.; Buck, C. Loren; Cresko, William A.

    2016-01-01

    Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown to affect primordial sexual differentiation in the aquatic model fishes zebrafish and threespine stickleback, but the mechanism has been unclear. Stickleback exposed to perchlorate from fertilization have increased androgen levels in the embryo and disrupted reproductive morphologies as adults, suggesting that perchlorate could disrupt the earliest stages of primordial sexual differentiation when primordial germ cells (PGCs) begin to form the gonad. Female stickleback have three to four times the number of PGCs as males during the first weeks of development. We hypothesized that perchlorate exposure affects primordial sexual differentiation by reducing the number of germ cells in the gonad during an important window of stickleback sex determination at 14–18 days post fertilization (dpf). We tested this hypothesis by quantifying the number of PGCs at 16 dpf in control and 100 mg/L perchlorate-treated male and female stickleback. Perchlorate exposure from the time of fertilization resulted in significantly reduced PGC number only in genotypic females, suggesting that the masculinizing effects of perchlorate observed in adult stickleback may result from early changes to the number of PGCs at a time critical for sex determination. To our knowledge, this is the first evidence of a connection between an endocrine disruptor and reduction in PGC number prior to the first meiosis during sex determination. These findings suggest that a mode of action of perchlorate on adult reproductive phenotypes in vertebrates, including humans, such as altered fecundity and sex reversal or intersex gonads, may stem from early changes to germ cell development. PMID:27383240

  14. Ultraviolet light and visual behaviour in the three-spined stickleback, Gasterosteus aculeatus.

    PubMed

    Boulcott, Philip; Braithwaite, Victoria

    2005-01-01

    The ability of various vertebrates to perceive visual information in the ultraviolet region of the electromagnetic spectrum (300-400 nm) is receiving increasing interest. To date, many of these studies have concentrated on the role of ultraviolet perception in mate choice, yet there are several ways in which the ability to perceive ultraviolet information may affect other behaviours. Until now, it has been widely assumed that colour in the three-spined stickleback can be quantified by methods appropriate to the human visual system. However, evidence does exist that suggests that, in some populations, sticklebacks are capable of perceiving ultraviolet wavelengths. Using a behavioural technique, we tested the ability of the stickleback to perceive ultraviolet light under full-spectrum conditions to establish whether such wavelengths are utilised within their normal behavioural repertoire. We tested this ability by assessing whether subjects could locate hidden food in a foraging task where food position was indicated by the position of landmarks. These landmarks differed only in their ultraviolet content, appearing identical when viewed across the human visible region of the spectrum. We found that sticklebacks were able to use ultraviolet perception to locate a foraging patch under full-spectrum conditions.

  15. Extensive linkage disequilibrium and parallel adaptive divergence across threespine stickleback genomes

    PubMed Central

    Hohenlohe, Paul A.; Bassham, Susan; Currey, Mark; Cresko, William A.

    2012-01-01

    Population genomic studies are beginning to provide a more comprehensive view of dynamic genome-scale processes in evolution. Patterns of genomic architecture, such as genomic islands of increased divergence, may be important for adaptive population differentiation and speciation. We used next-generation sequencing data to examine the patterns of local and long-distance linkage disequilibrium (LD) across oceanic and freshwater populations of threespine stickleback, a useful model for studies of evolution and speciation. We looked for associations between LD and signatures of divergent selection, and assessed the role of recombination rate variation in generating LD patterns. As predicted under the traditional biogeographic model of unidirectional gene flow from ancestral oceanic to derived freshwater stickleback populations, we found extensive local and long-distance LD in fresh water. Surprisingly, oceanic populations showed similar patterns of elevated LD, notably between large genomic regions previously implicated in adaptation to fresh water. These results support an alternative biogeographic model for the stickleback radiation, one of a metapopulation with appreciable bi-directional gene flow combined with strong divergent selection between oceanic and freshwater populations. As predicted by theory, these processes can maintain LD within and among genomic islands of divergence. These findings suggest that the genomic architecture in oceanic stickleback populations may provide a mechanism for the rapid re-assembly and evolution of multi-locus genotypes in newly colonized freshwater habitats, and may help explain genetic mapping of parallel phenotypic variation to similar loci across independent freshwater populations. PMID:22201169

  16. The genetic basis of divergent pigment patterns in juvenile threespine sticklebacks

    PubMed Central

    Greenwood, A K; Jones, F C; Chan, Y F; Brady, S D; Absher, D M; Grimwood, J; Schmutz, J; Myers, R M; Kingsley, D M; Peichel, C L

    2011-01-01

    Animal pigment patterns are important for a range of functions, including camouflage and communication. Repeating pigment patterns, such as stripes, bars and spots have been of particular interest to developmental and theoretical biologists, but the genetic basis of natural variation in such patterns is largely unexplored. In this study, we identify a difference in a periodic pigment pattern among juvenile threespine sticklebacks (Gasterosteus aculeatus) from different environments. Freshwater sticklebacks exhibit prominent vertical bars that visually break up the body shape, but sticklebacks from marine populations do not. We hypothesize that these distinct pigment patterns are tuned to provide crypsis in different habitats. This phenotypic difference is widespread and appears in most of the freshwater populations that we sampled. We used quantitative trait locus (QTL) mapping in freshwater–marine F2 hybrids to elucidate the genetic architecture underlying divergence in this pigmentation pattern. We identified two QTL that were significantly associated with variation in barring. Interestingly, these QTL were associated with two distinct aspects of the pigment pattern: melanophore number and overall pigment level. We compared the QTL locations with positions of known pigment candidate genes in the stickleback genome. We also identified two major QTL for juvenile body size, providing new insights into the genetic basis of juvenile growth rates in natural populations. In summary, although there is a growing literature describing simple genetic bases for adaptive coloration differences, this study emphasizes that pigment patterns can also possess a more complex genetic architecture. PMID:21304547

  17. Human-induced eutrophication maintains high parasite prevalence in breeding threespine stickleback populations.

    PubMed

    Budria, Alexandre; Candolin, Ulrika

    2015-04-01

    Anthropogenic activities are having profound impacts on species interactions, with further consequences for populations and communities. We investigated the influence that anthropogenic eutrophication has on the prevalence of the parasitic tapeworm Schistocephalus solidus in threespine stickleback Gasterosteus aculeatus populations. We caught stickleback from four areas along the coast of Finland, and within each area from one undisturbed and one eutrophied habitat. We found the prevalence of the parasite to be lower in the eutrophied habitats at the start of the breeding season, probably because of fewer piscivorous birds that transmit the parasite. However, while the prevalence of the parasite declined across the season in the undisturbed habitat, it did less so in eutrophied habitats. We discuss different processes that could be behind the differences, such as lower predation rate on infected fish, higher food availability and less dispersal in eutrophied habitats. We found no effect of eutrophication on the proportion of infected stickleback that entered reproductive condition. Together with earlier findings, this suggests that eutrophication increases the proportion of infected stickleback that reproduce. This could promote the evolution of less parasite resistant populations, with potential consequences for the viability of the interacting parties of the host-parasite system.

  18. Population-Specific Covariation between Immune Function and Color of Nesting Male Threespine Stickleback

    PubMed Central

    Bolnick, Daniel I.; Shim, Kum Chuan; Schmerer, Matthew; Brock, Chad D.

    2015-01-01

    Multiple biological processes can generate sexual selection on male visual signals such as color. For example, females may prefer colorful males because those males are more readily detected (perceptual bias), or because male color conveys information about male quality and associated direct or indirect benefits to females. For example, male threespine stickleback often exhibit red throat coloration, which females prefer both because red is more visible in certain environments, and red color is correlated with male immune function and parasite load. However, not all light environments favor red nuptial coloration: more tannin-stained water tends to favor the evolution of a melanic male phenotype. Do such population differences in stickleback male color, driven by divergent light environments, lead to changes in the relationship between color and immunity? Here, we show that, within stickleback populations, multiple components of male color (brightness and hue of four body parts) are correlated with multiple immune variables (ROS production, phagocytosis rates, and lymphocyte:leukocyte ratios). Some of these color-immune associations persist across stickleback populations with very different male color patterns, whereas other color-immune associations are population-specific. Overall, lakes with red males exhibit stronger color-immune covariance while melanic male populations exhibit weak if any color-immune associations. Our finding that color-immunity relationships are labile implies that any evolution of male color traits (e.g., due to female perceptual bias in a given light environment), can alter the utility of color as an indicator of male quality. PMID:26039044

  19. Purifying Selection Maintains Dosage-Sensitive Genes during Degeneration of the Threespine Stickleback Y Chromosome.

    PubMed

    White, Michael A; Kitano, Jun; Peichel, Catherine L

    2015-08-01

    Sex chromosomes are subject to unique evolutionary forces that cause suppression of recombination, leading to sequence degeneration and the formation of heteromorphic chromosome pairs (i.e., XY or ZW). Although progress has been made in characterizing the outcomes of these evolutionary processes on vertebrate sex chromosomes, it is still unclear how recombination suppression and sequence divergence typically occur and how gene dosage imbalances are resolved in the heterogametic sex. The threespine stickleback fish (Gasterosteus aculeatus) is a powerful model system to explore vertebrate sex chromosome evolution, as it possesses an XY sex chromosome pair at relatively early stages of differentiation. Using a combination of whole-genome and transcriptome sequencing, we characterized sequence evolution and gene expression across the sex chromosomes. We uncovered two distinct evolutionary strata that correspond with known structural rearrangements on the Y chromosome. In the oldest stratum, only a handful of genes remain, and these genes are under strong purifying selection. By comparing sex-linked gene expression with expression of autosomal orthologs in an outgroup, we show that dosage compensation has not evolved in threespine sticklebacks through upregulation of the X chromosome in males. Instead, in the oldest stratum, the genes that still possess a Y chromosome allele are enriched for genes predicted to be dosage sensitive in mammals and yeast. Our results suggest that dosage imbalances may have been avoided at haploinsufficient genes by retaining function of the Y chromosome allele through strong purifying selection.

  20. Thermal acclimation, growth, and burst swimming of threespine stickleback: enzymatic correlates and influence of photoperiod.

    PubMed

    Guderley, H; Leroy, P H; Gagné, A

    2001-01-01

    Threespine sticklebacks (Gasterosteus aculeatus) that had been reared in the laboratory under natural photoperiods were acclimated to 23 degrees and 8 degrees C in late spring under increasing day lengths and again in late fall under decreasing day lengths. The parents of these fish were from the anadromous Isle Verte population. In the spring, cold- and warm-acclimated fish grew at the same rates and attained similar condition factors (mass L(-3)), although food intake was considerably higher at 23 degrees C. As both groups had similar increases in mass and condition, the higher axial muscle activities of citrate synthase and phosphofructokinase (measured at 20 degrees C) after cold acclimation were likely a direct response to temperature. Multiple regression analysis showed that axial muscle levels of cytochrome C oxidase and citrate synthase were correlated with the burst swimming speeds of the spring sticklebacks, while growth rates were positively correlated with lactate dehydrogenase levels in pectoral and axial muscles and creatine kinase levels in the axial muscle. In the fall, the fish in both acclimation groups grew little, although they fed at similar rates as in the spring experiment. Overall, the sticklebacks showed lower burst swimming speeds in the fall. In both spring and fall, the burst speeds of cold- and warm-acclimated sticklebacks only differed at warm temperatures. In the spring experiment, the cold-acclimated fish swam faster, whereas in the fall experiment the warm-acclimated fish swam faster despite their lower percentage of axial muscle. Swimming speeds were measured both at a fish's acclimation temperature and after 12 h at the other temperature. Cold-acclimated sticklebacks seem to have more facility in rapidly adjusting to warm temperatures when they have experienced increasing rather than decreasing day lengths, perhaps as a result of the requirements of the spring migration to the intertidal breeding grounds. PMID:11226015

  1. Genetic Mapping of Natural Variation in Schooling Tendency in the Threespine Stickleback

    PubMed Central

    Greenwood, Anna K.; Ardekani, Reza; McCann, Shaugnessy R.; Dubin, Matthew E.; Sullivan, Amy; Bensussen, Seth; Tavaré, Simon; Peichel, Catherine L.

    2015-01-01

    Although there is a heritable basis for many animal behaviors, the genetic architecture of behavioral variation in natural populations remains mostly unknown, particularly in vertebrates. We sought to identify the genetic basis for social affiliation in two populations of threespine sticklebacks (Gasterosteus aculeatus) that differ in their propensity to school. Marine sticklebacks from Japan school strongly whereas benthic sticklebacks from a lake in Canada are more solitary. Here, we expanded on our previous efforts to identify quantitative trait loci (QTL) for differences in schooling tendency. We tested fish multiple times in two assays that test different aspects of schooling tendency: 1) the model school assay, which presents fish with a school of eight model sticklebacks; and 2) the choice assay, in which fish are given a choice between the model school and a stationary artificial plant. We found low-to-moderate levels of repeatability, ranging from 0.1 to 0.5, in schooling phenotypes. To identify the genomic regions that contribute to differences in schooling tendency, we used QTL mapping in two types of crosses: benthic × marine backcrosses and an F2 intercross. We found two QTL for time spent with the school in the model school assay, and one QTL for number of approaches to the school in the choice assay. These QTL were on three different linkage groups, not previously linked to behavioral differences in sticklebacks. Our results highlight the importance of using multiple crosses and robust behavioral assays to uncover the genetic basis of behavioral variation in natural populations. PMID:25717151

  2. The role of calcium and predation on plate morph evolution in the three-spined stickleback (Gasterosteus aculeatus)

    PubMed Central

    Smith, Carl; Spence, Rowena; Barber, Iain; Przybylski, Mirosław; Wootton, Robert J

    2014-01-01

    While the genetic basis to plate morph evolution of the three-spined stickleback (Gasterosteus aculeatus) is well described, the environmental variables that select for different plate and spine morphs are incompletely understood. Using replicate populations of three-spined sticklebacks on North Uist, Scotland, we previously investigated the role of predation pressure and calcium limitation on the adaptive evolution of stickleback morphology and behavior. While dissolved calcium proved a significant predictor of plate and spine morph, predator abundance did not. Ecol. Evol., xxx, 2014 and xxx performed a comparable analysis to our own to address the same question. They failed to detect a significant effect of dissolved calcium on morphological evolution, but did establish a significant effect of predation; albeit in the opposite direction to their prediction. PMID:25478147

  3. Among-lake reciprocal transplants induce convergent expression of immune genes in threespine stickleback.

    PubMed

    Stutz, William E; Schmerer, Matthew; Coates, Jessica L; Bolnick, Daniel I

    2015-09-01

    Geographic variation in parasite communities can drive evolutionary divergence in host immune genes. However, biotic and abiotic environmental variation can also induce plastic differences in immune function among populations. At present, there is little information concerning the relative magnitudes of heritable vs. induced immune divergence in natural populations. We examined immune gene expression profiles of threespine stickleback (Gasterosteus aculeatus) from six lakes on Vancouver Island, British Columbia. Parasite community composition differs between lake types (large or small, containing limnetic- or benthic-like stickleback) and between watersheds. We observed corresponding differences in immune gene expression profiles among wild-caught stickleback, using a set of seven immune genes representing distinct branches of the immune system. To evaluate the role of environmental effects on this differentiation, we experimentally transplanted wild-caught fish into cages in their native lake, or into a nearby foreign lake. Transplanted individuals' immune gene expression converged on patterns typical of their destination lake, deviating from their native expression profile. Transplant individuals' source population had a much smaller effect, suggesting relatively weak genetic underpinning of population differences in immunity, as viewed through gene expression. This strong environmental regulation of immune gene expression provides a counterpoint to the large emerging literature documenting microevolution and genetic diversification of immune function. Our findings illustrate the value of studying immunity in natural environmental settings where the immune system has evolved and actively functions. PMID:26118468

  4. Behavioral type–environment correlations in the field: a study of three-spined stickleback

    PubMed Central

    Pearish, Simon; Hostert, Lauren; Bell, Alison M.

    2014-01-01

    Behavioral type–environment correlations occur when specific behavioral types of individuals are more common in certain environments. Behavioral type–environment correlations can be generated by several different mechanisms that are probably very common such as niche construction and phenotypic plasticity. Moreover, behavioral type–environment correlations have important ecological and evolutionary implications. However, few studies have examined behavioral type–environment correlations in natural populations. In this study, we asked whether some behavioral types of three-spined stickleback were more likely to occur in certain social environments (alone or in a shoal with other stickleback) or in certain microhabitats in a river (in the open or under cover). We found that individuals that were in shoals with other stickleback at the time of collection from the field emerged from a refuge more quickly compared to individuals that were found alone. In addition, fish that were alone in an open microhabitat explored more of a pool compared to fish that were alone in cover, but this difference did not occur among fish that were in shoals at the time of collection. Subsequent analyses of gut contents suggested that differences in microhabitat use were consistent over time. Our study provides some of the first evidence for behavioral type–environment correlations in a natural population of non-human animals. PMID:24688167

  5. Female mate preferences for male body size and shape promote sexual isolation in threespine sticklebacks

    PubMed Central

    Head, Megan L; Kozak, Genevieve M; Boughman, Janette W

    2013-01-01

    Female mate preferences for ecologically relevant traits may enhance natural selection, leading to rapid divergence. They may also forge a link between mate choice within species and sexual isolation between species. Here, we examine female mate preference for two ecologically important traits: body size and body shape. We measured female preferences within and between species of benthic, limnetic, and anadromous threespine sticklebacks (Gasterosteus aculeatus species complex). We found that mate preferences differed between species and between contexts (i.e., within vs. between species). Within species, anadromous females preferred males that were deep bodied for their size, benthic females preferred larger males (as measured by centroid size), and limnetic females preferred males that were more limnetic shaped. In heterospecific mating trials between benthics and limnetics, limnetic females continued to prefer males that were more limnetic like in shape when presented with benthic males. Benthic females showed no preferences for size when presented with limnetic males. These results show that females use ecologically relevant traits to select mates in all three species and that female preference has diverged between species. These results suggest that sexual selection may act in concert with natural selection on stickleback size and shape. Further, our results suggest that female preferences may track adaptation to local environments and contribute to sexual isolation between benthic and limnetic sticklebacks. PMID:23919161

  6. Among-lake reciprocal transplants induce convergent expression of immune genes in threespine stickleback.

    PubMed

    Stutz, William E; Schmerer, Matthew; Coates, Jessica L; Bolnick, Daniel I

    2015-09-01

    Geographic variation in parasite communities can drive evolutionary divergence in host immune genes. However, biotic and abiotic environmental variation can also induce plastic differences in immune function among populations. At present, there is little information concerning the relative magnitudes of heritable vs. induced immune divergence in natural populations. We examined immune gene expression profiles of threespine stickleback (Gasterosteus aculeatus) from six lakes on Vancouver Island, British Columbia. Parasite community composition differs between lake types (large or small, containing limnetic- or benthic-like stickleback) and between watersheds. We observed corresponding differences in immune gene expression profiles among wild-caught stickleback, using a set of seven immune genes representing distinct branches of the immune system. To evaluate the role of environmental effects on this differentiation, we experimentally transplanted wild-caught fish into cages in their native lake, or into a nearby foreign lake. Transplanted individuals' immune gene expression converged on patterns typical of their destination lake, deviating from their native expression profile. Transplant individuals' source population had a much smaller effect, suggesting relatively weak genetic underpinning of population differences in immunity, as viewed through gene expression. This strong environmental regulation of immune gene expression provides a counterpoint to the large emerging literature documenting microevolution and genetic diversification of immune function. Our findings illustrate the value of studying immunity in natural environmental settings where the immune system has evolved and actively functions.

  7. Innate immune responses to gut microbiota differ between oceanic and freshwater threespine stickleback populations

    PubMed Central

    Milligan-Myhre, Kathryn; Small, Clayton M.; Mittge, Erika K.; Agarwal, Meghna; Currey, Mark; Cresko, William A.; Guillemin, Karen

    2016-01-01

    ABSTRACT Animal hosts must co-exist with beneficial microbes while simultaneously being able to mount rapid, non-specific, innate immune responses to pathogenic microbes. How this balance is achieved is not fully understood, and disruption of this relationship can lead to disease. Excessive inflammatory responses to resident microbes are characteristic of certain gastrointestinal pathologies such as inflammatory bowel disease (IBD). The immune dysregulation of IBD has complex genetic underpinnings that cannot be fully recapitulated with single-gene-knockout models. A deeper understanding of the genetic regulation of innate immune responses to resident microbes requires the ability to measure immune responses in the presence and absence of the microbiota using vertebrate models with complex genetic variation. Here, we describe a new gnotobiotic vertebrate model to explore the natural genetic variation that contributes to differences in innate immune responses to microbiota. Threespine stickleback, Gasterosteus aculeatus, has been used to study the developmental genetics of complex traits during the repeated evolution from ancestral oceanic to derived freshwater forms. We established methods to rear germ-free stickleback larvae and gnotobiotic animals monoassociated with single bacterial isolates. We characterized the innate immune response of these fish to resident gut microbes by quantifying the neutrophil cells in conventionally reared monoassociated or germ-free stickleback from both oceanic and freshwater populations grown in a common intermediate salinity environment. We found that oceanic and freshwater fish in the wild and in the laboratory share many intestinal microbial community members. However, oceanic fish mount a strong immune response to residential microbiota, whereas freshwater fish frequently do not. A strong innate immune response was uniformly observed across oceanic families, but this response varied among families of freshwater fish. The

  8. Innate immune responses to gut microbiota differ between oceanic and freshwater threespine stickleback populations.

    PubMed

    Milligan-Myhre, Kathryn; Small, Clayton M; Mittge, Erika K; Agarwal, Meghna; Currey, Mark; Cresko, William A; Guillemin, Karen

    2016-02-01

    Animal hosts must co-exist with beneficial microbes while simultaneously being able to mount rapid, non-specific, innate immune responses to pathogenic microbes. How this balance is achieved is not fully understood, and disruption of this relationship can lead to disease. Excessive inflammatory responses to resident microbes are characteristic of certain gastrointestinal pathologies such as inflammatory bowel disease (IBD). The immune dysregulation of IBD has complex genetic underpinnings that cannot be fully recapitulated with single-gene-knockout models. A deeper understanding of the genetic regulation of innate immune responses to resident microbes requires the ability to measure immune responses in the presence and absence of the microbiota using vertebrate models with complex genetic variation. Here, we describe a new gnotobiotic vertebrate model to explore the natural genetic variation that contributes to differences in innate immune responses to microbiota. Threespine stickleback, Gasterosteus aculeatus, has been used to study the developmental genetics of complex traits during the repeated evolution from ancestral oceanic to derived freshwater forms. We established methods to rear germ-free stickleback larvae and gnotobiotic animals monoassociated with single bacterial isolates. We characterized the innate immune response of these fish to resident gut microbes by quantifying the neutrophil cells in conventionally reared monoassociated or germ-free stickleback from both oceanic and freshwater populations grown in a common intermediate salinity environment. We found that oceanic and freshwater fish in the wild and in the laboratory share many intestinal microbial community members. However, oceanic fish mount a strong immune response to residential microbiota, whereas freshwater fish frequently do not. A strong innate immune response was uniformly observed across oceanic families, but this response varied among families of freshwater fish. The gnotobiotic

  9. Parasites contribute to ecologically dependent postmating isolation in the adaptive radiation of three-spined stickleback

    PubMed Central

    El Nagar, Aliya

    2016-01-01

    Spatial variation in parasitic infections is common, and has the potential to drive population divergence and the reproductive isolation of hosts. However, despite support from theory and model laboratory systems, little strong evidence has been forthcoming from the wild. Here, we show that parasites are likely to cause reproductive isolation in the adaptive radiation of three-spined stickleback. Adjacent wild populations on the Scottish island of North Uist differ greatly and consistently in the occurrence of different parasites that have substantial effects on fitness. Laboratory-reared fish are more resistant to experimental infection by parasite species from their own population. Furthermore, hybrid backcrosses between the host populations are more resistant to parasites from the parental population to which they are more closely related. These patterns provide strong evidence that parasites can cause ecological speciation, by contributing to selection against migrants and ecologically dependent postmating isolation. PMID:27512145

  10. Ecological divergence and habitat isolation between two migratory forms of Japanese threespine stickleback (Gasterosteus aculeatus).

    PubMed

    Kume, M; Kitano, J; Mori, S; Shibuya, T

    2010-07-01

    When two closely related species migrate to divergent spawning sites, divergent use of spawning habitats can directly reduce heterospecific mating. Furthermore, adaptations to divergent spawning habitats can promote speciation as a by-product of ecological divergence. Here, we investigated habitat isolation and ecological divergence between two anadromous forms of threespine stickleback (Gasterosteus aculeatus), the Japan Sea and Pacific Ocean forms. In several coastal regions of eastern Hokkaido, Japan, these forms migrate to the same watershed to spawn. Our field surveys in a single watershed revealed that segregation of distinct spawning sites between the two forms was maintained within the watershed across multiple years. These spawning sites diverged in salinity and predator composition. Morphological and physiological divergence between the forms also occurs in the direction predicted by ecological differences between the spawning sites. Our data indicate that migration into divergent spawning habitats can be an important mechanism contributing to speciation and phenotypic divergence in anadromous fishes. PMID:20456572

  11. Parasites contribute to ecologically dependent postmating isolation in the adaptive radiation of three-spined stickleback.

    PubMed

    El Nagar, Aliya; MacColl, Andrew D C

    2016-08-17

    Spatial variation in parasitic infections is common, and has the potential to drive population divergence and the reproductive isolation of hosts. However, despite support from theory and model laboratory systems, little strong evidence has been forthcoming from the wild. Here, we show that parasites are likely to cause reproductive isolation in the adaptive radiation of three-spined stickleback. Adjacent wild populations on the Scottish island of North Uist differ greatly and consistently in the occurrence of different parasites that have substantial effects on fitness. Laboratory-reared fish are more resistant to experimental infection by parasite species from their own population. Furthermore, hybrid backcrosses between the host populations are more resistant to parasites from the parental population to which they are more closely related. These patterns provide strong evidence that parasites can cause ecological speciation, by contributing to selection against migrants and ecologically dependent postmating isolation. PMID:27512145

  12. Occurrence of the parasitic copepod Ergasilus labracis on Threespine Sticklebacks from the south coast of Newfoundland.

    PubMed

    Eaves, Alexandra A; Ang, Keng Pee; Murray, Harry M

    2014-12-01

    A study conducted from August to October 2013 surveyed Threespine Sticklebacks Gasterosteus aculeatus (n = 822) for the presence of parasitic copepods in the vicinity of large sea-cage salmonid farms in Bay d'Espoir, Newfoundland. The majority of parasitic copepods surveyed were Ergasilus labracis (n = 4,684). Other parasitic copepods observed on Threespine Sticklebacks during the survey included chalimus-stage Lepeophtheirus spp. (n = 3), adult Argulus alosae (n = 2), and a single Thersitina gasterostei. This represents a new host record for E. labracis. The copepods were present on fish collected in a broad range of temperatures (6.9-17.7°C) and salinities (10.2-30.2 [Practical Salinity Scale]). The parasitic copepods were most commonly found on larger hosts estimated to be age 1 or older. Surprisingly, the highest infestations (approximately 65%) were found on regions of the hosts outside of the gills (behind the pectoral fins and pelvic spines); in some cases, the copepods had inflicted significant damage to the skin of their hosts. Among host fish with evidence of an additional infection, such as microsporidian tumors (xenomas) or hemorrhagic-like symptoms (dark red abdomens and bloody mucus), the prevalence of E. labracis was significantly higher (43.4%) than among healthy fish (28.9%) despite there being no significant difference in size between the two fish health groups. In contrast, intensity (mean number of individual parasites per host) was significantly higher among healthy hosts (23.6) than among unhealthy ones (7.63). Although this parasite has been listed as present in Newfoundland previously, it has a broad host range and has been reported to be pathogenic to farmed salmonids. Therefore, its potential impact on wild and farmed fish populations around Newfoundland should not be underestimated. PMID:25321153

  13. Consistent individual differences in paternal behavior: a field study of threespine stickleback

    PubMed Central

    Stein, Laura R.; Bell, Alison M.

    2014-01-01

    Consistent individual differences in parenting are widespread; however, we know little about why there is variation in parenting behavior among individuals within species. One possible explanation for consistent individual differences in parenting is that individuals invest in different aspects of parental care, such as provisioning or defense. In this field study we measured consistent individual differences in parenting behavior and evaluated correlations between parenting and other behaviors in threespine stickleback (Gasterosteus aculeatus). We repeatedly measured male parenting behavior and male behavior in the presence of three different types of live intruders: a female, a conspecific male, and a predator, meant to provoke courtship, aggressive and antipredator behavior, respectively. While males plastically adjusted their reactions to different types of intruders, we found consistent individual differences in behavior (behavioral types) both within and across contexts, even after accounting for variation in body size and nest characteristics. Males that performed more parenting behavior responded faster to all types of intruders. These results suggest that in nature, individual male stickleback exhibit robust parental behavioral types, and highly parental males are more attentive to their surroundings. Future studies are needed to examine the potential causes of individual variation in parental behavior in the field. PMID:25663736

  14. The ecology of an adaptive radiation of three-spined stickleback from North Uist, Scotland.

    PubMed

    Magalhaes, Isabel S; D'Agostino, Daniele; Hohenlohe, Paul A; MacColl, Andrew D C

    2016-09-01

    There has been a large focus on the genetics of traits involved in adaptation, but knowledge of the environmental variables leading to adaptive changes is surprisingly poor. Combined use of environmental data with morphological and genomic data should allow us to understand the extent to which patterns of phenotypic and genetic diversity within a species can be explained by the structure of the environment. Here, we analyse the variation of populations of three-spined stickleback from 27 freshwater lakes on North Uist, Scotland, that vary greatly in their environment, to understand how environmental and genetic constraints contribute to phenotypic divergence. We collected 35 individuals per population and 30 abiotic and biotic environmental parameters to characterize variation across lakes and analyse phenotype-environment associations. Additionally, we used RAD sequencing to estimate the genetic relationships among a subset of these populations. We found a large amount of phenotypic variation among populations, most prominently in armour and spine traits. Despite large variation in the abiotic environment, namely in ion composition, depth and dissolved organic Carbon, more phenotypic variation was explained by the biotic variables (presence of predators and density of predator and competitors), than by associated abiotic variables. Genetic structure among populations was partly geographic, with closer populations being more similar. Altogether, our results suggest that differences in body shape among stickleback populations are the result of both canalized genetic and plastic responses to environmental factors, which shape fish morphology in a predictable direction regardless of their genetic starting point. PMID:27374399

  15. Habitat-Specific Morphological Variation among Threespine Sticklebacks (Gasterosteus aculeatus) within a Drainage Basin

    PubMed Central

    Webster, Mike M.; Atton, Nicola; Hart, Paul J. B.; Ward, Ashley J. W.

    2011-01-01

    Habitat-specific morphological variation, often corresponding to resource specialization, is well documented in freshwater fishes. In this study we used landmark based morphometric analyses to investigate morphological variation among threespine sticklebacks (Gasterosteus aculeatus L.) from four interconnected habitat types within a single lowland drainage basin in eastern England. These included the upper and lower reaches of the river, the estuary, a connected ditch network and a coastal salt marsh. We found significant habitat-specific differences in morphology, with three axes of variation describing differences in orbit diameter, body depth, caudal peduncle shape and pectoral fin positioning as well as variation in relative dorsal and pelvic spine size. Interestingly, the ditch system, an artificial and heavily managed habitat, is populated by sticklebacks with a characteristic morphology, suggesting that human management of habitats can in some circumstances lead to morphological variation among the animals that inhabit them. We discuss the mechanisms that conceivably underlie the observed morphological variation and the further work necessary to identify them. Finally, we consider the implications of habitat-specific body shape variation for the behavioural ecology of this ecologically generalist species. PMID:21698269

  16. High degree of genetic differentiation in marine three-spined sticklebacks (Gasterosteus aculeatus).

    PubMed

    Defaveri, Jacquelin; Shikano, Takahito; Shimada, Yukinori; Merilä, Juha

    2013-09-01

    Populations of widespread marine organisms are typically characterized by a low degree of genetic differentiation in neutral genetic markers, but much less is known about differentiation in genes whose functional roles are associated with specific selection regimes. To uncover possible adaptive population divergence and heterogeneous genomic differentiation in marine three-spined sticklebacks (Gasterosteus aculeatus), we used a candidate gene-based genome-scan approach to analyse variability in 138 microsatellite loci located within/close to (<6 kb) functionally important genes in samples collected from ten geographic locations. The degree of genetic differentiation in markers classified as neutral or under balancing selection-as determined with several outlier detection methods-was low (F(ST) = 0.033 or 0.011, respectively), whereas average FST for directionally selected markers was significantly higher (F(ST) = 0.097). Clustering analyses provided support for genomic and geographic heterogeneity in selection: six genetic clusters were identified based on allele frequency differences in the directionally selected loci, whereas four were identified with the neutral loci. Allelic variation in several loci exhibited significant associations with environmental variables, supporting the conjecture that temperature and salinity, but not optic conditions, are important drivers of adaptive divergence among populations. In general, these results suggest that in spite of the high degree of physical connectivity and gene flow as inferred from neutral marker genes, marine stickleback populations are strongly genetically structured in loci associated with functionally relevant genes.

  17. Can gene flow have negative demographic consequences? Mixed evidence from stream threespine stickleback

    PubMed Central

    Moore, Jean-Sébastien; Hendry, Andrew P.

    2009-01-01

    Dispersal and gene flow can have both positive and negative effects on population size, but little empirical support from nature exists for the negative effects. We test for such effects in a stream population of threespine stickleback (Gasterosteus aculeatus L.) that is subject to high gene flow from a lake and is thus maladapted to stream conditions. In this system, maladaptation increases with distance along the stream, and this increase is associated with decreasing population densities until stickleback are no longer present (2.5 km from the lake). We conducted field experiments to inform whether this association might reflect a negative role for gene flow in constraining population size and therefore causing a local range limit. We specifically tested predictions deriving from theory: peripheral populations should show partial local adaptation, be under strong selection and not simply be maintained by dispersal. First, a transplant experiment suggested a weak home-site advantage in the peripheral population. Second, a mark–recapture study showed directional selection for a stream-adapted phenotype in 1 of 2 years. Third, another mark–recapture experiment showed that dispersal is limited to the point that positive demographic effects of dispersal are probably minimal. We conclude that, although gene flow does constrain morphological maladaptation in the outlet stream population, the evidence for its contribution to population size and range limits is mixed. We discuss the implications of our work for the study of factors influencing the evolution of species' ranges. PMID:19414468

  18. The ecology of an adaptive radiation of three-spined stickleback from North Uist, Scotland.

    PubMed

    Magalhaes, Isabel S; D'Agostino, Daniele; Hohenlohe, Paul A; MacColl, Andrew D C

    2016-09-01

    There has been a large focus on the genetics of traits involved in adaptation, but knowledge of the environmental variables leading to adaptive changes is surprisingly poor. Combined use of environmental data with morphological and genomic data should allow us to understand the extent to which patterns of phenotypic and genetic diversity within a species can be explained by the structure of the environment. Here, we analyse the variation of populations of three-spined stickleback from 27 freshwater lakes on North Uist, Scotland, that vary greatly in their environment, to understand how environmental and genetic constraints contribute to phenotypic divergence. We collected 35 individuals per population and 30 abiotic and biotic environmental parameters to characterize variation across lakes and analyse phenotype-environment associations. Additionally, we used RAD sequencing to estimate the genetic relationships among a subset of these populations. We found a large amount of phenotypic variation among populations, most prominently in armour and spine traits. Despite large variation in the abiotic environment, namely in ion composition, depth and dissolved organic Carbon, more phenotypic variation was explained by the biotic variables (presence of predators and density of predator and competitors), than by associated abiotic variables. Genetic structure among populations was partly geographic, with closer populations being more similar. Altogether, our results suggest that differences in body shape among stickleback populations are the result of both canalized genetic and plastic responses to environmental factors, which shape fish morphology in a predictable direction regardless of their genetic starting point.

  19. Divergent Macroparasite Infections in Parapatric Swiss Lake-Stream Pairs of Threespine Stickleback (Gasterosteus aculeatus)

    PubMed Central

    Karvonen, Anssi; Lucek, Kay; Marques, David A.; Seehausen, Ole

    2015-01-01

    Spatial heterogeneity in diversity and intensity of parasitism is a typical feature of most host-parasite interactions, but understanding of the evolutionary implications of such variation is limited. One possible outcome of infection heterogeneities is parasite-mediated divergent selection between host populations, ecotypes or species which may facilitate the process of ecological speciation. However, very few studies have described infections in population-pairs along the speciation continuum from low to moderate or high degree of genetic differentiation that would address the possibility of parasite-mediated divergent selection in the early stages of the speciation process. Here we provide an example of divergent parasitism in freshwater fish ecotypes by examining macroparasite infections in threespine stickleback (Gasterosteus aculeatus) of four Swiss lake systems each harbouring parapatric lake-stream ecotype pairs. We demonstrate significant differences in infections within and between the pairs that are driven particularly by the parasite taxa transmitted to fish from benthic invertebrates. The magnitude of the differences tended to correlate positively with the extent of neutral genetic differentiation between the parapatric lake and stream populations of stickleback, whereas no such correlation was found among allopatric populations from similar or contrasting habitats. This suggests that genetic differentiation is unrelated to the magnitude of parasite infection contrasts when gene flow is constrained by geographical barriers while in the absence of physical barriers, genetic differentiation and the magnitude of differences in infections tend to be positively correlated. PMID:26086778

  20. Cold acclimation increases levels of some heat shock protein and sirtuin isoforms in threespine stickleback.

    PubMed

    Teigen, Laura E; Orczewska, Julieanna I; McLaughlin, Jessica; O'Brien, Kristin M

    2015-10-01

    Molecular chaperones [heat shock proteins (HSPs)] increase in response to rapid changes in temperatures, but long-term acclimation to cold temperature may also warrant elevations in HSPs. In fishes, cold acclimation increases mitochondrial density and oxidative stress in some tissues, which may increase demand for HSPs. We hypothesized that levels of HSPs, as well as sirtuins (SIRTs), NAD-dependent deacetylases that mediate changes in metabolism and responses to oxidative stress (including increases in HSPs), would increase during cold acclimation of threespine stickleback (Gasterosteus aculeatus). Transcript levels of hsp70, hsc70, hsp60 and hsp90-α, sirts1-4, as well as protein levels of HSP60, HSP90 and HSC70 were quantified in liver and pectoral adductor muscle of stickleback during cold acclimation from 20 °C to 8 °C. In liver, cold acclimation stimulated a transient increase in mRNA levels of hsp60 and hsc70. Transcript levels of sirt1 and sirt2 also increased in response to cold acclimation and remained elevated. In pectoral muscle, mRNA levels of hsp60, hsp90-α, hsc70 and sirt1 all transiently increased in response to cold acclimation, while levels of sirts2-4 remained constant or declined. Similar to transcript levels, protein levels of HSC70 increased in both liver and pectoral muscle. Levels of HSP90 also increased in liver after 4 weeks at 8 °C. HSP60 remained unchanged in both tissues, as did HSP90 in pectoral muscle. Our results indicate that while both HSPs and SIRTs increase in response to cold acclimation in stickleback, the response is tissue and isoform specific, likely reflecting differences in metabolism and oxidative stress.

  1. A test of maternal programming of offspring stress response to predation risk in threespine sticklebacks.

    PubMed

    Mommer, Brett C; Bell, Alison M

    2013-10-01

    Non-genetic maternal effects are widespread across taxa and challenge our traditional understanding of inheritance. Maternal experience with predators, for example, can have lifelong consequences for offspring traits, including fitness. Previous work in threespine sticklebacks showed that females exposed to simulated predation risk produced eggs with higher cortisol content and offspring with altered anti-predator behavior. However, it is unknown whether this maternal effect is mediated via the offspring glucocorticoid stress response and if it is retained over the entire lifetime of offspring. Therefore, we tested the hypothesis that maternal exposure to simulated predation risk has long-lasting effects on the cortisol response to simulated predation risk in stickleback offspring. We measured circulating concentrations of cortisol before (baseline), 15 min after, and 60 min after exposure to a simulated predation risk. We compared adult offspring of predator-exposed mothers and control mothers in two different social environments (alone or in a group). Relative to baseline, offspring plasma cortisol was highest 15 min after exposure to simulated predation risk and decreased after 60 min. Offspring of predator-exposed mothers differed in the cortisol response to simulated predation risk compared to offspring of control mothers. In general, females had higher cortisol than males, and fish in a group had lower cortisol than fish that were by themselves. The buffering effect of the social environment did not differ between maternal treatments or between males and females. Altogether the results show that while a mother's experience with simulated predation risk might affect the physiological response of her adult offspring to a predator, sex and social isolation have much larger effects on the stress response to predation risk in sticklebacks.

  2. Latitudinal variation in photoperiodic response of the three-spined stickleback Gasterosteus aculeatus in western North America

    PubMed Central

    Yeates-Burghart, Q. S.; O’Brien, C.; Cresko, W. A.; Holzapfel, C. M.; Bradshaw, W. E.

    2014-01-01

    Reproductive maturation in both male and female three-spined stickleback Gasterosteus aculeatus was strongly photoperiodic in a northern population (Alaska, 61° N) but not in a southern population (Oregon, 43° N) from western North America. Increasing reliance on photoperiod with increasing latitude is a general phenomenon among vertebrates, and is probably due to the anticipation of a narrower window of opportunity for reproduction and development at higher latitudes. PMID:20738673

  3. Food intake rates of inactive fish are positively linked to boldness in three-spined sticklebacks Gasterosteus aculeatus.

    PubMed

    Jolles, J W; Manica, A; Boogert, N J

    2016-04-01

    To investigate the link between personality and maximum food intake of inactive individuals, food-deprived three-spined sticklebacks Gasterosteus aculeatus at rest in their home compartments were provided with ad libitum prey items. Bolder individuals ate considerably more than shyer individuals, even after accounting for body size, while sociability did not have an effect. These findings support pace-of-life theory predicting that life-history strategies are linked to boldness. PMID:26940195

  4. Latitudinal variation in photoperiodic response of the three-spined stickleback Gasterosteus aculeatus in western North America.

    PubMed

    Yeates-Burghart, Q S; O'Brien, C; Cresko, W A; Holzapfel, C M; Bradshaw, W E

    2009-11-01

    Reproductive maturation in both male and female three-spined stickleback Gasterosteus aculeatus was strongly photoperiodic in a northern population (Alaska, 61 degrees N) but not in a southern population (Oregon, 43 degrees N) from western North America. Increasing reliance on photoperiod with increasing latitude is a general phenomenon among vertebrates, and is probably due to the anticipation of a narrower window of opportunity for reproduction and development at higher latitudes.

  5. Conserved effects of salinity acclimation on thermal tolerance and hsp70 expression in divergent populations of threespine stickleback (Gasterosteus aculeatus).

    PubMed

    Metzger, David C H; Healy, Timothy M; Schulte, Patricia M

    2016-10-01

    In natural environments, organisms must cope with complex combinations of abiotic stressors. Here, we use threespine stickleback (Gasterosteus aculeatus) to examine how changes in salinity affect tolerance of high temperatures. Threespine stickleback inhabit a range of environments that vary in both salinity and thermal stability making this species an excellent system for investigating interacting stressors. We examined the effects of environmental salinity on maximum thermal tolerance (CTMax) and 70 kDa heat shock protein (hsp70) gene expression using divergent stickleback ecotypes from marine and freshwater habitats. In both ecotypes, the CTMax of fish acclimated to 20 ppt was significantly higher compared to fish acclimated to 2 ppt. The effect of salinity acclimation on the expression of hsp70-1 and hsp70-2 was similar in both the marine and freshwater stickleback ecotype. There were differences in the expression profiles of hsp70-1 and hsp70-2 during heat shock, with hsp70-2 being induced earlier and to a higher level compared to hsp70-1. These data suggest that the two hsp70 isoforms may have functionally different roles in the heat shock response. Lastly, acute salinity challenge coupled with heat shock revealed that the osmoregulatory demands experienced during the heat shock response have a larger effect on the hsp70 expression profile than does the acclimation salinity.

  6. Fecundity compensation and fecundity reduction among populations of the three-spined stickleback infected by Schistocephalus solidus in Alaska.

    PubMed

    Heins, David C; Baker, John A

    2014-07-01

    We surveyed nine populations of the three-spined stickleback infected by the diphyllobothriidean cestode Schistocephalus solidus from south-central Alaska for two apparent forms of tolerance to infection in females capable of producing egg clutches notwithstanding large parasite burdens. Seven populations exhibited fecundity reduction, whereas two populations showed fecundity compensation. Our data suggest that fecundity reduction, a side effect resulting from nutrient theft, occurs in two phases of host response influenced by the parasite : host body mass (BM) ratio. The first is significantly reduced ovum mass without significant reduction in clutch size, and the second one involves significant reductions in both ovum mass and clutch size. Thus, ovum mass of host females who are functionally being starved through nutrient theft seems to be more readily influenced by parasitism and, therefore, decreased before clutch size is reduced. This inference is consistent with expectations based on the biology of and effect of feeding ration on reproduction in stickleback females. Fecundity compensation appears to be uncommon among populations of three-spined stickleback in Alaska and rare among populations throughout the northern hemisphere. Fecundity reduction seems to be common, at least among stickleback populations in Alaska.

  7. Connectivity in a pond system influences migration and genetic structure in threespine stickleback

    PubMed Central

    Seymour, Mathew; Räsänen, Katja; Holderegger, Rolf; Kristjánsson, Bjarni K

    2013-01-01

    Neutral genetic structure of natural populations is primarily influenced by migration (the movement of individuals and, subsequently, their genes) and drift (the statistical chance of losing genetic diversity over time). Migration between populations is influenced by several factors, including individual behavior, physical barriers, and environmental heterogeneity among populations. However, drift is expected to be stronger in populations with low immigration rate and small effective population size. With the technological advancement in geological information systems and spatial analysis tools, landscape genetics now allows the development of realistic migration models and increased insight to important processes influencing diversity of natural populations. In this study, we investigated the relationship between landscape connectivity and genetic distance of threespine stickleback (Gasterosteus aculeatus) inhabiting a pond complex in Belgjarskógur, Northeast Iceland. We used two landscape genetic approaches (i.e., least-cost-path and isolation-by-resistance) and asked whether gene flow, as measured by genetic distance, was more strongly associated with Euclidean distance (isolation-by-distance) or with landscape connectivity provided by areas prone to flooding (as indicated by Carex sp. cover)? We found substantial genetic structure across the study area, with pairwise genetic distances among populations (DPS) ranging from 0.118 to 0.488. Genetic distances among populations were more strongly correlated with least-cost-path and isolation-by-resistance than with Euclidean distance, whereas the relative contribution of isolation-by-resistance and Euclidian distance could not be disentangled. These results indicate that migration among stickleback populations occurs via periodically flooded areas. Overall, this study highlights the importance of transient landscape elements influencing migration and genetic structure of populations at small spatial scales. PMID

  8. Impaired reproduction in three-spined sticklebacks exposed to ethinyl estradiol as juveniles.

    PubMed

    Maunder, Richard J; Matthiessen, Peter; Sumpter, John P; Pottinger, Tom G

    2007-12-01

    To investigate the population-level effects of exposure to environmental endocrine disrupters, a mesocosm-scale study was carried out in which the reproductive performance of groups of free-spawning three-spined sticklebacks, Gasterosteus aculeatus, exposed as juveniles to a model estrogen, was assessed. Juvenile sticklebacks were exposed to ethinyl estradiol (EE(2)) at measured concentrations of (mean +/- SEM) 1.75 +/- 0.37 ng L(-1) and 27.7 +/- 1.08 ng L(-1) for 4 wk posthatch and then reared thereafter in pristine lake water until they reached adulthood. Exposure to the higher EE(2) concentration resulted in the occurrence of ovotestis among males, whereas no gonadal abnormalities were evident among males exposed to the lower concentration of EE(2). In addition, when spawning was allowed in the mesocosm environment, fewer nests were built per male, and fewer eggs were deposited per nest, in the group exposed to 27.7 ng L(-1). Males from this group also exhibited a less intense nuptial coloration than control males. In the group exposed to 1.75 ng L(-1) EE(2) posthatch, significantly fewer nests were built than in the control group. These results demonstrate that the timing of exposure to estrogenic contaminants, in developmental terms, is critically important. Short-term exposure to estrogens as juveniles can clearly influence reproductive performance as adults, despite all growth and development subsequent to the exposure period taking place in an estrogen-free environment. In addition, these results suggest that reproductive dysfunction can occur even in fish with no gross abnormalities in gonadal structure. This suggests that the absence of gonadal intersex is not a reliable indicator of the reproductive potential, or estrogen-exposure history, of fish populations or the only important factor involved in compromising the reproduction of estrogen-exposed fish. PMID:17699736

  9. Water temperature, not fish morph, determines parasite infections of sympatric Icelandic threespine sticklebacks (Gasterosteus aculeatus)

    PubMed Central

    Karvonen, Anssi; Kristjánsson, Bjarni K; Skúlason, Skúli; Lanki, Maiju; Rellstab, Christian; Jokela, Jukka

    2013-01-01

    Parasite communities of fishes are known to respond directly to the abiotic environment of the host, for example, to water quality and water temperature. Biotic factors are also important as they affect the exposure profile through heterogeneities in parasite distribution in the environment. Parasites in a particular environment may pose a strong selection on fish. For example, ecological differences in selection by parasites have been hypothesized to facilitate evolutionary differentiation of freshwater fish morphs specializing on different food types. However, as parasites may also respond directly to abiotic environment the parasite risk does not depend only on biotic features of the host environment. It is possible that different morphs experience specific selection gradients by parasites but it is not clear how consistent the selection is when abiotic factors change. We examined parasite pressure in sympatric morphs of threespine stickleback (Gasterosteus aculeatus) across a temperature gradient in two large Icelandic lakes, Myvatn and Thingvallavatn. Habitat-specific temperature gradients in these lakes are opposite. Myvatn lava rock morph lives in a warm environment, while the mud morph lives in the cold. In Thingvallavatn, the lava rock morph lives in a cold environment and the mud morph in a warm habitat. We found more parasites in fish living in higher temperature in both lakes, independent of the fish morph, and this pattern was similar for the two dominating parasite taxa, trematodes and cestodes. However, at the same time, we also found higher parasite abundance in a third morph living in deep cold–water habitat in Thingvallavatn compared to the cold-water lava morph, indicating strong effect of habitat-specific biotic factors. Our results suggest complex interactions between water temperature and biotic factors in determining the parasite community structure, a pattern that may have implications for differentiation of stickleback morphs. PMID

  10. Fast evolution from precast bricks: genomics of young freshwater populations of threespine stickleback Gasterosteus aculeatus.

    PubMed

    Terekhanova, Nadezhda V; Logacheva, Maria D; Penin, Aleksey A; Neretina, Tatiana V; Barmintseva, Anna E; Bazykin, Georgii A; Kondrashov, Alexey S; Mugue, Nikolai S

    2014-10-01

    Adaptation is driven by natural selection; however, many adaptations are caused by weak selection acting over large timescales, complicating its study. Therefore, it is rarely possible to study selection comprehensively in natural environments. The threespine stickleback (Gasterosteus aculeatus) is a well-studied model organism with a short generation time, small genome size, and many genetic and genomic tools available. Within this originally marine species, populations have recurrently adapted to freshwater all over its range. This evolution involved extensive parallelism: pre-existing alleles that adapt sticklebacks to freshwater habitats, but are also present at low frequencies in marine populations, have been recruited repeatedly. While a number of genomic regions responsible for this adaptation have been identified, the details of selection remain poorly understood. Using whole-genome resequencing, we compare pooled genomic samples from marine and freshwater populations of the White Sea basin, and identify 19 short genomic regions that are highly divergent between them, including three known inversions. 17 of these regions overlap protein-coding genes, including a number of genes with predicted functions that are relevant for adaptation to the freshwater environment. We then analyze four additional independently derived young freshwater populations of known ages, two natural and two artificially established, and use the observed shifts of allelic frequencies to estimate the strength of positive selection. Adaptation turns out to be quite rapid, indicating strong selection acting simultaneously at multiple regions of the genome, with selection coefficients of up to 0.27. High divergence between marine and freshwater genotypes, lack of reduction in polymorphism in regions responsible for adaptation, and high frequencies of freshwater alleles observed even in young freshwater populations are all consistent with rapid assembly of G. aculeatus freshwater genotypes

  11. Family origin and the response of threespine stickleback, Gasterosteus aculeatus, to thermal acclimation.

    PubMed

    Guderley, H; Leroy, P H

    2001-03-01

    To establish whether family origin affects the response of the threespine stickleback (Gasterosteus aculeatus) to thermal acclimation, we examined the rates of feeding, growth, and food conversion, relative tissue and organ masses and activities of a mitochondrial and a glycolytic enzyme in pectoral and axial muscle of individually housed fish from six families during acclimation to 8 degrees C and 23 degrees C. Feeding rates differed among families but were consistently higher in warm-acclimated than cold-acclimated fish. Growth rates differed among families. In four families growth was greater at 8 degrees C; these families generally had higher conversion efficiencies at 8 degrees C than 23 degrees C. For two families, growth was greater at 23 degrees C than 8 degrees C and conversion efficiencies did not differ between 8 degrees C and 23 degrees C. Relative tissue and organ masses (percent axial muscle, hepatosomatic, gut and kidney indices) differed with gender and among families (hepatosomatic, gut and kidney indices) but little with acclimation status. In all families and in both muscles, activities of the mitochondrial enzyme, citrate synthase (CS), were increased by cold acclimation. Axial muscle levels of the glycolytic enzyme, lactate dehydrogenase (LDH), were not affected by thermal acclimation or family origin, but were strongly correlated with the hepatosomatic index and axial muscle protein content. Pectoral muscle levels of LDH were affected by family origin which also influenced the response to thermal acclimation. Similar patterns were observed for specific activities and total muscle contents of these enzymes. Stickleback family origin influenced rates of feeding and growth and the thermal sensitivity of growth rates but not the compensatory increase in muscle CS levels with cold acclimation. The differing thermal sensitivities of growth could reflect distinct strategies for the timing of juvenile growth. PMID:11302536

  12. Nonlinear effects of temperature on body form and developmental canalization in the threespine stickleback.

    PubMed

    Ramler, D; Mitteroecker, P; Shama, L N S; Wegner, K M; Ahnelt, H

    2014-03-01

    Theoretical models predict that nonlinear environmental effects on the phenotype also affect developmental canalization, which in turn can influence the tempo and course of organismal evolution. Here, we used an oceanic population of threespine stickleback (Gasterosteus aculeatus) to investigate temperature-induced phenotypic plasticity of body size and shape using a paternal half-sibling, split-clutch experimental design and rearing offspring under three different temperature regimes (13, 17 and 21 °C). Body size and shape of 466 stickleback individuals were assessed by a set of 53 landmarks and analysed using geometric morphometric methods. At approximately 100 days, individuals differed significantly in both size and shape across the temperature groups. However, the temperature-induced differences between 13 and 17 °C (mainly comprising relative head and eye size) deviated considerably from those between 17 and 21 °C (involving the relative size of the ectocoracoid, the operculum and the ventral process of the pelvic girdle). Body size was largest at 17 °C. For both size and shape, phenotypic variance was significantly smaller at 17 °C than at 13 and 21 °C, indicating that development is most stable at the intermediate temperature matching the conditions encountered in the wild. Higher additive genetic variance at 13 and 21 °C indicates that the plastic response to temperature had a heritable basis. Understanding nonlinear effects of temperature on development and the underlying genetics are important for modelling evolution and for predicting outcomes of global warming, which can lead not only to shifts in average morphology but also to destabilization of development.

  13. Fast Evolution from Precast Bricks: Genomics of Young Freshwater Populations of Threespine Stickleback Gasterosteus aculeatus

    PubMed Central

    Terekhanova, Nadezhda V.; Logacheva, Maria D.; Penin, Aleksey A.; Neretina, Tatiana V.; Barmintseva, Anna E.; Bazykin, Georgii A.; Kondrashov, Alexey S.; Mugue, Nikolai S.

    2014-01-01

    Adaptation is driven by natural selection; however, many adaptations are caused by weak selection acting over large timescales, complicating its study. Therefore, it is rarely possible to study selection comprehensively in natural environments. The threespine stickleback (Gasterosteus aculeatus) is a well-studied model organism with a short generation time, small genome size, and many genetic and genomic tools available. Within this originally marine species, populations have recurrently adapted to freshwater all over its range. This evolution involved extensive parallelism: pre-existing alleles that adapt sticklebacks to freshwater habitats, but are also present at low frequencies in marine populations, have been recruited repeatedly. While a number of genomic regions responsible for this adaptation have been identified, the details of selection remain poorly understood. Using whole-genome resequencing, we compare pooled genomic samples from marine and freshwater populations of the White Sea basin, and identify 19 short genomic regions that are highly divergent between them, including three known inversions. 17 of these regions overlap protein-coding genes, including a number of genes with predicted functions that are relevant for adaptation to the freshwater environment. We then analyze four additional independently derived young freshwater populations of known ages, two natural and two artificially established, and use the observed shifts of allelic frequencies to estimate the strength of positive selection. Adaptation turns out to be quite rapid, indicating strong selection acting simultaneously at multiple regions of the genome, with selection coefficients of up to 0.27. High divergence between marine and freshwater genotypes, lack of reduction in polymorphism in regions responsible for adaptation, and high frequencies of freshwater alleles observed even in young freshwater populations are all consistent with rapid assembly of G. aculeatus freshwater genotypes

  14. Connectivity in a pond system influences migration and genetic structure in threespine stickleback.

    PubMed

    Seymour, Mathew; Räsänen, Katja; Holderegger, Rolf; Kristjánsson, Bjarni K

    2013-03-01

    Neutral genetic structure of natural populations is primarily influenced by migration (the movement of individuals and, subsequently, their genes) and drift (the statistical chance of losing genetic diversity over time). Migration between populations is influenced by several factors, including individual behavior, physical barriers, and environmental heterogeneity among populations. However, drift is expected to be stronger in populations with low immigration rate and small effective population size. With the technological advancement in geological information systems and spatial analysis tools, landscape genetics now allows the development of realistic migration models and increased insight to important processes influencing diversity of natural populations. In this study, we investigated the relationship between landscape connectivity and genetic distance of threespine stickleback (Gasterosteus aculeatus) inhabiting a pond complex in Belgjarskógur, Northeast Iceland. We used two landscape genetic approaches (i.e., least-cost-path and isolation-by-resistance) and asked whether gene flow, as measured by genetic distance, was more strongly associated with Euclidean distance (isolation-by-distance) or with landscape connectivity provided by areas prone to flooding (as indicated by Carex sp. cover)? We found substantial genetic structure across the study area, with pairwise genetic distances among populations (DPS) ranging from 0.118 to 0.488. Genetic distances among populations were more strongly correlated with least-cost-path and isolation-by-resistance than with Euclidean distance, whereas the relative contribution of isolation-by-resistance and Euclidian distance could not be disentangled. These results indicate that migration among stickleback populations occurs via periodically flooded areas. Overall, this study highlights the importance of transient landscape elements influencing migration and genetic structure of populations at small spatial scales.

  15. Estrogenic and androgenic effects of municipal wastewater effluent on reproductive endpoint biomarkers in three-spined stickleback (Gasterosteus aculeatus).

    PubMed

    Björkblom, Carina; Högfors, Eva; Salste, Lotta; Bergelin, Eija; Olsson, Per-Erik; Katsiadaki, Ioanna; Wiklund, Tom

    2009-05-01

    Municipal wastewater treatment plants have been associated with the release of endocrine-disrupting chemicals, which consequently lead to alterations of reproductive function in aquatic organisms. The three-spined stickleback (Gasterosteus aculeatus) has quantifiable biomarkers for assessment of both estrogen (vitellogenin) and androgen (spiggin) activity, which makes this species very valuable in the research of endocrine disruption. The estrogenic and androgenic biomarkers were used for evaluating exposure effects of municipal wastewater effluent. We evaluated the effects of 17alpha-ethinylestradiol (EE2), 17alpha-methyltestosterone (MT), and wastewater effluents on induction of vitellogenin and spiggin production, gonadosomatic index, hepatosomatic index, nephrosomatic index, plasma steroid levels, and histopathology. Adult female and male sticklebacks were exposed to 20 ng/L of EE2, 10 microg/L of MT, and wastewater effluent (10, 50, and 80% of original concentration) in a flow-through system for an exposure of one week and an extended exposure of four weeks. Chemical analyses of the steroids were done for verification of exposure concentrations and presence in the used wastewater. Our results show that municipal wastewater effluent exerts estrogenic action on three-spined stickleback as observed by elevated vitellogenin levels in exposed fish, corresponding to the effect seen in fish exposed to EE2. Furthermore, wastewater and EE2 exerted similar histopathological effects on testis of exposed fish. Although domestic effluent is suspected to have a high content of natural androgens, no obvious androgenic effect of wastewater was observed in the present study.

  16. Males do not see only red: UV wavelengths and male territorial aggression in the three-spined stickleback ( Gasterosteus aculeatus)

    NASA Astrophysics Data System (ADS)

    Rick, Ingolf P.; Bakker, Theo C. M.

    2008-07-01

    Animal colour signals serve important functions in intraspecific interactions, including species recognition, mate choice and agonistic behaviour. An increasing interest concerns ultraviolet (UV) wavelengths, for instance studies on the effect of UV in mating decisions. More recently, some studies also established that UV signals affect intrasexual interactions. We studied the role of UV during aggressive encounters between male three-spined sticklebacks ( Gasterosteus aculeatus), a species in which UV has an effect on female and male mate choice and shoaling behaviour. To that aim, we compared the aggressive response of a territorial male to male intruders, either seen in UV-including (UV+) or UV-lacking (UV-) conditions. Our prediction was that, if UV wavelengths are used in male-male competition, a territorial male should show less competitive behaviour towards an intruder representing a lower threat, i.e. the one presented without UV light. Male sticklebacks showed significantly lower levels of aggression towards male opponents lacking an UV component to their coloration than male opponents possessing this colour component. Discrimination was not influenced by a difference in brightness between the UV+ and UV- stimuli. Finally, we present some reflectance-spectrophotometrical data of two skin regions (cheek and abdomen) of the experimental males and analysed relationships between colorimetric variables, body variables and behaviour. Our study emphasises that UV visual cues are of importance in different communicational tasks in the three-spined stickleback.

  17. Hidden reproductive costs in the three-spined stickleback (Gasterosteus aculeatus).

    PubMed

    FitzGerald, G J; Guderley, H; Picard, P

    1989-01-01

    The costs of parental behaviour (fanning) were examined in male 1+ and 2+ three-spined sticklebacks (Gasterosteus aculeatus) by comparing the loss of wet mass incurred by starved parental males during the egg care period to those incurred by starved non-parental males during this same period. To evaluate which tissues were most affected, we compared the wet and dry masses of the tissues in our starved fish with those of an additional group of fed non-parental fish. While parental and non-parentals did not differ in their absolute loss of wet mass (two age classes combined), parentals had a significantly lower total dry mass than both fed and starved non-parentals (two age classes combined). These data suggest that the parental behaviour of males imposes an energetic cost which these males hide by increasing their water content. The difference in dry mass of the tissues of parental and non-parental males was most pronounced in the tissues remaining after removal of the muscles from the carcass, i.e. the skin, the vertebral column and the head. While age 1+ fish lose significantly less wet mass over the breeding cycle than age 2+ fish, this loss of mass represented a greater proportion of the body mass of 1+ than of 2+ fish. This may explain why fewer age 1+ fish than age 2+ successfully breed at our field site. PMID:2620713

  18. Phylogeography of isolated freshwater three-spined stickleback Gasterosteus aculeatus populations in the Adriatic Sea basin.

    PubMed

    DeFaveri, J; Zanella, L N; Zanella, D; Mrakovčić, M; Merilä, J

    2012-01-01

    Analyses of mitochondrial (mt) DNA and microsatellite variation were carried out to examine the relationships between 10 freshwater populations of three-spined sticklebacks Gasterosteus aculeatus along the eastern coast of the Adriatic Sea. Partial sequences of the mtDNA control region and cytochrome b gene, in addition to 15 microsatellite loci, were used to analyse populations from four isolated river catchments. Results uncovered an Adriatic lineage that was clearly divergent from the European lineage, and confirmed that the most divergent and ancient populations are located within the Adriatic lineage as compared with other European populations. Two northern Adriatic populations formed independent clades within the European mitochondrial lineage, suggesting different colonization histories of the different Adriatic populations. Nuclear marker analyses also indicated deep divergence between Adriatic and European populations, albeit with some discordance between the mtDNA phylogeny of the northern Adriatic populations, further highlighting the strong differentiation among the Adriatic populations. The southern populations within the Adriatic lineage were further organized into distinct clades corresponding to respective river catchments and sub-clades corresponding to river tributaries, reflecting a high degree of population structuring within a small geographic region, concurrent with suggestions of existence of several microrefugia within the Balkan Peninsula. The highly divergent clades and haplotypes unique to the southern Adriatic populations further suggest, in accordance with an earlier, more limited survey, that southern Adriatic populations represent an important reservoir for ancient genetic diversity of G. aculeatus.

  19. Rapid adaptive evolution of colour vision in the threespine stickleback radiation.

    PubMed

    Rennison, Diana J; Owens, Gregory L; Heckman, Nancy; Schluter, Dolph; Veen, Thor

    2016-05-11

    Vision is a sensory modality of fundamental importance for many animals, aiding in foraging, detection of predators and mate choice. Adaptation to local ambient light conditions is thought to be commonplace, and a match between spectral sensitivity and light spectrum is predicted. We use opsin gene expression to test for local adaptation and matching of spectral sensitivity in multiple independent lake populations of threespine stickleback populations derived since the last ice age from an ancestral marine form. We show that sensitivity across the visual spectrum is shifted repeatedly towards longer wavelengths in freshwater compared with the ancestral marine form. Laboratory rearing suggests that this shift is largely genetically based. Using a new metric, we found that the magnitude of shift in spectral sensitivity in each population corresponds strongly to the transition in the availability of different wavelengths of light between the marine and lake environments. We also found evidence of local adaptation by sympatric benthic and limnetic ecotypes to different light environments within lakes. Our findings indicate rapid parallel evolution of the visual system to altered light conditions. The changes have not, however, yielded a close matching of spectrum-wide sensitivity to wavelength availability, for reasons we discuss.

  20. Rapid adaptive evolution of colour vision in the threespine stickleback radiation.

    PubMed

    Rennison, Diana J; Owens, Gregory L; Heckman, Nancy; Schluter, Dolph; Veen, Thor

    2016-05-11

    Vision is a sensory modality of fundamental importance for many animals, aiding in foraging, detection of predators and mate choice. Adaptation to local ambient light conditions is thought to be commonplace, and a match between spectral sensitivity and light spectrum is predicted. We use opsin gene expression to test for local adaptation and matching of spectral sensitivity in multiple independent lake populations of threespine stickleback populations derived since the last ice age from an ancestral marine form. We show that sensitivity across the visual spectrum is shifted repeatedly towards longer wavelengths in freshwater compared with the ancestral marine form. Laboratory rearing suggests that this shift is largely genetically based. Using a new metric, we found that the magnitude of shift in spectral sensitivity in each population corresponds strongly to the transition in the availability of different wavelengths of light between the marine and lake environments. We also found evidence of local adaptation by sympatric benthic and limnetic ecotypes to different light environments within lakes. Our findings indicate rapid parallel evolution of the visual system to altered light conditions. The changes have not, however, yielded a close matching of spectrum-wide sensitivity to wavelength availability, for reasons we discuss. PMID:27147098

  1. Molecular mechanisms and the conflict between courtship and aggression in three-spined sticklebacks.

    PubMed

    Sanogo, Yibayiri O; Bell, Alison M

    2016-09-01

    In nature, animals often face conflicting demands. For example, breeding males must attract a mate but at the same time be ready to defend against rivals. The molecular mechanisms by which the brain resolves behavioural trade-offs are largely unknown. In this study, we compared the brain transcriptional responses of territorial male three-spined sticklebacks to a mating opportunity with a female and to a territorial challenge by a rival male. We focused on the diencephalon and the cerebellum, two regions of the brain implicated in courtship and aggression. There was a set of genes that were differentially expressed in response to both a courtship opportunity and a territorial challenge. Closer inspection of the direction of regulation revealed that genes that were downregulated in response to a courtship opportunity were upregulated in response to a territorial challenge and vice versa. Our study reveals some of the potential molecular mechanisms underlying behavioural trade-offs between sex and aggression, along with a possible solution to the conflict via social context-dependent gene regulation. PMID:27452346

  2. Nutritional benefits of filial cannibalism in three-spined sticklebacks ( Gasterosteus aculeatus)

    NASA Astrophysics Data System (ADS)

    Mehlis, Marion; Bakker, Theo C. M.; Frommen, Joachim G.

    2009-03-01

    Although filial cannibalism (eating one’s own offspring) occurs in numerous species, including several teleost fishes, its adaptive value is still not well understood. One often-discussed explanation is that individuals enhance their mass and body condition by consuming part of their eggs. However, evidence for this assumption is scarce thus far. In this study, male three-spined sticklebacks ( Gasterosteus aculeatus), a species with paternal care, were allowed to care for a batch of eggs or for an empty nest under food-deprived conditions. All brood-caring males cannibalised at least part of their eggs and thus preserved their initial mass and body condition. Furthermore, mass as well as body condition was significant positively correlated with the number of cannibalised eggs. In contrast, empty-nest males that had no possibility to cannibalise eggs significantly lost mass and body condition. This is, to our knowledge, the first experimentally documented evidence that mass as well as body condition were preserved by filial cannibalism.

  3. Effect of Australian tea tree oil on Gyrodactylus spp. infection of the three-spined stickleback Gasterosteus aculeatus.

    PubMed

    Steverding, Dietmar; Morgan, Edward; Tkaczynski, Patrick; Walder, Foster; Tinsley, Richard

    2005-08-01

    Gyrodactylus spp. infections of commercially farmed fishes are responsible for significant economic losses. Existing treatments have proved uneconomic, stressful to the fishes, and ecologically damaging. Essential oils are naturally occurring compounds that exhibit a wide range of anti-microbial and anti-fungal activities. This study explored the possibility of using Australian tea tree (Melaleuca alternifolia) oil (TTO) to treat Gyrodactylus spp. infection on the three-spined stickleback Gasterosteus aculeatus. In the presence of 0.01 % Tween 80 as an emulsifier, TTO treatments at concentrations between 3 and 30 ppmv (parts per million by volume) lowered the prevalence and significantly reduced the parasite burden of sticklebacks naturally infected with Gyrodactylus spp. In addition, Tween 80 alone exhibited parasiticidal activity against Gyrodactylus spp. These findings show the potential of TTO in combination with Tween 80 as an effective treatment of Gyrodactylus spp. infection of fishes. PMID:16175965

  4. The population structure and recent colonization history of Oregon threespine stickleback determined using restriction-site associated DNA-sequencing.

    PubMed

    Catchen, Julian; Bassham, Susan; Wilson, Taylor; Currey, Mark; O'Brien, Conor; Yeates, Quick; Cresko, William A

    2013-06-01

    Understanding how genetic variation is partitioned across genomes within and among populations is a fundamental problem in ecological and evolutionary genetics. To address this problem, we studied the threespine stickleback fish, which has repeatedly undergone parallel phenotypic and genetic differentiation when oceanic fish have invaded freshwater habitats. While significant evolutionary genetic research has been performed using stickleback from geographic regions that have been deglaciated in the last 20 000 years, less research has focused on freshwater populations that predate the last glacial maximum. We performed restriction-site associated DNA-sequencing (RAD-seq) based population genomic analyses on stickleback from across Oregon, which was not glaciated during the last maximum. We sampled stickleback from coastal, Willamette Basin and central Oregon sites, analysed their genetic diversity using RAD-seq, performed structure analyses, reconstructed their phylogeographic history and tested the hypothesis of recent stickleback introduction into central Oregon, where incidence of this species was only recently documented. Our results showed a clear phylogeographic break between coastal and inland populations, with oceanic populations exhibiting the lowest levels of divergence from one another. Willamette Basin and central Oregon populations formed a clade of closely related populations, a finding consistent with a recent introduction of stickleback into central Oregon. Finally, genome-wide analysis of genetic diversity (π) and correlations of alleles within individuals in subpopulations (FIS) supported a role for introgressive hybridization in coastal populations and a recent expansion in central Oregon. Our results exhibit the power of next-generation sequencing genomic approaches such as RAD-seq to identify both historical population structure and recent colonization history.

  5. Comparison of catch per unit effort among four minnow trap models in the three-spined stickleback (Gasterosteus aculeatus) fishery

    PubMed Central

    Budria, Alexandre; DeFaveri, Jacquelin; Merilä, Juha

    2015-01-01

    Minnow traps are commonly used in the stickleback (Gasterostidae) fishery, but the potential differences in catch per unit effort (CPUE) among different minnow trap models are little studied. We compared the CPUE of four different minnow trap models in field experiments conducted with three-spined sticklebacks (Gasterosteus aculeatus). Marked (up to 26 fold) differences in median CPUE among different trap models were observed. Metallic uncoated traps yielded the largest CPUE (2.8 fish/h), followed by metallic black nylon-coated traps (1.3 fish/h). Collapsible canvas traps yielded substantially lower CPUEs (black: 0.7 fish/h; red: 0.1 fish/h) than the metallic traps. Laboratory trials further revealed significant differences in escape probabilities among the different trap models. While the differences in escape probability can explain at least part of the differences in CPUE among the trap models (e.g. high escape rate and low CPUE in red canvas traps), discrepancies between model-specific CPUEs and escape rates suggests that variation in entrance rate also contributes to the differences in CPUE. In general, and in accordance with earlier data on nine-spined stickleback (Pungitius pungitius) trapping, the results suggest that uncoated metallic (Gee-type) traps are superior to the other commonly used minnow trap models in stickleback fisheries. PMID:26685761

  6. Comparison of catch per unit effort among four minnow trap models in the three-spined stickleback (Gasterosteus aculeatus) fishery.

    PubMed

    Budria, Alexandre; DeFaveri, Jacquelin; Merilä, Juha

    2015-12-21

    Minnow traps are commonly used in the stickleback (Gasterostidae) fishery, but the potential differences in catch per unit effort (CPUE) among different minnow trap models are little studied. We compared the CPUE of four different minnow trap models in field experiments conducted with three-spined sticklebacks (Gasterosteus aculeatus). Marked (up to 26 fold) differences in median CPUE among different trap models were observed. Metallic uncoated traps yielded the largest CPUE (2.8 fish/h), followed by metallic black nylon-coated traps (1.3 fish/h). Collapsible canvas traps yielded substantially lower CPUEs (black: 0.7 fish/h; red: 0.1 fish/h) than the metallic traps. Laboratory trials further revealed significant differences in escape probabilities among the different trap models. While the differences in escape probability can explain at least part of the differences in CPUE among the trap models (e.g. high escape rate and low CPUE in red canvas traps), discrepancies between model-specific CPUEs and escape rates suggests that variation in entrance rate also contributes to the differences in CPUE. In general, and in accordance with earlier data on nine-spined stickleback (Pungitius pungitius) trapping, the results suggest that uncoated metallic (Gee-type) traps are superior to the other commonly used minnow trap models in stickleback fisheries.

  7. Genome-wide patterns of standing genetic variation in a marine population of three-spined sticklebacks.

    PubMed

    Feulner, Philine G D; Chain, Frédéric J J; Panchal, Mahesh; Eizaguirre, Christophe; Kalbe, Martin; Lenz, Tobias L; Mundry, Marvin; Samonte, Irene E; Stoll, Monika; Milinski, Manfred; Reusch, Thorsten B H; Bornberg-Bauer, Erich

    2013-02-01

    Since the end of the Pleistocene, the three-spined stickleback (Gasterosteus aculeatus) has repeatedly colonized and adapted to various freshwater habitats probably originating from ancestral marine populations. Standing genetic variation and the underlying genomic architecture both have been speculated to contribute to recent adaptive radiations of sticklebacks. Here, we expand on the current genomic resources of this fish by providing extensive genome-wide variation data from six individuals from a marine (North Sea) stickleback population. Using next-generation sequencing and a combination of paired-end and mate-pair libraries, we detected a wide size range of genetic variation. Among the six individuals, we found more than 7% of the genome is polymorphic, consisting of 2599111 SNPs, 233464 indels and structural variation (SV) (>50 bp) such as 1054 copy-number variable regions (deletions and duplications) and 48 inversions. Many of these polymorphisms affect gene and coding sequences. Based on SNP diversity, we determined outlier regions concordant with signatures expected under adaptive evolution. As some of these outliers overlap with pronounced regions of copy-number variation, we propose the consideration of such SV when analysing SNP data from re-sequencing approaches. We further discuss the value of this resource on genome-wide variation for further investigation upon the relative contribution of standing variation on the parallel evolution of sticklebacks and the importance of the genomic architecture in adaptive radiation.

  8. Multivariate modeling of PCB bioaccumulation in three-spined stickleback (Gasterosteus aculeatus)

    SciTech Connect

    Bavel, B. van; Andersson, P.; Wingfors, H.; Bergqvist, P.A.; Rappe, C.; Tysklind, M.; Aahgren, J.; Norrgren, L.

    1996-06-01

    Three-spined sticklebacks were exposed to 20 polychlorinated biphenyls (PCBs) through gastrointestinal intake. The PCBs, viz. 2,2{prime},3,4-TeCB, 2,2{prime},4,6{prime}-TeCB, 2,3,3{prime},5{prime}-TeCB, 2,3,4,4{prime}-TeCB, 2,3{prime},4,5{prime}-TeCB, 3,3{prime},4,5-TeCB, 2,2{prime},3,4{prime},6-PeCB, 2,2{prime},4,4{prime},5-PeCB, 2,2{prime},4,6,6{prime}-PeCB, 2,3,3{prime},5,6-PeCB, 2,3,4,4{prime},6-PeCB, 3,3{prime}4,4{prime}5-PeCB, 2,2{prime},3,4,5,6{prime}-HxCB, 2,2{prime},4,4{prime},5,5{prime}-HxCB, 3,3{prime},4,4{prime},5,5{prime}-HxCB, 2,2{prime},3,3{prime},4,5,6-HpCB, 2,2{prime},3,4,4{prime},6,6{prime}-HpCB, 2,2{prime},3,4{prime},5,6,6{prime}-HpCB, 2,3,3{prime},4,4{prime},5,6-HpCB, and 2,3,3{prime},4{prime},5,5{prime},6-HpCB, were selected by means of a full factorial design in combination with principal component analyses based on several physicochemical properties of tetra- through hepta-PCBs. After exposure to the training set, pooled samples of the sticklebacks were analyzed by GC-MS after lipid determination and cleanup using Florisil open-column chromatography. Bioaccumulation factors (BAFs) were calculated on a lipid basis by dividing the PCB concentrations in the fish by the respective concentrations in the feed. Higher chlorinated PCBs showed, in general, higher bioaccumulation than the lower chlorinated congeners. Polychlorinated biphenyls with vicinal hydrogens in the meta- and para-positions exhibited low bioaccumulation. Finally, 18 of the 20 measured BAFs were used to calculate a multivariate quantitative structure-activity relationship (QSAR) by means of partial least squares fitting to latent structures. By applying this QSAR, the bioaccumulation potentials of 136 nontested tetra- through hepta-PCB congeners were predicted.

  9. Routine handling methods affect behaviour of three-spined sticklebacks in a novel test of anxiety.

    PubMed

    Thompson, Ralph R J; Paul, Elizabeth S; Radford, Andrew N; Purser, Julia; Mendl, Michael

    2016-06-01

    Fish are increasingly popular subjects in behavioural and neurobiological research. It is therefore important that they are housed and handled appropriately to ensure good welfare and reliable scientific findings, and that species-appropriate behavioural tests (e.g. of cognitive/affective states) are developed. Routine handling of captive animals may cause physiological stress responses that lead to anxiety-like states (e.g. increased perception of danger). In fish, these may be particularly pronounced when handling during tank-to-tank transfer involves removal from water into air. Here we develop and use a new combined scototaxis (preference for dark over light areas) and novel-tank-diving test, alongside conventional open-field and novel-object tests, to measure the effects of transferring three-spined sticklebacks (Gasterosteus aculeatus) between tanks using a box or net (in and out of water respectively). Preference tests for dark over light areas confirmed the presence of scototaxis in this species. Open-field and novel-object tests failed to detect any significant differences between net and box-handled fish. However, the combined diving and scototaxis detected consistent differences between the treatments. Net-handled fish spent less time on the dark side of the tank, less time in the bottom third, and kept a greater distance from the 'safe' bottom dark area than box-handled fish. Possible explanations for this reduction in anxiety-like behaviour in net-handled fish are discussed. The combined diving and scototaxis test may be a sensitive and taxon-appropriate method for measuring anxiety-like states in fish.

  10. Routine handling methods affect behaviour of three-spined sticklebacks in a novel test of anxiety.

    PubMed

    Thompson, Ralph R J; Paul, Elizabeth S; Radford, Andrew N; Purser, Julia; Mendl, Michael

    2016-06-01

    Fish are increasingly popular subjects in behavioural and neurobiological research. It is therefore important that they are housed and handled appropriately to ensure good welfare and reliable scientific findings, and that species-appropriate behavioural tests (e.g. of cognitive/affective states) are developed. Routine handling of captive animals may cause physiological stress responses that lead to anxiety-like states (e.g. increased perception of danger). In fish, these may be particularly pronounced when handling during tank-to-tank transfer involves removal from water into air. Here we develop and use a new combined scototaxis (preference for dark over light areas) and novel-tank-diving test, alongside conventional open-field and novel-object tests, to measure the effects of transferring three-spined sticklebacks (Gasterosteus aculeatus) between tanks using a box or net (in and out of water respectively). Preference tests for dark over light areas confirmed the presence of scototaxis in this species. Open-field and novel-object tests failed to detect any significant differences between net and box-handled fish. However, the combined diving and scototaxis detected consistent differences between the treatments. Net-handled fish spent less time on the dark side of the tank, less time in the bottom third, and kept a greater distance from the 'safe' bottom dark area than box-handled fish. Possible explanations for this reduction in anxiety-like behaviour in net-handled fish are discussed. The combined diving and scototaxis test may be a sensitive and taxon-appropriate method for measuring anxiety-like states in fish. PMID:26965568

  11. Routine handling methods affect behaviour of three-spined sticklebacks in a novel test of anxiety

    PubMed Central

    Thompson, Ralph R.J.; Paul, Elizabeth S.; Radford, Andrew N.; Purser, Julia; Mendl, Michael

    2016-01-01

    Fish are increasingly popular subjects in behavioural and neurobiological research. It is therefore important that they are housed and handled appropriately to ensure good welfare and reliable scientific findings, and that species-appropriate behavioural tests (e.g. of cognitive/affective states) are developed. Routine handling of captive animals may cause physiological stress responses that lead to anxiety-like states (e.g. increased perception of danger). In fish, these may be particularly pronounced when handling during tank-to-tank transfer involves removal from water into air. Here we develop and use a new combined scototaxis (preference for dark over light areas) and novel-tank-diving test, alongside conventional open-field and novel-object tests, to measure the effects of transferring three-spined sticklebacks (Gasterosteus aculeatus) between tanks using a box or net (in and out of water respectively). Preference tests for dark over light areas confirmed the presence of scototaxis in this species. Open-field and novel-object tests failed to detect any significant differences between net and box-handled fish. However, the combined diving and scototaxis detected consistent differences between the treatments. Net-handled fish spent less time on the dark side of the tank, less time in the bottom third, and kept a greater distance from the ‘safe’ bottom dark area than box-handled fish. Possible explanations for this reduction in anxiety-like behaviour in net-handled fish are discussed. The combined diving and scototaxis test may be a sensitive and taxon-appropriate method for measuring anxiety-like states in fish. PMID:26965568

  12. Different behaviour-body length correlations in two populations of juvenile three-spined stickleback (Gasterosteus aculeatus).

    PubMed

    De Winter, Gunnar; Martins, Henrique Ramalho; Trovo, Rafael Arnoni; Chapman, Ben B

    2016-01-01

    Behavioural variation among individuals has received a lot of attention by behavioural ecologists in the past few years. Its causes and consequences are becoming vast areas of research. The origin and maintenance of individual variation in behaviour within and among populations is affected by many facets of the biotic and abiotic environment. Here, two populations of lab-reared juvenile three-spined sticklebacks (Gasterosteus aculeatus) are tested for three behaviours (boldness, exploration, and sociability). Given the identical rearing conditions, the only difference between these populations is the parental habitat. In both populations, correlations between behaviour and body length are found. Interestingly, these differ between the populations. In one population body length was negatively correlated with exploratory behaviour, while in the other one body length correlated negatively with sociability. Considering the identical environment these juvenile fish were exposed to, these findings suggest a potential (epi)genetic foundation for these correlations and shows that, in three-spined sticklebacks, the proximate basis for correlations between body length and behaviour appears quite malleable.

  13. Receptors rather than signals change in expression in four physiological regulatory networks during evolutionary divergence in threespine stickleback.

    PubMed

    Di Poi, Carole; Bélanger, Dominic; Amyot, Marc; Rogers, Sean; Aubin-Horth, Nadia

    2016-07-01

    The molecular mechanisms underlying behavioural evolution following colonization of novel environments are largely unknown. Molecules that interact to control equilibrium within an organism form physiological regulatory networks. It is essential to determine whether particular components of physiological regulatory networks evolve or if the network as a whole is affected in populations diverging in behavioural responses, as this may affect the nature, amplitude and number of impacted traits. We studied the regulation of four physiological regulatory networks in freshwater and marine populations of threespine stickleback raised in a common environment, which were previously characterized as showing evolutionary divergence in behaviour and stress reactivity. We measured nineteen components of these networks (ligands and receptors) using mRNA and monoamine levels in the brain, pituitary and interrenal gland, as well as hormone levels. Freshwater fish showed higher expression in the brain of adrenergic (adrb2a), serotonergic (htr2a) and dopaminergic (DRD2) receptors, but lower expression of the htr2b receptor. Freshwater fish also showed higher expression of the mc2r receptor of the glucocorticoid axis in the interrenals. Collectively, our results suggest that the inheritance of the regulation of these networks may be implicated in the evolution of behaviour and stress reactivity in association with population divergence. Our results also suggest that evolutionary change in freshwater threespine stickleback may be more associated with the expression of specific receptors rather than with global changes of all the measured constituents of the physiological regulatory networks.

  14. Perchlorate exposure does not modulate temporal variation of whole-body thyroid and androgen hormone content in threespine stickleback

    PubMed Central

    Gardell, Alison M.; Dillon, Danielle M.; Smayda, Lauren C.; von Hippel, Frank A.; Cresko, William A.; Postlethwait, John H.; Buck, C. Loren

    2015-01-01

    Previously we showed that exposure of threespine stickleback (Gasterosteus aculeatus) to the endocrine disruptor perchlorate results in pronounced structural changes in thyroid and gonad, while surprisingly, whole-body thyroid hormone concentrations remain unaffected. To test for hormone titer variations on a finer scale, we evaluated the interactive effects of time (diel and reproductive season) and perchlorate exposure on whole-body contents of triiodothyronine (T3), thyroxine (T4), and 11-ketotestosterone (11-KT) in captive stickleback. Adult stickleback were exposed to 100 ppm perchlorate or control water and sampled at four-hour intervals across the 24-hour day and at one time-point (1100 h) weekly across the reproductive season (May-July). Neither whole-body T3 nor T4 concentration significantly differed across the day in control or perchlorate treated stickleback. Across the reproductive season, whole-body T3 concentration remained stable while T4 significantly increased. However, neither hormone concentration was significantly affected by perchlorate, verifying our previous studies. The concentration of whole-body 11-KT, a major fish androgen, displayed significant diel variation and also steadily declined across the reproductive season in untreated males; perchlorate exposure did not influence the concentration of 11-KT in either diel or reproductive season schedules. Diel and reproductive season variations in 11-KT content in male stickleback are likely related to reproductive physiology and behavior. The observed increase in T4 content across the reproductive season may be reflective of increased energy investment in reproduction near the end of the life cycle. PMID:25733204

  15. Spatial phenotypic and genetic structure of threespine stickleback (Gasterosteus aculeatus) in a heterogeneous natural system, Lake Mývatn, Iceland

    PubMed Central

    Millet, Antoine; Kristjánsson, Bjarni K; Einarsson, Árni; Räsänen, Katja

    2013-01-01

    Eco-evolutionary responses of natural populations to spatial environmental variation strongly depend on the relative strength of environmental differences/natural selection and dispersal/gene flow. In absence of geographic barriers, as often is the case in lake ecosystems, gene flow is expected to constrain adaptive divergence between environments – favoring phenotypic plasticity or high trait variability. However, if divergent natural selection is sufficiently strong, adaptive divergence can occur in face of gene flow. The extent of divergence is most often studied between two contrasting environments, whereas potential for multimodal divergence is little explored. We investigated phenotypic (body size, defensive structures, and feeding morphology) and genetic (microsatellites) structure in threespine stickleback (Gasterosteus aculeatus) across five habitat types and two basins (North and South) within the geologically young and highly heterogeneous Lake Mývatn, North East Iceland. We found that (1) North basin stickleback were, on average, larger and had relatively longer spines than South basin stickleback, whereas (2) feeding morphology (gill raker number and gill raker gap width) differed among three of five habitat types, and (3) there was only subtle genetic differentiation across the lake. Overall, our results indicate predator and prey mediated phenotypic divergence across multiple habitats in the lake, in face of gene flow. PMID:24223263

  16. Conspicuous carotenoid-based pelvic spine ornament in three-spined stickleback populations—occurrence and inheritance

    PubMed Central

    Amundsen, CR; Gjøen, HM; Larsen, B; Egeland, ES

    2015-01-01

    Reports on reddish carotenoid-based ornaments in female three-spined sticklebacks (Gasterosteus aculeatus) are few, despite the large interest in the species’ behaviour, ornamentation, morphology and evolution. We sampled sticklebacks from 17 sites in north-western Europe in this first extensive study on the occurrence of carotenoid-based female pelvic spines and throat ornaments. The field results showed that females, and males, with reddish spines were found in all 17 populations. Specimens of both sexes with conspicuous red spines were found in several of the sites. The pelvic spines of males were more intensely red compared to the females’ spines, and large specimens were more red than small ones. Fish infected with the tapeworm (Schistocephalus solidus) had drabber spines than uninfected fish. Both sexes had red spines both during and after the spawning period, but the intensity of the red colour was more exaggerated during the spawning period. As opposed to pelvic spines, no sign of red colour at the throat was observed in any female from any of the 17 populations. A rearing experiment was carried out to estimate a potential genetic component of the pelvic spine ornament by artificial crossing and rearing of 15 family groups during a 12 months period. The results indicated that the genetic component of the red colour at the spines was low or close to zero. Although reddish pelvic spines seem common in populations of stickleback, the potential adaptive function of the reddish pelvic spines remains largely unexplained. PMID:25861558

  17. Conspicuous carotenoid-based pelvic spine ornament in three-spined stickleback populations-occurrence and inheritance.

    PubMed

    Amundsen, C R; Nordeide, J T; Gjøen, H M; Larsen, B; Egeland, E S

    2015-01-01

    Reports on reddish carotenoid-based ornaments in female three-spined sticklebacks (Gasterosteus aculeatus) are few, despite the large interest in the species' behaviour, ornamentation, morphology and evolution. We sampled sticklebacks from 17 sites in north-western Europe in this first extensive study on the occurrence of carotenoid-based female pelvic spines and throat ornaments. The field results showed that females, and males, with reddish spines were found in all 17 populations. Specimens of both sexes with conspicuous red spines were found in several of the sites. The pelvic spines of males were more intensely red compared to the females' spines, and large specimens were more red than small ones. Fish infected with the tapeworm (Schistocephalus solidus) had drabber spines than uninfected fish. Both sexes had red spines both during and after the spawning period, but the intensity of the red colour was more exaggerated during the spawning period. As opposed to pelvic spines, no sign of red colour at the throat was observed in any female from any of the 17 populations. A rearing experiment was carried out to estimate a potential genetic component of the pelvic spine ornament by artificial crossing and rearing of 15 family groups during a 12 months period. The results indicated that the genetic component of the red colour at the spines was low or close to zero. Although reddish pelvic spines seem common in populations of stickleback, the potential adaptive function of the reddish pelvic spines remains largely unexplained. PMID:25861558

  18. Hypoxia and the pharmaceutical diclofenac influence the circadian responses of three-spined stickleback.

    PubMed

    Prokkola, Jenni M; Nikinmaa, Mikko; Lubiana, Pedro; Kanerva, Mirella; McCairns, R J Scott; Götting, Miriam

    2015-01-01

    Pollution with low concentrations of pharmaceuticals, especially when combined with low-oxygen conditions (hypoxia), is a threat to aquatic ecosystems worldwide. The non-steroidal anti-inflammatory drug diclofenac is commonly detected in wastewater effluents, and has potential to accumulate in the bile of fish. Diclofenac has been shown to activate aryl hydrocarbon receptor (AHR), which induces transcription in the metabolic enzyme cytochrome P450 1a (cyp1a). Previously, crosstalk has been shown to occur between AHR and hypoxia inducible factor 1 (HIF-1). In addition, both of these transcription factors interact with the proteins regulating circadian (24-h) rhythms in vertebrates. Yet little is known about the significance of these interactions during simultaneous exposure to chemicals and hypoxia in fish in vivo. We exposed wild-caught three-spined sticklebacks (Gasterosteus aculeatus) to diclofenac (1 μg/L, 14 days), hypoxia (2.0 mg/L, up to 24h) and the combination of both. We then analyzed markers of chemical biotransformation (EROD activity, cyp1a and ahr mRNA levels), glycolysis (lactate dehydrogenase (LDH) enzyme activity, ldh and enolase 1a mRNA levels), and the transcription of core circadian clock genes clock and period 1 in liver tissue. Samples were taken at three time points during the light period in order to address disturbances in the circadian variation of metabolic processes. The results show that mRNA levels and LDH activity tended to be lowest before the dark period, but this pattern was disturbed by hypoxia and diclofenac. Diclofenac and hypoxia co-exposure induced EROD activity more strongly than diclofenac exposure alone, while cyp1a mRNA level was increased also by hypoxia and diclofenac alone. LDH activity and mRNA expression showed a clear time-dependent response during hypoxia, which is consistent with the previously suggested decreased accumulation of HIF-1 during the dark period. Furthermore, LDH activity and transcription was

  19. A microsatellite linkage map of striped bass (Morone saxatilis) reveals conserved synteny with the three-spined stickleback (Gasterosteus aculeatus).

    PubMed

    Liu, Sixin; Rexroad, Caird E; Couch, Charlene R; Cordes, Jan F; Reece, Kimberly S; Sullivan, Craig V

    2012-04-01

    The striped bass (Morone saxatilis) and its relatives (genus Morone) are of great importance to fisheries and aquaculture in North America. As part of a collaborative effort to employ molecular genetics technologies in striped bass breeding programs, we previously developed nearly 500 microsatellite markers. The objectives of this study were to construct a microsatellite linkage map of striped bass and to examine conserved synteny between striped bass and three-spined stickleback (Gasterosteus aculeatus). Of 480 microsatellite markers screened for polymorphism, 289 informative markers were identified and used to genotype two half-sib mapping families. Twenty-six linkage groups were assembled, and only two markers remain unlinked. The sex-averaged map spans 1,623.8 cM with an average marker density of 5.78 cM per marker. Among 287 striped bass microsatellite markers assigned to linkage groups, 169 (58.9%) showed homology to sequences on stickleback chromosomes or scaffolds. Comparison between the stickleback genome and the striped bass linkage map revealed conserved synteny between these two species. This is the first linkage map for any of the Morone species. This map will be useful for molecular mapping and marker-assisted selection of genes of interest in striped bass breeding programs. The conserved synteny between striped bass and stickleback will facilitate fine mapping of genome regions of interest and will serve as a new resource for comparative mapping with other Perciform fishes such as European sea bass (Dicentrarchus labrax), gilthead sea bream (Sparus aurata), and tilapia (Oreochromis ssp.). PMID:21968826

  20. A microsatellite linkage map of striped bass (Morone saxatilis) reveals conserved synteny with the three-spined stickleback (Gasterosteus aculeatus).

    PubMed

    Liu, Sixin; Rexroad, Caird E; Couch, Charlene R; Cordes, Jan F; Reece, Kimberly S; Sullivan, Craig V

    2012-04-01

    The striped bass (Morone saxatilis) and its relatives (genus Morone) are of great importance to fisheries and aquaculture in North America. As part of a collaborative effort to employ molecular genetics technologies in striped bass breeding programs, we previously developed nearly 500 microsatellite markers. The objectives of this study were to construct a microsatellite linkage map of striped bass and to examine conserved synteny between striped bass and three-spined stickleback (Gasterosteus aculeatus). Of 480 microsatellite markers screened for polymorphism, 289 informative markers were identified and used to genotype two half-sib mapping families. Twenty-six linkage groups were assembled, and only two markers remain unlinked. The sex-averaged map spans 1,623.8 cM with an average marker density of 5.78 cM per marker. Among 287 striped bass microsatellite markers assigned to linkage groups, 169 (58.9%) showed homology to sequences on stickleback chromosomes or scaffolds. Comparison between the stickleback genome and the striped bass linkage map revealed conserved synteny between these two species. This is the first linkage map for any of the Morone species. This map will be useful for molecular mapping and marker-assisted selection of genes of interest in striped bass breeding programs. The conserved synteny between striped bass and stickleback will facilitate fine mapping of genome regions of interest and will serve as a new resource for comparative mapping with other Perciform fishes such as European sea bass (Dicentrarchus labrax), gilthead sea bream (Sparus aurata), and tilapia (Oreochromis ssp.).

  1. Waterborne citalopram has anxiolytic effects and increases locomotor activity in the three-spine stickleback (Gasterosteus aculeatus).

    PubMed

    Kellner, M; Porseryd, T; Hallgren, S; Porsch-Hällström, I; Hansen, S H; Olsén, K H

    2016-04-01

    Citalopram is an antidepressant drug, which acts by inhibiting the re-uptake of serotonin from the synaptic cleft into the pre-synaptic nerve ending. It is one of the most common drugs used in treatment of depression, it is highly lipophilic and frequently found in sewage treatment plant effluents and surface waters around the world. Citalopram and other selective serotonin re-uptake inhibitors have, at concentrations that occur in nature, been shown to have behavioural as well as physiological effects on fish and other animals. This study is the result of several different experiments, intended to analyse different aspects of behavioural effects of chronic citalopram exposure in fish. Our model species the three-spine stickleback is common in the entire northern hemisphere and is considered to be a good environmental sentinel species. Female three-spine sticklebacks were exposed to 0, 1.5 and 15μg/l nominal concentrations of citalopram for 21 days and subjected to the novel tank (NT) diving test. In the NT test, the fish exposed to 1.5μg/l, but not the 15μg/l fish made a significantly higher number of transitions to the upper half and stayed there for significantly longer time than the fish exposed to 0μg/l. The 15μg/l group, however, displayed a significantly lower number of freeze bouts and a shorter total freezing time. The test for locomotor activity included in the NT test showed that fish treated with 1.5 and 15μg/l displayed a significantly higher swimming activity than control fish both 5-7 and 15-17min after the start of the experiment. In the next experiment we compared fish exposed to 1.5μg/l and 0.15μg/l to pure water controls with regard to shoaling intensity and found no effect of treatment. In the final experiment the propensity of fish treated with 1.5μg/l to approach an unknown object and aggressive behaviour was investigated using the Novel Object test and a mirror test, respectively. The exposed fish ventured close to the unknown object

  2. Environmental concentrations of an androgenic progestin disrupts the seasonal breeding cycle in male three-spined stickleback (Gasterosteus aculeatus).

    PubMed

    Svensson, Johan; Fick, Jerker; Brandt, Ingvar; Brunström, Björn

    2014-02-01

    Synthetic steroid hormones from contraceptive pharmaceuticals have become global aquatic contaminants. Progestins, the synthetic analogs to progesterone, are receiving increasing attention as contaminants and have been shown to impair reproduction in fish and amphibians at low ng L(-1) concentrations. Certain progestins, such as levonorgestrel have androgenic properties and seem to be several orders of magnitude more potent in terms of reproductive impairment in fish than non-androgenic progestins and progestagens. We recently reported that levonorgestrel has strong androgenic effects in female three-spined sticklebacks (Gasterosteus aculeatus), including induction of the normally male-specific glue protein spiggin and suppression of vitellogenesis. In light of this we investigated if exposure to levonorgestrel could disrupt the highly androgen-dependent seasonal reproductive cycle in male sticklebacks. Male sticklebacks that were in the final stage of a breeding period were exposed to various concentrations of levonorgestrel for six weeks in winter conditions in terms of light and temperature, after which reproductive status was evaluated from gross morphology, histology and key gene transcript levels. During the experimental period the controls had transitioned from full breeding condition into the non-breeding state, including regression of secondary sex characteristics, cessation of spiggin production in the kidney, and resumption of spermatogenesis in the testes. This is ascribed to the natural drop in plasma androgen levels after breeding. However, in the groups concurrently exposed to levonorgestrel, transition to the non-breeding condition was dose-dependently inhibited. Our results show that levonorgestrel can disrupt the seasonal breeding cycle in male sticklebacks. The fitness costs of such an effect could be detrimental to natural stickleback populations. Some effects occurred at a levonorgestrel concentration of 6.5 ng L(-1), well within the range of

  3. Maternal Experience with Predation Risk Influences Genome-Wide Embryonic Gene Expression in Threespined Sticklebacks (Gasterosteus aculeatus)

    PubMed Central

    Mommer, Brett C.; Bell, Alison M.

    2014-01-01

    There is growing evidence for nongenetic effects of maternal experience on offspring. For example, previous studies have shown that female threespined stickleback fish (Gasterosteus aculeatus) exposed to predation risk produce offspring with altered behavior, metabolism and stress physiology. Here, we investigate the effect of maternal exposure to predation risk on the embryonic transcriptome in sticklebacks. Using RNA-sequencing we compared genome-wide transcription in three day post-fertilization embryos of predator-exposed and control mothers. There were hundreds of differentially expressed transcripts between embryos of predator-exposed mothers and embryos of control mothers including several non-coding RNAs. Gene Ontology analysis revealed biological pathways involved in metabolism, epigenetic inheritance, and neural proliferation and differentiation that differed between treatments. Interestingly, predation risk is associated with an accelerated life history in many vertebrates, and several of the genes and biological pathways that were identified in this study suggest that maternal exposure to predation risk accelerates the timing of embryonic development. Consistent with this hypothesis, embryos of predator-exposed mothers were larger than embryos of control mothers. These findings point to some of the molecular mechanisms that might underlie maternal effects. PMID:24887438

  4. The impact of selection, gene flow and demographic history on heterogeneous genomic divergence: three-spine sticklebacks in divergent environments.

    PubMed

    Ferchaud, Anne-Laure; Hansen, Michael M

    2016-01-01

    Heterogeneous genomic divergence between populations may reflect selection, but should also be seen in conjunction with gene flow and drift, particularly population bottlenecks. Marine and freshwater three-spine stickleback (Gasterosteus aculeatus) populations often exhibit different lateral armour plate morphs. Moreover, strikingly parallel genomic footprints across different marine-freshwater population pairs are interpreted as parallel evolution and gene reuse. Nevertheless, in some geographic regions like the North Sea and Baltic Sea, different patterns are observed. Freshwater populations in coastal regions are often dominated by marine morphs, suggesting that gene flow overwhelms selection, and genomic parallelism may also be less pronounced. We used RAD sequencing for analysing 28 888 SNPs in two marine and seven freshwater populations in Denmark, Europe. Freshwater populations represented a variety of environments: river populations accessible to gene flow from marine sticklebacks and large and small isolated lakes with and without fish predators. Sticklebacks in an accessible river environment showed minimal morphological and genomewide divergence from marine populations, supporting the hypothesis of gene flow overriding selection. Allele frequency spectra suggested bottlenecks in all freshwater populations, and particularly two small lake populations. However, genomic footprints ascribed to selection could nevertheless be identified. No genomic regions were consistent freshwater-marine outliers, and parallelism was much lower than in other comparable studies. Two genomic regions previously described to be under divergent selection in freshwater and marine populations were outliers between different freshwater populations. We ascribe these patterns to stronger environmental heterogeneity among freshwater populations in our study as compared to most other studies, although the demographic history involving bottlenecks should also be considered in the

  5. Osmoregulatory physiology and rapid evolution of salinity tolerance in threespine stickleback recently introduced to fresh water

    USGS Publications Warehouse

    Divino, Jeffrey N; Monette, Michelle Y.; McCormick, Stephen; Yancey, Paul H.; Flannery, Kyle G.; Bell, Michael A.; Rollins, Jennifer L.; von Hippel, Frank A.; Schultz, Eric T.

    2016-01-01

    Conclusion: Enhanced freshwater tolerance has evolved rapidly in recently landlocked stickleback compared with their anadromous ancestors (0.569 haldanes), but the former have retained ancestral seawater-osmoregulatory function.

  6. Comparative Analysis of Japanese Three-Spined Stickleback Clades Reveals the Pacific Ocean Lineage Has Adapted to Freshwater Environments while the Japan Sea Has Not

    PubMed Central

    Ravinet, Mark; Takeuchi, Naoko; Kume, Manabu; Mori, Seiichi; Kitano, Jun

    2014-01-01

    Divergent selection and adaptive divergence can increase phenotypic diversification amongst populations and lineages. Yet adaptive divergence between different environments, habitats or niches does not occur in all lineages. For example, the colonization of freshwater environments by ancestral marine species has triggered adaptive radiation and phenotypic diversification in some taxa but not in others. Studying closely related lineages differing in their ability to diversify is an excellent means of understanding the factors promoting and constraining adaptive evolution. A well-known example of the evolution of increased phenotypic diversification following freshwater colonization is the three-spined stickleback. Two closely related stickleback lineages, the Pacific Ocean and the Japan Sea occur in Japan. However, Japanese freshwater stickleback populations are derived from the Pacific Ocean lineage only, suggesting the Japan Sea lineage is unable to colonize freshwater. Using stable isotope data and trophic morphology, we first show higher rates of phenotypic and ecological diversification between marine and freshwater populations within the Pacific Ocean lineage, confirming adaptive divergence has occurred between the two lineages and within the Pacific Ocean lineage but not in the Japan Sea lineage. We further identified consistent divergence in diet and foraging behaviour between marine forms from each lineage, confirming Pacific Ocean marine sticklebacks, from which all Japanese freshwater populations are derived, are better adapted to freshwater environments than Japan Sea sticklebacks. We suggest adaptive divergence between ancestral marine populations may have played a role in constraining phenotypic diversification and adaptive evolution in Japanese sticklebacks. PMID:25460163

  7. Comparative analysis of Japanese three-spined stickleback clades reveals the Pacific Ocean lineage has adapted to freshwater environments while the Japan Sea has not.

    PubMed

    Ravinet, Mark; Takeuchi, Naoko; Kume, Manabu; Mori, Seiichi; Kitano, Jun

    2014-01-01

    Divergent selection and adaptive divergence can increase phenotypic diversification amongst populations and lineages. Yet adaptive divergence between different environments, habitats or niches does not occur in all lineages. For example, the colonization of freshwater environments by ancestral marine species has triggered adaptive radiation and phenotypic diversification in some taxa but not in others. Studying closely related lineages differing in their ability to diversify is an excellent means of understanding the factors promoting and constraining adaptive evolution. A well-known example of the evolution of increased phenotypic diversification following freshwater colonization is the three-spined stickleback. Two closely related stickleback lineages, the Pacific Ocean and the Japan Sea occur in Japan. However, Japanese freshwater stickleback populations are derived from the Pacific Ocean lineage only, suggesting the Japan Sea lineage is unable to colonize freshwater. Using stable isotope data and trophic morphology, we first show higher rates of phenotypic and ecological diversification between marine and freshwater populations within the Pacific Ocean lineage, confirming adaptive divergence has occurred between the two lineages and within the Pacific Ocean lineage but not in the Japan Sea lineage. We further identified consistent divergence in diet and foraging behaviour between marine forms from each lineage, confirming Pacific Ocean marine sticklebacks, from which all Japanese freshwater populations are derived, are better adapted to freshwater environments than Japan Sea sticklebacks. We suggest adaptive divergence between ancestral marine populations may have played a role in constraining phenotypic diversification and adaptive evolution in Japanese sticklebacks.

  8. PARTIAL REPRODUCTIVE ISOLATION OF A RECENTLY DERIVED RESIDENT-FRESHWATER POPULATION OF THREESPINE STICKLEBACK (GASTEROSTEUS ACULEATUS) FROM ITS PUTATIVE ANADROMOUS ANCESTOR

    PubMed Central

    Furin, Christoff G.; Von Hippel, Frank A.; Bell, Michael A.

    2012-01-01

    We used no-choice mating trials to test for assortative mating between a newly derived resident-freshwater population (8 – 22 generations since founding) of threespine stickleback (Gasterosteus aculeatus) in Loberg Lake, Alaska and its putative anadromous ancestor as well as a morphologically convergent but distantly related resident-freshwater population. Partial reproductive isolation has evolved between the Loberg Lake population and its ancestor within a remarkably short time period. However, Loberg stickleback readily mate with morphologically similar, but distantly related resident-freshwater stickleback. Partial pre-mating isolation is asymmetrical; anadromous females and smaller, resident-freshwater males from Loberg Lake readily mate, but the anadromous males and smaller Loberg females do not. Our results indicate that pre-mating isolation can begin to evolve in allopatry within a few generations after isolation as a correlated effect of evolution of reduced body size. PMID:23025615

  9. Differences in rheotactic responses contribute to divergent habitat use between parapatric lake and stream threespine stickleback.

    PubMed

    Jiang, Yuexin; Torrance, Louisa; Peichel, Catherine L; Bolnick, Daniel I

    2015-09-01

    Migration among populations is widely thought to undermine adaptive divergence, assuming gene flow arises from random movement of individuals. If individuals instead differ in dispersal behavior, phenotype-dependent dispersal can reduce the effective rate of gene flow or even facilitate divergence. For example, parapatric populations of lake and stream stickleback tend to actively avoid dispersing into the adjoining habitat. However, the behavioral basis of this nonrandom dispersal was previously unknown. Here, we show that lake and stream stickleback exhibit divergent rheotactic responses (behavioral response to currents). During the breeding season, wild-caught inlet stream stickleback were better than lake fish at maintaining position in currents, faced upstream more, and spent more time in low-current areas. As a result, stream fish expended significantly less energy in currents than did lake fish. These divergent rheotactic responses likely contribute to divergent habitat use by lake and stream stickleback. Although rheotactic differences were absent in nonbreeding fish, divergent behavior of breeding-season fish may suffice for assortative mating by breeding location. The resulting reproductive isolation between lake and stream fish may explain the fine-scale evolutionary differentiation in parapatric stickleback populations.

  10. Heat and immunity: an experimental heat wave alters immune functions in three-spined sticklebacks (Gasterosteus aculeatus).

    PubMed

    Dittmar, Janine; Janssen, Hannah; Kuske, Andra; Kurtz, Joachim; Scharsack, Jörn P

    2014-07-01

    Global climate change is predicted to lead to increased temperatures and more extreme climatic events. This may influence host-parasite interactions, immunity and therefore the impact of infectious diseases on ecosystems. However, little is known about the effects of rising temperatures on immune defence, in particular in ectothermic animals, where the immune system is directly exposed to external temperature change. Fish are ideal models for studying the effect of temperature on immunity, because they are poikilothermic, but possess a complete vertebrate immune system with both innate and adaptive immunity. We used three-spined sticklebacks ( Gasterosteus aculeatus) originating from a stream and a pond, whereby the latter supposedly were adapted to higher temperature variation. We studied the effect of increasing and decreasing temperatures and a simulated heat wave with subsequent recovery on body condition and immune parameters. We hypothesized that the immune system might be less active at low temperatures, but will be even more suppressed at temperatures towards the upper tolerable temperature range. Contrary to our expectation, we found innate and adaptive immune activity to be highest at a temperature as low as 13 °C. Exposure to a simulated heat wave induced long-lasting immune disorders, in particular in a stickleback population that might be less adapted to temperature variation in its natural environment. The results show that the activity of the immune system of an ectothermic animal species is temperature dependent and suggest that heat waves associated with global warming may immunocompromise host species, thereby potentially facilitating the spread of infectious diseases.

  11. The stress response of three-spined sticklebacks is modified in proportion to effluent exposure downstream of wastewater treatment works.

    PubMed

    Pottinger, Tom G; Henrys, Peter A; Williams, Richard J; Matthiessen, Peter

    2013-01-15

    This study was conducted to investigate whether exposure to wastewater treatment works (WWTW) effluent affects the adaptive stress axis of fish resident within the receiving water. Three-spined sticklebacks (Gasterosteus aculeatus) were sampled from sites downstream of ten WWTWs in north-west England, selected to represent a range of human population equivalents between 1000 and 125,000. Following capture, indices of stress (whole-body cortisol and glucose concentrations) were measured both prior to, and following, the imposition of a standardised stressor to establish both baseline and stress-induced concentrations of cortisol and glucose. There was considerable between-site variation in size, and to a lesser extent condition, of the fish. Pre- and post-stress cortisol and glucose concentrations also varied significantly between-sites. A large proportion of the variation in both the somatic data and the stress response was explained by variation in the proportion of effluent contributing to total river flow at the study sites. Mass (r(2)=0.35, P<0.001) and length (r(2)=0.37, P<0.001) of the fish, and cortisol (r(2)=0.26, P<0.001) and glucose (r(2)=0.12, P<0.01) concentrations in unstressed sticklebacks, were positively related to the concentration of effluent across the sample sites. However, in stressed fish, cortisol (r(2)=0.32, P<0.001) and glucose (r(2)=0.14, P<0.001) concentrations exhibited a negative trend in relation to the effluent concentrations across sites. Individual variation in fish size did not account for the variation in either cortisol or glucose levels. These data provide the first indication that modulation of the stress axis in fish by anthropogenic factors might be widespread and of greater significance than hitherto assumed. PMID:23021553

  12. Quantifying the constraining influence of gene flow on adaptive divergence in the lake-stream threespine stickleback system.

    PubMed

    Moore, Jean-Sébastien; Gow, Jennifer L; Taylor, Eric B; Hendry, Andrew P

    2007-08-01

    The constraining effect of gene flow on adaptive divergence is often inferred but rarely quantified. We illustrate ways of doing so using stream populations of threespine stickleback (Gasterosteus aculeatus) that experience different levels of gene flow from a parapatric lake population. In the Misty Lake watershed (British Columbia, Canada), the inlet stream population is morphologically divergent from the lake population, and presumably experiences little gene flow from the lake. The outlet stream population, however, shows an intermediate phenotype and may experience more gene flow from the lake. We first used microsatellite data to demonstrate that gene flow from the lake is low into the inlet but high into the outlet, and that gene flow from the lake remains relatively constant with distance along the outlet. We next combined gene flow data with morphological and habitat data to quantify the effect of gene flow on morphological divergence. In one approach, we assumed that inlet stickleback manifest well-adapted phenotypic trait values not constrained by gene flow. We then calculated the deviation between the observed and expected phenotypes for a given habitat in the outlet. In a second approach, we parameterized a quantitative genetic model of adaptive divergence. Both approaches suggest a large impact of gene flow, constraining adaptation by 80-86% in the outlet (i.e., only 14-20% of the expected morphological divergence in the absence of gene flow was observed). Such approaches may be useful in other taxa to estimate how important gene flow is in constraining adaptive divergence in nature. PMID:17683442

  13. Perchlorate disrupts embryonic androgen synthesis and reproductive development in threespine stickleback without changing whole-body levels of thyroid hormone

    PubMed Central

    Petersen, Ann M.; Dillon, Danielle; Bernhardt, Richard A.; Torunsky, Roberta; Postlethwait, John H.; von Hippel, Frank A.; Buck, C. Loren; Cresko, William A.

    2014-01-01

    Perchlorate, an environmental contaminant, disrupts normal functioning of the thyroid. We previously showed that perchlorate disrupts behavior and gonad development, and induces external morphological changes in a vertebrate model organism, the threespine stickleback. Whether perchlorate alters these phenotypes via a thyroid-mediated mechanism, and the extent to which the effects depend on dose, are unknown. To address these questions, we chronically exposed stickleback to control conditions and to three concentrations of perchlorate (10, 30 and 100 ppm) at various developmental stages from fertilization to reproductive maturity. Adults chronically exposed to perchlorate had increased numbers of thyroid follicles and decreased numbers of thyrocytes. Surprisingly, T4 and T3 levels in larval, juvenile, and adult whole fish chronically exposed to perchlorate did not differ from controls, except at the lowest perchlorate dose, suggesting a non-monotonic dose response curve. We found no detectable abnormalities in external phenotype at any dose of perchlorate, indicating that the increased number of thyroid follicles compensated for the disruptive effects of these doses. In contrast to external morphology, gonadal development was altered substantially, with the highest dose of perchlorate causing the largest effects. Perchlorate increased the number both of early stage ovarian follicles in females and of advanced spermatogenic stages in males. Perchlorate also disrupted embryonic androgen levels. We conclude that chronic perchlorate exposure may not result in lasting adult gross morphological changes but can produce lasting modifications to gonads when compensation of T3 and T4 levels occurs by thyroid follicle hyperplasia. Perchlorate may therefore affect vertebrate development via both thyroidal and non-thyroidal mechanisms. PMID:25448260

  14. Whole-genome sequencing reveals small genomic regions of introgression in an introduced crater lake population of threespine stickleback.

    PubMed

    Yoshida, Kohta; Miyagi, Ryutaro; Mori, Seiichi; Takahashi, Aya; Makino, Takashi; Toyoda, Atsushi; Fujiyama, Asao; Kitano, Jun

    2016-04-01

    Invasive species pose a major threat to biological diversity. Although introduced populations often experience population bottlenecks, some invasive species are thought to be originated from hybridization between multiple populations or species, which can contribute to the maintenance of high genetic diversity. Recent advances in genome sequencing enable us to trace the evolutionary history of invasive species even at whole-genome level and may help to identify the history of past hybridization that may be overlooked by traditional marker-based analysis. Here, we conducted whole-genome sequencing of eight threespine stickleback (Gasterosteus aculeatus) individuals, four from a recently introduced crater lake population and four of the putative source population. We found that both populations have several small genomic regions with high genetic diversity, which resulted from introgression from a closely related species (Gasterosteus nipponicus). The sizes of the regions were too small to be detected with traditional marker-based analysis or even some reduced-representation sequencing methods. Further amplicon sequencing revealed linkage disequilibrium around an introgression site, which suggests the possibility of selective sweep at the introgression site. Thus, interspecies introgression might predate introduction and increase genetic variation in the source population. Whole-genome sequencing of even a small number of individuals can therefore provide higher resolution inference of history of introduced populations. PMID:27069575

  15. Whole-genome sequencing reveals small genomic regions of introgression in an introduced crater lake population of threespine stickleback.

    PubMed

    Yoshida, Kohta; Miyagi, Ryutaro; Mori, Seiichi; Takahashi, Aya; Makino, Takashi; Toyoda, Atsushi; Fujiyama, Asao; Kitano, Jun

    2016-04-01

    Invasive species pose a major threat to biological diversity. Although introduced populations often experience population bottlenecks, some invasive species are thought to be originated from hybridization between multiple populations or species, which can contribute to the maintenance of high genetic diversity. Recent advances in genome sequencing enable us to trace the evolutionary history of invasive species even at whole-genome level and may help to identify the history of past hybridization that may be overlooked by traditional marker-based analysis. Here, we conducted whole-genome sequencing of eight threespine stickleback (Gasterosteus aculeatus) individuals, four from a recently introduced crater lake population and four of the putative source population. We found that both populations have several small genomic regions with high genetic diversity, which resulted from introgression from a closely related species (Gasterosteus nipponicus). The sizes of the regions were too small to be detected with traditional marker-based analysis or even some reduced-representation sequencing methods. Further amplicon sequencing revealed linkage disequilibrium around an introgression site, which suggests the possibility of selective sweep at the introgression site. Thus, interspecies introgression might predate introduction and increase genetic variation in the source population. Whole-genome sequencing of even a small number of individuals can therefore provide higher resolution inference of history of introduced populations.

  16. Directional genetic selection by pulp mill effluent on multiple natural populations of three-spined stickleback (Gasterosteus aculeatus).

    PubMed

    Lind, Emma E; Grahn, Mats

    2011-05-01

    Contamination can cause a rapid environmental change which may require populations to respond with evolutionary changes. To evaluate the effects of pulp mill effluents on population genetics, we sampled three-spined sticklebacks (Gasterosteus aculeatus) near four pulp mills and four adjacent reference sites and analyzed Amplified Fragment Length Polymorphism (AFLP) to compare genetic variability. A fine scale genetic structure was detected and samples from polluted sites separated from reference sites in multidimensional scaling plots (P<0.005, 1000 permutations) and locus-by-locus Analysis of Molecular Variance (AMOVA) further confirmed that habitats are significantly separated (F(ST)=0.021, P<0.01, 1023 permutations). The amount of genetic variation between populations did not differ between habitats, and populations from both habitats had similar levels of heterozygosity (polluted sites Nei's Hs=0.11, reference sites Nei's Hs=0.11). Still, pairwise F(ST): s between three, out of four, pairs of polluted-reference sites were significant. A F(ST)-outlier analysis showed that 21 (8.4%) loci were statistically different from a neutral distribution at the P<0.05 level and therefore indicated to be under divergent selection. When removing 13 F(ST)-outlier loci, significant at the P<0.01 level, differentiation between habitats disappeared in a multidimensional scaling plot. In conclusion, pulp mill effluence has acted as a selective agent on natural populations of G. aculeatus, causing a convergence in genotype composition change at multiple sites in an open environment.

  17. Rapid analysis of diclofenac and some of its transformation products in the three-spined stickleback, Gasterosteus aculeatus, by liquid chromatography-tandem mass spectrometry.

    PubMed

    Daniele, Gaëlle; Fieu, Maëva; Joachim, Sandrine; Bado-Nilles, Anne; Baudoin, Patrick; Turies, Cyril; Porcher, Jean-Marc; Andres, Sandrine; Vulliet, Emmanuelle

    2016-06-01

    Pharmaceuticals are emerging organic contaminants ubiquitously present in the environment due to incessant input into the aquatic compartment mainly resulting from incomplete removal in wastewater treatment plants. One of the major preoccupations concerning pharmaceuticals released into surface waters is their potential for bioaccumulation in biota, possibly leading to deleterious effects on ecosystems especially as they could affect a broad variety of organisms living in or depending on the aquatic environment. Thus, the development of accurate and sensitive methods is necessary to detect these compounds in aquatic ecosystems. Considering this need, this study deals with the analytical development of a methodology to quantify traces of diclofenac together with some of its biotic and abiotic transformation products in whole-body tissue of three-spined stickleback. A simple and reliable extraction method based on a modified QuEChERS extraction is implemented on 200 mg of fish. The detection and quantification of the ten target compounds are performed using liquid chromatography-tandem mass spectrometry. The whole process was successfully validated regarding linearity, recovery, repeatability, and reproducibility. The method limits of detection and quantification do not exceed 1 ng/g. To reproduce environmental conditions, we measured the concentration of DCF and its transformation products in three-spined sticklebacks after a 6-month exposure in mesocosms at several levels of DCF ranging from 0.05 to 4.1 μg/L. The phase I metabolite 4'-hydroxydiclofenac was detected in fish samples exposed at the highest DCF concentration. Graphical abstract Analysis of diclofenac and some of its transformation products in the three-spined stickleback, Gasterosteus aculeatus, by QuEChERS extraction followed by LC-MS/MS. PMID:27086017

  18. Population genetic dynamics of three-spined sticklebacks (Gasterosteus aculeatus) in anthropogenic altered habitats

    PubMed Central

    Scharsack, Joern P; Schweyen, Hannah; Schmidt, Alexander M; Dittmar, Janine; Reusch, Thorsten BH; Kurtz, Joachim

    2012-01-01

    In industrialized and/or agriculturally used landscapes, inhabiting species are exposed to a variety of anthropogenic changes in their environments. Genetic diversity may be reduced if populations encounter founder events, bottlenecks, or isolation. Conversely, genetic diversity may increase if populations adapt to changes in selective regimes in newly created habitats. With the present study, genetic variability of 918 sticklebacks from 43 samplings (21.3 ± 3.8 per sample) at 36 locations from cultivated landscapes in Northwest Germany was analyzed at nine neutral microsatellite loci. To test if differentiation is influenced by habitat alterations, sticklebacks were collected from ancient running waters and adjacent artificial stagnant waters, from brooks with salt water inflow of anthropogenic and natural origin and adjacent freshwater sites. Overall population structure was dominated by isolation by distance (IBD), which was significant across all populations, and analysis of molecular variance (AMOVA) revealed that 10.6% of the variation was explained by river catchment area. Populations in anthropogenic modified habitats deviated from the general IBD structure and in the AMOVA, grouping by habitat type running/stagnant water explained 4.9% of variation and 1.4% of the variation was explained by salt-/freshwater habitat. Sticklebacks in salt-polluted water systems seem to exhibit elevated migratory activity between fresh- and saltwater habitats, reducing IBD. In other situations, populations showed distinct signs of genetic isolation, which in some locations was attributed to mechanical migration barriers, but in others to potential anthropogenic induced bottleneck or founder effects. The present study shows that anthropogenic habitat alterations may have diverse effects on the population genetic structure of inhabiting species. Depending on the type of habitat change, increased genetic differentiation, diversification, or isolation are possible consequences

  19. In situ experiments to assess effects of constraints linked to caging on ecotoxicity biomarkers of the three-spined stickleback (Gasterosteus aculeatus L.).

    PubMed

    Le Guernic, Antoine; Sanchez, Wilfried; Palluel, Olivier; Bado-Nilles, Anne; Turies, Cyril; Chadili, Edith; Cavalié, Isabelle; Adam-Guillermin, Christelle; Porcher, Jean-Marc; Geffard, Alain; Betoulle, Stéphane; Gagnaire, Béatrice

    2016-04-01

    The aim of this study was to evaluate the effects of caging constraints on multiple fish biomarkers used during ecotoxicological studies (biometric data, immune and antioxidant systems, and energetic status). Two of these constraints were linked to caging: starvation and fish density in cages, and one in relation to the post-caging handling: a short transport. Three in situ experiments were conducted with three-spined sticklebacks (Gasterosteus aculeatus). The first experiment compared the effects of three densities (low, medium, and high). The second experiment compared effects of starvation in fish fed every two days with fish that were not fed. Finally comparisons between sticklebacks which have suffered a short car transport after caging and sticklebacks killed without preliminary transport were made. The lack of food had no effect on fish energetic reserves but negatively affected their condition index and their immune system. Transport and high density induced oxidative stress, defined as an overproduction of reactive oxygen species and a stimulation of the antioxidant system. These two constraints also harmed the leucocyte viability. In order not to have any impact on ecotoxicity biomarkers during in situ experiments, it is preferable to decrease fish density in cages, prevent transport before dissections, and feed fish when the caging lasts more than two weeks.

  20. Accumulation and rapid decay of non-LTR retrotransposons in the genome of the three-spine stickleback.

    PubMed

    Blass, Eryn; Bell, Michael; Boissinot, Stéphane

    2012-01-01

    The diversity and abundance of non-long terminal repeat (LTR) retrotransposons (nLTR-RT) differ drastically among vertebrate genomes. At one extreme, the genome of placental mammals is littered with hundreds of thousands of copies resulting from the activity of a single clade of nLTR-RT, the L1 clade. In contrast, fish genomes contain a much more diverse repertoire of nLTR-RT, represented by numerous active clades and families. Yet, the number of nLTR-RT copies in teleostean fish is two orders of magnitude smaller than in mammals. The vast majority of insertions appear to be very recent, suggesting that nLTR-RT do not accumulate in fish genomes. This pattern had previously been explained by a high rate of turnover, in which the insertion of new elements is offset by the selective loss of deleterious inserts. The turnover model was proposed because of the similarity between fish and Drosophila genomes with regard to their nLTR-RT profile. However, it is unclear if this model applies to fish. In fact, a previous study performed on the puffer fish suggested that transposable element insertions behave as neutral alleles. Here we examined the dynamics of amplification of nLTR-RT in the three-spine stickleback (Gasterosteus aculeatus). In this species, the vast majority of nLTR-RT insertions are relatively young, as suggested by their low level of divergence. Contrary to expectations, a majority of these insertions are fixed in lake and oceanic populations; thus, nLTR-RT do indeed accumulate in the genome of their fish host. This is not to say that nLTR-RTs are fully neutral, as the lack of fixed long elements in this genome suggests a deleterious effect related to their length. This analysis does not support the turnover model and strongly suggests that a much higher rate of DNA loss in fish than in mammals is responsible for the relatively small number of nLTR-RT copies and for the scarcity of ancient elements in fish genomes. We further demonstrate that nLTR-RT decay

  1. Disruption of the stress response in wastewater treatment works effluent-exposed three-spined sticklebacks persists after translocation to an unpolluted environment.

    PubMed

    Pottinger, Tom G; Matthiessen, Peter

    2016-04-01

    The hypothalamic-pituitary-adrenal/interrenal (HPA/I) axis plays a key role in responding to biotic and abiotic challenges in all vertebrates. Recent studies have shown that the apical response of the HPI axis to stressors in three-spined sticklebacks varies in proportion to the concentration of wastewater treatment works (WWTW) effluent to which the fish are exposed. This study was conducted to determine whether between-site variation in stress responsiveness among WWTW effluent-exposed sticklebacks is persistent or reversible. Sticklebacks from eight sites in north-west England affected by WWTW effluent and exhibiting between-population variation in HPI axis reactivity, were moved to a clean-water aquarium environment. After five months in the contaminant-free environment the responsiveness of these fish to a standardised stressor was determined, by measuring the rate of stress-induced cortisol release across the gills, and compared with the responses of fish newly sampled from the eight original capture sites. Inter-site differences in the reactivity of the HPI axis, proportional to the effluent concentration at each site, persisted among the translocated female sticklebacks for at least 5 months. In male fish however, the direct relationship between stress responsiveness and site-specific effluent was not evident 5 months post-translocation. These results support previous observations that the HPA/I axis, a non-reproductive endocrine system, is vulnerable to modulation by anthropogenic factors in fish and show for the first time that, in female fish at least, this modulation is not transient. The mechanisms underlying these observations, and the implications for the fitness and resilience of affected populations, requires investigation. PMID:26821232

  2. Excretory products of the cestode, Schistocephalus solidus, modulate in vitro responses of leukocytes from its specific host, the three-spined stickleback (Gasterosteus aculeatus).

    PubMed

    Scharsack, Jörn Peter; Gossens, Anabel; Franke, Frederik; Kurtz, Joachim

    2013-12-01

    Helminth parasites have evolved remarkable strategies to manipulate the immune system of their hosts. During infections of three-spined stickleback (Gasterosteus aculeatus) with the cestode Schistocephalus solidus prominent immunological changes occur, presumably due to manipulative activity of the parasite. We hypothesise that excretory/secretory products of the parasite are involved in the manipulation of the stickleback's immune system and that this may depend on the individual parasite and its origin. We therefore produced S. solidus conditioned cell culture media (SSCM) with parasites from different origins (Norway, Spain and Germany) and exposed head kidney leukocytes (HKL) from un-infected sticklebacks in cell cultures to SSCM. After in vitro culture, HKL were subjected to differential cell counts (granulocytes/lymphocytes) by means of flow cytometry. Leukocyte sub-populations were analysed for cell viability and changes in cell morphology. The respiratory burst activity was measured with a luminescence assay. Exposure of HKL to SSCM induced an up-regulation of respiratory burst activity after already 1 h, which was still elevated at 24 h, but which was in some cases significantly down-regulated after 96 h. Respiratory burst was positively correlated with the number of live granulocytes in the culture, suggesting that the respiratory burst activity was changed by SSCM effects on granulocyte viability. After 1 h and 24 h of HKL culture, no lymphocyte responses to SSCM were detectable, but after 96 h lymphocyte viability was significantly decreased with SSCM from Spanish S. solidus. In these cultures, residual lymphocytes increased in size, suggesting that cell death and activation might have occurred in parallel. The highest respiratory burst activity was induced by SSCM from Spanish parasites, in particular when they were grown in sympatric sticklebacks. The in vitro HKL responses to SSCM depended on the individual parasite and its population of origin

  3. Disruption of the stress response in wastewater treatment works effluent-exposed three-spined sticklebacks persists after translocation to an unpolluted environment.

    PubMed

    Pottinger, Tom G; Matthiessen, Peter

    2016-04-01

    The hypothalamic-pituitary-adrenal/interrenal (HPA/I) axis plays a key role in responding to biotic and abiotic challenges in all vertebrates. Recent studies have shown that the apical response of the HPI axis to stressors in three-spined sticklebacks varies in proportion to the concentration of wastewater treatment works (WWTW) effluent to which the fish are exposed. This study was conducted to determine whether between-site variation in stress responsiveness among WWTW effluent-exposed sticklebacks is persistent or reversible. Sticklebacks from eight sites in north-west England affected by WWTW effluent and exhibiting between-population variation in HPI axis reactivity, were moved to a clean-water aquarium environment. After five months in the contaminant-free environment the responsiveness of these fish to a standardised stressor was determined, by measuring the rate of stress-induced cortisol release across the gills, and compared with the responses of fish newly sampled from the eight original capture sites. Inter-site differences in the reactivity of the HPI axis, proportional to the effluent concentration at each site, persisted among the translocated female sticklebacks for at least 5 months. In male fish however, the direct relationship between stress responsiveness and site-specific effluent was not evident 5 months post-translocation. These results support previous observations that the HPA/I axis, a non-reproductive endocrine system, is vulnerable to modulation by anthropogenic factors in fish and show for the first time that, in female fish at least, this modulation is not transient. The mechanisms underlying these observations, and the implications for the fitness and resilience of affected populations, requires investigation.

  4. Small Variations in Early-Life Environment Can Affect Coping Behaviour in Response to Foraging Challenge in the Three-Spined Stickleback

    PubMed Central

    2016-01-01

    Context An increasing concern in the face of human expansion throughout natural habitats is whether animal populations can respond adaptively when confronted with challenges like environmental change and novelty. Behavioural flexibility is an important factor in estimating the adaptive potential of both individuals and populations, and predicting the degree to which they can cope with change. Study Design This study on the three-spined stickleback (Gasterosteus aculeatus) is an empiric illustration of the degree of behavioural variation that can emerge between semi-natural systems within only a single generation. Wild-caught adult sticklebacks (P, N = 400) were randomly distributed in equal densities over 20 standardized semi-natural environments (ponds), and one year later offspring (F1, N = 652) were presented with repeated behavioural assays. Individuals were challenged to reach a food source through a novel transparent obstacle, during which exploration, activity, foraging, sociability and wall-biting behaviours were recorded through video observation. We found that coping responses of individuals from the first generation to this unfamiliar foraging challenge were related to even relatively small, naturally diversified variation in developmental environment. All measured behaviours were correlated with each other. Especially exploration, sociability and wall-biting were found to differ significantly between ponds. These differences could not be explained by stickleback density or the turbidity of the water. Findings Our findings show that a) differences in early-life environment appear to affect stickleback feeding behaviour later in life; b) this is the case even when the environmental differences are only small, within natural parameters and diversified gradually; and c) effects are present despite semi-natural conditions that fluctuate during the year. Therefore, in behaviourally plastic animals like the stickleback, the adaptive response to human

  5. Ephemeral stream reaches preserve the evolutionary and distributional history of threespine stickleback in the Santa Clara and Ventura River watersheds of southern California

    USGS Publications Warehouse

    Richmond, Jonathan Q.; Jacobs, David K.; Backlin, Adam R.; Swift, Camm C.; Dellith, Chris; Fisher, Robert N.

    2015-01-01

    Much remains to be understood about the evolutionary history and contemporary landscape genetics of unarmored threespine stickleback in southern California, where populations collectively referred to as Gasterosteus aculeatus williamsoni have severely declined over the past 70+ years and are now endangered. We used mitochondrial sequence and microsatellite data to assess the population genetics and phylogeography of unarmored populations sampled immediately downstream from the type locality of G. a. williamsoni in the upper Santa Clara River, and assessed their distinctiveness with respect to low-armor populations in the downstream sections of the river and the adjacent Ventura River. We also characterized the geographic limits of different plate morphs and evaluated the congruence of those boundaries with barriers to dispersal in both river systems and to neutral genetic variation. We show substantial population structuring within the upper reach of the Santa Clara River, but little partitioning between the lower Santa Clara and Ventura Rivers—we attribute these patterns to different ancestry between spatially subdivided populations within the same drainage, a predominance of downstream gene flow, and ability for coastal dispersal between the Santa Clara and Ventura Rivers. We also show that alleles from introduced low-plate stock have infiltrated a native population in at least one upper Santa Clara River tributary, causing this formerly unarmored population to become gradually low-plated over a 30 + year time period. Measures of genetic diversity, census surveys, and severe habitat disturbance all indicate that unarmored stickleback near the type locality are currently at high risk of extinction.

  6. Costly major histocompatibility complex signals produced only by reproductively active males, but not females, must be validated by a ‘maleness signal’ in three-spined sticklebacks

    PubMed Central

    Milinski, Manfred; Griffiths, Siân W.; Reusch, Thorsten B. H.; Boehm, Thomas

    2010-01-01

    Olfactory information about individual major histocompatibility complex (MHC) immune genotypes is important for mate choice in several species. For example, during the mate choice decisions of three-spined sticklebacks, females assess males on the basis of odour cues that convey information about their MHC diversity. Here, we show that an additional ‘maleness’ signal is needed to validate the MHC signal. Furthermore, using interaction between natural odour of sticklebacks and synthetic MHC-ligand peptides, we show that MHC signals are conditional on the reproductive state in males. By contrast, we find that gravid females do not produce such signals. Since MHC olfactory signals relevant to mate choice decisions are conditional upon gender and reproductive state, we suggest that their manufacture is likely to be costly to senders, and therefore, potentially conditional on the health/parasitization status of the sender. We hypothesize that shedding of peptide–MHC complexes compromises immune function, selecting against unconditional use of these signals. PMID:19846459

  7. Measuring the immune system of the three-spined stickleback - investigating natural variation by quantifying immune expression in the laboratory and the wild.

    PubMed

    Robertson, Shaun; Bradley, Janette E; MacColl, Andrew D C

    2016-05-01

    Current understanding of the immune system comes primarily from laboratory-based studies. There has been substantial interest in examining how it functions in the wild, but studies have been limited by a lack of appropriate assays and study species. The three-spined stickleback (Gasterosteus aculeatus L.) provides an ideal system in which to advance the study of wild immunology, but requires the development of suitable immune assays. We demonstrate that meaningful variation in the immune response of stickleback can be measured using real-time PCR to quantify the expression of eight genes, representing the innate response and Th1-, Th2- and Treg-type adaptive responses. Assays are validated by comparing the immune expression profiles of wild and laboratory-raised stickleback, and by examining variation across populations on North Uist, Scotland. We also compare the immune response potential of laboratory-raised individuals from two Icelandic populations by stimulating cells in culture. Immune profiles of wild fish differed from laboratory-raised fish from the same parental population, with immune expression patterns in the wild converging relative to those in the laboratory. Innate measures differed between wild populations, whilst the adaptive response was associated with variation in age, relative size of fish, reproductive status and S. solidus infection levels. Laboratory-raised individuals from different populations showed markedly different innate immune response potential. The ability to combine studies in the laboratory and in the wild underlines the potential of this toolkit to advance our understanding of the ecological and evolutionary relevance of immune system variation in a natural setting.

  8. Displaced phylogeographic signals from Gyrodactylus arcuatus, a parasite of the three-spined stickleback Gasterosteus aculeatus, suggest freshwater glacial refugia in Europe.

    PubMed

    Lumme, Jaakko; Mäkinen, Hannu; Ermolenko, Alexey V; Gregg, Jacob L; Ziętara, Marek S

    2016-08-01

    We examined the global mitochondrial phylogeography of Gyrodactylus arcuatus, a flatworm ectoparasite of three-spined stickleback Gasterosteus aculeatus. In accordance with the suggested high divergence rate of 13%/million years, the genetic variation of the parasite was high: haplotype diversity h=0.985 and nucleotide diversity π=0.0161. The differentiation among the parasite populations was substantial (Φst=0.759), with two main allopatric clades (here termed Euro and North) accounting for 54% of the total genetic variation. The diversity center of the Euro clade was in the Baltic Sea, while the North clade was spread across the Barents and White Seas. A single haplotype within the North clade was found in the western and eastern Pacific Ocean. Divergence of main clades was estimated to be circa 200 thousand years ago. Each main clade was further divided into six distinct subclades, estimated to have diverged in isolation since 135 thousand years ago. This second division corresponds approximately to the Eemian interglacial predating the last glacial maximum. A demographic expansion of the subclades is associated with colonisation of northern Europe since the last glacial maximum, circa 15-40 thousand years ago. The parasite phylogeny is most likely explained by sequential isolated bottlenecks and expansions in numerous allopatric refugia. The postglacial intermingling and high variation in the marine parasite populations, separately in the Baltic and Barents Seas, suggest low competition of divergent parasite matrilines, coupled with a large population size and high rate of dispersal of hosts. The genetic contribution of the assumed refugial fish populations maintaining the parasite during the last glacial maximum was not detected among the marine sticklebacks, which perhaps were infected after range expansion. PMID:27155331

  9. Muscle metabolic capacities and plasma cortisol levels of the male three-spine stickleback Gasterosteus aculeatus: are there "femme fatale" or "macho male" effects?

    PubMed

    Guderley, Helga

    2009-01-01

    To evaluate whether decreases in muscle metabolic capacities and increases in plasma cortisol explain the effects of neighboring conspecifics on male three-spine sticklebacks Gasterosteus aculeatus, we housed mature males alone, with a mature female, or with a rival mature male. The neighbors were separated from the focal male by a partition that allowed him to smell, see, and hear his neighbor. In the first experiment, focal males were allowed to reproduce, whereas in the second experiment, no reproduction occurred. Coloration and behaviors were monitored while the males tended their nests (or for the same period in the second experiment). The presence of a neighbor markedly affected the reproductive coloration of the focal male, with solitary males being less colorful than males housed with a rival male or a female. Solitary males showed greater aggression toward a model male stickleback than did males with neighbors. The presence of neighbors affected the anatomic and metabolic characteristics of the focal males primarily during nesting, when males housed with rival males had a lower hepatosomatic index and lower activities of mitochondrial and glycolytic enzymes in the axial muscle than did solitary males or males housed with females. Cortisol levels were highly variable in nesting males and did not differ with social condition but were higher in males that had been quick to construct their nests. On the other hand, when focal males were not provided with nesting material, solitary males tended to have lower cortisol levels than did males housed with rival males. While these results do not provide a mechanism for a "femme fatale" effect, they indicate that nesting males decrease metabolic status when housed with rival "macho males." PMID:19758091

  10. Characterization of a genotoxicity biomarker in three-spined stickleback (Gasterosteus aculeatus L.): Biotic variability and integration in a battery of biomarkers for environmental monitoring.

    PubMed

    Santos, Raphael; Joyeux, Aude; Palluel, Olivier; Palos-Ladeiro, Mélissa; Besnard, Aurélien; Blanchard, Christophe; Porcher, Jean Marc; Bony, Sylvie; Devaux, Alain; Sanchez, Wilfried

    2016-04-01

    As a large array of hazardous substances exhibiting genotoxicity are discharged into surface water, this work aimed at assessing the relevance of adding a genotoxicity biomarker in a battery of biomarkers recently developed in the model fish three-spined stickleback (Gasterosteus aculeatus). First the confounding influence of gender, body length, and season (used as a proxy of age and of the fish reproductive status, respectively) on the level of primary DNA damage in erythrocytes was investigated in wild sticklebacks. Then, the genotoxity biomarker was included in a large battery of biomarkers assessing xenobiotic biotransformation, oxidative stress and neurotoxicity, and implemented in five sites. Gender, age and reproductive status did not influence DNA damage level in fish from the reference site. A significant relationship between the level of primary DNA damage and fish length (as a proxy of age also correlated to the season) was highlighted in the contaminated site. Among all biomarkers investigated in the field, the level of DNA damage was one of the four most discriminating biomarkers with EROD, catalase activity and the level of lipid peroxidation representing together 75.40% of the discriminating power in sampled fish. The level of DNA damage was correlated to the EROD activity and to the level of peroxidation, which mainly discriminated fish from sites under urban pressure. Finally, Integrated Biomarker Response indexes (IBRv2), which were calculated with the whole biomarker response dataset exhibited higher values in the Reveillon (9.62), the Scarpe and Rhonelle contaminated sites (5.11 and 4.90) compared with the two reference sites (2.38 and 2.55). The present work highlights that integration of a genotoxicity biomarker in a multiparametric approach is relevant to assess ecotoxicological risk in freshwater aquatic organisms.

  11. In situ effects of metal contamination from former uranium mining sites on the health of the three-spined stickleback (Gasterosteus aculeatus, L.).

    PubMed

    Le Guernic, Antoine; Sanchez, Wilfried; Bado-Nilles, Anne; Palluel, Olivier; Turies, Cyril; Chadili, Edith; Cavalié, Isabelle; Delahaut, Laurence; Adam-Guillermin, Christelle; Porcher, Jean-Marc; Geffard, Alain; Betoulle, Stéphane; Gagnaire, Béatrice

    2016-08-01

    Human activities have led to increased levels of various pollutants including metals in aquatic ecosystems. Increase of metallic concentrations in aquatic environments represents a potential risk to exposed organisms, including fish. The aim of this study was to characterize the environmental risk to fish health linked to a polymetallic contamination from former uranium mines in France. This contamination is characterized by metals naturally present in the areas (manganese and iron), uranium, and metals (aluminum and barium) added to precipitate uranium and its decay products. Effects from mine releases in two contaminated ponds (Pontabrier for Haute-Vienne Department and Saint-Pierre for Cantal Department) were compared to those assessed at four other ponds outside the influence of mine tailings (two reference ponds/department). In this way, 360 adult three-spined sticklebacks (Gasterosteus aculeatus) were caged for 28 days in these six ponds before biomarker analyses (immune system, antioxidant system, biometry, histology, DNA integrity, etc.). Ponds receiving uranium mine tailings presented higher concentrations of uranium, manganese and aluminum, especially for the Haute-Vienne Department. This uranium contamination could explain the higher bioaccumulation of this metal in fish caged in Pontabrier and Saint-Pierre Ponds. In the same way, many fish biomarkers (antioxidant and immune systems, acetylcholinesterase activity and biometric parameters) were impacted by this environmental exposure to mine tailings. This study shows the interest of caging and the use of a multi-biomarker approach in the study of a complex metallic contamination.

  12. In situ effects of metal contamination from former uranium mining sites on the health of the three-spined stickleback (Gasterosteus aculeatus, L.).

    PubMed

    Le Guernic, Antoine; Sanchez, Wilfried; Bado-Nilles, Anne; Palluel, Olivier; Turies, Cyril; Chadili, Edith; Cavalié, Isabelle; Delahaut, Laurence; Adam-Guillermin, Christelle; Porcher, Jean-Marc; Geffard, Alain; Betoulle, Stéphane; Gagnaire, Béatrice

    2016-08-01

    Human activities have led to increased levels of various pollutants including metals in aquatic ecosystems. Increase of metallic concentrations in aquatic environments represents a potential risk to exposed organisms, including fish. The aim of this study was to characterize the environmental risk to fish health linked to a polymetallic contamination from former uranium mines in France. This contamination is characterized by metals naturally present in the areas (manganese and iron), uranium, and metals (aluminum and barium) added to precipitate uranium and its decay products. Effects from mine releases in two contaminated ponds (Pontabrier for Haute-Vienne Department and Saint-Pierre for Cantal Department) were compared to those assessed at four other ponds outside the influence of mine tailings (two reference ponds/department). In this way, 360 adult three-spined sticklebacks (Gasterosteus aculeatus) were caged for 28 days in these six ponds before biomarker analyses (immune system, antioxidant system, biometry, histology, DNA integrity, etc.). Ponds receiving uranium mine tailings presented higher concentrations of uranium, manganese and aluminum, especially for the Haute-Vienne Department. This uranium contamination could explain the higher bioaccumulation of this metal in fish caged in Pontabrier and Saint-Pierre Ponds. In the same way, many fish biomarkers (antioxidant and immune systems, acetylcholinesterase activity and biometric parameters) were impacted by this environmental exposure to mine tailings. This study shows the interest of caging and the use of a multi-biomarker approach in the study of a complex metallic contamination. PMID:27272751

  13. Population structure and effective/census population size ratio in threatened three-spined stickleback populations from an isolated river basin in northwest Spain.

    PubMed

    Pérez-Figueroa, A; Fernández, C; Amaro, R; Hermida, M; San Miguel, E

    2015-08-01

    Variability at 20 microsatellite loci was examined to assess the population genetic structure, gene flow, and effective population size (N(e)) in three populations of three-spined stickleback (Gasterosteus aculeatus) from the upper basin of the Miño River in Galicia, NW Spain, where this species is threatened. The three populations showed similar levels of genetic diversity. There is a significant genetic differentiation between the three populations, but also significant gene flow. N(e) estimates based on linkage disequilibrium yielded values of 355 for the Miño River population and 241 and 311 for the Rato and Guisande Rivers, respectively, although we expect that these are overestimates. N(e) estimates based on temporal methods, considering gene flow or not, for the tributaries yielded values of 30-56 and 47-56 for the Rato and Guisande Rivers, respectively. Estimated census size (N(c)) for the Rato River was 880 individuals. This yielded a N(e)/N(c) estimate of 3-6 % for temporal estimation of N(e), which is within the empirical range observed in freshwater fishes. We suggest that the three populations analyzed have a sufficient level of genetic diversity with some genetic structure. Additionally, the absence of physical barriers suggests that conservation efforts and monitoring should focus in the whole basin as a unit.

  14. Microarray analysis of di-n-butyl phthalate and 17α ethinyl-oestradiol responses in three-spined stickleback testes reveals novel candidate genes for endocrine disruption.

    PubMed

    Prokkola, Jenni M; Katsiadaki, Ioanna; Sebire, Marion; Elphinstone-Davis, Jessica; Pausio, Sanna; Nikinmaa, Mikko; Leder, Erica H

    2016-02-01

    Phthalate esters are plasticizers frequently found in wastewater effluents. Previous studies on phthalates have reported anti-androgenic activity in mammals, causing concerns of their potential effects on the reproduction of aquatic organisms. Another group of environmental endocrine disrupters, steroidal estrogens, are known to inhibit steroid biosynthesis in the gonads, but the effects related to spermatogenesis are not well understood in fish. In this study, three-spined sticklebacks were exposed to di-n-butyl phthalate (DBP) and 17α ethinyl-oestradiol (EE2) at nominal concentrations 35μg/L and 40ng/L, respectively, for four days. The aim of the study was to obtain insight into the acute transcriptional responses putatively associated with endocrine disruption. RNA samples from eight individual male fish per treatment (including controls) were used in microarray analysis, covering the expression of approximately 21,000 genes. In the EE2 treatment the results show transcriptional downregulation of genes associated with steroid biosynthesis pathway and up-regulation of genes involved in pathways related to epidermal growth factor signaling and xenobiotic metabolism. The transcriptional response to DBP was in general weaker than to EE2, but based on enrichment analysis, we suggest adverse effects on retinoid metabolism, creatine kinase activity and cell adhesion. Among the genes showing highest fold changes after DBP treatment compared to control was the teleost fish -specific cytochrome P450 17A2. Overall, this study promotes our understanding on molecular responses to anti-androgens and estrogens in fish testes. PMID:26476330

  15. Sexual maturation and changes in water and salt transport components in the kidney and intestine of three-spined stickleback (Gasterosteus aculeatus L.).

    PubMed

    Madsen, Steffen S; Weber, Claus; Nielsen, Andreas M; Mohiseni, Mohammad; Bosssus, Maryline C; Tipsmark, Christian K; Borg, Bertil

    2015-10-01

    Mature three-spined stickleback males use spiggin threads secreted from their kidney to glue together nest material. This requires strongly hypertrophied renal proximal tubular cells, which compromises renal osmoregulatory function during the breeding period. Experimental evidence suggests that the intestine takes over hypotonic fluid secretion at that stage but the mechanism is unexplored. To unravel the molecular mechanism we analyzed and compared transcript levels of several membrane proteins involved in water and salt transport in intestinal and renal tissues, in non-mature males (NM), mature males (MM), and mature females (MF). Aquaporin paralogs aqp1a, -3a, -8aa, -8ab, -10a, and -10b, two Na(+),K(+)-ATPase alpha-1 subunit isoforms (nka547, nka976), Na(+),K(+),2Cl(-)-, and Na(+),Cl(-)-cotransporters (nkcc1a, nkcc2, ncc), the cystic fibrosis transmembrane conductance regulator (cftr) and two claudin isoforms (cldn2, cldn15a) were expressed in the intestine and kidney in all groups. There were no differences in aqp and cldn expression between intestines of NM and MM; nkcc2 was lower and nka levels tended to be higher in intestines of MM than in NM. In the kidney, aqp1 and aqp8ab levels were lower in MM than in NM, whereas aqp3a, nkcc1a, cldn15a, and spiggin were markedly elevated. This was accompanied by marked hypertrophy of kidney tubules in MM. The data support an altered kidney function in terms of water handling in mature males, whereas there was no support for modified trans-epithelial water permeability or salt-secretory activity in the intestine of mature males. Salt-absorptive activity in the intestine may, however, be down-regulated during male maturation.

  16. Immunity comes first: the effect of parasite genotypes on adaptive immunity and immunization in three-spined sticklebacks.

    PubMed

    Haase, David; Rieger, Jennifer K; Witten, Anika; Stoll, Monika; Bornberg-Bauer, Erich; Kalbe, Martin; Reusch, Thorsten B H

    2016-01-01

    Adaptive immunity in vertebrates can confer increased resistance against invading pathogens upon re-infection. But how specific parasite genotypes affect the temporal transition from innate to adaptive immunity under continual exposure to parasites is poorly understood. Here, we investigated the effects of homologous and heterologous exposures of genetically distinct parasite lineages of the eye fluke Diplostomum pseudospathaceum on gene expression patterns of adaptive immunity in sticklebacks (Gasterosteus aculeatus). Observable differences in gene expression were largely attributable to final exposures while there was no transcription pattern characteristic for a general response to repeated infections with D. pseudospathaceum. None of the final exposure treatments was able to erase the distinct expression patterns resulting from a heterologous pre-exposed fish. Interestingly, heterologous final exposures showed similarities between different treatment groups subjected to homologous pre-exposure. The observed pattern was supported by parasite infection rates and suggests that host immunization was optimized towards an adaptive immune response that favored effectiveness against parasite diversity over specificity.

  17. The interaction among age, thermal acclimation and growth rate in determining muscle metabolic capacities and tissue masses in the threespine stickleback, Gasterosteus aculeatus.

    PubMed

    Guderley, H; Lavoie, B A; Dubois, N

    1994-11-01

    Thermal acclimation may directly modify muscle metabolic capacities, or may modify them indirectly via effects upon physiological processes such as growth, reproduction or senescence. To evaluate these interacting effects, we examined the influence of thermal acclimation and acclimatization upon muscle metabolic capacities and tissue masses in 1 + stickleback, Gasterosteus aculeatus, in which confounding interactions between temperature and senescense should be absent. Furthermore, we examined the influence of thermal acclimation upon individual growth rate, muscle enzyme levels and tissue masses in 2 + stickleback sampled at the beginning of their final reproductive season. For 1 + stickleback, cold acclimation more than doubles mitochondrial enzyme levels in the axial muscle. Thermal acclimation did not change the condition of 1 + stickleback at feeding levels which could not maintain the condition of 2+ stickleback. Compensatory metabolic responses to temperature were not apparent in field acclimatized 1 + stickleback. The growth rate of 2 + stickleback was markedly affected by temperature: warm-acclimated fish generally lost mass even at very high levels of feeding (up to 78 enchytraid worms per day) while cold-acclimated fish gained mass. This suggests that warm temperatures accelerate the senescence of 2 + stickleback. Generally, muscle enzyme activities increased with growth rate. In axial muscle, the relationships between CS activity and growth rate differed with acclimation temperature. Independent of the influence of growth rate, CS activities were consistently higher in cold- than warm-acclimated 2 + stickleback, suggesting compensatory increases of CS activity with cold acclimation. PMID:24197078

  18. Disentangling the role of MHC-dependent 'good genes' and 'compatible genes' in mate-choice decisions of three-spined sticklebacks Gasterosteus aculeatus under semi-natural conditions.

    PubMed

    Lenz, T L; Eizaguirre, C; Scharsack, J P; Kalbe, M; Milinski, M

    2009-11-01

    To investigate and disentangle the role of major histocompatibility complex (MHC)-based 'good genes' and 'compatible genes' in mate choice, three-spined sticklebacks Gasterosteus aculeatus with specific MHC IIB genotypes were allowed to reproduce in an outdoor enclosure system. Here, fish were protected from predators but encountered their natural parasites. Mate choice for an intermediate genetic distance between parental MHC genotypes was observed, which would result in intermediate diversity in the offspring, but no mate choice based on good genes was found under the current semi-natural conditions. Investigation of immunological variables revealed that the less-specific innate immune system was more active in individuals with a genetically more divergent MHC allele repertoire. This suggests the need to compensate for an MHC-diminished T-cell repertoire and potentially explains the observed mate choice for intermediate MHC genetic distance. The present findings support a general pattern of mate choice for intermediate MHC diversity (i.e. compatible genes). In addition, the potentially dynamic role of MHC good genes in mate choice under different parasite pressures is discussed in the light of present and previous results.

  19. Where the Lake Meets the Sea: Strong Reproductive Isolation Is Associated with Adaptive Divergence between Lake Resident and Anadromous Three-Spined Sticklebacks

    PubMed Central

    Ravinet, Mark; Hynes, Rosaleen; Poole, Russell; Cross, Tom F.; McGinnity, Phil; Harrod, Chris; Prodöhl, Paulo A.

    2015-01-01

    Contact zones between divergent forms of the same species are often characterised by high levels of phenotypic diversity over small geographic distances. What processes are involved in generating such high phenotypic diversity? One possibility is that introgression and recombination between divergent forms in contact zones results in greater phenotypic and genetic polymorphism. Alternatively, strong reproductive isolation between forms may maintain distinct phenotypes, preventing homogenisation by gene flow. Contact zones between divergent freshwater-resident and anadromous stickleback (Gasterosteus aculeatus L.) forms are numerous and common throughout the species distribution, offering an opportunity to examine these contrasting hypotheses in greater detail. This study reports on an interesting new contact zone located in a tidally influenced lake catchment in western Ireland, characterised by high polymorphism for lateral plate phenotypes. Using neutral and QTL-linked microsatellite markers, we tested whether the high diversity observed in this contact zone arose as a result of introgression or reproductive isolation between divergent forms: we found strong support for the latter hypothesis. Three phenotypic and genetic clusters were identified, consistent with two divergent resident forms and a distinct anadromous completely plated population that migrates in and out of the system. Given the strong neutral differentiation detected between all three morphotypes (mean FST = 0.12), we hypothesised that divergent selection between forms maintains reproductive isolation. We found a correlation between neutral genetic and adaptive genetic differentiation that support this. While strong associations between QTL linked markers and phenotypes were also observed in this wild population, our results support the suggestion that such associations may be more complex in some Atlantic populations compared to those in the Pacific. These findings provide an important foundation

  20. Where the lake meets the sea: strong reproductive isolation is associated with adaptive divergence between lake resident and anadromous three-spined sticklebacks.

    PubMed

    Ravinet, Mark; Hynes, Rosaleen; Poole, Russell; Cross, Tom F; McGinnity, Phil; Harrod, Chris; Prodöhl, Paulo A

    2015-01-01

    Contact zones between divergent forms of the same species are often characterised by high levels of phenotypic diversity over small geographic distances. What processes are involved in generating such high phenotypic diversity? One possibility is that introgression and recombination between divergent forms in contact zones results in greater phenotypic and genetic polymorphism. Alternatively, strong reproductive isolation between forms may maintain distinct phenotypes, preventing homogenisation by gene flow. Contact zones between divergent freshwater-resident and anadromous stickleback (Gasterosteus aculeatus L.) forms are numerous and common throughout the species distribution, offering an opportunity to examine these contrasting hypotheses in greater detail. This study reports on an interesting new contact zone located in a tidally influenced lake catchment in western Ireland, characterised by high polymorphism for lateral plate phenotypes. Using neutral and QTL-linked microsatellite markers, we tested whether the high diversity observed in this contact zone arose as a result of introgression or reproductive isolation between divergent forms: we found strong support for the latter hypothesis. Three phenotypic and genetic clusters were identified, consistent with two divergent resident forms and a distinct anadromous completely plated population that migrates in and out of the system. Given the strong neutral differentiation detected between all three morphotypes (mean FST = 0.12), we hypothesised that divergent selection between forms maintains reproductive isolation. We found a correlation between neutral genetic and adaptive genetic differentiation that support this. While strong associations between QTL linked markers and phenotypes were also observed in this wild population, our results support the suggestion that such associations may be more complex in some Atlantic populations compared to those in the Pacific. These findings provide an important foundation

  1. Anti-androgens act jointly in suppressing spiggin concentrations in androgen-primed female three-spined sticklebacks - prediction of combined effects by concentration addition.

    PubMed

    Pottinger, T G; Katsiadaki, I; Jolly, C; Sanders, M; Mayer, I; Scott, A P; Morris, S; Kortenkamp, A; Scholze, M

    2013-09-15

    Increasing attention is being directed at the role played by anti-androgenic chemicals in endocrine disruption of wildlife within the aquatic environment. The co-occurrence of multiple contaminants with anti-androgenic activity highlights a need for the predictive assessment of combined effects, but information about anti-androgen mixture effects on wildlife is lacking. This study evaluated the suitability of the androgenised female stickleback screen (AFSS), in which inhibition of androgen-induced spiggin production provides a quantitative assessment of anti-androgenic activity, for predicting the effect of a four component mixture of anti-androgens. The anti-androgenic activity of four known anti-androgens (vinclozolin, fenitrothion, flutamide, linuron) was evaluated from individual concentration-response data and used to design a mixture containing each chemical at equipotent concentrations. Across a 100-fold concentration range, a concentration addition approach was used to predict the response of fish to the mixture. Two studies were conducted independently at each of two laboratories. By using a novel method to adjust for differences between nominal and measured concentrations, good agreement was obtained between the actual outcome of the mixture exposure and the predicted outcome. This demonstrated for the first time that androgen receptor antagonists act in concert in an additive fashion in fish and that existing mixture methodology is effective in predicting the outcome, based on concentration-response data for individual chemicals. The sensitivity range of the AFSS assay lies within the range of anti-androgenicity reported in rivers across many locations internationally. The approach taken in our study lays the foundations for understanding how androgen receptor antagonists work together in fish and is essential in informing risk assessment methods for complex anti-androgenic mixtures in the aquatic environment.

  2. Reversed brain size sexual dimorphism accompanies loss of parental care in white sticklebacks

    PubMed Central

    Samuk, Kieran; Iritani, Davis; Schluter, Dolph

    2014-01-01

    Uncovering factors that shape variation in brain morphology remains a major challenge in evolutionary biology. Recently, it has been shown that brain size is positively associated with level of parental care behavior in various taxa. One explanation for this pattern is that the cognitive demands of performing complex parental care may require increased brain size. This idea is known as the parental brain hypothesis (PBH). We set out to test the predictions of this hypothesis in wild populations of threespine stickleback (Gasterosteus aculeatus). These fish are commonly known to exhibit (1) uniparental male care and (2) sexual dimorphism in brain size (males>females). To test the PBH, we took advantage of the existence of closely related populations of stickleback that display variation in parental care behavior: common marine threespine sticklebacks (uniparental male care) and white threespine sticklebacks (no care). To begin, we quantified genetic differentiation among two common populations and three white populations from Nova Scotia. We found overall low differentiation among populations, although FST was increased in between-type comparisons. We then measured the brain weights of males and females from all five populations along with two additional common populations from British Columbia. We found that sexual dimorphism in brain size is reversed in white stickleback populations: males have smaller brains than females. Thus, while several alternatives need to be ruled out, the PBH appears to be a reasonable explanation for sexual dimorphism in brain size in threespine sticklebacks. PMID:25473476

  3. Sticklebacks as model hosts in ecological and evolutionary parasitology.

    PubMed

    Barber, Iain

    2013-11-01

    The three-spined stickleback is a small teleost fish, native to coastal regions of the Northern Hemisphere, which has emerged as a key model organism in evolutionary biology and ecology. Sticklebacks possess a well-documented and experimentally amenable parasite fauna, and are well suited to both laboratory and field parasitological investigation. As a consequence, sticklebacks have been extensively used as model hosts in studies of host-parasite interactions, and these studies have provided considerable insight into the roles of parasites in ecology and evolutionary biology. In this review, I discuss key advances in our understanding of host-parasite interactions that have arisen from studies involving stickleback hosts, highlight areas of current research activity, and identify potentially promising areas for future research.

  4. Female stickleback prefer shallow males: Sexual selection on nest microhabitat.

    PubMed

    Bolnick, Daniel I; Shim, Kum Chuan; Brock, Chad D

    2015-06-01

    Sexual selection is most often thought of as acting on organismal traits, such as size or color. However, individuals' habitat use may also affect mating success. Here, we show that, in threespine stickleback, nest depth can be a target of sexual selection. In postglacial lakes in British Columbia, male threespine stickleback nest in a narrow range of depths. Prior studies revealed heritable variation in males' preferred nest microhabitat. We surveyed four natural populations, finding that male stickleback with shallower nests were more successful at breeding. Indeed, nest depth was a much stronger predictor of male mating success than more commonly studied targets of sexual selection in stickleback (size, condition, shape, color, infection status). This selection on nest depth means that variance in fitness changed predictably across microhabitats, altering the opportunity for sexual selection to act on other traits. Accordingly, we show that sexual selection on other male traits is strongest where variance in nesting success is highest (at intermediate nest depths in some lakes). We conclude that males' choice of nesting microhabitat is an especially important target of sexual selection, resulting in fine-scale spatial variation in sexual selection on other traits. PMID:25958935

  5. Species difference in adaptive use of public information in sticklebacks.

    PubMed Central

    Coolen, Isabelle; van Bergen, Yfke; Day, Rachel L; Laland, Kevin N

    2003-01-01

    Animals foraging on variable food sources can refine their estimates of patch quality by monitoring the success of others (i.e. collect 'public information'). Here, we show that both three-spined sticklebacks (Gasterosteus aculeatus) and nine-spined sticklebacks (Pungitius pungitius) use past cues provided by others to locate food but only nine-spined sticklebacks use prior public information to assess patch quality, regardless of whether demonstrators were conspecifics or heterospecifics. Moreover, nine-spined but not three-spined sticklebacks preferentially hid in vegetation during the demonstration, a position from which they could observe both patches simultaneously and collect public information. We conclude that species differences in the use of public information can be explained by variations in habitat choice and response to predation. Our findings expand current understanding of the scope of public-information use in animals by showing that fishes can use public-information in a foraging context and from heterospecifics. The study suggests that public-information use is an adaptation that allows animals vulnerable to predation to acquire valuable foraging information at low risk. PMID:14667359

  6. Genetic Architecture of Parallel Pelvic Reduction in Ninespine Sticklebacks

    PubMed Central

    Shikano, Takahito; Laine, Veronika N.; Herczeg, Gábor; Vilkki, Johanna; Merilä, Juha

    2013-01-01

    Teleost fish genomes are known to be evolving faster than those of other vertebrate taxa. Thus, fish are suited to address the extent to which the same vs. different genes are responsible for similar phenotypic changes in rapidly evolving genomes of evolutionary independent lineages. To gain insights into the genetic basis and evolutionary processes behind parallel phenotypic changes within and between species, we identified the genomic regions involved in pelvic reduction in Northern European ninespine sticklebacks (Pungitius pungitius) and compared them to those of North American ninespine and threespine sticklebacks (Gasterosteus aculeatus). To this end, we conducted quantitative trait locus (QTL) mapping using 283 F2 progeny from an interpopulation cross. Phenotypic analyses indicated that pelvic reduction is a recessive trait and is inherited in a simple Mendelian fashion. Significant QTL for pelvic spine and girdle lengths were identified in the region of the Pituitary homeobox transcription factor 1 (Pitx1) gene, also responsible for pelvic reduction in threespine sticklebacks. The fact that no QTL was observed in the region identified in the mapping study of North American ninespine sticklebacks suggests that an alternative QTL for pelvic reduction has emerged in this species within the past 1.6 million years after the split between Northern European and North American populations. In general, our study provides empirical support for the view that alternative genetic mechanisms that lead to similar phenotypes can evolve over short evolutionary time scales. PMID:23979937

  7. Shifts in morphology and diet of non-native sticklebacks introduced into Japanese crater lakes

    PubMed Central

    Adachi, Tatsuya; Ishikawa, Asano; Mori, Seiichi; Makino, Wataru; Kume, Manabu; Kawata, Masakado; Kitano, Jun

    2012-01-01

    An increasing number of exotic animals are causing ecological problems. Therefore, for better ecosystem management, it is important to understand how exotic species colonize and adapt to novel environments. The threespine sticklebacks (Gasterosteus aculeatus) can be a good vertebrate model system to explore the ecological and genetic mechanisms of adaptation not only in natural populations, but also in non-native populations. Although morphological changes have been documented in several introduced populations of stickleback, little is known about the dietary changes during colonization into novel environments. Here, we investigated the morphological and dietary changes of exotic threespine stickleback populations introduced into three Japanese crater lakes (Lake Towada, Lake Kussharo, and Lake Shikotsu). Sticklebacks were introduced into the crater lakes likely along with salmonids transplanted for aquaculture. The stickleback population in Lake Kussharo had multiple mitochondrial haplotypes and had larger phenotypic variances than other crater lake stickleback populations that had only one mitochondrial haplotype. Compilation of historical data on the morphology and stomach contents of the Lake Towada stickleback population showed that substantial shifts in body size and stomach contents occurred after colonization. Some of these changes may be related to an outbreak of the Schistocephalus parasite. These results suggest that sticklebacks can change their morphology and trophic ecology when they colonize novel environments. Therefore, extreme care should be taken when salmonids are transported between watersheds for aquaculture and that long-term monitoring of exotic species is essential for ecosystem management. In addition, further genetic studies on phenotypic changes in crater lake sticklebacks would help elucidate the genetic mechanisms underlying the adaptation of exotic fishes to novel environments. PMID:22833786

  8. Shifts in morphology and diet of non-native sticklebacks introduced into Japanese crater lakes.

    PubMed

    Adachi, Tatsuya; Ishikawa, Asano; Mori, Seiichi; Makino, Wataru; Kume, Manabu; Kawata, Masakado; Kitano, Jun

    2012-06-01

    An increasing number of exotic animals are causing ecological problems. Therefore, for better ecosystem management, it is important to understand how exotic species colonize and adapt to novel environments. The threespine sticklebacks (Gasterosteus aculeatus) can be a good vertebrate model system to explore the ecological and genetic mechanisms of adaptation not only in natural populations, but also in non-native populations. Although morphological changes have been documented in several introduced populations of stickleback, little is known about the dietary changes during colonization into novel environments. Here, we investigated the morphological and dietary changes of exotic threespine stickleback populations introduced into three Japanese crater lakes (Lake Towada, Lake Kussharo, and Lake Shikotsu). Sticklebacks were introduced into the crater lakes likely along with salmonids transplanted for aquaculture. The stickleback population in Lake Kussharo had multiple mitochondrial haplotypes and had larger phenotypic variances than other crater lake stickleback populations that had only one mitochondrial haplotype. Compilation of historical data on the morphology and stomach contents of the Lake Towada stickleback population showed that substantial shifts in body size and stomach contents occurred after colonization. Some of these changes may be related to an outbreak of the Schistocephalus parasite. These results suggest that sticklebacks can change their morphology and trophic ecology when they colonize novel environments. Therefore, extreme care should be taken when salmonids are transported between watersheds for aquaculture and that long-term monitoring of exotic species is essential for ecosystem management. In addition, further genetic studies on phenotypic changes in crater lake sticklebacks would help elucidate the genetic mechanisms underlying the adaptation of exotic fishes to novel environments.

  9. Copper accumulation by stickleback nests containing spiggin.

    PubMed

    Pinho, G L L; Martins, C M G; Barber, I

    2016-07-01

    The three-spined stickleback is a ubiquitous fish of marine, brackish and freshwater ecosystems across the Northern hemisphere that presents intermediate sensitivity to copper. Male sticklebacks display a range of elaborate reproductive behaviours that include nest construction. To build the nests, each male binds nesting material together using an endogenous glycoprotein nesting glue, known as 'spiggin'. Spiggin is a cysteine-rich protein and, therefore, potentially binds heavy metals present in the environment. The aim of this study was to investigate the capacity of stickleback nests to accumulate copper from environmental sources. Newly built nests, constructed by male fish from polyester threads in laboratory aquaria, were immersed in copper solutions ranging in concentration from 21.1-626.6 μg Cu L(-1). Bundles of polyester threads from aquaria without male fish were also immersed in the same copper solutions. After immersion, nests presented higher amounts of copper than the thread bundles, indicating a higher capacity of nests to bind this metal. A significant, positive correlation between the concentration of copper in the exposure solution and in the exposed nests was identified, but there was no such relationship for thread bundles. Since both spiggin synthesis and male courtship behaviour are under the control of circulating androgens, we predicted that males with high courtship scores would produce and secrete high levels of the spiggin protein. In the present study, nests built by high courtship score males accumulated more copper than those built by low courtship score males. Considering the potential of spiggin to bind metals, the positive relationship between fish courtship and spiggin secretion seems to explain the higher amount of copper on the nests from the fish showing high behaviour scores. Further work is now needed to determine the consequences of the copper binding potential of spiggin in stickleback nests for the health and survival of

  10. Role of the iridescent eye in stickleback female mate choice.

    PubMed

    Flamarique, Iñigo Novales; Bergstrom, Carolyn; Cheng, Christiana L; Reimchen, Thomas E

    2013-08-01

    Many vertebrates exhibit prominent body colours that are used in courtship and territorial communication. Some fishes also have an eye whose iris becomes iridescent during the mating season, as in the threespine stickleback. Behavioural studies in this species have focused on the redness of the throat/jaw as the primary determinant of female mate choice. Unlike the iridescent eye, however, the red throat/jaw is not present in all stickleback populations, suggesting that the colour of the eye may be equally important for female mate choice. Here, we used data on photoreceptors and environmental light to assess body conspicuousness and the colour contrast of courtship signals for stickleback populations living in a range of waters, from clear (mesotrophic) to red light shifted (dystrophic). This analysis indicated that the redness of the throat/jaw is expressed to enhance the contrast of the eye. To test the importance of eye colour as a courtship signal, we carried out mate choice experiments in which females were presented with identical videos of a courting male but for the colour of the eye and/or the throat/jaw. Females did not choose based on differences in throat/jaw redness between videos, but preferred males with the highest contrast between the eye and the throat/jaw. This result points to the blue iridescent eye as a primary courtship signal in stickleback female mate choice.

  11. Genetic divergence in morphology-performance mapping between Misty Lake and inlet stickleback.

    PubMed

    Hendry, A P; Hudson, K; Walker, J A; Räsänen, K; Chapman, L J

    2011-01-01

    Different environments should select for different aspects of organismal performance, which should lead to correlated divergence in morphological traits that influence performance. The result should be genetic divergence in aspects of performance, morphology and associations ('maps') between morphology and performance. Testing this hypothesis requires quantifying performance and morphology in multiple populations after controlling for environmental differences, but this is rarely attempted. We used a common-garden experiment to examine morphology and several aspects of swimming performance within and between the lake and inlet populations of threespine stickleback (Gasterosteus aculeatus) from the Misty system, Vancouver Island, Canada. Controlling for body size, lake stickleback had shallower bodies, larger caudal fins and smaller pelvic girdles. With or without morphological covariates, lake stickleback showed greater performance in both sustained and burst swimming. In contrast, inlet stickleback showed greater manoeuverability than did lake stickleback in some analyses. Morphology-performance relationships were decoupled when considering variation within vs. between populations. Moreover, morphology-performance mapping differed between the two populations. Based on these observations, we advance a hypothesis for why populations adapting to different environments should show adaptive genetic divergence in morphology-performance mapping. PMID:21091565

  12. Major histocompatibility complex diversity influences parasite resistance and innate immunity in sticklebacks.

    PubMed

    Kurtz, Joachim; Kalbe, Martin; Aeschlimann, Peter B; Häberli, Michael A; Wegner, K Mathias; Reusch, Thorsten B H; Milinski, Manfred

    2004-01-22

    Proteins of the major histocompatibility complex (MHC) play a central role in the presentation of antigens to the adaptive immune system. The MHC also influences the odour-based choice of mates in humans and several animal taxa. It has recently been shown that female three-spined sticklebacks (Gasterosteus aculeatus) aim at a moderately high MHC diversity in their offspring when choosing a mate. Do they optimize the immune systems of their offspring? Using three-spined sticklebacks that varied in their individual numbers of MHC class IIB molecules, we tested, experimentally, whether allelic diversity at the MHC influences parasite resistance and immune parameters. We found that sticklebacks with low MHC diversity suffered more from parasite infection after experimental exposure to Schistocephalus solidus tapeworms and Glugea anomala microsporidians. They also showed the highest proportion of granulocytes and the strongest respiratory burst reaction, which are correlates of innate immunity. This indicates a strong activity of the innate immune system after challenge by parasites when MHC diversity is suboptimal. Individuals with very high allelic diversity at the MHC seemed inferior to those with moderately high diversity. Such a pattern is consistent with theoretical expectations of an optimal balance between the number of recognizable antigens and self-tolerance. PMID:15058398

  13. CHRONIC PERCHLORATE EXPOSURE CAUSES MORPHOLOGICAL ABNORMALITIES IN DEVELOPING STICKLEBACK

    PubMed Central

    Bernhardt, Richard R.; Von Hippel, Frank A.; O’Hara, Todd M.

    2011-01-01

    Few studies have examined the effects of chronic perchlorate exposure during growth and development, and fewer still have analyzed the effects of perchlorate over multiple generations. We describe morphological and developmental characteristics for threespine stickleback (Gasterosteus aculeatus) that were spawned and raised to sexual maturity in perchlorate-treated water (G1,2003) and for their offspring (G2,2004) that were not directly treated with perchlorate. The G1,2003 displayed a variety of abnormalities, including impaired formation of calcified traits, slower growth rates, aberrant sexual development, poor survivorship, and reduced pigmentation that allowed internal organs to be visible. Yet these conditions were absent when the offspring of contaminated fish (G2,2004) were raised in untreated water, suggesting a lack of transgenerational effects and that surviving populations may be able to recover following remediation of perchlorate-contaminated sites PMID:21465539

  14. Hybridization between distant lineages increases adaptive variation during a biological invasion: stickleback in Switzerland.

    PubMed

    Lucek, Kay; Roy, Denis; Bezault, Etienne; Sivasundar, Arjun; Seehausen, Ole

    2010-09-01

    The three-spined stickleback is a widespread Holarctic species complex that radiated from the sea into freshwaters after the retreat of the Pleistocene ice sheets. In Switzerland, sticklebacks were absent with the exception of the far northwest, but different introduced populations have expanded to occupy a wide range of habitats since the late 19th century. A well-studied adaptive phenotypic trait in sticklebacks is the number of lateral plates. With few exceptions, freshwater and marine populations in Europe are fixed for either the low plated phenotype or the fully plated phenotype, respectively. Switzerland, in contrast, harbours in close proximity the full range of phenotypic variation known from across the continent. We addressed the phylogeographic origins of Swiss sticklebacks using mitochondrial partial cytochrome b and control region sequences. We found only five different haplotypes but these originated from three distinct European regions, fixed for different plate phenotypes. These lineages occur largely in isolation at opposite ends of Switzerland, but co-occur in a large central part. Across the country, we found a strong correlation between a microsatellite linked to the high plate ectodysplasin allele and the mitochondrial haplotype from a region where the fully plated phenotype is fixed. Phylogenomic and population genomic analysis of 481 polymorphic amplified fragment length polymorphism loci indicate genetic admixture in the central part of the country. The same part of the country also carries elevated within-population phenotypic variation. We conclude that during the recent invasive range expansion of sticklebacks in Switzerland, adaptive and neutral between-population genetic variation was converted into within-population variation, raising the possibility that hybridization between colonizing lineages contributed to the ecological success of sticklebacks in Switzerland.

  15. Adaptive Divergence in the Thyroid Hormone Signaling Pathway in the Stickleback Radiation

    PubMed Central

    Kitano, Jun; Lema, Sean C.; Luckenbach, J. Adam; Mori, Seiichi; Kawagishi, Yui; Kusakabe, Makoto; Swanson, Penny; Peichel, Catherine L.

    2010-01-01

    Summary During adaptive radiations, animals colonize diverse environments, which requires adaptation in multiple phenotypic traits [1]. Because hormones mediate the dynamic regulation of suites of phenotypic traits [2–4], evolutionary changes in hormonal signaling pathways might contribute to adaptation to new environments. Here, we report changes in the thyroid hormone signaling pathway in stream-resident ecotypes of threespine stickleback fish (Gasterosteus aculeatus), which have repeatedly evolved from ancestral marine ecotypes [5–8]. Stream-resident fish exhibit a lower plasma concentration of thyroid hormone and a lower metabolic rate, which is likely adaptive for permanent residency in small streams. The thyroid stimulating hormone-β2 (TSHβ2) gene exhibited significantly lower mRNA expression in pituitary glands of stream-resident sticklebacks relative to marine sticklebacks. Some of the difference in TSHβ2 transcript levels can be explained by cis-regulatory differences at the TSHβ2 gene locus. Consistent with these expression differences, a strong signature of divergent natural selection was found at the TSHβ2 genomic locus. By contrast, there were no differences between the marine and stream-resident ecotypes in mRNA levels or genomic sequence in the paralogous TSHβ1 gene. Our data indicate that evolutionary changes in hormonal signaling have played an important role in the postglacial adaptive radiation of sticklebacks. PMID:21093265

  16. Transcriptome profiling of immune tissues reveals habitat-specific gene expression between lake and river sticklebacks.

    PubMed

    Huang, Yun; Chain, Frédéric J J; Panchal, Mahesh; Eizaguirre, Christophe; Kalbe, Martin; Lenz, Tobias L; Samonte, Irene E; Stoll, Monika; Bornberg-Bauer, Erich; Reusch, Thorsten B H; Milinski, Manfred; Feulner, Philine G D

    2016-02-01

    The observation of habitat-specific phenotypes suggests the action of natural selection. The three-spined stickleback (Gasterosteus aculeatus) has repeatedly colonized and adapted to diverse freshwater habitats across the northern hemisphere since the last glaciation, while giving rise to recurring phenotypes associated with specific habitats. Parapatric lake and river populations of sticklebacks harbour distinct parasite communities, a factor proposed to contribute to adaptive differentiation between these ecotypes. However, little is known about the transcriptional response to the distinct parasite pressure of those fish in a natural setting. Here, we sampled wild-caught sticklebacks across four geographical locations from lake and river habitats differing in their parasite load. We compared gene expression profiles between lake and river populations using 77 whole-transcriptome libraries from two immune-relevant tissues, the head kidney and the spleen. Differential expression analyses revealed 139 genes with habitat-specific expression patterns across the sampled population pairs. Among the 139 differentially expressed genes, eight are annotated with an immune function and 42 have been identified as differentially expressed in previous experimental studies in which fish have been immune challenged. Together, these findings reinforce the hypothesis that parasites contribute to adaptation of sticklebacks in lake and river habitats.

  17. Alaskan Voices.

    ERIC Educational Resources Information Center

    Achatz, Mary, Ed.; Caldera, Debra, Ed.; Saylor, Brian; DeGross, Denny

    This paper examines the attitudes of adults and teenagers in 10 predominantly rural Alaskan communities toward their own health and well-being and that of children and families in their community. The communities were located across the state and ranged in size from populations of under 900 to over 50,000. The proportion of Alaska Natives in the…

  18. Evolution of growth by genetic accommodation in Icelandic freshwater stickleback

    PubMed Central

    Robinson, Beren W.

    2013-01-01

    Classical Darwinian adaptation to a change in environment can ensue when selection favours beneficial genetic variation. How plastic trait responses to new conditions affect this process depends on how plasticity reveals to selection the influence of genotype on phenotype. Genetic accommodation theory predicts that evolutionary rate may sharply increase when a new environment induces plastic responses and selects on sufficient genetic variation in those responses to produce an immediate evolutionary response, but natural examples are rare. In Iceland, marine threespine stickleback that have colonized freshwater habitats have evolved more rapid individual growth. Heritable variation in growth is greater for marine full-siblings reared at low versus high salinity, and genetic variation exists in plastic growth responses to low salinity. In fish from recently founded freshwater populations reared at low salinity, the plastic response was strongly correlated with growth. Plasticity and growth were not correlated in full-siblings reared at high salinity nor in marine fish at either salinity. In well-adapted lake populations, rapid growth evolved jointly with stronger plastic responses to low salinity and the persistence of strong plastic responses indicates that growth is not genetically assimilated. Thus, beneficial plastic growth responses to low salinity have both guided and evolved along with rapid growth as stickleback adapted to freshwater. PMID:24132309

  19. The molecular evolution of spiggin nesting glue in sticklebacks.

    PubMed

    Seear, P J; Rosato, E; Goodall-Copestake, W P; Barber, I

    2015-09-01

    Gene duplication and subsequent divergence can lead to the evolution of new functions and lineage-specific traits. In sticklebacks, the successive duplication of a mucin gene (MUC19) into a tandemly arrayed, multigene family has enabled the production of copious amounts of 'spiggin', a secreted adhesive protein essential for nest construction. Here, we examine divergence between spiggin genes among three-spined sticklebacks (Gasterosteus aculeatus) from ancestral marine and derived freshwater populations, and propose underpinning gene duplication mechanisms. Sanger sequencing revealed substantial diversity among spiggin transcripts, including alternatively spliced variants and interchromosomal spiggin chimeric genes. Comparative analysis of the sequenced transcripts and all other spiggin genes in the public domain support the presence of three main spiggin lineages (spiggin A, spiggin B and spiggin C) with further subdivisions within spiggin B (B1, B2) and spiggin C (C1, C2). Spiggin A had diverged least from the ancestral MUC19, while the spiggin C duplicates had diversified most substantially. In silico translations of the spiggin gene open reading frames predicted that spiggins A and B are secreted as long mucin-like polymers, while spiggins C1 and C2 are secreted as short monomers, with putative antimicrobial properties. We propose that diversification of duplicated spiggin genes has facilitated local adaptation of spiggin to a range of aquatic habitats. PMID:26173374

  20. Evolution of growth by genetic accommodation in Icelandic freshwater stickleback.

    PubMed

    Robinson, Beren W

    2013-12-01

    Classical Darwinian adaptation to a change in environment can ensue when selection favours beneficial genetic variation. How plastic trait responses to new conditions affect this process depends on how plasticity reveals to selection the influence of genotype on phenotype. Genetic accommodation theory predicts that evolutionary rate may sharply increase when a new environment induces plastic responses and selects on sufficient genetic variation in those responses to produce an immediate evolutionary response, but natural examples are rare. In Iceland, marine threespine stickleback that have colonized freshwater habitats have evolved more rapid individual growth. Heritable variation in growth is greater for marine full-siblings reared at low versus high salinity, and genetic variation exists in plastic growth responses to low salinity. In fish from recently founded freshwater populations reared at low salinity, the plastic response was strongly correlated with growth. Plasticity and growth were not correlated in full-siblings reared at high salinity nor in marine fish at either salinity. In well-adapted lake populations, rapid growth evolved jointly with stronger plastic responses to low salinity and the persistence of strong plastic responses indicates that growth is not genetically assimilated. Thus, beneficial plastic growth responses to low salinity have both guided and evolved along with rapid growth as stickleback adapted to freshwater.

  1. Parallel developmental genetic features underlie stickleback gill raker evolution

    PubMed Central

    2014-01-01

    Background Convergent evolution, the repeated evolution of similar phenotypes in independent lineages, provides natural replicates to study mechanisms of evolution. Cases of convergent evolution might have the same underlying developmental and genetic bases, implying that some evolutionary trajectories might be predictable. In a classic example of convergent evolution, most freshwater populations of threespine stickleback fish have independently evolved a reduction of gill raker number to adapt to novel diets. Gill rakers are a segmentally reiterated set of dermal bones important for fish feeding. A previous large quantitative trait locus (QTL) mapping study using a marine × freshwater F2 cross identified QTL on chromosomes 4 and 20 with large effects on evolved gill raker reduction. Results By examining skeletal morphology in adult and developing sticklebacks, we find heritable marine/freshwater differences in gill raker number and spacing that are specified early in development. Using the expression of the Ectodysplasin receptor (Edar) gene as a marker of raker primordia, we find that the differences are present before the budding of gill rakers occurs, suggesting an early change to a lateral inhibition process controlling raker primordia spacing. Through linkage mapping in F2 fish from crosses with three independently derived freshwater populations, we find in all three crosses QTL overlapping both previously identified QTL on chromosomes 4 and 20 that control raker number. These two QTL affect the early spacing of gill raker buds. Conclusions Collectively, these data demonstrate that parallel developmental genetic features underlie the convergent evolution of gill raker reduction in freshwater sticklebacks, suggesting that even highly polygenic adaptive traits can have a predictable developmental genetic basis. PMID:24851181

  2. Dietary input of microbes and host genetic variation shape among-population differences in stickleback gut microbiota.

    PubMed

    Smith, Chris C R; Snowberg, Lisa K; Gregory Caporaso, J; Knight, Rob; Bolnick, Daniel I

    2015-11-01

    To explain differences in gut microbial communities we must determine how processes regulating microbial community assembly (colonization, persistence) differ among hosts and affect microbiota composition. We surveyed the gut microbiota of threespine stickleback (Gasterosteus aculeatus) from 10 geographically clustered populations and sequenced environmental samples to track potential colonizing microbes and quantify the effects of host environment and genotype. Gut microbiota composition and diversity varied among populations. These among-population differences were associated with multiple covarying ecological variables: habitat type (lake, stream, estuary), lake geomorphology and food- (but not water-) associated microbiota. Fish genotype also covaried with gut microbiota composition; more genetically divergent populations exhibited more divergent gut microbiota. Our results suggest that population level differences in stickleback gut microbiota may depend more on internal sorting processes (host genotype) than on colonization processes (transient environmental effects). PMID:25909977

  3. Evolution of stickleback in 50 years on earthquake-uplifted islands.

    PubMed

    Lescak, Emily A; Bassham, Susan L; Catchen, Julian; Gelmond, Ofer; Sherbick, Mary L; von Hippel, Frank A; Cresko, William A

    2015-12-29

    How rapidly can animal populations in the wild evolve when faced with sudden environmental shifts? Uplift during the 1964 Great Alaska Earthquake abruptly created freshwater ponds on multiple islands in Prince William Sound and the Gulf of Alaska. In the short time since the earthquake, the phenotypes of resident freshwater threespine stickleback fish on at least three of these islands have changed dramatically from their oceanic ancestors. To test the hypothesis that these freshwater populations were derived from oceanic ancestors only 50 y ago, we generated over 130,000 single-nucleotide polymorphism genotypes from more than 1,000 individuals using restriction site-associated DNA sequencing (RAD-seq). Population genomic analyses of these data support the hypothesis of recent and repeated, independent colonization of freshwater habitats by oceanic ancestors. We find evidence of recurrent gene flow between oceanic and freshwater ecotypes where they co-occur. Our data implicate natural selection in phenotypic diversification and support the hypothesis that the metapopulation organization of this species helps maintain a large pool of genetic variation that can be redeployed rapidly when oceanic stickleback colonize freshwater environments. We find that the freshwater populations, despite population genetic analyses clearly supporting their young age, have diverged phenotypically from oceanic ancestors to nearly the same extent as populations that were likely founded thousands of years ago. Our results support the intriguing hypothesis that most stickleback evolution in fresh water occurs within the first few decades after invasion of a novel environment. PMID:26668399

  4. Two developmentally temporal quantitative trait loci underlie convergent evolution of increased branchial bone length in sticklebacks.

    PubMed

    Erickson, Priscilla A; Glazer, Andrew M; Cleves, Phillip A; Smith, Alyson S; Miller, Craig T

    2014-08-01

    In convergent evolution, similar phenotypes evolve repeatedly in independent populations, often reflecting adaptation to similar environments. Understanding whether convergent evolution proceeds via similar or different genetic and developmental mechanisms offers insight towards the repeatability and predictability of evolution. Oceanic populations of threespine stickleback fish, Gasterosteus aculeatus, have repeatedly colonized countless freshwater lakes and streams, where new diets lead to morphological adaptations related to feeding. Here, we show that heritable increases in branchial bone length have convergently evolved in two independently derived freshwater stickleback populations. In both populations, an increased bone growth rate in juveniles underlies the convergent adult phenotype, and one population also has a longer cartilage template. Using F2 crosses from these two freshwater populations, we show that two quantitative trait loci (QTL) control branchial bone length at distinct points in development. In both populations, a QTL on chromosome 21 controls bone length throughout juvenile development, and a QTL on chromosome 4 controls bone length only in adults. In addition to these similar developmental profiles, these QTL show similar chromosomal locations in both populations. Our results suggest that sticklebacks have convergently evolved longer branchial bones using similar genetic and developmental programmes in two independently derived populations.

  5. Evolution of stickleback in 50 years on earthquake-uplifted islands.

    PubMed

    Lescak, Emily A; Bassham, Susan L; Catchen, Julian; Gelmond, Ofer; Sherbick, Mary L; von Hippel, Frank A; Cresko, William A

    2015-12-29

    How rapidly can animal populations in the wild evolve when faced with sudden environmental shifts? Uplift during the 1964 Great Alaska Earthquake abruptly created freshwater ponds on multiple islands in Prince William Sound and the Gulf of Alaska. In the short time since the earthquake, the phenotypes of resident freshwater threespine stickleback fish on at least three of these islands have changed dramatically from their oceanic ancestors. To test the hypothesis that these freshwater populations were derived from oceanic ancestors only 50 y ago, we generated over 130,000 single-nucleotide polymorphism genotypes from more than 1,000 individuals using restriction site-associated DNA sequencing (RAD-seq). Population genomic analyses of these data support the hypothesis of recent and repeated, independent colonization of freshwater habitats by oceanic ancestors. We find evidence of recurrent gene flow between oceanic and freshwater ecotypes where they co-occur. Our data implicate natural selection in phenotypic diversification and support the hypothesis that the metapopulation organization of this species helps maintain a large pool of genetic variation that can be redeployed rapidly when oceanic stickleback colonize freshwater environments. We find that the freshwater populations, despite population genetic analyses clearly supporting their young age, have diverged phenotypically from oceanic ancestors to nearly the same extent as populations that were likely founded thousands of years ago. Our results support the intriguing hypothesis that most stickleback evolution in fresh water occurs within the first few decades after invasion of a novel environment.

  6. Testing for mating isolation between ecotypes: laboratory experiments with lake, stream and hybrid stickleback.

    PubMed

    Raeymaekers, J A M; Boisjoly, M; Delaire, L; Berner, D; Räsänen, K; Hendry, A P

    2010-12-01

    Mating isolation is a frequent contributor to ecological speciation - but how consistently does it evolve as a result of divergent selection? We tested for genetically based mating isolation between lake and stream threespine stickleback (Gasterosteus aculeatus L.) from the Misty watershed, Vancouver Island, British Columbia. We combined several design elements that are uncommon in the studies of stickleback mate choice: (i) we used second-generation laboratory-reared fish (to reduce environmental and maternal effects), (ii) we allowed for male-male competitive interactions (instead of the typical no-choice trials) and (iii) we included hybrids along with pure types. Males of different types (Lake, Inlet, hybrid) were paired in aquaria, allowed to build nests and then exposed sequentially to females of all three types. We found that Lake and Inlet males differed in behaviours thought to influence stickleback mate choice (inter- and intra-sexual aggression, display and nest activities), whereas hybrids were either intermediate or apparently 'inferior' in these behaviours. Despite these differences, Lake and Inlet fish did not mate assortatively and hybrid males did not have a mating disadvantage. Our study reinforces the noninevitability of mating isolation evolving in response to ecological differences and highlights the need to further investigate the factors promoting and constraining progress towards ecological speciation. PMID:20939859

  7. Distinct developmental genetic mechanisms underlie convergently evolved tooth gain in sticklebacks

    PubMed Central

    Ellis, Nicholas A.; Glazer, Andrew M.; Donde, Nikunj N.; Cleves, Phillip A.; Agoglia, Rachel M.; Miller, Craig T.

    2015-01-01

    Teeth are a classic model system of organogenesis, as repeated and reciprocal epithelial and mesenchymal interactions pattern placode formation and outgrowth. Less is known about the developmental and genetic bases of tooth formation and replacement in polyphyodonts, which are vertebrates with continual tooth replacement. Here, we leverage natural variation in the threespine stickleback fish Gasterosteus aculeatus to investigate the genetic basis of tooth development and replacement. We find that two derived freshwater stickleback populations have both convergently evolved more ventral pharyngeal teeth through heritable genetic changes. In both populations, evolved tooth gain manifests late in development. Using pulse-chase vital dye labeling to mark newly forming teeth in adult fish, we find that both high-toothed freshwater populations have accelerated tooth replacement rates relative to low-toothed ancestral marine fish. Despite the similar evolved phenotype of more teeth and an accelerated adult replacement rate, the timing of tooth number divergence and the spatial patterns of newly formed adult teeth are different in the two populations, suggesting distinct developmental mechanisms. Using genome-wide linkage mapping in marine-freshwater F2 genetic crosses, we find that the genetic basis of evolved tooth gain in the two freshwater populations is largely distinct. Together, our results support a model whereby increased tooth number and an accelerated tooth replacement rate have evolved convergently in two independently derived freshwater stickleback populations using largely distinct developmental and genetic mechanisms. PMID:26062935

  8. Evolution of stickleback in 50 years on earthquake-uplifted islands

    PubMed Central

    Lescak, Emily A.; Bassham, Susan L.; Catchen, Julian; Gelmond, Ofer; Sherbick, Mary L.; von Hippel, Frank A.

    2015-01-01

    How rapidly can animal populations in the wild evolve when faced with sudden environmental shifts? Uplift during the 1964 Great Alaska Earthquake abruptly created freshwater ponds on multiple islands in Prince William Sound and the Gulf of Alaska. In the short time since the earthquake, the phenotypes of resident freshwater threespine stickleback fish on at least three of these islands have changed dramatically from their oceanic ancestors. To test the hypothesis that these freshwater populations were derived from oceanic ancestors only 50 y ago, we generated over 130,000 single-nucleotide polymorphism genotypes from more than 1,000 individuals using restriction site-associated DNA sequencing (RAD-seq). Population genomic analyses of these data support the hypothesis of recent and repeated, independent colonization of freshwater habitats by oceanic ancestors. We find evidence of recurrent gene flow between oceanic and freshwater ecotypes where they co-occur. Our data implicate natural selection in phenotypic diversification and support the hypothesis that the metapopulation organization of this species helps maintain a large pool of genetic variation that can be redeployed rapidly when oceanic stickleback colonize freshwater environments. We find that the freshwater populations, despite population genetic analyses clearly supporting their young age, have diverged phenotypically from oceanic ancestors to nearly the same extent as populations that were likely founded thousands of years ago. Our results support the intriguing hypothesis that most stickleback evolution in fresh water occurs within the first few decades after invasion of a novel environment. PMID:26668399

  9. Two developmentally temporal quantitative trait loci underlie convergent evolution of increased branchial bone length in sticklebacks

    PubMed Central

    Erickson, Priscilla A.; Glazer, Andrew M.; Cleves, Phillip A.; Smith, Alyson S.; Miller, Craig T.

    2014-01-01

    In convergent evolution, similar phenotypes evolve repeatedly in independent populations, often reflecting adaptation to similar environments. Understanding whether convergent evolution proceeds via similar or different genetic and developmental mechanisms offers insight towards the repeatability and predictability of evolution. Oceanic populations of threespine stickleback fish, Gasterosteus aculeatus, have repeatedly colonized countless freshwater lakes and streams, where new diets lead to morphological adaptations related to feeding. Here, we show that heritable increases in branchial bone length have convergently evolved in two independently derived freshwater stickleback populations. In both populations, an increased bone growth rate in juveniles underlies the convergent adult phenotype, and one population also has a longer cartilage template. Using F2 crosses from these two freshwater populations, we show that two quantitative trait loci (QTL) control branchial bone length at distinct points in development. In both populations, a QTL on chromosome 21 controls bone length throughout juvenile development, and a QTL on chromosome 4 controls bone length only in adults. In addition to these similar developmental profiles, these QTL show similar chromosomal locations in both populations. Our results suggest that sticklebacks have convergently evolved longer branchial bones using similar genetic and developmental programmes in two independently derived populations. PMID:24966315

  10. Distinct developmental genetic mechanisms underlie convergently evolved tooth gain in sticklebacks.

    PubMed

    Ellis, Nicholas A; Glazer, Andrew M; Donde, Nikunj N; Cleves, Phillip A; Agoglia, Rachel M; Miller, Craig T

    2015-07-15

    Teeth are a classic model system of organogenesis, as repeated and reciprocal epithelial and mesenchymal interactions pattern placode formation and outgrowth. Less is known about the developmental and genetic bases of tooth formation and replacement in polyphyodonts, which are vertebrates with continual tooth replacement. Here, we leverage natural variation in the threespine stickleback fish Gasterosteus aculeatus to investigate the genetic basis of tooth development and replacement. We find that two derived freshwater stickleback populations have both convergently evolved more ventral pharyngeal teeth through heritable genetic changes. In both populations, evolved tooth gain manifests late in development. Using pulse-chase vital dye labeling to mark newly forming teeth in adult fish, we find that both high-toothed freshwater populations have accelerated tooth replacement rates relative to low-toothed ancestral marine fish. Despite the similar evolved phenotype of more teeth and an accelerated adult replacement rate, the timing of tooth number divergence and the spatial patterns of newly formed adult teeth are different in the two populations, suggesting distinct developmental mechanisms. Using genome-wide linkage mapping in marine-freshwater F2 genetic crosses, we find that the genetic basis of evolved tooth gain in the two freshwater populations is largely distinct. Together, our results support a model whereby increased tooth number and an accelerated tooth replacement rate have evolved convergently in two independently derived freshwater stickleback populations using largely distinct developmental and genetic mechanisms.

  11. Extreme sexual brain size dimorphism in sticklebacks: a consequence of the cognitive challenges of sex and parenting?

    PubMed

    Kotrschal, Alexander; Räsänen, Katja; Kristjánsson, Bjarni K; Senn, Mike; Kolm, Niclas

    2012-01-01

    Selection pressures that act differently on males and females produce numerous differences between the sexes in morphology and behaviour. However, apart from the controversial report that males have slightly heavier brains than females in humans, evidence for substantial sexual dimorphism in brain size is scarce. This apparent sexual uniformity is surprising given that sexually distinct selection pressures are ubiquitous and that brains are one of the most plastic vertebrate organs. Here we demonstrate the highest level of sexual brain size dimorphism ever reported in any vertebrate: male three-spined stickleback of two morphs in an Icelandic lake have 23% heavier brains than females. We suggest that this dramatic sexual size dimorphism is generated by the many cognitively demanding challenges that males are faced in this species, such as an elaborate courtship display, the construction of an ornate nest and a male-only parental care system. However, we consider also alternative explanations for smaller brains in females, such as life-history trade-offs. Our demonstration of unprecedented levels of sexual dimorphism in brain size in the three-spined stickleback implies that behavioural and life-history differences among the sexes can have strong effects also on neural development and proposes new fields of research for understanding brain evolution.

  12. Recent social conditions affect boldness repeatability in individual sticklebacks

    PubMed Central

    Jolles, Jolle Wolter; Aaron Taylor, Benjamin; Manica, Andrea

    2016-01-01

    Animal personalities are ubiquitous across the animal kingdom and have been shown both to influence individual behaviour in the social context and to be affected by it. However, little attention has been paid to possible carryover effects of social conditions on personality expression, especially when individuals are alone. Here we investigated how the recent social context affected the boldness and repeatability of three-spined sticklebacks, Gasterosteus aculeatus, during individual assays. We housed fish either solitarily, solitarily part of the time or socially in groups of four, and subjected them twice to a risk-taking task. The social conditions had a large effect on boldness repeatability, with fish housed solitarily before the trials showing much higher behavioural repeatability than fish housed socially, for which repeatability was not significant. Social conditions also had a temporal effect on the boldness of the fish, with only fish housed solitarily taking more risks during the first than the second trial. These results show that recent social conditions can thus affect the short-term repeatability of behaviour and obfuscate the expression of personality even in later contexts when individuals are alone. This finding highlights the need to consider social housing conditions when designing personality studies and emphasizes the important link between animal personality and the social context by showing the potential role of social carryover effects. PMID:26949265

  13. Sex-differences and temporal consistency in stickleback fish boldness.

    PubMed

    King, Andrew J; Fürtbauer, Ines; Mamuneas, Diamanto; James, Charlotte; Manica, Andrea

    2013-01-01

    Behavioural traits that co-vary across contexts or situations often reflect fundamental trade-offs which individuals experience in different contexts (e.g. fitness trade-offs between exploration and predation risk). Since males tend to experience greater variance in reproductive success than females, there may be considerable fitness benefits associated with "bolder" behavioural types, but only recently have researchers begun to consider sex-specific and life-history strategies associated with these. Here we test the hypothesis that male three-spined sticklebacks (Gasterosteus aculeatus) show high risk but potentially high return behaviours compared to females. According to this hypothesis we predicted that male fish would show greater exploration of their environment in a foraging context, and be caught sooner by an experimenter than females. We found that the time fish spent out of cover exploring their environment was correlated over two days, and males spent significantly more time out of cover than females. Also, the order in which fish were net-caught from their holding aquarium by an experimenter prior to experiments was negatively correlated with the time spent out of cover during tests, and males tended to be caught sooner than females. Moreover, we found a positive correlation between the catch number prior to our experiments and nine months after, pointing towards consistent, long-term individual differences in behaviour.

  14. Ornaments or offspring? Female sticklebacks (Gasterosteus aculeatus L.) trade off carotenoids between spines and eggs.

    PubMed

    Nordeide, J T; Rudolfsen, G; Egeland, E S

    2006-03-01

    Hypotheses and models to explain female ornaments often assume that the elaborated traits are condition dependent; nevertheless, few empirical studies have addressed this topic. We studied a population of three-spined sticklebacks (Gasterosteus aculeatus) in which the females have conspicuous, carotenoid-based red coloration to their pelvic spines. The red coloration seems not to be condition dependent, as coloration is negatively associated with age and body length and not associated with condition. Furthermore, redder females did not have a lower density of leucocytes. We found a negative association between the females' red carotenoid-based coloration in the spines and the amount of carotenoids in the female's gonads. Males choosing red-coloured females will fertilize eggs with small amounts of carotenoids and appear not to gain any benefit from their mates' phenotypic quality that could result in offspring of improved quality. These results do not support the 'direct selection hypothesis' to explain the existence of the female ornaments. PMID:16599919

  15. Ornaments or offspring? Female sticklebacks (Gasterosteus aculeatus L.) trade off carotenoids between spines and eggs.

    PubMed

    Nordeide, J T; Rudolfsen, G; Egeland, E S

    2006-03-01

    Hypotheses and models to explain female ornaments often assume that the elaborated traits are condition dependent; nevertheless, few empirical studies have addressed this topic. We studied a population of three-spined sticklebacks (Gasterosteus aculeatus) in which the females have conspicuous, carotenoid-based red coloration to their pelvic spines. The red coloration seems not to be condition dependent, as coloration is negatively associated with age and body length and not associated with condition. Furthermore, redder females did not have a lower density of leucocytes. We found a negative association between the females' red carotenoid-based coloration in the spines and the amount of carotenoids in the female's gonads. Males choosing red-coloured females will fertilize eggs with small amounts of carotenoids and appear not to gain any benefit from their mates' phenotypic quality that could result in offspring of improved quality. These results do not support the 'direct selection hypothesis' to explain the existence of the female ornaments.

  16. Altered neurotransmitter function in CO2-exposed stickleback (Gasterosteus aculeatus): a temperate model species for ocean acidification research

    PubMed Central

    Lai, Floriana; Jutfelt, Fredrik; Nilsson, Göran E.

    2015-01-01

    Studies on the consequences of ocean acidification for the marine ecosystem have revealed behavioural changes in coral reef fishes exposed to sustained near-future CO2 levels. The changes have been linked to altered function of GABAergic neurotransmitter systems, because the behavioural alterations can be reversed rapidly by treatment with the GABAA receptor antagonist gabazine. Characterization of the molecular mechanisms involved would be greatly aided if these can be examined in a well-characterized model organism with a sequenced genome. It was recently shown that CO2-induced behavioural alterations are not confined to tropical species, but also affect the three-spined stickleback, although an involvement of the GABAA receptor was not examined. Here, we show that loss of lateralization in the stickleback can be restored rapidly and completely by gabazine treatment. This points towards a worrying universality of disturbed GABAA function after high-CO2 exposure in fishes from tropical to temperate marine habitats. Importantly, the stickleback is a model species with a sequenced and annotated genome, which greatly facilitates future studies on underlying molecular mechanisms. PMID:27293703

  17. Female sticklebacks use male coloration in mate choice and hence avoid parasitized males

    NASA Astrophysics Data System (ADS)

    Milinski, Manfred; Bakker, Theo C. M.

    1990-03-01

    AN important problem in evolutionary biology since the time of Darwin has been to understand why females preferentially mate with males handicapped by secondary sexual ornaments1-3. One hypothesis of sexual selection theory is that these ornaments reliably reveal the male's condition4-6, which can be affected for example by parasites4,7-13. Here we show that in the three-spined stickleback (Gasterosteus aculeatus) the intensity of male red breeding coloration positively correlates with physical condition. Gravid females base their active mate choice on the intensity of the male's red coloration. Choice experiments under green light prevent the use of red colour cues by females, and males that were previously preferred are now chosen no more than randomly, although the courtship behaviour of the males remains unchanged. Parasitieation causes a deterioration in the males' condition and a decrease in the intensity of their red coloration. Tests under both lighting conditions reveal that the females recognize the formerly parasitized males by the lower intensity of their breeding coloration. Female sticklebacks possibly select a male with a good capacity for paternal care14 but if there is additive genetic variation for parasite resistance, then they might also select for resistance genes, as proposed by Hamilton and Zuk4.

  18. Developmental timing of sodium perchlorate exposure alters angiogenesis, thyroid follicle proliferation and sexual maturation in stickleback

    PubMed Central

    Furin, Christoff G.; von Hippel, Frank A.; Postlethwait, John H.; Buck, C. Loren; Cresko, William A.; O’Hara, Todd M.

    2015-01-01

    Perchlorate, a common aquatic contaminant, is well known to disrupt homeostasis of the hypothalamus-pituitary-thyroid axis. This study utilizes the threespine stickleback (Gasterosteus aculeatus) fish to determine if perchlorate exposure during certain windows of development has morphological effects on thyroid and gonads. Fish were moved from untreated water to perchlorate-contaminated water (30 and 100 mg/L) starting at 0, 3, 7, 14, 21, 42, 154 and 305 days post fertilization until approximately one year old. A reciprocal treatment (fish in contaminated water switched to untreated water) was conducted on the same schedule. Perchlorate exposure increased angiogenesis and follicle proliferation in thyroid tissue, delayed gonadal maturity, and skewed sex ratios towards males; effects depended on concentration and timing of exposure. This study demonstrates that perchlorate exposure beginning during the first 42 days of development has profound effects on stickleback reproductive and thyroid tissues, and by implication can impact population dynamics. Long-term exposure studies that assess contaminant effects at various stages of development provide novel information to characterize risk to aquatic organisms, to facilitate management of resources, and to determine sensitive developmental windows for further study of underlying mechanisms. PMID:25865142

  19. Genome Assembly Improvement and Mapping Convergently Evolved Skeletal Traits in Sticklebacks with Genotyping-by-Sequencing.

    PubMed

    Glazer, Andrew M; Killingbeck, Emily E; Mitros, Therese; Rokhsar, Daniel S; Miller, Craig T

    2015-07-01

    Marine populations of the threespine stickleback (Gasterosteus aculeatus) have repeatedly colonized and rapidly adapted to freshwater habitats, providing a powerful system to map the genetic architecture of evolved traits. Here, we developed and applied a binned genotyping-by-sequencing (GBS) method to build dense genome-wide linkage maps of sticklebacks using two large marine by freshwater F2 crosses of more than 350 fish each. The resulting linkage maps significantly improve the genome assembly by anchoring 78 new scaffolds to chromosomes, reorienting 40 scaffolds, and rearranging scaffolds in 4 locations. In the revised genome assembly, 94.6% of the assembly was anchored to a chromosome. To assess linkage map quality, we mapped quantitative trait loci (QTL) controlling lateral plate number, which mapped as expected to a 200-kb genomic region containing Ectodysplasin, as well as a chromosome 7 QTL overlapping a previously identified modifier QTL. Finally, we mapped eight QTL controlling convergently evolved reductions in gill raker length in the two crosses, which revealed that this classic adaptive trait has a surprisingly modular and nonparallel genetic basis.

  20. Developmental timing of sodium perchlorate exposure alters angiogenesis, thyroid follicle proliferation and sexual maturation in stickleback.

    PubMed

    Furin, Christoff G; von Hippel, Frank A; Postlethwait, John H; Buck, C Loren; Cresko, William A; O'Hara, Todd M

    2015-08-01

    Perchlorate, a common aquatic contaminant, is well known to disrupt homeostasis of the hypothalamus-pituitary-thyroid axis. This study utilizes the threespine stickleback (Gasterosteus aculeatus) fish to determine if perchlorate exposure during certain windows of development has morphological effects on thyroid and gonads. Fish were moved from untreated water to perchlorate-contaminated water (30 and 100mg/L) starting at 0, 3, 7, 14, 21, 42, 154 and 305 days post fertilization until approximately one year old. A reciprocal treatment (fish in contaminated water switched to untreated water) was conducted on the same schedule. Perchlorate exposure increased angiogenesis and follicle proliferation in thyroid tissue, delayed gonadal maturity, and skewed sex ratios toward males; effects depended on concentration and timing of exposure. This study demonstrates that perchlorate exposure beginning during the first 42 days of development has profound effects on stickleback reproductive and thyroid tissues, and by implication can impact population dynamics. Long-term exposure studies that assess contaminant effects at various stages of development provide novel information to characterize risk to aquatic organisms, to facilitate management of resources, and to determine sensitive developmental windows for further study of underlying mechanisms. PMID:25865142

  1. MHC genes and oxidative stress in sticklebacks: an immuno-ecological approach

    PubMed Central

    Kurtz, Joachim; Wegner, K. Mathias; Kalbe, Martin; Reusch, Thorsten B.H; Schaschl, Helmut; Hasselquist, Dennis; Milinski, Manfred

    2006-01-01

    Individual variation in the susceptibility to infection may result from the varying ability of hosts to specifically recognize different parasite strains. Alternatively, there could be individual host differences in fitness costs of immune defence. Although, these two explanations are not mutually exclusive, they have so far been treated in separate experimental approaches. To analyse potential relationships, we studied body condition and oxidative stress, which may reflect costs of immunity, in three-spined sticklebacks that had been experimentally exposed to three species of naturally occurring parasite. These sticklebacks differed in a trait, which is crucial to specific parasite defence, i.e. individual genetic diversity at major histocompatibility complex (MHC) class IIB loci. Oxidative stress was quantified as tissue acrolein, a technique that has been applied to questions of immuno-ecology for the first time. We measured gene expression at the MHC and other estimates of immune activation. We found that fish with high levels of MHC expression had poor condition and elevated oxidative stress. These results indicate that MHC-based specific immunity is connected with oxidative stress. They could, thus, also be relevant in the broader context of the evolution of sexually selected signals that are based on carotenoids and are, thus supposed to reflect oxidative stress resistance. PMID:16777730

  2. Natural selection drives patterns of lake-stream divergence in stickleback foraging morphology.

    PubMed

    Berner, D; Adams, D C; Grandchamp, A-C; Hendry, A P

    2008-11-01

    To what extent are patterns of biological diversification determined by natural selection? We addressed this question by exploring divergence in foraging morphology of threespine stickleback fish inhabiting lake and stream habitats within eight independent watersheds. We found that lake fish generally displayed more developed gill structures and had more streamlined bodies than did stream fish. Diet analysis revealed that these morphological differences were associated with limnetic vs. benthic foraging modes, and that the extent of morphological divergence within watersheds reflected differences in prey resources utilized by lake and stream fish. We also found that patterns of divergence were unrelated to patterns of phenotypic trait (co)variance within populations (i.e. the 'line of least resistance'). Instead, phenotypic (co)variances were more likely to have been shaped by adaptation to lake vs. stream habitats. Our study thus implicates natural selection as a strong deterministic force driving morphological diversification in lake-stream stickleback. The strength of this inference was obtained by complementing a standard analysis of parallel divergence in means between discrete habitat categories (lake vs. stream) with quantitative estimates of selective forces and information on trait (co)variances. PMID:18691241

  3. Stickleback fights: why do winners win? Influence of metabolic and morphometric parameters.

    PubMed

    Guderley, Helga; Couture, Patrice

    2005-01-01

    Pairs of reproductively mature male three-spined stickleback (Gasterosteus aculeatus) were introduced into unfamiliar aquaria and observed until one male became dominant. Skin carotenoid content, morphometric indexes, and metabolic capacities of the axial and pectoral muscles were examined to establish whether morphological or physiological parameters differentiated winners and losers. Stickleback that initiated fights typically won. Quick initiation led to quick victory. Overall, winners and losers differed in few morphological or metabolic characteristics, but these properties and the differences between these attributes for losers and winners of specific fights were linked with initiation time and fight duration. Morphometric indexes of losers were the primary determinants of initiation time and fight duration, whereas for winners muscle metabolic capacities were linked to these fight characteristics. The greater the hepatosomatic index (HSI) of losers, the longer the fight initiation times. Similarly, losers with high HSI and carotenoid levels resisted defeat longer. In winners, initiation time decreased as axial muscle phosphofructokinase levels increased and citrate synthase levels decreased, whereas the metabolic capacities of the pectoral muscle were linked with time to achieve victory. When losers had greater HSI values than the winners of a specific fight, fight initiation was delayed and fights lasted longer. When losers had higher carotenoid levels than winners, fights also lasted longer. On the other hand, when losers had more visceral fat (fat body mass over somatic mass) than winners, both initiation time and combat duration were reduced. These results suggest that male stickleback assess their physiological status and that of their opponents, in particular the HSI, and adjust their combat strategies accordingly. PMID:15778937

  4. Phylogeography and adaptation genetics of stickleback from the Haida Gwaii archipelago revealed using genome-wide single nucleotide polymorphism genotyping

    PubMed Central

    Deagle, Bruce E; Jones, Felicity C; Absher, Devin M; Kingsley, David M; Reimchen, Thomas E

    2013-01-01

    Threespine stickleback populations are model systems for studying adaptive evolution and the underlying genetics. In lakes on the Haida Gwaii archipelago (off western Canada), stickleback have undergone a remarkable local radiation and show phenotypic diversity matching that seen throughout the species distribution. To provide a historical context for this radiation, we surveyed genetic variation at >1000 single nucleotide polymorphism (SNP) loci in stickleback from over 100 populations. SNPs included markers evenly distributed throughout genome and candidate SNPs tagging adaptive genomic regions. Based on evenly distributed SNPs, the phylogeographic pattern differs substantially from the disjunct pattern previously observed between two highly divergent mtDNA lineages. The SNP tree instead shows extensive within watershed population clustering and different watersheds separated by short branches deep in the tree. These data are consistent with separate colonizations of most watersheds, despite underlying genetic connections between some independent drainages. This supports previous suppositions that morphological diversity observed between watersheds has been shaped independently, with populations exhibiting complete loss of lateral plates and giant size each occurring in several distinct clades. Throughout the archipelago, we see repeated selection of SNPs tagging candidate freshwater adaptive variants at several genomic regions differentiated between marine–freshwater populations on a global scale (e.g. EDA, Na/K ATPase). In estuarine sites, both marine and freshwater allelic variants were commonly detected. We also found typically marine alleles present in a few freshwater lakes, especially those with completely plated morphology. These results provide a general model for postglacial colonization of freshwater habitat by sticklebacks and illustrate the tremendous potential of genome-wide SNP data sets hold for resolving patterns and processes underlying recent

  5. Coexistence of Fish Species in a Large Lowland River: Food Niche Partitioning between Small-Sized Percids, Cyprinids and Sticklebacks in Submersed Macrophytes

    PubMed Central

    Dukowska, Małgorzata; Grzybkowska, Maria

    2014-01-01

    In the spring and summer of each year, large patches of submersed aquatic macrophytes overgrow the bottom of the alluvial Warta River downstream of a large dam reservoir owing to water management practices. Environmental variables, macroinvertebrates (zoobenthos and epiphytic fauna, zooplankton) and fish abundance and biomass were assessed at this biologically productive habitat to learn intraseasonal dynamics of food types, and their occurrence in the gut contents of small-sized roach, dace, perch, ruffe and three-spined stickleback. Gut fullness coefficient, niche breadth and niche overlap indicated how the fishes coexist in the macrophytes. Chironomidae dominated in the diet of the percids. However, ruffe consumed mostly benthic chironomids, while perch epiphytic chironomids and zooplankton. The diet of dace resembled that in fast flowing water although this rheophilic species occurred at unusual density there. The generalist roach displayed the lowest gut fullness coefficient values and widest niche breadth; consequently, intraspecific rather than interspecific competition decided the fate of roach. Three-spined stickleback differed from the other fishes by consuming epiphytic simuliids and fish eggs. The diet overlap between fishes reaching higher gut fullness coefficient values was rather low when the food associated with the submersed aquatic macrophytes was most abundant; this is congruent with the niche overlap hypothesis that maximal tolerable niche overlap can be higher in less intensely competitive conditions. PMID:25365420

  6. Foraging trait (co)variances in stickleback evolve deterministically and do not predict trajectories of adaptive diversification.

    PubMed

    Berner, Daniel; Stutz, William E; Bolnick, Daniel I

    2010-08-01

    How does natural selection shape the structure of variance and covariance among multiple traits, and how do (co)variances influence trajectories of adaptive diversification? We investigate these pivotal but open questions by comparing phenotypic (co)variances among multiple morphological traits across 18 derived lake-dwelling populations of threespine stickleback, and their marine ancestor. Divergence in (co)variance structure among populations is striking and primarily attributable to shifts in the variance of a single key foraging trait (gill raker length). We then relate this divergence to an ecological selection proxy, to population divergence in trait means, and to the magnitude of sexual dimorphism within populations. This allows us to infer that evolution in (co)variances is linked to variation among habitats in the strength of resource-mediated disruptive selection. We further find that adaptive diversification in trait means among populations has primarily involved shifts in gill raker length. The direction of evolutionary trajectories is unrelated to the major axes of ancestral trait (co)variance. Our study demonstrates that natural selection drives both means and (co)variances deterministically in stickleback, and strongly challenges the view that the (co)variance structure biases the direction of adaptive diversification predictably even over moderate time spans.

  7. Quantitative genetic analysis of brain size variation in sticklebacks: support for the mosaic model of brain evolution

    PubMed Central

    Noreikiene, Kristina; Herczeg, Gábor; Gonda, Abigél; Balázs, Gergely; Husby, Arild; Merilä, Juha

    2015-01-01

    The mosaic model of brain evolution postulates that different brain regions are relatively free to evolve independently from each other. Such independent evolution is possible only if genetic correlations among the different brain regions are less than unity. We estimated heritabilities, evolvabilities and genetic correlations of relative size of the brain, and its different regions in the three-spined stickleback (Gasterosteus aculeatus). We found that heritabilities were low (average h2 = 0.24), suggesting a large plastic component to brain architecture. However, evolvabilities of different brain parts were moderate, suggesting the presence of additive genetic variance to sustain a response to selection in the long term. Genetic correlations among different brain regions were low (average rG = 0.40) and significantly less than unity. These results, along with those from analyses of phenotypic and genetic integration, indicate a high degree of independence between different brain regions, suggesting that responses to selection are unlikely to be severely constrained by genetic and phenotypic correlations. Hence, the results give strong support for the mosaic model of brain evolution. However, the genetic correlation between brain and body size was high (rG = 0.89), suggesting a constraint for independent evolution of brain and body size in sticklebacks. PMID:26108633

  8. Foraging trait (co)variances in stickleback evolve deterministically and do not predict trajectories of adaptive diversification.

    PubMed

    Berner, Daniel; Stutz, William E; Bolnick, Daniel I

    2010-08-01

    How does natural selection shape the structure of variance and covariance among multiple traits, and how do (co)variances influence trajectories of adaptive diversification? We investigate these pivotal but open questions by comparing phenotypic (co)variances among multiple morphological traits across 18 derived lake-dwelling populations of threespine stickleback, and their marine ancestor. Divergence in (co)variance structure among populations is striking and primarily attributable to shifts in the variance of a single key foraging trait (gill raker length). We then relate this divergence to an ecological selection proxy, to population divergence in trait means, and to the magnitude of sexual dimorphism within populations. This allows us to infer that evolution in (co)variances is linked to variation among habitats in the strength of resource-mediated disruptive selection. We further find that adaptive diversification in trait means among populations has primarily involved shifts in gill raker length. The direction of evolutionary trajectories is unrelated to the major axes of ancestral trait (co)variance. Our study demonstrates that natural selection drives both means and (co)variances deterministically in stickleback, and strongly challenges the view that the (co)variance structure biases the direction of adaptive diversification predictably even over moderate time spans. PMID:20199566

  9. Prozac affects stickleback nest quality without altering androgen, spiggin or aggression levels during a 21-day breeding test.

    PubMed

    Sebire, Marion; Elphinstone Davis, Jessica; Hatfield, Robert; Winberg, Svante; Katsiadaki, Ioanna

    2015-11-01

    Pharmaceuticals are increasingly being used in human and veterinary medicine, and their presence in the aquatic environment may present a threat to non-target aquatic organisms. The selective serotonin reuptake inhibitor fluoxetine (Prozac) has been reported to affect diverse behaviours (feeding, aggression, and reproduction) and also the endocrine system (steroid biosynthesis pathway) in fish. To investigate these claims further, and in particular effects on androgen synthesis, male three-spined sticklebacks (Gasterosteus aculeatus) were exposed to fluoxetine at 0, 3.2, 10 and 32μg/L in a flow-through system for 21 days. Their sex was determined prior to exposure using a non-invasive method to collect DNA for determining the genetic sex, reported here for the first time. This was necessary as the exposure required males of a non-breeding status which had not developed secondary characteristics. Post exposure a number of biochemical (serotonin, steroid and spiggin levels) and apical (aggressive behaviour) endpoints were measured. No effects were detected on morphometric parameters, spiggin or androgen (11-ketotestosterone) levels. However, all fluoxetine-exposed male fish had higher cortisol levels in comparison to the control fish, although this effect only persisted throughout the whole exposure duration at the highest concentration (32μg/L). In addition, the ratio of 5-HIAA/5-HT (serotonin metabolite/serotonin) was significantly lower in the brains of males exposed to fluoxetine at all concentrations tested. Although we found no differences in the number of nests built by the males, the quality of the nests produced by the fluoxetine-exposed males was generally inferior consisting only of a basic, rudimentary structure. Males exposed to 32μg/L of fluoxetine displayed a delayed response to a simulated threat (rival male via own mirror image) and were less aggressive (number of bites and attacks) toward their mirror image, but these differences were not

  10. Chronic perchlorate exposure impairs stickleback reproductive behaviour and swimming performance

    PubMed Central

    Bernhardt, Richard R.; von Hippel, Frank A.

    2011-01-01

    Summary We describe behavioural changes in two generations of threespine stickleback (Gasterosteus aculeatus) exposed to environmentally relevant concentrations of perchlorate. The first generation (G0,2002) was exposed as two-year-old adults to perchlorate in experimental groups ranging in concentration from less than the method detection limit (<1.1 ppb) to 18.6 ppm for up to 22 days during their courtship, spawning, egg guarding, and first five days of fry guarding. No differences were noted in the behaviour or reproductive output of these fish that were exposed as adults. However, perchlorate exposure throughout development caused widespread effects in the second generation (G1,2003), which was spawned and raised through sexual maturity in one of four nominal experimental groups (0, 30 and 100 ppm, and a ‘variable’ treatment that progressively increased from <1.1 ppb to approximately 60 ppm perchlorate). Dose-dependent effects were found during the G1,2003’s swimming and behavioural evaluations, including higher mortality rates among treated fish following stressful events. Perchlorate-exposed fish had higher failure rates during swimming trials and failed at lower flow rates than control fish. A number of treated fish exhibited seizures. Progressively fewer males completed benchmark metrics, such as nest building, spawning, nursery formation, or fry production, in a dose-dependent manner. Fewer males from higher treatments courted females, and those that did initiated courtship later and had a reduced behavioural repertoire compared to fish from lower treatments. The lowest observed adverse effect level (LOAEL) for swimming performance, reproductive behaviour, survivorship and recruitment was 30 ppm perchlorate (our lowest G1,2003 treatment), and near complete inhibition of reproductive activity was noted among males raised in 100 ppm perchlorate. A small number of treated G1,2003 females were isolated in aquaria, and some performed reproductive

  11. A test of ecologically dependent postmating isolation between sympatric sticklebacks.

    PubMed

    Rundle, Howard D

    2002-02-01

    Ecological speciation occurs when reproductive isolation evolves ultimately as a result of divergent natural selection between populations inhabiting different environments or exploiting alternative resources. I tested a prediction of the ecological model concerning the fitness of hybrids between two young, sympatric species of threespine sticklebacks (Benthics and Limnetics). The two species are ecologically and morphologically divergent: the Benthic is adapted to feeding on invertebrates in the littoral zone of the lake whereas the Limnetic is adapted to feeding on zooplankton in the open water. The growth rate of two types of hybrids, the Benthic backcross and the Limnetic backcross, as well as both parent species, was evaluated in enclosures in both parental habitats in the lake. The use of backcrosses is ideal because a comparison of their growth rates in the two habitats estimates an ecologically dependent component of their fitness while controlling for any intrinsic genetic incompatibilities that may exist between the Benthic and Limnetic genomes. The backcross results revealed a striking pattern of ecological dependence: in the littoral zone, Benthic backcrosses grew at approximately twice the rate of Limnetic backcrosses, while in the open water, Limnetic backcrosses grew at approximately twice the rate of Benthic backcrosses. Such a reversal of relative fitness of the two cross-types in the two environments provides strong evidence that divergent natural selection has played a central role in the evolution of postmating isolation between Benthics and Limnetics. Although the rank order of growth rates of all cross-types in the littoral zone was Benthic > Benthic backcross > Limnetic backcross > Limnetic, neither backcross differed significantly from the parent from which it was mainly derived. Implications of this result are discussed in terms of ecological speciation and possible introgressive hybridization between the species. Results in the open water

  12. Changes in expression and honesty of sexual signalling over the reproductive lifetime of sticklebacks.

    PubMed Central

    Candolin, U

    2000-01-01

    Fitness costs of signalling are essential in order for reliable sexual signalling to prevail when the interests of the sexes conflict. This means that signalling can be subjected to a life history trade-off between present and future signalling effort. Here, I show that three-spined stickleback males (Gasterosteus aculeatus), who have a single breeding season during which they breed repeatedly, change their red nuptial coloration over the season depending on their body size at the start of breeding. Large males that completed several breeding cycles increased their red coloration over the season, whereas small males, who completed only a few cycles, did not. The increase in coloration was accompanied by an increase in parental success when males were energy constrained, but not when they had access to an unlimited food supply. Red coloration was thus an honest signal of male parental ability despite changes in signal expression when both signalling and parental care were costly and the investments in them changed simultaneously over the reproductive lifetime. However, the honesty of the signal varied over a lifetime. At the penultimate cycle, bright males cannibalized some of their eggs, probably to increase survival to the last cycle, whereas males cared for their offspring independent of coloration at the ultimate cycle. PMID:11133033

  13. Maintenance of a genetic polymorphism with disruptive natural selection in stickleback.

    PubMed

    Marchinko, Kerry B; Matthews, Blake; Arnegard, Matthew E; Rogers, Sean M; Schluter, Dolph

    2014-06-01

    The role of natural selection in the maintenance of genetic variation in wild populations remains a major problem in evolution. The influence of disruptive natural selection on genetic variation is especially interesting because it might lead to the evolution of assortative mating or dominance [1, 2]. In theory, variation can persist at a gene under disruptive natural selection, but the process is little studied and there are few examples [3, 4]. We report a stable polymorphism in the bony armor of threespine stickleback maintained with a deficit of heterozygotes at the major underlying gene, Ectodysplasin (Eda) [5]. The deficit vanishes at the embryo life stage only to re-emerge in adults, indicating that disruptive natural selection, rather than nonrandom mating, is the cause. The mechanism enabling long-term persistence of the polymorphism is unknown, but disruptive selection is predicted to be frequency dependent, favoring homozygous genotypes when they become rare. Further research on the ecological and evolutionary processes affecting individual genes will ultimately lead to a better understanding of the causes of genetic variation in populations.

  14. Predator experience overrides learned aversion to heterospecifics in stickleback species pairs

    PubMed Central

    Kozak, Genevieve M.; Boughman, Janette W.

    2015-01-01

    Predation risk can alter female mating decisions because the costs of mate searching and selecting attractive mates increase when predators are present. In response to predators, females have been found to plastically adjust mate preference within species, but little is known about how predators alter sexual isolation and hybridization among species. We tested the effects of predator exposure on sexual isolation between benthic and limnetic threespine sticklebacks (Gasterosteus spp.). Female discrimination against heterospecific mates was measured before and after females experienced a simulated attack by a trout predator or a control exposure to a harmless object. In the absence of predators, females showed increased aversion to heterospecifics over time. We found that predator exposure made females less discriminating and precluded this learned aversion to heterospecifics. Benthic and limnetic males differ in coloration, and predator exposure also affected sexual isolation by weakening female preferences for colourful males. Predator effects on sexual selection were also tested but predators had few effects on female choosiness among conspecific mates. Our results suggest that predation risk may disrupt the cognitive processes associated with mate choice and lead to fluctuations in the strength of sexual isolation between species. PMID:25808887

  15. Genome divergence during evolutionary diversification as revealed in replicate lake-stream stickleback population pairs.

    PubMed

    Roesti, Marius; Hendry, Andrew P; Salzburger, Walter; Berner, Daniel

    2012-06-01

    Evolutionary diversification is often initiated by adaptive divergence between populations occupying ecologically distinct environments while still exchanging genes. The genetic foundations of this divergence process are largely unknown and are here explored through genome scans in multiple independent lake-stream population pairs of threespine stickleback. We find that across the pairs, overall genomic divergence is associated with the magnitude of divergence in phenotypes known to be under divergent selection. Along this same axis of increasing diversification, genomic divergence becomes increasingly biased towards the centre of chromosomes as opposed to the peripheries. We explain this pattern by within-chromosome variation in the physical extent of hitchhiking, as recombination is greatly reduced in chromosome centres. Correcting for this effect suggests that a great number of genes distributed widely across the genome are involved in the divergence into lake vs. stream habitats. Analyzing additional allopatric population pairs, however, reveals that strong divergence in some genomic regions has been driven by selection unrelated to lake-stream ecology. Our study highlights a major contribution of large-scale variation in recombination rate to generating heterogeneous genomic divergence and indicates that elucidating the genetic basis of adaptive divergence might be more challenging than currently recognized.

  16. Phenotypic integration between antipredator behavior and camouflage pattern in juvenile sticklebacks.

    PubMed

    Kim, Sin-Yeon; Velando, Alberto

    2015-03-01

    Predation is a strong selective force that promotes the evolution of antipredator behaviors and camouflage in prey animals. However, the independent evolution of single traits cannot explain how observed phenotypic variations of these traits are maintained within populations. We studied genetic and phenotypic correlations between antipredator behaviors (shoaling and risk-taking) and morphology traits (pigmentation and size) in juvenile three-spined sticklebacks by using pedigree-based quantitative genetic analysis to test phenotypic integration (or complex phenotype) as an evolutionary response to predation risk. Individuals with strongly melanized (i.e., camouflaged) phenotype and genotype were less sociable to conspecifics, but bolder during foraging under predation risk. Individuals with faster growing phenotype and genotype were bolder, and those with lager eyes were more fearful. These phenotypic integrations were not confounded with correlated plastic responses to predation risk because the phenotypes were measured in naïve fish born in the laboratory, but originated from a natural population with predation pressure. Consistent selection for particular combinations of traits under predation pressure or pleiotropic genes might influence the maintenance of the genetic (co)variations and polymorphism in melanin color, growth trajectory, and behavior patterns. PMID:25572122

  17. Changes in expression and honesty of sexual signalling over the reproductive lifetime of sticklebacks.

    PubMed

    Candolin, U

    2000-12-01

    Fitness costs of signalling are essential in order for reliable sexual signalling to prevail when the interests of the sexes conflict. This means that signalling can be subjected to a life history trade-off between present and future signalling effort. Here, I show that three-spined stickleback males (Gasterosteus aculeatus), who have a single breeding season during which they breed repeatedly, change their red nuptial coloration over the season depending on their body size at the start of breeding. Large males that completed several breeding cycles increased their red coloration over the season, whereas small males, who completed only a few cycles, did not. The increase in coloration was accompanied by an increase in parental success when males were energy constrained, but not when they had access to an unlimited food supply. Red coloration was thus an honest signal of male parental ability despite changes in signal expression when both signalling and parental care were costly and the investments in them changed simultaneously over the reproductive lifetime. However, the honesty of the signal varied over a lifetime. At the penultimate cycle, bright males cannibalized some of their eggs, probably to increase survival to the last cycle, whereas males cared for their offspring independent of coloration at the ultimate cycle. PMID:11133033

  18. Widespread positive but weak assortative mating by diet within stickleback populations

    PubMed Central

    Ingram, Travis; Jiang, Yuexin; Rangel, Racine; Bolnick, Daniel I

    2015-01-01

    Assortative mating – correlation between male and female traits – is common within populations and has the potential to promote genetic diversity and in some cases speciation. Despite its importance, few studies have sought to explain variation in the extent of assortativeness across populations. Here, we measure assortative mating based on an ecologically important trait, diet as inferred from stable isotopes, in 16 unmanipulated lake populations of three-spine stickleback. As predicted, we find a tendency toward positive assortment on the littoral–pelagic axis, although the magnitude is consistently weak. These populations vary relatively little in the strength of assortativeness, and what variation occurs is not explained by hypothesized drivers including habitat cosegregation, the potential for disruptive selection, costs to choosiness, and the strength of the relationship between diet and body size. Our results support recent findings that most assortative mating is positive, while suggesting that new approaches may be required to identify the environmental variables that drive the evolution of nonrandom mating within populations. PMID:26380669

  19. Pleiotropic effects of a single gene on skeletal development and sensory system patterning in sticklebacks

    PubMed Central

    2014-01-01

    Background Adaptation to a new environment can be facilitated by co-inheritance of a suite of phenotypes that are all advantageous in the new habitat. Although experimental evidence demonstrates that multiple phenotypes often map to the same genomic regions, it is challenging to determine whether phenotypes are associated due to pleiotropic effects of a single gene or to multiple tightly linked genes. In the threespine stickleback fish (Gasterosteus aculeatus), multiple phenotypes are associated with a genomic region around the gene Ectodysplasin (Eda), but only the presence of bony lateral plates has been conclusively shown to be caused by Eda. Results Here, we ask whether pleiotropy or linkage is responsible for the association between lateral plates and the distribution of the neuromasts of the lateral line. We first identify a strong correlation between plate appearance and changes in the spatial distribution of neuromasts through development. We then use an Eda transgene to induce the formation of ectopic plates in low plated fish, which also results in alterations to neuromast distribution. Our results also show that other loci may modify the effects of Eda on plate formation and neuromast distribution. Conclusions Together, these results demonstrate that Eda has pleiotropic effects on at least two phenotypes, highlighting the role of pleiotropy in the genetic basis of adaptation. PMID:24499504

  20. Female sticklebacks count alleles in a strategy of sexual selection explaining MHC polymorphism.

    PubMed

    Reusch, T B; Häberli, M A; Aeschlimann, P B; Milinski, M

    2001-11-15

    The origin and maintenance of polymorphism in major histocompatibility complex (MHC) genes in natural populations is still unresolved. Sexual selection, frequency-dependent selection by parasites and pathogens, and heterozygote advantage have been suggested to explain the maintenance of high allele diversity at MHC genes. Here we argue that there are two (non-exclusive) strategies for MHC-related sexual selection, representing solutions to two different problems: inbreeding avoidance and parasite resistance. In species prone to inadvertent inbreeding, partners should prefer dissimilar MHC genotypes to similar ones. But if the goal is to maximize the resistance of offspring towards potential infections, the choosing sex should prefer mates with a higher diversity of MHC alleles. This latter strategy should apply when there are several MHC loci, as is the case in most vertebrates. We tested the relative importance of an 'allele counting' strategy compared to a disassortative mating strategy using wild-caught three-spined sticklebacks (Gasterosteus aculeatus) from an interconnected system of lakes. Here we show that gravid female fish preferred the odour of males with a large number of MHC class-IIB alleles to that of males with fewer alleles. Females did not prefer male genotypes dissimilar to their own. PMID:11713527

  1. Population genomics of parallel phenotypic evolution in stickleback across stream–lake ecological transitions

    PubMed Central

    Deagle, Bruce E.; Jones, Felicity C.; Chan, Yingguang F.; Absher, Devin M.; Kingsley, David M.; Reimchen, Thomas E.

    2012-01-01

    Understanding the genetics of adaptation is a central focus in evolutionary biology. Here, we use a population genomics approach to examine striking parallel morphological divergences of parapatric stream–lake ecotypes of threespine stickleback fish in three watersheds on the Haida Gwaii archipelago, western Canada. Genome-wide variation at greater than 1000 single nucleotide polymorphism loci indicate separate origin of giant lake and small-bodied stream fish within each watershed (mean FST between watersheds = 0.244 and within = 0.114). Genome scans within watersheds identified a total of 21 genomic regions that are highly differentiated between ecotypes and are probably subject to directional selection. Most outliers were watershed-specific, but genomic regions undergoing parallel genetic changes in multiple watersheds were also identified. Interestingly, several of the stream–lake outlier regions match those previously identified in marine–freshwater and benthic–limnetic genome scans, indicating reuse of the same genetic loci in different adaptive scenarios. We also identified multiple new outlier loci, which may contribute to unique aspects of differentiation in stream–lake environments. Overall, our data emphasize the important role of ecological boundaries in driving both local and broadly occurring parallel genetic changes during adaptation. PMID:21976692

  2. Predator experience overrides learned aversion to heterospecifics in stickleback species pairs.

    PubMed

    Kozak, Genevieve M; Boughman, Janette W

    2015-04-22

    Predation risk can alter female mating decisions because the costs of mate searching and selecting attractive mates increase when predators are present. In response to predators, females have been found to plastically adjust mate preference within species, but little is known about how predators alter sexual isolation and hybridization among species. We tested the effects of predator exposure on sexual isolation between benthic and limnetic threespine sticklebacks (Gasterosteus spp.). Female discrimination against heterospecific mates was measured before and after females experienced a simulated attack by a trout predator or a control exposure to a harmless object. In the absence of predators, females showed increased aversion to heterospecifics over time. We found that predator exposure made females less discriminating and precluded this learned aversion to heterospecifics. Benthic and limnetic males differ in coloration, and predator exposure also affected sexual isolation by weakening female preferences for colourful males. Predator effects on sexual selection were also tested but predators had few effects on female choosiness among conspecific mates. Our results suggest that predation risk may disrupt the cognitive processes associated with mate choice and lead to fluctuations in the strength of sexual isolation between species.

  3. Environmental change disrupts communication and sexual selection in a stickleback population.

    PubMed

    Candolin, Ulrika; Tukiainen, Iina; Bertell, Elina

    2016-04-01

    Environmental change that disrupts communication during mate choice and alters sexual selection could influence population dynamics. Yet little is known about such long-term effects. We investigated experimentally the consequences that disrupted visual communication during mate choice has for the quantity and viability of offspring produced in a threespine stickleback population (Gasterosteus aculeatus). We further related the results to long-term monitoring of population dynamics in the field to determine if changes are apparent under natural conditions. The results show that impaired visual communication because of algal blooms reduces reliability of male visual signals as indicators of offspring survival during their first weeks of life. This relaxes sexual selection but has no effect on the number of offspring hatching, as most males have a high hatching success in turbid water. Despite eutrophication and high turbidity levels that interfere with communication during mate choice, the population has grown during recent decades. Large numbers of offspring hatching, combined with high variation in juvenile fitness, has probably shifted selection to later life history stages and maintained a viable population. Together with reduced cost of sexual selection and ongoing ecosystem changes caused by human activities, this could have promoted population growth. These results point to the complexity of ecosystems and the necessity to consider all influencing factors when attempting to understand impacts of human activities on populations. PMID:27220213

  4. Genome divergence during evolutionary diversification as revealed in replicate lake-stream stickleback population pairs.

    PubMed

    Roesti, Marius; Hendry, Andrew P; Salzburger, Walter; Berner, Daniel

    2012-06-01

    Evolutionary diversification is often initiated by adaptive divergence between populations occupying ecologically distinct environments while still exchanging genes. The genetic foundations of this divergence process are largely unknown and are here explored through genome scans in multiple independent lake-stream population pairs of threespine stickleback. We find that across the pairs, overall genomic divergence is associated with the magnitude of divergence in phenotypes known to be under divergent selection. Along this same axis of increasing diversification, genomic divergence becomes increasingly biased towards the centre of chromosomes as opposed to the peripheries. We explain this pattern by within-chromosome variation in the physical extent of hitchhiking, as recombination is greatly reduced in chromosome centres. Correcting for this effect suggests that a great number of genes distributed widely across the genome are involved in the divergence into lake vs. stream habitats. Analyzing additional allopatric population pairs, however, reveals that strong divergence in some genomic regions has been driven by selection unrelated to lake-stream ecology. Our study highlights a major contribution of large-scale variation in recombination rate to generating heterogeneous genomic divergence and indicates that elucidating the genetic basis of adaptive divergence might be more challenging than currently recognized. PMID:22384978

  5. Ecosystem size matters: the dimensionality of intralacustrine diversification in Icelandic stickleback is predicted by lake size.

    PubMed

    Lucek, Kay; Kristjánsson, Bjarni K; Skúlason, Skúli; Seehausen, Ole

    2016-08-01

    Cases of evolutionary diversification can be characterized along a continuum from weak to strong genetic and phenotypic differentiation. Several factors may facilitate or constrain the differentiation process. Comparative analyses of replicates of the same taxon at different stages of differentiation can be useful to identify these factors. We estimated the number of distinct phenotypic groups in three-spine stickleback populations from nine lakes in Iceland and in one marine population. Using the inferred number of phenotypic groups in each lake, genetic divergence from the marine population, and physical lake and landscape variables, we tested whether ecosystem size, approximated by lake size and depth, or isolation from the ancestral marine gene pool predicts the occurrence and the extent of phenotypic and genetic diversification within lakes. We find intralacustrine phenotypic diversification to be the rule rather than the exception, occurring in all but the youngest lake population and being manifest in ecologically important phenotypic traits. Neutral genetic data further indicate nonrandom mating in four of nine studied lakes, and restricted gene flow between sympatric phenotypic groups in two. Although neither the phenotypic variation nor the number of intralacustrine phenotypic groups was associated with any of our environmental variables, the number of phenotypic traits that were differentiated was significantly positively related to lake size, and evidence for restricted gene flow between sympatric phenotypic groups was only found in the largest lakes where trait specific phenotypic differentiation was highest. PMID:27551381

  6. Women and Minorities in Alaskan Aviation. Alaskan Equity Publication.

    ERIC Educational Resources Information Center

    Dordan, Mary Lou; Nicholson, Deborah

    This resource guide tells the story of Alaskan women and minority aviators and those in aviation-related businesses, from the early 20th century to the present. Developed for secondary students but also suitable for younger students, the guide combines six accounts of Alaskan women and minority aviators with classroom activities centered around…

  7. Alaskan Commodities Irradiation Project

    SciTech Connect

    Zarling, J.P.; Swanson, R.B.; Logan, R.R.; Das, D.K.; Lewis, C.E.; Workman, W.G.; Tumeo, M.A.; Hok, C.I.; Birklid, C.A.; Bennett, F.L.

    1988-12-01

    The ninety-ninth US Congress commissioned a six-state food irradiation research and development program to evaluate the commercial potential of this technology. Hawaii, Washington, Iowa, Oklahoma and Florida as well as Alaska have participated in the national program; various food products including fishery products, red meats, tropical and citrus fruits and vegetables have been studied. The purpose of the Alaskan study was to review and evaluate those factors related to the technical and economic feasibility of an irradiator in Alaska. This options analysis study will serve as a basis for determining the state's further involvement in the development of food irradiation technology. 40 refs., 50 figs., 53 tabs.

  8. Construction of Ultradense Linkage Maps with Lep-MAP2: Stickleback F2 Recombinant Crosses as an Example.

    PubMed

    Rastas, Pasi; Calboli, Federico C F; Guo, Baocheng; Shikano, Takahito; Merilä, Juha

    2016-01-01

    High-density linkage maps are important tools for genome biology and evolutionary genetics by quantifying the extent of recombination, linkage disequilibrium, and chromosomal rearrangements across chromosomes, sexes, and populations. They provide one of the best ways to validate and refine de novo genome assemblies, with the power to identify errors in assemblies increasing with marker density. However, assembly of high-density linkage maps is still challenging due to software limitations. We describe Lep-MAP2, a software for ultradense genome-wide linkage map construction. Lep-MAP2 can handle various family structures and can account for achiasmatic meiosis to gain linkage map accuracy. Simulations show that Lep-MAP2 outperforms other available mapping software both in computational efficiency and accuracy. When applied to two large F2-generation recombinant crosses between two nine-spined stickleback (Pungitius pungitius) populations, it produced two high-density (∼6 markers/cM) linkage maps containing 18,691 and 20,054 single nucleotide polymorphisms. The two maps showed a high degree of synteny, but female maps were 1.5-2 times longer than male maps in all linkage groups, suggesting genome-wide recombination suppression in males. Comparison with the genome sequence of the three-spined stickleback (Gasterosteus aculeatus) revealed a high degree of interspecific synteny with a low frequency (<5%) of interchromosomal rearrangements. However, a fairly large (ca. 10 Mb) translocation from autosome to sex chromosome was detected in both maps. These results illustrate the utility and novel features of Lep-MAP2 in assembling high-density linkage maps, and their usefulness in revealing evolutionarily interesting properties of genomes, such as strong genome-wide sex bias in recombination rates. PMID:26668116

  9. Construction of Ultradense Linkage Maps with Lep-MAP2: Stickleback F2 Recombinant Crosses as an Example.

    PubMed

    Rastas, Pasi; Calboli, Federico C F; Guo, Baocheng; Shikano, Takahito; Merilä, Juha

    2016-01-01

    High-density linkage maps are important tools for genome biology and evolutionary genetics by quantifying the extent of recombination, linkage disequilibrium, and chromosomal rearrangements across chromosomes, sexes, and populations. They provide one of the best ways to validate and refine de novo genome assemblies, with the power to identify errors in assemblies increasing with marker density. However, assembly of high-density linkage maps is still challenging due to software limitations. We describe Lep-MAP2, a software for ultradense genome-wide linkage map construction. Lep-MAP2 can handle various family structures and can account for achiasmatic meiosis to gain linkage map accuracy. Simulations show that Lep-MAP2 outperforms other available mapping software both in computational efficiency and accuracy. When applied to two large F2-generation recombinant crosses between two nine-spined stickleback (Pungitius pungitius) populations, it produced two high-density (∼6 markers/cM) linkage maps containing 18,691 and 20,054 single nucleotide polymorphisms. The two maps showed a high degree of synteny, but female maps were 1.5-2 times longer than male maps in all linkage groups, suggesting genome-wide recombination suppression in males. Comparison with the genome sequence of the three-spined stickleback (Gasterosteus aculeatus) revealed a high degree of interspecific synteny with a low frequency (<5%) of interchromosomal rearrangements. However, a fairly large (ca. 10 Mb) translocation from autosome to sex chromosome was detected in both maps. These results illustrate the utility and novel features of Lep-MAP2 in assembling high-density linkage maps, and their usefulness in revealing evolutionarily interesting properties of genomes, such as strong genome-wide sex bias in recombination rates.

  10. Construction of Ultradense Linkage Maps with Lep-MAP2: Stickleback F2 Recombinant Crosses as an Example

    PubMed Central

    Rastas, Pasi; Calboli, Federico C. F.; Guo, Baocheng; Shikano, Takahito; Merilä, Juha

    2016-01-01

    High-density linkage maps are important tools for genome biology and evolutionary genetics by quantifying the extent of recombination, linkage disequilibrium, and chromosomal rearrangements across chromosomes, sexes, and populations. They provide one of the best ways to validate and refine de novo genome assemblies, with the power to identify errors in assemblies increasing with marker density. However, assembly of high-density linkage maps is still challenging due to software limitations. We describe Lep-MAP2, a software for ultradense genome-wide linkage map construction. Lep-MAP2 can handle various family structures and can account for achiasmatic meiosis to gain linkage map accuracy. Simulations show that Lep-MAP2 outperforms other available mapping software both in computational efficiency and accuracy. When applied to two large F2-generation recombinant crosses between two nine-spined stickleback (Pungitius pungitius) populations, it produced two high-density (∼6 markers/cM) linkage maps containing 18,691 and 20,054 single nucleotide polymorphisms. The two maps showed a high degree of synteny, but female maps were 1.5–2 times longer than male maps in all linkage groups, suggesting genome-wide recombination suppression in males. Comparison with the genome sequence of the three-spined stickleback (Gasterosteus aculeatus) revealed a high degree of interspecific synteny with a low frequency (<5%) of interchromosomal rearrangements. However, a fairly large (ca. 10 Mb) translocation from autosome to sex chromosome was detected in both maps. These results illustrate the utility and novel features of Lep-MAP2 in assembling high-density linkage maps, and their usefulness in revealing evolutionarily interesting properties of genomes, such as strong genome-wide sex bias in recombination rates. PMID:26668116

  11. An Alaskan legend

    USGS Publications Warehouse

    Mann, H.; Blodgett, R.B.

    2009-01-01

    Jack Lee is a prominent personality, an Alaskan individualist and a skeptic worthy of remembrance if for no other reason than being inextricably associated with the catastrophic Katmai eruption in 1912. Jack remains a provocative reminder of Alaska's pre-1958 drilling and was quite possibly the earliest observer (excepting natives and possibly Russians) of the oil seeps in the area now encompassed by the Becharof National Wildlife Refuge. His observation of the impressive live oil seeps in the Ugashik and Becharof Lakes area, and his subsequent involvement in the early drilling entirely consumed his future interests. He is a firm believer that individualism and suspicion are powerful tools when forced to reconsider alternatives to readily accepted interpretations of modern exploration results. His individualism and sometimes annoying, but thought-provoking skepticism remains useful in any field where clich??s provide safe guards from new concepts.

  12. Convergence and non-convergence in ecological, phenotypic, and genetic divergence across replicate population pairs of lake and stream stickleback

    PubMed Central

    Kaeuffer, Renaud; Peichel, Catherine L.; Bolnick, Daniel I.; Hendry, Andrew P.

    2015-01-01

    Convergent (or parallel) evolution provides strong evidence for a deterministic role of natural selection: similar phenotypes evolve when independent populations colonize similar environments. In reality, however, independent populations in similar environments always show some differences: some non-convergent evolution is present. It is therefore important to explicitly quantify the convergent and non-convergent aspects of trait variation, and to investigate the ecological and genetic explanations for each. We performed such an analysis for threespine stickleback (Gasterosteus aculeatus) populations inhabiting lake and stream habitats in independent watersheds. Morphological traits differed in the degree to which lake-stream divergence was convergent across watersheds. Some aspects of this variation were correlated with ecological variables related to diet, presumably reflecting the strength and specifics of divergent selection. Furthermore, a genetic scan revealed some markers that diverged between lakes and streams in many of the watersheds and some that diverged in only a few watersheds. Moreover, some of the lake-stream divergence in genetic markers was associated within some of the lake-stream divergence in morphological traits. Our results suggest that convergent evolution, and deviations from it, are primarily the result of natural selection, which corresponds in only some respect to the dichotomous habitat classifications frequently used in such studies. PMID:22276537

  13. Quick divergence but slow convergence during ecotype formation in lake and stream stickleback pairs of variable age.

    PubMed

    Lucek, K; Sivasundar, A; Kristjánsson, B K; Skúlason, S; Seehausen, O

    2014-09-01

    When genetic constraints restrict phenotypic evolution, diversification can be predicted to evolve along so-called lines of least resistance. To address the importance of such constraints and their resolution, studies of parallel phenotypic divergence that differ in their age are valuable. Here, we investigate the parapatric evolution of six lake and stream threespine stickleback systems from Iceland and Switzerland, ranging in age from a few decades to several millennia. Using phenotypic data, we test for parallelism in ecotypic divergence between parapatric lake and stream populations and compare the observed patterns to an ancestral-like marine population. We find strong and consistent phenotypic divergence, both among lake and stream populations and between our freshwater populations and the marine population. Interestingly, ecotypic divergence in low-dimensional phenotype space (i.e. single traits) is rapid and seems to be often completed within 100 years. Yet, the dimensionality of ecotypic divergence was highest in our oldest systems and only there parallel evolution of unrelated ecotypes was strong enough to overwrite phylogenetic contingency. Moreover, the dimensionality of divergence in different systems varies between trait complexes, suggesting different constraints and evolutionary pathways to their resolution among freshwater systems.

  14. Quick divergence but slow convergence during ecotype formation in lake and stream stickleback pairs of variable age.

    PubMed

    Lucek, K; Sivasundar, A; Kristjánsson, B K; Skúlason, S; Seehausen, O

    2014-09-01

    When genetic constraints restrict phenotypic evolution, diversification can be predicted to evolve along so-called lines of least resistance. To address the importance of such constraints and their resolution, studies of parallel phenotypic divergence that differ in their age are valuable. Here, we investigate the parapatric evolution of six lake and stream threespine stickleback systems from Iceland and Switzerland, ranging in age from a few decades to several millennia. Using phenotypic data, we test for parallelism in ecotypic divergence between parapatric lake and stream populations and compare the observed patterns to an ancestral-like marine population. We find strong and consistent phenotypic divergence, both among lake and stream populations and between our freshwater populations and the marine population. Interestingly, ecotypic divergence in low-dimensional phenotype space (i.e. single traits) is rapid and seems to be often completed within 100 years. Yet, the dimensionality of ecotypic divergence was highest in our oldest systems and only there parallel evolution of unrelated ecotypes was strong enough to overwrite phylogenetic contingency. Moreover, the dimensionality of divergence in different systems varies between trait complexes, suggesting different constraints and evolutionary pathways to their resolution among freshwater systems. PMID:24976108

  15. Indirect fitness consequences of mate choice in sticklebacks: offspring of brighter males grow slowly but resist parasitic infections.

    PubMed Central

    Barber, I; Arnott, S A; Braithwaite, V A; Andrew, J; Huntingford, F A

    2001-01-01

    'Good genes' models of sexual selection suggest that elaborate male sexual ornaments have evolved as reliable signals of male quality because only males of high genetic viability are able to develop and maintain them. Females benefit from choosing such individuals if quality is heritable. A key prediction is that the offspring of males with elaborate mating displays will perform better than those of less elaborate males, but it has proved difficult to demonstrate such an effect independently of the effects of differences in parental investment. We tested for 'good genes' linked to male ornamentation in the three-spined stickleback Gasterosteus aculeatus using in vitro fertilization to generate maternal half-siblings, which were raised without parental care. Maternal half-siblings sired by brightly coloured males grew less quickly than half-siblings sired by dull males but were more resistant to a controlled disease challenge. Among the offspring that became infected, those with brighter fathers had higher white blood cell counts. This suggests that highly ornamented males confer disease resistance on their offspring. The association with reduced growth suggests a mechanism for the maintenance of heritable variation in both disease resistance and male sexual coloration. PMID:12123300

  16. Functional basis of ecological divergence in sympatric stickleback

    PubMed Central

    2013-01-01

    Background The evolution of ecological divergence in closely related species is a key component of adaptive radiation. However, in most examples of adaptive radiation the mechanistic basis of ecological divergence remains unclear. A classic example is seen in the young benthic and limnetic stickleback species pairs of British Columbia. In each pair the benthic species feeds on littoral macroinvertebrates whereas the limnetic feeds on pelagic zooplankton. Previous studies indicate that in both short-term feeding trials and long-term enclosure studies, benthics and limnetics exhibit enhanced performance on their own resource but fare more poorly on the other species’ resource. We examined the functional basis of ecological divergence in the stickleback species pair from Paxton Lake, BC, using biomechanical models of fish feeding applied to morphological traits. We examined the consequences of morphological differences using high speed video of feeding fish. Results Benthic stickleback possess morphological traits that predict high suction generation capacity, including greatly hypertrophied epaxial musculature. In contrast, limnetic stickleback possess traits thought to enhance capture of evasive planktonic prey, including greater jaw protrusion than benthics and greater displacement advantage in both the lower jaw-opening lever system and the opercular four-bar linkage. Kinematic data support the expectations from the morphological analysis that limnetic stickleback exhibit faster strikes and greater jaw protrusion than benthic fish, whereas benthics exert greater suction force on attached prey. Conclusions We reveal a previously unknown suite of complex morphological traits that affect rapid ecological divergence in sympatric stickleback. These results indicate that postglacial divergence in stickleback involves many functional systems and shows the value of investigating the functional consequences of phenotypic divergence in adaptive radiation. PMID:24380474

  17. Magnetic and electric order in the spin-1/2 XX model with three-spin interactions

    NASA Astrophysics Data System (ADS)

    Thakur, Pradeep; Durganandini, P.

    2016-05-01

    We study the spin-1/2 XX model in the presence of three-spin interactions of the XZX+YZY and XZY-YZX types. We solve the problem exactly and show that there is both finite magnetization and electric polarization for low non-zero strengths of the three-spin interactions.

  18. Cardiovascular Deaths among Alaskan Natives, 1980-86.

    ERIC Educational Resources Information Center

    Middaugh, John P.

    1990-01-01

    Analyzes death certificate data to discover the number of deaths of Alaskan natives caused by cardiovascular disease. Rates from cardiovascular diseases and atherosclerosis from 1980-86 among Alaskan natives were lower than rates among other Alaskans, while death rates from other causes were higher. Discusses the possible impact of diet. (JS)

  19. 7 CFR 1780.49 - Rural or Native Alaskan villages.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...) Rural or Native Alaskan village. A rural or Native Alaskan community which meets the definition of a... waterborne communicable disease have been documented; or (ii) No community-wide water and sewer system exists... 7 Agriculture 12 2012-01-01 2012-01-01 false Rural or Native Alaskan villages. 1780.49...

  20. 7 CFR 1780.49 - Rural or Native Alaskan villages.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) Rural or Native Alaskan village. A rural or Native Alaskan community which meets the definition of a... waterborne communicable disease have been documented; or (ii) No community-wide water and sewer system exists... 7 Agriculture 12 2014-01-01 2013-01-01 true Rural or Native Alaskan villages. 1780.49 Section...

  1. 7 CFR 1780.49 - Rural or Native Alaskan villages.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...) Rural or Native Alaskan village. A rural or Native Alaskan community which meets the definition of a... waterborne communicable disease have been documented; or (ii) No community-wide water and sewer system exists... 7 Agriculture 12 2013-01-01 2013-01-01 false Rural or Native Alaskan villages. 1780.49...

  2. Helping Kids Succeed--Alaskan Style.

    ERIC Educational Resources Information Center

    Association of Alaska School Boards, Juneau.

    The purpose of this book is to serve as a tool for individuals helping to make Alaskan communities places where youth can grow up to be strong, capable, and caring. The book is built around the Search Institute's Youth Developmental Assets Framework, which is comprised of the key building blocks in youth development. The book notes 40 assets that…

  3. Alaskan North Slope petroleum systems

    USGS Publications Warehouse

    Magoon, L.B.; Lillis, P.G.; Bird, K.J.; Lampe, C.; Peters, K.E.

    2003-01-01

    Six North Slope petroleum systems are identified, described, and mapped using oil-to-oil and oil-to-source rock correlations, pods of active source rock, and overburden rock packages. To map these systems, we assumed that: a) petroleum source rocks contain 3.2 wt. % organic carbon (TOC); b) immature oil-prone source rocks have hydrogen indices (HI) >300 (mg HC/gm TOC); c) the top and bottom of the petroleum (oil plus gas) window occur at vitrinite reflectance values of 0.6 and 1.0% Ro, respectively; and d) most hydrocarbons are expelled within the petroleum window. The six petroleum systems we have identified and mapped are: a) a southern system involving the Kuna-Lisburne source rock unit that was active during the Late Jurassic and Early Cretaceous; b) two western systems involving source rock in the Kingak-Blankenship, and GRZ-lower Torok source rock units that were active during the Albian; and c) three eastern systems involving the Shublik-Otuk, Hue Shale and Canning source rock units that were active during the Cenozoic. The GRZ-lower Torok in the west is correlative with the Hue Shale to the east. Four overburden rock packages controlled the time of expulsion and gross geometry of migration paths: a) a southern package of Early Cretaceous and older rocks structurally-thickened by early Brooks Range thrusting; b) a western package of Early Cretaceous rocks that filled the western part of the foreland basin; c) an eastern package of Late Cretaceous and Paleogene rocks that filled the eastern part of the foreland basin; and d) an offshore deltaic package of Neogene rocks deposited by the Colville, Canning, and Mackenzie rivers. This petroleum system poster is part of a series of Northern Alaska posters on modeling. The poster in this session by Saltus and Bird present gridded maps for the greater Northern Alaskan onshore and offshore that are used in the 3D modeling poster by Lampe and others. Posters on source rock units are by Keller and Bird as well as

  4. Offshore oil in the Alaskan Arctic

    NASA Technical Reports Server (NTRS)

    Weeks, W. F.; Weller, G.

    1984-01-01

    Oil and gas deposits in the Alaskan Arctic are estimated to contain up to 40 percent of the remaining undiscovered crude oil and oil-equivalent natural gas within U.S. jurisdiction. Most (65 to 70 percent) of these estimated reserves are believed to occuur offshore beneath the shallow, ice-covered seas of the Alaskan continental shelf. Offshore recovery operations for such areas are far from routine, with the primary problems associated with the presence of ice. Some problems that must be resolved if efficient, cost-effective, environmentally safe, year-round offshore production is to be achieved include the accurate estimation of ice forces on offshore structures, the proper placement of pipelines beneath ice-produced gouges in the sea floor, and the cleanup of oil spills in pack ice areas.

  5. Diversifying and correlational selection on behavior toward conspecific and heterospecific competitors in brook stickleback (Culaea inconstans)

    PubMed Central

    Peiman, Kathryn S; Robinson, Beren W

    2012-01-01

    Behaviors toward heterospecifics and conspecifics may be correlated because of shared mechanisms of expression in both social contexts (nonadaptive covariation) or because correlational selection favors adaptive covariation. We evaluated these hypotheses by comparing behavior toward conspecifics and heterospecifics in brook stickleback (Culaea inconstans) from three populations sympatric with and three allopatric from a competitor, the ninespine stickleback (Pungitius pungitius). Behavioral traits were classified into three multivariate components: overt aggression, sociability, and activity. The correlation of behavior between social contexts for both overt aggression and activity varied among populations in a way unrelated to sympatry with ninespine stickleback, while mean aggression was reduced in sympatry. Correlations in allopatric populations suggest that overt aggression and activity may genetically covary between social contexts for nonadaptive reasons. Sociability was rarely correlated in allopatry but was consistently correlated in sympatry despite reduced mean sociability, suggesting that correlational selection may favor a sociability syndrome in brook stickleback when they coexist with ninespine stickleback. Thus, interspecific competition may impose diversifying selection on behavior among populations, although the causes of correlated behavior toward conspecifics and heterospecifics and whether it can evolve in one social context independent of the other may depend on the type of behavior. PMID:23139874

  6. 7 CFR 1780.49 - Rural or Native Alaskan villages.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... providing grants to remedy the dire sanitation conditions in rural Alaskan villages using funds specifically... 7 Agriculture 12 2011-01-01 2011-01-01 false Rural or Native Alaskan villages. 1780.49 Section 1780.49 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES...

  7. 7 CFR 1780.49 - Rural or Native Alaskan villages.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... providing grants to remedy the dire sanitation conditions in rural Alaskan villages using funds specifically... 7 Agriculture 12 2010-01-01 2010-01-01 false Rural or Native Alaskan villages. 1780.49 Section 1780.49 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES...

  8. Educational Provisions for the Alaskan Natives Since 1867.

    ERIC Educational Resources Information Center

    Hopkins, Thomas Robert

    The study compiles and records the history of the administration of education for Alaskan natives since the United States purchased the territory from Russia in 1876. Chapter 1, An Overview of the Development of the Alaskan Native, covers the development of missionary and government schools, the growth and development of Native education from 1906…

  9. Ninespine Stickleback Abundance in Lake Michigan Increases After Dreissenid Mussel Invasion

    USGS Publications Warehouse

    Madenjian, Charles P.; Bunnell, David B.; Gorman, Owen T.

    2010-01-01

    Based on data from our annual lakewide bottom trawl survey of Lake Michigan, we determined that density of ninespine sticklebacks Pungitius pungitius increased from an average of 0.234 kg/ha during 1973–1995 to an average of 1.318 kg/ha during 1996–2007. This greater-than-fivefold increase in density coincided with the dreissenid mussel invasion of Lake Michigan. Intervention analysis revealed that ninespine stickleback density in Lake Michigan significantly increased between the two time periods. In contrast, based on data from our annual bottom trawl survey of U.S. waters of Lake Superior, ninespine stickleback density decreased from an average of 0.133 kg/ha during 1978–1999 to an average of only 0.026 kg/ha during 2000–2007. This greater-than-fivefold density decrease, which was found to be significant via intervention analysis, coincided with population recovery for both lean and fat morphotypes of lake trout Salvelinus namaycush in Lake Superior. In contrast to Lake Michigan, dreissenid mussels have not invaded Lake Superior on a lakewide basis. Thus, a comparison of these two lakes indicated that the increase in ninespine stickleback abundance in Lake Michigan was most likely attributable to the dreissenid mussel invasion. In addition, based on our correlation analysis, alewives Alosa pseudoharengus did not have an adverse effect on ninespine stickleback abundance in Lake Michigan. Perhaps the recent increase in biomass of green algae Cladophora spp. associated with the dreissenid mussel invasion improved spawning habitat quality for ninespine sticklebacks and led to their stepwise abundance increase in Lake Michigan beginning in 1996

  10. Grandparental effects in marine sticklebacks: transgenerational plasticity across multiple generations.

    PubMed

    Shama, L N S; Wegner, K M

    2014-11-01

    Nongenetic inheritance mechanisms such as transgenerational plasticity (TGP) can buffer populations against rapid environmental change such as ocean warming. Yet, little is known about how long these effects persist and whether they are cumulative over generations. Here, we tested for adaptive TGP in response to simulated ocean warming across parental and grandparental generations of marine sticklebacks. Grandparents were acclimated for two months during reproductive conditioning, whereas parents experienced developmental acclimation, allowing us to compare the fitness consequences of short-term vs. prolonged exposure to elevated temperature across multiple generations. We found that reproductive output of F1 adults was primarily determined by maternal developmental temperature, but carry-over effects from grandparental acclimation environments resulted in cumulative negative effects of elevated temperature on hatching success. In very early stages of growth, F2 offspring reached larger sizes in their respective paternal and grandparental environment down the paternal line, suggesting that other factors than just the paternal genome may be transferred between generations. In later growth stages, maternal and maternal granddam environments strongly influenced offspring body size, but in opposing directions, indicating that the mechanism(s) underlying the transfer of environmental information may have differed between acute and developmental acclimation experienced by the two generations. Taken together, our results suggest that the fitness consequences of parental and grandparental TGP are highly context dependent, but will play an important role in mediating some of the impacts of rapid climate change in this system.

  11. Carbon cycle uncertainty in the Alaskan Arctic

    NASA Astrophysics Data System (ADS)

    Fisher, J. B.; Sikka, M.; Oechel, W. C.; Huntzinger, D. N.; Melton, J. R.; Koven, C. D.; Ahlström, A.; Arain, M. A.; Baker, I.; Chen, J. M.; Ciais, P.; Davidson, C.; Dietze, M.; El-Masri, B.; Hayes, D.; Huntingford, C.; Jain, A. K.; Levy, P. E.; Lomas, M. R.; Poulter, B.; Price, D.; Sahoo, A. K.; Schaefer, K.; Tian, H.; Tomelleri, E.; Verbeeck, H.; Viovy, N.; Wania, R.; Zeng, N.; Miller, C. E.

    2014-08-01

    Climate change is leading to a disproportionately large warming in the high northern latitudes, but the magnitude and sign of the future carbon balance of the Arctic are highly uncertain. Using 40 terrestrial biosphere models for the Alaskan Arctic from four recent model intercomparison projects - NACP (North American Carbon Program) site and regional syntheses, TRENDY (Trends in net land atmosphere carbon exchanges), and WETCHIMP (Wetland and Wetland CH4 Inter-comparison of Models Project) - we provide a baseline of terrestrial carbon cycle uncertainty, defined as the multi-model standard deviation (σ) for each quantity that follows. Mean annual absolute uncertainty was largest for soil carbon (14.0 ± 9.2 kg C m-2), then gross primary production (GPP) (0.22 ± 0.50 kg C m-2 yr-1), ecosystem respiration (Re) (0.23 ± 0.38 kg C m-2 yr-1), net primary production (NPP) (0.14 ± 0.33 kg C m-2 yr-1), autotrophic respiration (Ra) (0.09 ± 0.20 kg C m-2 yr-1), heterotrophic respiration (Rh) (0.14 ± 0.20 kg C m-2 yr-1), net ecosystem exchange (NEE) (-0.01 ± 0.19 kg C m-2 yr-1), and CH4 flux (2.52 ± 4.02 g CH4 m-2 yr-1). There were no consistent spatial patterns in the larger Alaskan Arctic and boreal regional carbon stocks and fluxes, with some models showing NEE for Alaska as a strong carbon sink, others as a strong carbon source, while still others as carbon neutral. Finally, AmeriFlux data are used at two sites in the Alaskan Arctic to evaluate the regional patterns; observed seasonal NEE was captured within multi-model uncertainty. This assessment of carbon cycle uncertainties may be used as a baseline for the improvement of experimental and modeling activities, as well as a reference for future trajectories in carbon cycling with climate change in the Alaskan Arctic and larger boreal region.

  12. Engaging Alaskan Students in Cryospheric Research

    NASA Astrophysics Data System (ADS)

    Yoshikawa, K.; Sparrow, E. B.; Kopplin, M.

    2011-12-01

    The Permafrost/Active Layer Monitoring Program is an ongoing project, which builds on work begun in 2005 to establish long-term permafrost and active layer monitoring sites adjacent to schools in Alaskan communities and in the circumpolar permafrost region. Currently, there are about 200 schools in Alaska involved in the project including also Denali National Park and Preserve. The project has both scientific and outreach components. The monitoring sites collect temperature data on permafrost, and the length and depth of the active layer (the layer above the permafrost that thaws during summer and freezes again during winter). To ensure scientific integrity, the scientist installed all of the monitoring instruments and selected the sites representative of the surrounding biome and thermal conditions. This is a unique collaboration opportunity in that 1) uses scientifically accurate instruments, 2) is scientist led and supervised including instrumentation set-up and data quality check, 3)has teacher/student organized observation network, 4) increased spatial scale of monitoring sites that covers all of the Alaskan communities. Most of the monitoring sites are located in remote communities, where the majority of residents depend on a subsistence lifestyle. Changes in climate, length of seasons, and permafrost conditions directly impact natural resources and subsistence activities. Changes in permafrost conditions also affect local ecosystems and hydrological regimes, and can influence the severity of natural disasters. In addition to extending our knowledge of the arctic environment, the program involves school-age students. Several students have been using the data for their projects and have been inspired to continue their studies. The data gathered from these stations are shared with other schools and made available to the public through our web site (http://www.uaf.edu/permafrost). Also communities have increasingly become interested in this project not only as

  13. Comparative metagenome analysis of an Alaskan glacier.

    PubMed

    Choudhari, Sulbha; Lohia, Ruchi; Grigoriev, Andrey

    2014-04-01

    The temperature in the Arctic region has been increasing in the recent past accompanied by melting of its glaciers. We took a snapshot of the current microbial inhabitation of an Alaskan glacier (which can be considered as one of the simplest possible ecosystems) by using metagenomic sequencing of 16S rRNA recovered from ice/snow samples. Somewhat contrary to our expectations and earlier estimates, a rich and diverse microbial population of more than 2,500 species was revealed including several species of Archaea that has been identified for the first time in the glaciers of the Northern hemisphere. The most prominent bacterial groups found were Proteobacteria, Bacteroidetes, and Firmicutes. Firmicutes were not reported in large numbers in a previously studied Alpine glacier but were dominant in an Antarctic subglacial lake. Representatives of Cyanobacteria, Actinobacteria and Planctomycetes were among the most numerous, likely reflecting the dependence of the ecosystem on the energy obtained through photosynthesis and close links with the microbial community of the soil. Principal component analysis (PCA) of nucleotide word frequency revealed distinct sequence clusters for different taxonomic groups in the Alaskan glacier community and separate clusters for the glacial communities from other regions of the world. Comparative analysis of the community composition and bacterial diversity present in the Byron glacier in Alaska with other environments showed larger overlap with an Arctic soil than with a high Arctic lake, indicating patterns of community exchange and suggesting that these bacteria may play an important role in soil development during glacial retreat.

  14. Sufentanil citrate immobilization of Alaskan moose calves.

    PubMed

    Kreeger, Terry J; Kellie, Kalin A

    2012-10-01

    Free-ranging Alaskan moose calves (Alces alces gigas) were immobilized with 0.12 mg/kg sufentanil (S; n=16), 0.12 mg/kg sufentanil plus 0.27 mg/kg xylazine (SX; n=11), or 0.007 mg/kg carfentanil plus 0.36 mg/kg xylazine (CX; n=13). Immobilants were antagonized with 1.2 mg/kg naltrexone (S) or 1.2 mg/kg naltrexone plus 2.4 mg/kg tolazoline (SX, CX). There were no differences in induction (P ≥ 0.29) or processing (P ≥ 0.44) times between groups. Moose given either S or SX had significantly shorter recovery times than moose given CX (P=0.001) and recovery times from S were shorter than from SX (P=0.02). Oxygen saturation values for all groups averaged 85 ± 8%, but were significantly higher (P=0.048) for CX (89 ± 7%) than for S (82 ± 8%). Based on these data, sufentanil at 0.1 mg/kg or sufentanil at 0.1 mg/kg plus xylazine at 0.25 mg/kg could provide effective remote immobilization for Alaskan moose calves and could be substituted for carfentanil or thiafentanil should the need arise.

  15. Baiting improves CPUE in nine-spined stickleback (Pungitius pungitius) minnow trap fishery

    PubMed Central

    Merilä, Juha

    2015-01-01

    Whether or not baiting influences stickleback catch per unit effort (CPUE) remains a matter of debate among stickleback researchers: While the opinions about the impact of baiting on CPUE differ, supporting quantitative data are scarce. The effect of baiting and trap type on nine-spined stickleback (Pungitius pungitius) CPUE was studied in a field experiment conducted over four consecutive days in a small pond in northeastern Finland. The results show that baited traps yielded better (mean CPUE = 1.24 fish/trap/d) catches than unbaited traps (mean CPUE = 0.66); however, there were also differences in CPUE depending on the type of collapsible trap that was used. The trap type effect on CPUE seemed to differ among age classes – the finer meshed trap caught more young-of-the-year fish than the coarse-meshed one, whereas the opposite was true for the older and larger individuals. The results agree with those of an earlier more restricted study conducted in the same locality: Together, these results provide strong evidence for the positive impact of baiting on nine-spined stickleback CPUE. PMID:26380701

  16. Baiting improves CPUE in nine-spined stickleback (Pungitius pungitius) minnow trap fishery.

    PubMed

    Merilä, Juha

    2015-09-01

    Whether or not baiting influences stickleback catch per unit effort (CPUE) remains a matter of debate among stickleback researchers: While the opinions about the impact of baiting on CPUE differ, supporting quantitative data are scarce. The effect of baiting and trap type on nine-spined stickleback (Pungitius pungitius) CPUE was studied in a field experiment conducted over four consecutive days in a small pond in northeastern Finland. The results show that baited traps yielded better (mean CPUE = 1.24 fish/trap/d) catches than unbaited traps (mean CPUE = 0.66); however, there were also differences in CPUE depending on the type of collapsible trap that was used. The trap type effect on CPUE seemed to differ among age classes - the finer meshed trap caught more young-of-the-year fish than the coarse-meshed one, whereas the opposite was true for the older and larger individuals. The results agree with those of an earlier more restricted study conducted in the same locality: Together, these results provide strong evidence for the positive impact of baiting on nine-spined stickleback CPUE.

  17. Nuclear magnetic relaxation by the dipolar EMOR mechanism: Three-spin systems

    NASA Astrophysics Data System (ADS)

    Chang, Zhiwei; Halle, Bertil

    2016-07-01

    In aqueous systems with immobilized macromolecules, including biological tissue, the longitudinal spin relaxation of water protons is primarily induced by exchange-mediated orientational randomization (EMOR) of intra- and intermolecular magnetic dipole-dipole couplings. Starting from the stochastic Liouville equation, we have developed a non-perturbative theory that can describe relaxation by the dipolar EMOR mechanism over the full range of exchange rates, dipole couplings, and Larmor frequencies. Here, we implement the general dipolar EMOR theory for a macromolecule-bound three-spin system, where one, two, or all three spins exchange with the bulk solution phase. In contrast to the previously studied two-spin system with a single dipole coupling, there are now three dipole couplings, so relaxation is affected by distinct correlations as well as by self-correlations. Moreover, relaxation can now couple the magnetizations with three-spin modes and, in the presence of a static dipole coupling, with two-spin modes. As a result of this complexity, three secondary dispersion steps with different physical origins can appear in the longitudinal relaxation dispersion profile, in addition to the primary dispersion step at the Larmor frequency matching the exchange rate. Furthermore, and in contrast to the two-spin system, longitudinal relaxation can be significantly affected by chemical shifts and by the odd-valued ("imaginary") part of the spectral density function. We anticipate that the detailed studies of two-spin and three-spin systems that have now been completed will provide the foundation for developing an approximate multi-spin dipolar EMOR theory sufficiently accurate and computationally efficient to allow quantitative molecular-level interpretation of frequency-dependent water-proton longitudinal relaxation data from biophysical model systems and soft biological tissue.

  18. Nuclear magnetic relaxation by the dipolar EMOR mechanism: Three-spin systems.

    PubMed

    Chang, Zhiwei; Halle, Bertil

    2016-07-21

    In aqueous systems with immobilized macromolecules, including biological tissue, the longitudinal spin relaxation of water protons is primarily induced by exchange-mediated orientational randomization (EMOR) of intra- and intermolecular magnetic dipole-dipole couplings. Starting from the stochastic Liouville equation, we have developed a non-perturbative theory that can describe relaxation by the dipolar EMOR mechanism over the full range of exchange rates, dipole couplings, and Larmor frequencies. Here, we implement the general dipolar EMOR theory for a macromolecule-bound three-spin system, where one, two, or all three spins exchange with the bulk solution phase. In contrast to the previously studied two-spin system with a single dipole coupling, there are now three dipole couplings, so relaxation is affected by distinct correlations as well as by self-correlations. Moreover, relaxation can now couple the magnetizations with three-spin modes and, in the presence of a static dipole coupling, with two-spin modes. As a result of this complexity, three secondary dispersion steps with different physical origins can appear in the longitudinal relaxation dispersion profile, in addition to the primary dispersion step at the Larmor frequency matching the exchange rate. Furthermore, and in contrast to the two-spin system, longitudinal relaxation can be significantly affected by chemical shifts and by the odd-valued ("imaginary") part of the spectral density function. We anticipate that the detailed studies of two-spin and three-spin systems that have now been completed will provide the foundation for developing an approximate multi-spin dipolar EMOR theory sufficiently accurate and computationally efficient to allow quantitative molecular-level interpretation of frequency-dependent water-proton longitudinal relaxation data from biophysical model systems and soft biological tissue. PMID:27448879

  19. Dimerizations in spin- S antiferromagnetic chains with three-spin interaction

    NASA Astrophysics Data System (ADS)

    Wang, Zheng-Yuan; Furuya, Shunsuke C.; Nakamura, Masaaki; Komakura, Ryo

    2014-03-01

    We discuss spin- S antiferromagnetic Heisenberg chains with three-spin interactions, next-nearest interactions, and bond alternation. First, we prove rigorouslly that there exist parameter regions of the exact dimerized ground state in this system. This is a generalization of the Majumdar-Ghosh model to arbitral S. Next, we discuss the ground state phase diagram of the models by introducing several effective field theories and universality classes of the transitions are described by the level- 2 S SU(2) Wess-Zumino-Witten model and the Gaussian model. Finally, we determine the phase diagrams of S = 1 and S = 3 / 2 systems by using exact diagonalization and level spectroscopy method.

  20. Chiral phase from three-spin interactions in an optical lattice

    SciTech Connect

    D'Cruz, Christian; Pachos, Jiannis K.

    2005-10-15

    A spin-1/2 chain model that includes three-spin interactions can effectively describe the dynamics of two species of bosons trapped in an optical lattice with a triangular-ladder configuration. A perturbative theoretical approach and numerical study of its ground state is performed that reveals a rich variety of phases and criticalities. We identify phases with periodicity one, two, or three, as well as critical points that belong in the same universality class as the Ising or the three-state Potts model. We establish a range of parameters, corresponding to a large degeneracy present between phases with period 2 and 3, that nests a gapless incommensurate chiral phase.

  1. Carbon cycle uncertainty in the Alaskan Arctic

    NASA Astrophysics Data System (ADS)

    Fisher, J. B.; Sikka, M.; Oechel, W. C.; Huntzinger, D. N.; Melton, J. R.; Koven, C. D.; Ahlström, A.; Arain, A. M.; Baker, I.; Chen, J. M.; Ciais, P.; Davidson, C.; Dietze, M.; El-Masri, B.; Hayes, D.; Huntingford, C.; Jain, A.; Levy, P. E.; Lomas, M. R.; Poulter, B.; Price, D.; Sahoo, A. K.; Schaefer, K.; Tian, H.; Tomelleri, E.; Verbeeck, H.; Viovy, N.; Wania, R.; Zeng, N.; Miller, C. E.

    2014-02-01

    Climate change is leading to a disproportionately large warming in the high northern latitudes, but the magnitude and sign of the future carbon balance of the Arctic are highly uncertain. Using 40 terrestrial biosphere models for Alaska, we provide a baseline of terrestrial carbon cycle structural and parametric uncertainty, defined as the multi-model standard deviation (σ) against the mean (x\\bar) for each quantity. Mean annual uncertainty (σ/x\\bar) was largest for net ecosystem exchange (NEE) (-0.01± 0.19 kg C m-2 yr-1), then net primary production (NPP) (0.14 ± 0.33 kg C m-2 yr-1), autotrophic respiration (Ra) (0.09 ± 0.20 kg C m-2 yr-1), gross primary production (GPP) (0.22 ± 0.50 kg C m-2 yr-1), ecosystem respiration (Re) (0.23 ± 0.38 kg C m-2 yr-1), CH4 flux (2.52 ± 4.02 g CH4 m-2 yr-1), heterotrophic respiration (Rh) (0.14 ± 0.20 kg C m-2 yr-1), and soil carbon (14.0± 9.2 kg C m-2). The spatial patterns in regional carbon stocks and fluxes varied widely with some models showing NEE for Alaska as a strong carbon sink, others as a strong carbon source, while still others as carbon neutral. Additionally, a feedback (i.e., sensitivity) analysis was conducted of 20th century NEE to CO2 fertilization (β) and climate (γ), which showed that uncertainty in γ was 2x larger than that of β, with neither indicating that the Alaskan Arctic is shifting towards a certain net carbon sink or source. Finally, AmeriFlux data are used at two sites in the Alaskan Arctic to evaluate the regional patterns; observed seasonal NEE was captured within multi-model uncertainty. This assessment of carbon cycle uncertainties may be used as a baseline for the improvement of experimental and modeling activities, as well as a reference for future trajectories in carbon cycling with climate change in the Alaskan Arctic.

  2. Development of Alaskan gas hydrate resources

    SciTech Connect

    Kamath, V.A.; Sharma, G.D.; Patil, S.L.

    1991-06-01

    The research undertaken in this project pertains to study of various techniques for production of natural gas from Alaskan gas hydrates such as, depressurization, injection of hot water, steam, brine, methanol and ethylene glycol solutions through experimental investigation of decomposition characteristics of hydrate cores. An experimental study has been conducted to measure the effective gas permeability changes as hydrates form in the sandpack and the results have been used to determine the reduction in the effective gas permeability of the sandpack as a function of hydrate saturation. A user friendly, interactive, menu-driven, numerical difference simulator has been developed to model the dissociation of natural gas hydrates in porous media with variable thermal properties. A numerical, finite element simulator has been developed to model the dissociation of hydrates during hot water injection process.

  3. Subacute necrotising encephalopathy in an Alaskan husky.

    PubMed

    Wakshlag, J J; de Lahunta, A; Robinson, T; Cooper, B J; Brenner, O; O'Toole, T D; Olson, J; Beckman, K B; Glass, E; Reynolds, A J

    1999-12-01

    A 29-month-old female Alaskan husky was presented recumbent, tetraparetic and in a state of dementia, with blindness and cranial nerve deficits. The dog's progress was followed for over two months, as the signs resolved to an non-progressive mild hypermetria with slight proprioceptive ataxia, a diminished menace response and inability to prehend food. Magnetic resonance imaging (MRI) revealed bilateral cavitation extending from the thalamus to the medulla, with less pronounced degenerative lesions in the caudate nucleus, putamen and claustrum. Cerebrospinal fluid lactate and pyruvate concentrations were in their normal ranges. Necropsy and histological examination confirmed the MRI findings as well as neuronal degeneration of the cerebellar cortex in the vermis and degenerative changes in the neocortex at the depths of the cerebral sulci. In view of the similarity of lesions to subacute necrotising encephalomyelopathy, known as Leigh's disease in humans, a tentative diagnosis of a mitochondrial encephalopathy was made.

  4. Gastritis in Alaskan racing sled dogs.

    PubMed

    Ritchey, J W; Davis, M S; Breshears, M A; Willard, M D; Williamson, K K; Royer, C M; Payton, M E; Cragun, A S

    2011-07-01

    Alaskan racing sled dogs are a well-established model of exercise-induced gastric disease. The aim of this study was to define the temporal development of microscopical gastric lesions during long distance racing. Two groups of dogs were examined: group I comprised conditioned dogs that were exercising and group II were conditioned dogs not exercising. The gastric mucosa was examined endoscopically and sampled for routine histopathology and microscopical scoring, immunohistochemistry (IHC) and detection of apoptotic epithelial cells. Overall, group I dogs exhibited more significant epithelial lesions, including ulcers, compared with dogs in group II. Group II dogs exhibited the most severe mucosal inflammatory infiltrates. Although the intensity of inflammation differed, the nature of the inflammation was similar between groups, consisting of diffuse lymphocytic infiltration and a unique interface-type infiltrate that obscured the basement membrane zone and was accompanied by intraepithelial infiltration of lymphocytes. IHC confirmed the presence of CD3(+) T and CD79(+) B lymphocytes within the mucosal infiltrates; however, most of the intraepithelial and interface infiltrates were CD3(+) T cells. Spiral-shaped bacterial organisms were seen in the gastric tissues; however, their presence did not correlate with either the severity of epithelial lesions, inflammation or the pattern of interface inflammation. The number of apoptotic epithelial cells was widely variable and not significantly different between groups. These findings confirm previous observations that gastric ulcers develop in conditioned dogs under racing stress. The unique nature of the interface-type gastric inflammation is similar to that of human lymphocytic gastritis and may suggest an immune-mediated mechanism for the changes seen in Alaskan racing sled dogs.

  5. Evolved tooth gain in sticklebacks is associated with a cis-regulatory allele of Bmp6

    PubMed Central

    Cleves, Phillip A.; Ellis, Nicholas A.; Jimenez, Monica T.; Nunez, Stephanie M.; Schluter, Dolph; Kingsley, David M.; Miller, Craig T.

    2014-01-01

    Developmental genetic studies of evolved differences in morphology have led to the hypothesis that cis-regulatory changes often underlie morphological evolution. However, because most of these studies focus on evolved loss of traits, the genetic architecture and possible association with cis-regulatory changes of gain traits are less understood. Here we show that a derived benthic freshwater stickleback population has evolved an approximate twofold gain in ventral pharyngeal tooth number compared with their ancestral marine counterparts. Comparing laboratory-reared developmental time courses of a low-toothed marine population and this high-toothed benthic population reveals that increases in tooth number and tooth plate area and decreases in tooth spacing arise at late juvenile stages. Genome-wide linkage mapping identifies largely separate sets of quantitative trait loci affecting different aspects of dental patterning. One large-effect quantitative trait locus controlling tooth number fine-maps to a genomic region containing an excellent candidate gene, Bone morphogenetic protein 6 (Bmp6). Stickleback Bmp6 is expressed in developing teeth, and no coding changes are found between the high- and low-toothed populations. However, quantitative allele-specific expression assays of Bmp6 in developing teeth in F1 hybrids show that cis-regulatory changes have elevated the relative expression level of the freshwater benthic Bmp6 allele at late, but not early, stages of stickleback development. Collectively, our data support a model where a late-acting cis-regulatory up-regulation of Bmp6 expression underlies a significant increase in tooth number in derived benthic sticklebacks. PMID:25205810

  6. Anatomic and metabolic responses to thermal acclimation in the ninespine stickleback, Pungitius pungitius.

    PubMed

    Guderley, H; Foley, L

    1990-11-01

    Male ninespine sticklebacks, Pungitius pungitius, acclimated to 3°C have higher activities of mitochondrial enzymes in their axial muscles than males acclimated to 20°C. Phosphofructokinase and pyruvate kinase activities tended to be higher in cold than warm acclimated males. For females, warm acclimation tended to decrease only mitochondrial enzyme activities. As thermal acclimation did not change the physical condition and most anatomic parameters of the sticklebacks, the enzymatic changes do not seem due to mobilization of somatic reserves. Field acclimatization to warm temperatures led to a marked decrease in physical condition in both males and females. This decrease in physical condition could largely be attributed to atrophy of the carcass mass. Spring males had higher activities of phosphofructokinase, citrate synthase and cytochrome oxidase in the axial muscle than summer males. Again, females showed a less marked response. These data suggest that environmental temperature is a major determinant of muscle aerobic capacity, at least for male ninespine sticklebacks. Thus, these northern temperate zone fish retain the capacity for thermal compensation, much like their temperate zone counterparts. PMID:24221033

  7. Alaska Is Our Home--Book 3: A Natural Science Handbook for Alaskan Students.

    ERIC Educational Resources Information Center

    Bury, John; Bury, Susan

    The third book in a series of natural science handbooks for Alaskan students focuses on Alaskan plantlife. The first chapter, on trees, gives general information about trees and explains how to identify and locate trees in the three main Alaskan tree families: pine, willow, and birch. The second chapter, on plants, describes 14 kinds of edible…

  8. 40 CFR 408.90 - Applicability; description of the non-remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-remote Alaskan shrimp processing subcategory. 408.90 Section 408.90 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing Subcategory § 408.90 Applicability; description of the non-remote Alaskan shrimp processing subcategory. The provisions of this subpart...

  9. 40 CFR 408.100 - Applicability; description of the remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... remote Alaskan shrimp processing subcategory. 408.100 Section 408.100 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Shrimp Processing Subcategory § 408.100 Applicability; description of the remote Alaskan shrimp processing subcategory. The provisions of this subpart are...

  10. 40 CFR 408.100 - Applicability; description of the remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... remote Alaskan shrimp processing subcategory. 408.100 Section 408.100 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Shrimp Processing Subcategory § 408.100 Applicability; description of the remote Alaskan shrimp processing subcategory. The provisions of this subpart are...

  11. 40 CFR 408.90 - Applicability; description of the non-remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-remote Alaskan shrimp processing subcategory. 408.90 Section 408.90 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing Subcategory § 408.90 Applicability; description of the non-remote Alaskan shrimp processing subcategory. The provisions of this subpart...

  12. 40 CFR 408.100 - Applicability; description of the remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... remote Alaskan shrimp processing subcategory. 408.100 Section 408.100 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Shrimp Processing Subcategory § 408.100 Applicability; description of the remote Alaskan shrimp processing subcategory. The provisions of this subpart are...

  13. 40 CFR 408.90 - Applicability; description of the non-remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-remote Alaskan shrimp processing subcategory. 408.90 Section 408.90 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing Subcategory § 408.90 Applicability; description of the non-remote Alaskan shrimp processing subcategory. The provisions of this subpart...

  14. 40 CFR 408.100 - Applicability; description of the remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... remote Alaskan shrimp processing subcategory. 408.100 Section 408.100 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Shrimp Processing Subcategory § 408.100 Applicability; description of the remote Alaskan shrimp processing subcategory. The provisions of this subpart are...

  15. 40 CFR 408.90 - Applicability; description of the non-remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-remote Alaskan shrimp processing subcategory. 408.90 Section 408.90 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing Subcategory § 408.90 Applicability; description of the non-remote Alaskan shrimp processing subcategory. The provisions of this subpart...

  16. 40 CFR 408.100 - Applicability; description of the remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... remote Alaskan shrimp processing subcategory. 408.100 Section 408.100 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Shrimp Processing Subcategory § 408.100 Applicability; description of the remote Alaskan shrimp processing subcategory. The provisions of this subpart are...

  17. 40 CFR 408.90 - Applicability; description of the non-remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-remote Alaskan shrimp processing subcategory. 408.90 Section 408.90 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing Subcategory § 408.90 Applicability; description of the non-remote Alaskan shrimp processing subcategory. The provisions of this subpart...

  18. 40 CFR 408.200 - Applicability; description of the Alaskan bottom fish processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Alaskan bottom fish processing subcategory. 408.200 Section 408.200 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Bottom Fish Processing Subcategory § 408.200 Applicability; description of the Alaskan bottom fish processing subcategory. The provisions of this subpart are...

  19. 40 CFR 408.200 - Applicability; description of the Alaskan bottom fish processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Alaskan bottom fish processing subcategory. 408.200 Section 408.200 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Bottom Fish Processing Subcategory § 408.200 Applicability; description of the Alaskan bottom fish processing subcategory. The provisions of this subpart are...

  20. 40 CFR 408.200 - Applicability; description of the Alaskan bottom fish processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Alaskan bottom fish processing subcategory. 408.200 Section 408.200 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Bottom Fish Processing Subcategory § 408.200 Applicability; description of the Alaskan bottom fish processing subcategory. The provisions of this subpart are...

  1. 40 CFR 408.200 - Applicability; description of the Alaskan bottom fish processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Alaskan bottom fish processing subcategory. 408.200 Section 408.200 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Bottom Fish Processing Subcategory § 408.200 Applicability; description of the Alaskan bottom fish processing subcategory. The provisions of this subpart are...

  2. 40 CFR 408.200 - Applicability; description of the Alaskan bottom fish processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Alaskan bottom fish processing subcategory. 408.200 Section 408.200 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Bottom Fish Processing Subcategory § 408.200 Applicability; description of the Alaskan bottom fish processing subcategory. The provisions of this subpart are...

  3. American Indian Policy Review Commission Special Joint Task Force Report on Alaskan Native Issues.

    ERIC Educational Resources Information Center

    Congress of the U.S. Washington, DC. American Indian Policy Review Commission.

    Impact of the Alaskan Native Claims Settlement Act (ANCSA) on Alaskan Natives, particularly at village levels, is the focus of a joint task force report on Alaskan Native issues. Prepared for the American Indian Policy Review Commission, the report is the work of representatives from task forces on tribal government, federal, state, and tribal…

  4. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  5. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  6. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  7. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  8. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  9. 40 CFR 408.320 - Applicability; description of the non-Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-Alaskan herring fillet processing subcategory. 408.320 Section 408.320 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Herring Fillet Processing Subcategory § 408.320 Applicability; description of the non-Alaskan herring fillet processing subcategory. The provisions of this subpart...

  10. 40 CFR 408.320 - Applicability; description of the non-Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-Alaskan herring fillet processing subcategory. 408.320 Section 408.320 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Herring Fillet Processing Subcategory § 408.320 Applicability; description of the non-Alaskan herring fillet processing subcategory. The provisions of this subpart...

  11. 40 CFR 408.320 - Applicability; description of the non-Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-Alaskan herring fillet processing subcategory. 408.320 Section 408.320 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Herring Fillet Processing Subcategory § 408.320 Applicability; description of the non-Alaskan herring fillet processing subcategory. The provisions of this subpart...

  12. 40 CFR 408.310 - Applicability; description of the Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Alaskan herring fillet processing subcategory. 408.310 Section 408.310 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Herring Fillet Processing Subcategory § 408.310 Applicability; description of the Alaskan herring fillet processing subcategory. The provisions of this subpart...

  13. 40 CFR 408.310 - Applicability; description of the Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Alaskan herring fillet processing subcategory. 408.310 Section 408.310 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Herring Fillet Processing Subcategory § 408.310 Applicability; description of the Alaskan herring fillet processing subcategory. The provisions of this subpart...

  14. 40 CFR 408.310 - Applicability; description of the Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Alaskan herring fillet processing subcategory. 408.310 Section 408.310 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Herring Fillet Processing Subcategory § 408.310 Applicability; description of the Alaskan herring fillet processing subcategory. The provisions of this subpart...

  15. 40 CFR 408.320 - Applicability; description of the non-Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-Alaskan herring fillet processing subcategory. 408.320 Section 408.320 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Herring Fillet Processing Subcategory § 408.320 Applicability; description of the non-Alaskan herring fillet processing subcategory. The provisions of this subpart...

  16. 40 CFR 408.310 - Applicability; description of the Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Alaskan herring fillet processing subcategory. 408.310 Section 408.310 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Herring Fillet Processing Subcategory § 408.310 Applicability; description of the Alaskan herring fillet processing subcategory. The provisions of this subpart...

  17. 40 CFR 408.310 - Applicability; description of the Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Alaskan herring fillet processing subcategory. 408.310 Section 408.310 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Herring Fillet Processing Subcategory § 408.310 Applicability; description of the Alaskan herring fillet processing subcategory. The provisions of this subpart...

  18. 40 CFR 408.320 - Applicability; description of the non-Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-Alaskan herring fillet processing subcategory. 408.320 Section 408.320 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Herring Fillet Processing Subcategory § 408.320 Applicability; description of the non-Alaskan herring fillet processing subcategory. The provisions of this subpart...

  19. 40 CFR 408.160 - Applicability; description of the Alaskan hand-butchered salmon processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Alaskan hand-butchered salmon processing subcategory. 408.160 Section 408.160 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Hand-Butchered Salmon Processing Subcategory § 408.160 Applicability; description of the Alaskan hand-butchered salmon processing subcategory. The provisions of this subpart...

  20. 40 CFR 408.170 - Applicability; description of the Alaskan mechanized salmon processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Alaskan mechanized salmon processing subcategory. 408.170 Section 408.170 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.170 Applicability; description of the Alaskan mechanized salmon processing subcategory. The provisions of this subpart...

  1. 40 CFR 408.160 - Applicability; description of the Alaskan hand-butchered salmon processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Alaskan hand-butchered salmon processing subcategory. 408.160 Section 408.160 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Hand-Butchered Salmon Processing Subcategory § 408.160 Applicability; description of the Alaskan hand-butchered salmon processing subcategory. The provisions of this subpart...

  2. 40 CFR 408.170 - Applicability; description of the Alaskan mechanized salmon processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Alaskan mechanized salmon processing subcategory. 408.170 Section 408.170 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.170 Applicability; description of the Alaskan mechanized salmon processing subcategory. The provisions of this subpart...

  3. 40 CFR 408.160 - Applicability; description of the Alaskan hand-butchered salmon processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Alaskan hand-butchered salmon processing subcategory. 408.160 Section 408.160 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Hand-Butchered Salmon Processing Subcategory § 408.160 Applicability; description of the Alaskan hand-butchered salmon processing subcategory. The provisions of this subpart...

  4. 40 CFR 408.160 - Applicability; description of the Alaskan hand-butchered salmon processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Alaskan hand-butchered salmon processing subcategory. 408.160 Section 408.160 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Hand-Butchered Salmon Processing Subcategory § 408.160 Applicability; description of the Alaskan hand-butchered salmon processing subcategory. The provisions of this subpart...

  5. 40 CFR 408.170 - Applicability; description of the Alaskan mechanized salmon processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Alaskan mechanized salmon processing subcategory. 408.170 Section 408.170 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.170 Applicability; description of the Alaskan mechanized salmon processing subcategory. The provisions of this subpart...

  6. 40 CFR 408.170 - Applicability; description of the Alaskan mechanized salmon processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Alaskan mechanized salmon processing subcategory. 408.170 Section 408.170 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.170 Applicability; description of the Alaskan mechanized salmon processing subcategory. The provisions of this subpart...

  7. 40 CFR 408.160 - Applicability; description of the Alaskan hand-butchered salmon processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Alaskan hand-butchered salmon processing subcategory. 408.160 Section 408.160 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Hand-Butchered Salmon Processing Subcategory § 408.160 Applicability; description of the Alaskan hand-butchered salmon processing subcategory. The provisions of this subpart...

  8. 40 CFR 408.170 - Applicability; description of the Alaskan mechanized salmon processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Alaskan mechanized salmon processing subcategory. 408.170 Section 408.170 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.170 Applicability; description of the Alaskan mechanized salmon processing subcategory. The provisions of this subpart...

  9. Thematic mapper study of Alaskan ophiolites

    NASA Technical Reports Server (NTRS)

    Bird, John M.

    1988-01-01

    The two principle objectives of the project Thematic Mapper Study of Alaskan Ophiolites were to further develop techniques for producing geologic maps, and to study the tectonics of the ophiolite terrains of the Brooks Range and Ruby Geanticline of northern Alaska. Ophiolites, sections of oceanic lithosphere emplaced along island arcs and continental margins, are important to the understanding of mountain belt evolution. Ophiolites also provide an opportunity to study the structural, lithologic, and geochemical characteristics of ocean lithosphere, yielding a better understanding of the processes forming lithosphere. The first part of the report is a description of the methods and results of the TM mapping and gravity modeling. The second part includes papers being prepared for publication. These papers are the following: (1) an analysis of basalt spectral variations; (2) a study of basalt geochemical variations; (3) an examination of the cooling history of the ophiolites using radiometric data; (4) an analysis of shortening produced by thrusting during the Brooks Range orogeny; and (5) a study of an ophiolite using digital aeromagnetic and topographic data. Additional papers are in preparation.

  10. Dimerizations in spin-S antiferromagnetic chains with three-spin interaction

    NASA Astrophysics Data System (ADS)

    Wang, Zheng-Yuan; Furuya, Shunsuke C.; Nakamura, Masaaki; Komakura, Ryo

    2013-12-01

    We discuss spin-S antiferromagnetic Heisenberg chains with three-spin interactions, next-nearest-neighbor interactions, and bond alternation. First, we prove rigorously that there exist parameter regions of the exact dimerized ground state in this system. This is a generalization of the Majumdar-Ghosh model to arbitrary S. Next, we discuss the ground-state phase diagram of the models by introducing several effective field theories and the universality classes of the transitions are described by the level-2S SU (2) Wess-Zumino-Witten model and the Gaussian model. Finally, we determine the phase diagrams of S =1 and S =3/2 systems by using exact diagonalization and level spectroscopy.

  11. Strength and deformation characteristics of Alaskan offshore silts

    SciTech Connect

    Fleming, L.N.

    1985-01-01

    A comprehensive series of undrained shear tests were performed on representative samples of Alaskan silts in both the normally consolidated and overconsolidated state. The type of tests performed were triaxial compression and extension, torvane and miniature laboratory vane tests. It was found that the Alaskan silt exhibited dilative behavior during undrained shear. Also, the silt is highly anisotropic with respect to the stress-strain characteristics and the undrained shear strength. Sample disturbance reduced the measured strength in the unconsolidated undrained tests. The normalized strength parameter was shown to vary from one silt to another. The importance of evaluating the properties of each new silt deposit are described.

  12. Policy Statements on Collection Development. A Compendium from Alaskan Libraries.

    ERIC Educational Resources Information Center

    McCabe, Carol, Ed.

    Developed as part of a statewide coordinated collection development effort, this document is a compendium of the narrative statements of collection development policies from 19 Alaskan university, public, school, and special libraries. Only the basic narrative plus any unique appendices are included for each policy, and some of the policies are…

  13. Village Science: A Resource Handbook for Rural Alaskan Teachers.

    ERIC Educational Resources Information Center

    Dick, Alan

    A resource handbook for rural Alaskan teachers covers village science, to make basic science concepts relevant to the physical environment in villages. Material is intended for use as filler for weeks that come up short on science materials, to provide stimulation for students who cannot see the relevance of science in their lives, and to help…

  14. Definition of Alaskan Aviation Training Requirements. Final Report.

    ERIC Educational Resources Information Center

    Mitchell, M. K.; And Others

    Because of high accident rates and the unique conditions faced in Arctic flying, a project was conducted to develop a training program for airline pilots flying over Alaska. Data were gathered, through the critical incident method in conjunction with traditional job-analysis procedures, about how experienced Alaskan pilots learned to cope with the…

  15. Rural Alaskan Schools: Educational Specifications. Reprinted September, 1971.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau. Office of Public Information and Publications.

    The educational specifications of facilities for rural Alaskan schools are given in this 1964 report. Alaska's 6 recognized geographic regions are briefly described with consideration to topography, climate, permafrost conditions, latitude position, and transportation difficulties which present problems in planning schools. Since the school design…

  16. Standard Implications: Alaskans Reflect on a Movement To Change Teaching.

    ERIC Educational Resources Information Center

    Calkins, Annie, Ed.; Christian, Scott, Ed.

    In this anthology, rural Alaskan English teachers in the Bread Loaf Rural Teacher Network describe their experiences implementing new state education standards while continuing their commitment to learner-centered and place-based practice. The book presents narratives about teaching grounded in knowledge and understanding of students and…

  17. RESIDUAL MUTAGENICITY OF THE ALASKAN OIL SPILL ORGANICS

    EPA Science Inventory

    RESIDUAL MUTAGENICITY OF THE ALASKAN OIL SPILL ORGANICS. L.D.

    The Exxon Valdez, on March 24, 1989, spilled approximately eleven million gallons of Prudhoe Bay crude oil into the waters of Prince William Sound. Approximately 300 miles of
    contaminated beach are potential...

  18. Effects of the Oil Spill on Alaskan Education.

    ERIC Educational Resources Information Center

    Oldaker, Lawrence Lee

    Oil-industry-produced revenues, help finance Alaskan state and local governmental services including education. Capital losses incurred by the Exxon Corporation and by commerical fisheries as a consequence of the Exxon Valdez oil spill caused an economic recession, the result being diminished financing for a number of governmental programs and…

  19. STARS (Secondary Training for Alaskan Rural Students): Science. Draft Copy.

    ERIC Educational Resources Information Center

    Shepard, Gary; Costello, Bill

    STARS (Secondary Training for Alaskan Rural Students) materials resulted from extensive rewriting of the Vocational Adult Secondary Training (VAST) materials produced by the British Columbia Department of Education, after those materials had been used with the 9th and 10th graders on Kodiak Island. Revision was done by teachers who had been using…

  20. A test for within-lake niche differentiation in the nine-spined sticklebacks (Pungitius pungitius).

    PubMed

    Calboli, Federico C F; Byström, Pär; Merilä, Juha

    2016-07-01

    Specialization for the use of different resources can lead to ecological speciation. Accordingly, there are numerous examples of ecologically specialized pairs of fish "species" in postglacial lakes. Using a polymorphic panel of single nucleotide variants, we tested for genetic footprints of within-lake population stratification in nine-spined sticklebacks (Pungitius pungitius) collected from three habitats (viz. littoral, benthic, and pelagic) within a northern Swedish lake. Analyses of admixture, population structure, and relatedness all supported the conclusion that the fish from this lake form a single interbreeding unit. PMID:27547310

  1. Organochlorine residues in eggs of Alaskan seabirds

    USGS Publications Warehouse

    Ohlendorf, H.M.; Bartonek, J.C.; Divoky, G.J.; Klass, E.

    1982-01-01

    One egg from each of 440 clutches of eggs of 19 species of Alaskan seabirds collected in 1973-76 was analyzed for organochlorine residues. All eggs contained DDE; 98.9% contained PCB's; 84.3%, oxychlordane; and 82.7%, HCB. Endrin was found in only one egg, but DDD, DDT, dieldrin, heptachlor epoxide, mirex, cis-chlordane (or trans-nonachlor), cis-nonachlor, and toxaphene each occurred in at least 22% of the samples.Concentrations of organochlorines in the samples were generally low. Mean concentrations of eight compounds were highest in eggs of glaucous-winged gulls (Larus glaucescens) from three sites: DDE (5.16 ppm, wet weight), dieldrin (0.214 ppm), oxychlordane (0.251 ppm), and PCB's (3.55 ppm) in eggs from Bogoslof Island; heptachlor epoxide (0.037 ppm), cis-chlordane (0.075 ppm), and HCB (0.188 ppm) in eggs from Buldir Island; and cis-nonachlor (0.026 ppm) in eggs from the Semidi Islands. Highest concentrations of DDD (0.157 ppm), DDT (0.140 ppm), and toxaphene (0.101 ppm) were in eggs of fork-tailed storm-petrel (Oceanodroma furcata) from Buldir Island, and the highest concentration of mirex (0.044 ppm) was in fork-tailed storm-petrel eggs from the Barren Islands.Both frequency of occurrence and concentration of residues in the eggs differed geographically and by species, apparently reflecting non-uniform distribution of organochlorines in the environment, dissimilar feeding habits and migration patterns of the species, or metabolic differences among the species.The overall frequency of residue occurrence was highest in eggs from the Pribilof Islands, but only three species were represented in the samples collected there. Detectable residues also were more frequent in eggs from the Gulf of Alaska colonies than elsewhere, and the lowest frequency was in eggs from nesting colonies on or near the Seward Peninsula. Regionally, concentrations of DDE and PCB's were usually higher than average in eggs from the Gulf of Alaska and lower than average in eggs from the

  2. Who directs group movement? Leader effort versus follower preference in stickleback fish of different personality.

    PubMed

    Nakayama, Shinnosuke; Harcourt, Jennifer L; Johnstone, Rufus A; Manica, Andrea

    2016-05-01

    During collective movement, bolder individuals often emerge as leaders. Here, we investigate whether this reflects a greater propensity of bold individuals to initiate movement, or a preference for shy individuals to follow a bolder leader. We set up trios of stickleback fish comprising a focal individual who was either bold or shy, and one other individual of each personality. We then recorded the movements of all individuals in and out of cover in a foraging context to determine how assiduously the focal fish followed the movements of each other partner. We found that a shy focal fish preferred to follow a leader whose personality matched its own, but we did not detect such a difference in bold fish. Despite this preference, however, the greater propensity of bold individuals to initiate movements out of cover meant that they successfully led more joint trips. Thus, when offered a choice of leaders, sticklebacks prefer to follow individuals whose personality matches their own, but bolder individuals may, nevertheless, be able to impose their leadership, even among shy followers, simply through greater effort.

  3. Familiarity affects social network structure and discovery of prey patch locations in foraging stickleback shoals

    PubMed Central

    Atton, N.; Galef, B. J.; Hoppitt, W.; Webster, M. M.; Laland, K. N.

    2014-01-01

    Numerous factors affect the fine-scale social structure of animal groups, but it is unclear how important such factors are in determining how individuals encounter resources. Familiarity affects shoal choice and structure in many social fishes. Here, we show that familiarity between shoal members of sticklebacks (Gasterosteus aculeatus) affects both fine-scale social organization and the discovery of resources. Social network analysis revealed that sticklebacks remained closer to familiar than to unfamiliar individuals within the same shoal. Network-based diffusion analysis revealed that there was a strong untransmitted social effect on patch discovery, with individuals tending to discover a task sooner if a familiar individual from their group had previously done so than if an unfamiliar fish had done so. However, in contrast to the effect of familiarity, the frequency with which individuals had previously associated with one another had no effect upon the likelihood of prey patch discovery. This may have been due to the influence of fish on one another's movements; the effect of familiarity on discovery of an empty ‘control’ patch was as strong as for discovery of an actual prey patch. Our results demonstrate that factors affecting fine-scale social interactions can also influence how individuals encounter and exploit resources. PMID:25009061

  4. Asymmetric reproductive barriers and mosaic reproductive isolation: insights from Misty lake-stream stickleback.

    PubMed

    Räsänen, Katja; Hendry, Andrew P

    2014-04-01

    Ecological speciation seems to occur readily but is clearly not ubiquitous - and the relative contributions of different reproductive barriers remain unclear in most systems. We here investigate the potential importance of selection against migrants in lake/stream stickleback (Gasterosteus aculeatus) from the Misty Lake system, Canada. This system is of particular interest because one population contrast (Lake vs. Outlet stream) shows very low genetic and morphological divergence, whereas another population contrast (Lake vs. Inlet stream) shows dramatic genetic and morphological divergence apparently without strong and symmetric reproductive barriers. To test whether selection against migrants might solve this "conundrum of missing reproductive isolation", we performed a fully factorial reciprocal transplant experiment using 225 individually marked stickleback collected from the wild. Relative fitness of the different ecotypes (Lake, Inlet, and Outlet) was assessed based on survival and mass change in experimental enclosures. We found that Inlet fish performed poorly in the lake (selection against migrants in that direction), whereas Lake fish outperformed Inlet fish in all environments (no selection against migrants in the opposite direction). As predicted from their phenotypic and genetic similarity, Outlet and Lake fish performed similarly in all environments. These results suggest that selection against migrants is asymmetric and, together with previous work, indicates that multiple reproductive barriers contribute to reproductive isolation. Similar mosaic patterns of reproductive isolation are likely in other natural systems. PMID:24772291

  5. Hereditary encephalomyelopathy and polyneuropathy in an Alaskan husky.

    PubMed

    Wakshlag, J J; de Lahunta, A

    2009-12-01

    An Alaskan husky puppy was examined for a neurologic disease which began at six weeks of age with generalised paresis that progressed resulting in recumbency by 18 weeks. Thoracic limbs primarily exhibited lower motor neuron signs that included distal muscle atrophy and persistent elbow and carpal flexion that resisted manual extension. Pelvic limb signs primarily exhibited upper motor neuron and general proprioceptive deficits, but also included lower motor neuron signs. Abnormal vocalisation suggested a laryngeal paresis. Histopathologic lesions included a diffuse axonopathy and secondary demyelination in the nerves of the limbs and larynx and a similar bilaterally symmetrical degeneration in the spinal cord white matter suggestive of a dying back axonopathy. In addition, a degenerative process was present in nuclei in the brain stem and cerebellum. Recognition of this disease through clinical and pathologic examination in other related Alaskan Huskies suggested an autosomal recessive inherited disorder.

  6. Revegetation of Alaskan coal mine spoils. Progress report

    SciTech Connect

    Mitchell, W W; Mitchell, G A; McKendrick, J D

    1980-05-23

    Activities initiated after the start of the revegetation project on Alaskan coal mine spoils on September 1, 1979 have consisted mainly of some fall plantings (dormant seedings) and soil and coal spoil samplings and analyses. Because of the late summer start for the project, only a limited amount of field work could be initiated in plant material studies. This consisted of a fall planting at the Usibelli mine site at Healy in interior Alaska. The planting was intended to test the efficacy of seeding in the frost period following the growing season, requiring the seed to remain dormant over winter and to germinate when conditions become favorable in late spring. It also was intended as a comparison of a number of different grasses. Thirty entries were seeded in three replications. Fifteen species of grasses and a clover were included in the trial. The site provided for the trial was on overburden material along a streambed. Among the entries were eight cultivars of introduced grasses, five cultivars of native Alaskan germplasm, one introduced clover cultivar, and sixteen experimental grasses mainly of Alaskan origin.

  7. 40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions...

  8. 40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions...

  9. 40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions...

  10. 40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions...

  11. 40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions...

  12. 40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions...

  13. 40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions...

  14. 40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions...

  15. 40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions...

  16. 40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions...

  17. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  18. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  19. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  20. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  1. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  2. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  3. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  4. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  5. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  6. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  7. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  8. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  9. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  10. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  11. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  12. 25 CFR 243.11 - Are transfers of Alaskan reindeer that occurred before issuance of this part valid?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Are transfers of Alaskan reindeer that occurred before... INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.11 Are transfers of Alaskan reindeer that occurred before issuance of this part valid? All transfers of live Alaskan reindeer or reindeer products that...

  13. 25 CFR 243.11 - Are transfers of Alaskan reindeer that occurred before issuance of this part valid?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Are transfers of Alaskan reindeer that occurred before... INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.11 Are transfers of Alaskan reindeer that occurred before issuance of this part valid? All transfers of live Alaskan reindeer or reindeer products that...

  14. 25 CFR 243.11 - Are transfers of Alaskan reindeer that occurred before issuance of this part valid?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Are transfers of Alaskan reindeer that occurred before... INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.11 Are transfers of Alaskan reindeer that occurred before issuance of this part valid? All transfers of live Alaskan reindeer or reindeer products that...

  15. 25 CFR 243.11 - Are transfers of Alaskan reindeer that occurred before issuance of this part valid?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Are transfers of Alaskan reindeer that occurred before... INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.11 Are transfers of Alaskan reindeer that occurred before issuance of this part valid? All transfers of live Alaskan reindeer or reindeer products that...

  16. 25 CFR 243.11 - Are transfers of Alaskan reindeer that occurred before issuance of this part valid?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Are transfers of Alaskan reindeer that occurred before... INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.11 Are transfers of Alaskan reindeer that occurred before issuance of this part valid? All transfers of live Alaskan reindeer or reindeer products that...

  17. Longitudinal relaxation in dipole-coupled homonuclear three-spin systems: Distinct correlations and odd spectral densities

    SciTech Connect

    Chang, Zhiwei; Halle, Bertil

    2015-12-21

    A system of three dipole-coupled spins exhibits a surprisingly intricate relaxation behavior. Following Hubbard’s pioneering 1958 study, many authors have investigated different aspects of this problem. Nevertheless, on revisiting this classic relaxation problem, we obtain several new results, some of which are at variance with conventional wisdom. Most notably from a fundamental point of view, we find that the odd-valued spectral density function influences longitudinal relaxation. We also show that the effective longitudinal relaxation rate for a non-isochronous three-spin system can exhibit an unusual inverted dispersion step. To clarify these and other issues, we present a comprehensive theoretical treatment of longitudinal relaxation in a three-spin system of arbitrary geometry and with arbitrary rotational dynamics. By using the Liouville-space formulation of Bloch-Wangsness-Redfield theory and a basis of irreducible spherical tensor operators, we show that the number of relaxation components in the different cases can be deduced from symmetry arguments. For the isochronous case, we present the relaxation matrix in analytical form, whereas, for the non-isochronous case, we employ a computationally efficient approach based on the stochastic Liouville equation.

  18. Longitudinal relaxation in dipole-coupled homonuclear three-spin systems: Distinct correlations and odd spectral densities

    NASA Astrophysics Data System (ADS)

    Chang, Zhiwei; Halle, Bertil

    2015-12-01

    A system of three dipole-coupled spins exhibits a surprisingly intricate relaxation behavior. Following Hubbard's pioneering 1958 study, many authors have investigated different aspects of this problem. Nevertheless, on revisiting this classic relaxation problem, we obtain several new results, some of which are at variance with conventional wisdom. Most notably from a fundamental point of view, we find that the odd-valued spectral density function influences longitudinal relaxation. We also show that the effective longitudinal relaxation rate for a non-isochronous three-spin system can exhibit an unusual inverted dispersion step. To clarify these and other issues, we present a comprehensive theoretical treatment of longitudinal relaxation in a three-spin system of arbitrary geometry and with arbitrary rotational dynamics. By using the Liouville-space formulation of Bloch-Wangsness-Redfield theory and a basis of irreducible spherical tensor operators, we show that the number of relaxation components in the different cases can be deduced from symmetry arguments. For the isochronous case, we present the relaxation matrix in analytical form, whereas, for the non-isochronous case, we employ a computationally efficient approach based on the stochastic Liouville equation.

  19. 25 CFR 243.9 - Who may inherit live Alaskan reindeer and by what means?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... provisions of 43 CFR part 4, subpart D. During the pendency of such a proceeding, the authority to assume control over the affected Alaskan reindeer pursuant to 43 CFR 4.270 may be exercised by the Alaska... 25 Indians 1 2011-04-01 2011-04-01 false Who may inherit live Alaskan reindeer and by what...

  20. 25 CFR 243.9 - Who may inherit live Alaskan reindeer and by what means?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... provisions of 43 CFR part 4, subpart D. During the pendency of such a proceeding, the authority to assume control over the affected Alaskan reindeer pursuant to 43 CFR 4.270 may be exercised by the Alaska... 25 Indians 1 2014-04-01 2014-04-01 false Who may inherit live Alaskan reindeer and by what...

  1. 25 CFR 243.4 - Who can own or possess Alaskan reindeer?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Who can own or possess Alaskan reindeer? 243.4 Section 243.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.4 Who can own or possess Alaskan reindeer? (a) Only Alaska Natives, organizations of...

  2. 25 CFR 243.9 - Who may inherit live Alaskan reindeer and by what means?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... provisions of 43 CFR part 4, subpart D. During the pendency of such a proceeding, the authority to assume control over the affected Alaskan reindeer pursuant to 43 CFR 4.270 may be exercised by the Alaska... 25 Indians 1 2012-04-01 2011-04-01 true Who may inherit live Alaskan reindeer and by what...

  3. 25 CFR 243.4 - Who can own or possess Alaskan reindeer?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Who can own or possess Alaskan reindeer? 243.4 Section 243.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.4 Who can own or possess Alaskan reindeer? (a) Only Alaska Natives, organizations of...

  4. 25 CFR 243.4 - Who can own or possess Alaskan reindeer?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Who can own or possess Alaskan reindeer? 243.4 Section 243.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.4 Who can own or possess Alaskan reindeer? (a) Only Alaska Natives, organizations of...

  5. 25 CFR 243.4 - Who can own or possess Alaskan reindeer?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Who can own or possess Alaskan reindeer? 243.4 Section 243.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.4 Who can own or possess Alaskan reindeer? (a) Only Alaska Natives, organizations of...

  6. 25 CFR 243.9 - Who may inherit live Alaskan reindeer and by what means?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... provisions of 43 CFR part 4, subpart D. During the pendency of such a proceeding, the authority to assume control over the affected Alaskan reindeer pursuant to 43 CFR 4.270 may be exercised by the Alaska... 25 Indians 1 2013-04-01 2013-04-01 false Who may inherit live Alaskan reindeer and by what...

  7. 25 CFR 243.4 - Who can own or possess Alaskan reindeer?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Who can own or possess Alaskan reindeer? 243.4 Section 243.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.4 Who can own or possess Alaskan reindeer? (a) Only Alaska Natives, organizations of...

  8. An Authentic Voice in the Technocratic Wilderness: Alaskan Natives and the "Tundra Times."

    ERIC Educational Resources Information Center

    Daley, Patrick; James, Beverly

    1986-01-01

    Examines a pair of critical challenges to the cultural integrity of Alaskan Natives around 1960 as pivotal episodes in the process of native resistance to U. S. dominance. Historically evaluates the fragility of native culture in terms of the political, scientific, and economic interests expressed in the mainstream Alaskan press, particularly the…

  9. 25 CFR 243.9 - Who may inherit live Alaskan reindeer and by what means?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... provisions of 43 CFR part 4, subpart D. During the pendency of such a proceeding, the authority to assume control over the affected Alaskan reindeer pursuant to 43 CFR 4.270 may be exercised by the Alaska... live Alaskan reindeer may pass to the deceased owner's Native heirs by descent or devise. (b) In...

  10. Intruder colour and light environment jointly determine how nesting male stickleback respond to simulated territorial intrusions.

    PubMed

    Bolnick, Daniel I; Hendrix, Kimberly; Jordan, Lyndon Alexander; Veen, Thor; Brock, Chad D

    2016-08-01

    Variation in male nuptial colour signals might be maintained by negative frequency-dependent selection. This can occur if males are more aggressive towards rivals with locally common colour phenotypes. To test this hypothesis, we introduced red or melanic three-dimensional printed-model males into the territories of nesting male stickleback from two optically distinct lakes with different coloured residents. Red-throated models were attacked more in the population with red males, while melanic models were attacked more in the melanic male lake. Aggression against red versus melanic models also varied across a depth gradient within each lake, implying that the local light environment also modulated the strength of negative frequency dependence acting on male nuptial colour. PMID:27512135

  11. Ontogenetic and evolutionary effects of predation and competition on nine-spined stickleback (Pungitius pungitius) body size.

    PubMed

    Välimäki, Kaisa; Herczeg, Gábor

    2012-07-01

    1. Individual- and population-level variation in body size and growth often correlates with many fitness traits. Predation and food availability are expected to affect body size and growth as important agents of both natural selection and phenotypic plasticity. How differences in predation and food availability affect body size/growth during ontogeny in populations adapted to different predation and competition regimes is rarely studied. 2. Nine-spined stickleback (Pungitius pungitius) populations originating from habitats with varying levels of predation and competition are known to be locally adapted to their respective habitats in terms of body size and growth. Here, we studied how different levels of perceived predation risk and competition during ontogeny affect the reaction norms of body size and growth in (i) marine and pond populations adapted to different levels of predation and competition and (ii) different sexes. We reared nine-spined stickleback in a factorial experiment under two levels of perceived predation risk (present/absent) and competition (high/low food supply). 3. We found divergence in the reaction norms at two levels: (i) predation-adapted marine stickleback had stronger reactions to predatory cues than intraspecific competition-adapted pond stickleback, the latter being more sensitive to available food than the marine fish and (ii) females reacting more strongly to the treatments than males. 4. The repeated, habitat-dependent nature of the differences suggests that natural selection is the agent behind the observed patterns. Our results suggest that genetic adaptation to certain environmental factors also involves an increase in the range of expressible phenotypic plasticity. We found support for this phenomenon at two levels: (i) across populations driven by habitat type and (ii) within populations driven by sex.

  12. Histological changes in the kidneys and gills of the stickleback, Gasterosteus aculeatus L, exposed to dissolved cadmium in hard water

    SciTech Connect

    Oronsaye, J.A.

    1989-06-01

    Damage to the kidneys and gills of the three spined stickleback Gasterosteus aculeatus have been investigated, using light microscopy after exposure of fish to 2 to 6 mg Cd2+ liter-1 hard water (299 mg liter-1 as CaCO/sub 3/). Cytological breakdown of kidneys and gill tissue appears to be the cause of death, since oxygen uptake and cadmium excretion are impaired, leading to tissue hypoxia and fish poisoning.

  13. Food intake rates of inactive fish are positively linked to boldness in three‐spined sticklebacks Gasterosteus aculeatus

    PubMed Central

    Manica, A.; Boogert, N. J.

    2016-01-01

    To investigate the link between personality and maximum food intake of inactive individuals, food‐deprived three‐spined sticklebacks Gasterosteus aculeatus at rest in their home compartments were provided with ad libitum prey items. Bolder individuals ate considerably more than shyer individuals, even after accounting for body size, while sociability did not have an effect. These findings support pace‐of‐life theory predicting that life‐history strategies are linked to boldness. PMID:26940195

  14. Acanthocephalan parasites of slimy sculpin, Cottus cognatus, and Ninespine Stickleback, Pungitius pungitius, from Lake Michigan, U.S.A.

    USGS Publications Warehouse

    Muzzall, Patrick M.; Lima, Michael; Gentile, Alex; Gunn, Jacob; Jones, Amanda; Morrison, Jamie; French, John R. P.

    2012-01-01

    In total, 288 slimy sculpins, Cottus cognatus, were collected in September 2003 from 6 Lake Michigan, U.S.A., ports, along with 220 ninespine sticklebacks, Pungitius pungitius, from 3 ports. The ports included Waukegan, Illinois; Port Washington (PW) and Sturgeon Bay (SB), Wisconsin; and Manistique (MS), Frankfort (FF), Ludington (LD), and Saugatuck, Michigan. Echinorhynchus salmonis infected sculpins from 6 ports, Acanthocephalus dirus infected sculpins from 4 ports, and Neoechinorhynchus pungitius infected sculpins from 3 ports. Echinorhynchus salmonis infected significantly more sculpins at PW and at FF than at MS and LD. There were several significant differences in the intensities and abundances of E. salmonis among ports. Acanthocephalus dirus significantly infected more sculpins and had significantly higher abundances at FF than at PW, MS, and LD. Echinorhynchus salmonis, A. dirus, and N. pungitius infected sticklebacks from SB, MS, and FF. Neoechinorhynchus pungitius significantly infected more sculpins and more sticklebacks, and it had significantly higher abundances at MS than at FF. Neoechinorhynchus pungitius was the most common acanthocephalan in C. cognatus and P. pungitius at MS. These acanthocephalan species infecting C. cognatus and P. pungitius corresponded in their occurrence to those organisms that serve as their intermediate hosts found in the stomachs of both fish species. Potential changes in the diet of C. cognatus played a role in significant differences found for E. salmonis and N. pungitius at MS. One of these acanthocephalan species was always the most numerous helminth species found in the digestive tracts of P. pungitius and C. cognatus from these Lake Michigan ports.

  15. A genome-wide SNP genotyping array reveals patterns of global and repeated species-pair divergence in sticklebacks.

    PubMed

    Jones, Felicity C; Chan, Yingguang Frank; Schmutz, Jeremy; Grimwood, Jane; Brady, Shannon D; Southwick, Audrey M; Absher, Devin M; Myers, Richard M; Reimchen, Thomas E; Deagle, Bruce E; Schluter, Dolph; Kingsley, David M

    2012-01-10

    Genes underlying repeated adaptive evolution in natural populations are still largely unknown. Stickleback fish (Gasterosteus aculeatus) have undergone a recent dramatic evolutionary radiation, generating numerous examples of marine-freshwater species pairs and a small number of benthic-limnetic species pairs found within single lakes [1]. We have developed a new genome-wide SNP genotyping array to study patterns of genetic variation in sticklebacks over a wide geographic range, and to scan the genome for regions that contribute to repeated evolution of marine-freshwater or benthic-limnetic species pairs. Surveying 34 global populations with 1,159 informative markers revealed substantial genetic variation, with predominant patterns reflecting demographic history and geographic structure. After correcting for geographic structure and filtering for neutral markers, we detected large repeated shifts in allele frequency at some loci, identifying both known and novel loci likely contributing to marine-freshwater and benthic-limnetic divergence. Several novel loci fall close to genes implicated in epithelial barrier or immune functions, which have likely changed as sticklebacks adapt to contrasting environments. Specific alleles differentiating sympatric benthic-limnetic species pairs are shared in nearby solitary populations, suggesting an allopatric origin for adaptive variants and selection pressures unrelated to sympatry in the initial formation of these classic vertebrate species pairs.

  16. (Alaskan commodities irradiation project: An options analysis study)

    SciTech Connect

    Zarling, J.P.; Swanson, R.B.; Logan, R.R.; Das, D.K.; Lewis, C.E.; Workman, W.G.; Tumeo, M.A.; Hok, C.I.; Birklind, C.A.; Bennett, F.L. . Inst. of Northern Engineering)

    1989-09-01

    The ninety-ninth US Congress commissioned a six-state food irradiation research and development program to evaluate the commercial potential of this technology. Hawaii, Washington, Iowa, Oklahoma and Florida as well as Alaska have participated in the national program; various food products including fishery products, red meats, tropical and citrus fruits and vegetables have been studied. The purpose of the Alaskan study was to review and evaluate those factors related to the technical and economic feasibility of an irradiator in Alaska. This options analysis study will serve as a basis for determining the state's further involvement in the development of food irradiation technology.

  17. Analysis of Alaskan burn severity patterns using remotely sensed data

    USGS Publications Warehouse

    Duffy, P.A.; Epting, J.; Graham, J.M.; Rupp, T.S.; McGuire, A.D.

    2007-01-01

    Wildland fire is the dominant large-scale disturbance mechanism in the Alaskan boreal forest, and it strongly influences forest structure and function. In this research, patterns of burn severity in the Alaskan boreal forest are characterised using 24 fires. First, the relationship between burn severity and area burned is quantified using a linear regression. Second, the spatial correlation of burn severity as a function of topography is modelled using a variogram analysis. Finally, the relationship between vegetation type and spatial patterns of burn severity is quantified using linear models where variograms account for spatial correlation. These results show that: 1) average burn severity increases with the natural logarithm of the area of the wildfire, 2) burn severity is more variable in topographically complex landscapes than in flat landscapes, and 3) there is a significant relationship between burn severity and vegetation type in flat landscapes but not in topographically complex landscapes. These results strengthen the argument that differential flammability of vegetation exists in some boreal landscapes of Alaska. Additionally, these results suggest that through feedbacks between vegetation and burn severity, the distribution of forest vegetation through time is likely more stable in flat terrain than it is in areas with more complex topography. ?? IAWF 2007.

  18. Phlorotannins from Alaskan seaweed inhibit carbolytic enzyme activity.

    PubMed

    Kellogg, Joshua; Grace, Mary H; Lila, Mary Ann

    2014-10-22

    Global incidence of type 2 diabetes has escalated over the past few decades, necessitating a continued search for natural sources of enzyme inhibitors to offset postprandial hyperglycemia. The objective of this study was to evaluate coastal Alaskan seaweed inhibition of α-glucosidase and α-amylase, two carbolytic enzymes involved in serum glucose regulation. Of the six species initially screened, the brown seaweeds Fucus distichus and Alaria marginata possessed the strongest inhibitory effects. F. distichus fractions were potent mixed-mode inhibitors of α-glucosidase and α-amylase, with IC50 values of 0.89 and 13.9 μg/mL, respectively; significantly more efficacious than the pharmaceutical acarbose (IC50 of 112.0 and 137.8 μg/mL, respectively). The activity of F. distichus fractions was associated with phlorotannin oligomers. Normal-phase liquid chromatography-mass spectrometry (NPLC-MS) was employed to characterize individual oligomers. Accurate masses and fragmentation patterns confirmed the presence of fucophloroethol structures with degrees of polymerization from 3 to 18 monomer units. These findings suggest that coastal Alaskan seaweeds are sources of α-glucosidase and α-amylase inhibitory phlorotannins, and thus have potential to limit the release of sugar from carbohydrates and thus alleviate postprandial hyperglycemia.

  19. Reanalysis of the USGS Alaskan benchmark glacier dataset

    NASA Astrophysics Data System (ADS)

    van Beusekom, A. E.; O'Neel, S.; March, R. S.; Sass, L. C.

    2010-12-01

    Resolving the relationship between glacier surface-forcing (climate) and glacier geometry changes is accomplished through mass-balance estimates which can be made with remote sensing methods or field-based observations. The small scale of Alaskan glaciers has prevented remote sensing methods until recently, and field data are essential for validating new techniques. Field data provide the only long duration record that can be studied with respect to climate. The United States Geological Survey has maintained a 44-year mass-balance program at Alaska’s Gulkana Glacier and Wolverine Glacier. We have reanalyzed the Alaskan benchmark glaciers mass balance time series so that all data are treated similarly and systematically. Both glaciers are undergoing sustained mass loss with an increasing rate in recent years. However, the magnitude of the calculated loss depends on the number and location of the data collection sites. We explore the sensitivity of the glacier-wide balance estimates to the method of integration used on the necessarily point data. The robustness of the balance is strengthened with use of independent photogrammetric measurements.

  20. Oestrogenic pollutants promote the growth of a parasite in male sticklebacks.

    PubMed

    Macnab, Vicki; Katsiadaki, Ioanna; Tilley, Ceinwen A; Barber, Iain

    2016-05-01

    Aquatic environments are especially susceptible to anthropogenic chemical pollution. Yet although knowledge on the biological effects of pollutants on aquatic organisms is increasing, far less is known about how ecologically-important interspecific interactions are affected by chemicals. In particular, the consequences of anthropogenic pollution for the interaction of hosts and parasites are poorly understood. Here, we examine how exposure to 17β-oestradiol (E2)-a natural oestrogen and a model endocrine disrupting chemical (EDC) -affects infection susceptibility and emergent infection phenotypes in an experimental host-parasite system; three spined sticklebacks (Gasterosteus aculeatus) infected with the common, debilitating cestode Schistocephalus solidus. We exposed individual sticklebacks to a 0ngl(-1) (control), 10ngl(-1) or 100ngl(-1) E2 treatment before feeding them infective stages of S. solidus. E2 exposure significantly elevated vitellogenin (VTG) levels-a biomarker of exposure to xenoestrogens-in both female and male fish, and reduced their body condition. Susceptibility to parasite infection was unaffected by EDC exposure; however, E2 treatment and fish sex interacted significantly to determine the growth rate of parasites, which grew quickest in male hosts held under the higher (100ngl(-1)) E2 treatment. Tissue VTG levels and parasite mass correlated positively across the whole sample of experimentally infected fish, but separate regressions run on the male and female datasets demonstrated a significant relationship only among male fish. Hence, among males-but not females-elevated VTG levels elicited by E2 exposure led to more rapid parasite growth. We outline plausible physiological mechanisms that could explain these results. Our results demonstrate that oestrogenic pollutants can alter host-parasite interactions by promoting parasite growth, and that male hosts may be disproportionately affected. Because ecologically-relevant effects of infection on

  1. Oestrogenic pollutants promote the growth of a parasite in male sticklebacks

    PubMed Central

    Macnab, Vicki; Katsiadaki, Ioanna; Tilley, Ceinwen A.; Barber, Iain

    2016-01-01

    Aquatic environments are especially susceptible to anthropogenic chemical pollution. Yet although knowledge on the biological effects of pollutants on aquatic organisms is increasing, far less is known about how ecologically-important interspecific interactions are affected by chemicals. In particular, the consequences of anthropogenic pollution for the interaction of hosts and parasites are poorly understood. Here, we examine how exposure to 17β-oestradiol (E2)—a natural oestrogen and a model endocrine disrupting chemical (EDC) —affects infection susceptibility and emergent infection phenotypes in an experimental host–parasite system; three spined sticklebacks (Gasterosteus aculeatus) infected with the common, debilitating cestode Schistocephalus solidus. We exposed individual sticklebacks to a 0 ng l−1 (control), 10 ng l−1 or 100 ng l−1 E2 treatment before feeding them infective stages of S. solidus. E2 exposure significantly elevated vitellogenin (VTG) levels—a biomarker of exposure to xenoestrogens—in both female and male fish, and reduced their body condition. Susceptibility to parasite infection was unaffected by EDC exposure; however, E2 treatment and fish sex interacted significantly to determine the growth rate of parasites, which grew quickest in male hosts held under the higher (100 ng l−1) E2 treatment. Tissue VTG levels and parasite mass correlated positively across the whole sample of experimentally infected fish, but separate regressions run on the male and female datasets demonstrated a significant relationship only among male fish. Hence, among males—but not females—elevated VTG levels elicited by E2 exposure led to more rapid parasite growth. We outline plausible physiological mechanisms that could explain these results. Our results demonstrate that oestrogenic pollutants can alter host–parasite interactions by promoting parasite growth, and that male hosts may be disproportionately affected. Because ecologically

  2. Oestrogenic pollutants promote the growth of a parasite in male sticklebacks.

    PubMed

    Macnab, Vicki; Katsiadaki, Ioanna; Tilley, Ceinwen A; Barber, Iain

    2016-05-01

    Aquatic environments are especially susceptible to anthropogenic chemical pollution. Yet although knowledge on the biological effects of pollutants on aquatic organisms is increasing, far less is known about how ecologically-important interspecific interactions are affected by chemicals. In particular, the consequences of anthropogenic pollution for the interaction of hosts and parasites are poorly understood. Here, we examine how exposure to 17β-oestradiol (E2)-a natural oestrogen and a model endocrine disrupting chemical (EDC) -affects infection susceptibility and emergent infection phenotypes in an experimental host-parasite system; three spined sticklebacks (Gasterosteus aculeatus) infected with the common, debilitating cestode Schistocephalus solidus. We exposed individual sticklebacks to a 0ngl(-1) (control), 10ngl(-1) or 100ngl(-1) E2 treatment before feeding them infective stages of S. solidus. E2 exposure significantly elevated vitellogenin (VTG) levels-a biomarker of exposure to xenoestrogens-in both female and male fish, and reduced their body condition. Susceptibility to parasite infection was unaffected by EDC exposure; however, E2 treatment and fish sex interacted significantly to determine the growth rate of parasites, which grew quickest in male hosts held under the higher (100ngl(-1)) E2 treatment. Tissue VTG levels and parasite mass correlated positively across the whole sample of experimentally infected fish, but separate regressions run on the male and female datasets demonstrated a significant relationship only among male fish. Hence, among males-but not females-elevated VTG levels elicited by E2 exposure led to more rapid parasite growth. We outline plausible physiological mechanisms that could explain these results. Our results demonstrate that oestrogenic pollutants can alter host-parasite interactions by promoting parasite growth, and that male hosts may be disproportionately affected. Because ecologically-relevant effects of infection on

  3. Mercury concentration of stickleback Gasterosteus aculeatus from the Gulf of Gdansk

    SciTech Connect

    Falandysz, J.; Kowalewska, M.

    1993-11-01

    Mercury, because of its high toxicity and large anthropogenic inputs and bioaccumulation when transferred through the food chain, is a metal of great environmental interest. Relatively high concentrations of industrial discharge with mercury were detected in fish from the Sound, in the western part of the Baltic Sea in the early 1980s. The Gulf of Gdansk is an area also potentially receiving some kinds of anthropogenic emissions of mercury due to widespread burning of coal and lignite, and consumption-related discharges of that metal in Poland. For example, 357 and 277 tons of mercury had been imported to Poland in 1976 and 1979, respectively. High concentrations of 0.28-0.63 {mu}g Hg/L were reported recently in water in the Gulf of Gdansk. These values are of one to two orders of magnitude higher than those reported in water for any other site around the Baltic Sea. Our recent data on mercury in sediment samples collected from the Gulf of Gdansk showed relatively low contamination. To gain a better insight into the fate and distribution of mercury in the Gdansk Basin, the levels of mercury were determined in stickleback Gasterosteus aculeatus from different sites along the western coastline of the Gulf of Gdansk, Baltic Sea. 8 refs., 3 figs.

  4. Population divergence in compensatory growth responses and their costs in sticklebacks

    PubMed Central

    Ab Ghani, Nurul Izza; Merilä, Juha

    2015-01-01

    Compensatory growth (CG) may be an adaptive mechanism that helps to restore an organisms’ growth trajectory and adult size from deviations caused by early life resource limitation. Yet, few studies have investigated the genetic basis of CG potential and existence of genetically based population differentiation in CG potential. We studied population differentiation, genetic basis, and costs of CG potential in nine-spined sticklebacks (Pungitius pungitius) differing in their normal growth patterns. As selection favors large body size in pond and small body size in marine populations, we expected CG to occur in the pond but not in the marine population. By manipulating feeding conditions (viz. high, low and recovery feeding treatments), we found clear evidence for CG in the pond but not in the marine population, as well as evidence for catch-up growth (i.e., size compensation without growth acceleration) in both populations. In the marine population, overcompensation occurred individuals from the recovery treatment grew eventually larger than those from the high feeding treatment. In both populations, the recovery feeding treatment reduced maturation probability. The recovery feeding treatment also reduced survival probability in the marine but not in the pond population. Analysis of interpopulation hybrids further suggested that both genetic and maternal effects contributed to the population differences in CG. Hence, apart from demonstrating intrinsic costs for recovery growth, both genetic and maternal effects were identified to be important modulators of CG responses. The results provide an evidence for adaptive differentiation in recovery growth potential. PMID:25628860

  5. Context-dependent dynamic UV signaling in female three spine sticklebacks

    PubMed Central

    Hiermes, Meike; Bakker, Theo C. M.; Mehlis, Marion; Rick, Ingolf P.

    2015-01-01

    Color signals, including ultraviolet (UV) signals, are widespread throughout the animal kingdom and color changes can be influenced by reproductive and motivational state. However, studies on dynamic changes of UV signals are scarce. Three spine sticklebacks (Gasterosteus aculeatus) that show intraspecific UV communication were used to study dynamic UV signaling in females. Reflectance measurements were taken from the distended abdomen, which serves as signal of female fecundity and readiness to spawn for courting males, and the melanized dorsal region. Scans were taken during egg maturation as well as before and after stimulation with a male to investigate context-dependent color changes. We used a physiological model of vision to determine how females might be perceived by conspecifics and quantified chromatic contrasts among both body regions and between body regions and the background for all stages. Females showed a significant increase in abdominal UV intensity during egg maturation and in response to a courting male. Measures of chromatic contrast among body regions (abdomen vs. dorsal region) and against the background (abdomen vs. background) were also increased during egg maturation and in response to the male stimulus (abdomen vs. background). Our results provide evidence for dynamic UV signaling in females in a reproductive context. PMID:26658986

  6. Neuromolecular responses to social challenge: common mechanisms across mouse, stickleback fish, and honey bee.

    PubMed

    Rittschof, Clare C; Bukhari, Syed Abbas; Sloofman, Laura G; Troy, Joseph M; Caetano-Anollés, Derek; Cash-Ahmed, Amy; Kent, Molly; Lu, Xiaochen; Sanogo, Yibayiri O; Weisner, Patricia A; Zhang, Huimin; Bell, Alison M; Ma, Jian; Sinha, Saurabh; Robinson, Gene E; Stubbs, Lisa

    2014-12-16

    Certain complex phenotypes appear repeatedly across diverse species due to processes of evolutionary conservation and convergence. In some contexts like developmental body patterning, there is increased appreciation that common molecular mechanisms underlie common phenotypes; these molecular mechanisms include highly conserved genes and networks that may be modified by lineage-specific mutations. However, the existence of deeply conserved mechanisms for social behaviors has not yet been demonstrated. We used a comparative genomics approach to determine whether shared neuromolecular mechanisms could underlie behavioral response to territory intrusion across species spanning a broad phylogenetic range: house mouse (Mus musculus), stickleback fish (Gasterosteus aculeatus), and honey bee (Apis mellifera). Territory intrusion modulated similar brain functional processes in each species, including those associated with hormone-mediated signal transduction and neurodevelopment. Changes in chromosome organization and energy metabolism appear to be core, conserved processes involved in the response to territory intrusion. We also found that several homologous transcription factors that are typically associated with neural development were modulated across all three species, suggesting that shared neuronal effects may involve transcriptional cascades of evolutionarily conserved genes. Furthermore, immunohistochemical analyses of a subset of these transcription factors in mouse again implicated modulation of energy metabolism in the behavioral response. These results provide support for conserved genetic "toolkits" that are used in independent evolutions of the response to social challenge in diverse taxa.

  7. Genome-wide linkage disequilibrium in nine-spined stickleback populations.

    PubMed

    Yang, Ji; Shikano, Takahito; Li, Meng-Hua; Merilä, Juha

    2014-08-12

    Variation in the extent and magnitude of genome-wide linkage disequilibrium (LD) among populations residing in different habitats has seldom been studied in wild vertebrates. We used a total of 109 microsatellite markers to quantify the level and patterns of genome-wide LD in 13 Fennoscandian nine-spined stickleback (Pungitius pungitius) populations from four (viz. marine, lake, pond, and river) different habitat types. In general, high magnitude (D' > 0.5) of LD was found both in freshwater and marine populations, and the magnitude of LD was significantly greater in inland freshwater than in marine populations. Interestingly, three coastal freshwater populations located in close geographic proximity to the marine populations exhibited similar LD patterns and genetic diversity as their marine neighbors. The greater levels of LD in inland freshwater compared with marine and costal freshwater populations can be explained in terms of their contrasting demographic histories: founder events, long-term isolation, small effective sizes, and population bottlenecks are factors likely to have contributed to the high levels of LD in the inland freshwater populations. In general, these findings shed new light on the patterns and extent of variation in genome-wide LD, as well as the ecological and evolutionary factors driving them.

  8. Population genetic structure and colonization history of short ninespine sticklebacks (Pungitius kaibarae)

    PubMed Central

    Bae, Han-Gyu; Suk, Ho Young

    2015-01-01

    The contemporary distribution and genetic structure of a freshwater fish provide insight into its historical geodispersal and geographical isolation following Quaternary climate changes. The short ninespine stickleback, Pungitius kaibarae, is a small gasterosteid fish occurring in freshwater systems on the Korean Peninsula and in southeast Russia. On the Korean Peninsula, P. kaibarae populations are distributed in three geographically separated regions: the NE (northeast coast), SE (southeast coast), and a limited area in the ND (Nakdong River). In this study, we used mitochondrial loci and microsatellites to investigate the evolutionary history of P. kaibarae populations by assessing their pattern of genetic structure. Our analyses revealed a marked level of divergence among three regional populations, suggesting a long history of isolation following colonization, although ND individuals showed relatively higher genetic affinity to populations from SE than those from NE. The populations from NE showed a great degree of interpopulation differentiation, whereas populations from SE exhibited only weak genetic structuring. Upon robust phylogenetic analysis, P. kaibarae formed a monophyletic group with Russian P. sinensis and P. tymensis with strong node confidence values, indicating that P. kaibarae populations on the Korean Peninsula originated from the southward migration of its ancestral lineage around the middle Pleistocene. PMID:26356579

  9. Characteristics of Nest Site of Ninespine Stickleback, Pungititus sp.2, in Preserved Pond

    NASA Astrophysics Data System (ADS)

    Takeshi, Takemura; Noriyuki, Koizumi; Hiroshi, Jinguji; Atsushi, Mori; Keiji, Watabe

    We set experimental circumstances controlled by aquatic plant mowing in the preserved pond, Komaba-Kita district. Aquatic plant mowing for a space of the pond had not been performed for over two years. For other space of the pond, eco-friendly type of aquatic plant mowing had been performed twice a year usually. There were many of small and medium scales of aquatic plant communities and only one large scale of aquatic plant community in the pond. Then we investigated characteristics of nest sites of the ninespine stickleback in the pond. We found total number of 20 nests. Almost all of those nests occurred at rim of these communities, whereas there were not any nests in central parts of medium and large scale of the communities. It was suggested that nest sites would concern deeply with aquatic plant mowing. To establish many of small and medium scales of aquatic plant communities owing to eco-friendly type of aquatic plant mowing appeared to increase a lot of rim of plant communities, indicating leading to increase in extent of rim areas of the suitable site for nesting.

  10. Applications of remote sensing data to the Alaskan environment

    NASA Technical Reports Server (NTRS)

    Belon, A. E.; Iller, J. M.

    1973-01-01

    The ERTS program provides a means to overcome the formidable logistic and economic costs of preparing environmental surveys of the vast and relatively unexplored regions of Alaska. There is an excellent potential in satellite remote sensing to benefit Federal, state, local, and private agencies, by providing a new synoptic data base which is necessary for the preparation of the needed surveys and the search for solutions to environmental management problems. One approach in coupling satellite data to Alaskan problems is a major program initiated by the University of Alaska and funded by NASA's Goddard Space Flight Center. This included 12 projects whose aims were to study the feasibility of applying ERTS data to the disciplines of ecology, agriculture, hydrology, wildlife management, oceanography, geology, glaciology, volcanology, and archaeology.

  11. Development of Alaskan gas hydrate resources. Final report

    SciTech Connect

    Kamath, V.A.; Sharma, G.D.; Patil, S.L.

    1991-06-01

    The research undertaken in this project pertains to study of various techniques for production of natural gas from Alaskan gas hydrates such as, depressurization, injection of hot water, steam, brine, methanol and ethylene glycol solutions through experimental investigation of decomposition characteristics of hydrate cores. An experimental study has been conducted to measure the effective gas permeability changes as hydrates form in the sandpack and the results have been used to determine the reduction in the effective gas permeability of the sandpack as a function of hydrate saturation. A user friendly, interactive, menu-driven, numerical difference simulator has been developed to model the dissociation of natural gas hydrates in porous media with variable thermal properties. A numerical, finite element simulator has been developed to model the dissociation of hydrates during hot water injection process.

  12. Biocorrosive Thermophilic Microbial Communities in Alaskan North Slope Oil Facilities

    SciTech Connect

    Duncan, Kathleen E.; Gieg, Lisa M.; Parisi, Victoria A.; Tanner, Ralph S.; Green Tringe, Susannah; Bristow, Jim; Suflita, Joseph M.

    2009-09-16

    Corrosion of metallic oilfield pipelines by microorganisms is a costly but poorly understood phenomenon, with standard treatment methods targeting mesophilic sulfatereducing bacteria. In assessing biocorrosion potential at an Alaskan North Slope oil field, we identified thermophilic hydrogen-using methanogens, syntrophic bacteria, peptideand amino acid-fermenting bacteria, iron reducers, sulfur/thiosulfate-reducing bacteria and sulfate-reducing archaea. These microbes can stimulate metal corrosion through production of organic acids, CO2, sulfur species, and via hydrogen oxidation and iron reduction, implicating many more types of organisms than are currently targeted. Micromolar quantities of putative anaerobic metabolites of C1-C4 n-alkanes in pipeline fluids were detected, implying that these low molecular weight hydrocarbons, routinely injected into reservoirs for oil recovery purposes, are biodegraded and provide biocorrosive microbial communities with an important source of nutrients.

  13. Air-cushion tankers for Alaskan North Slope oil

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.

    1973-01-01

    A concept is described for transporting oil from the Arctic to southern markets in 10,000-ton, chemically fueled air-cushion vehicles (ACV's) configured as tankers. Based on preliminary cost estimates the conceptual ACV tanker system as tailored to the transportation of Alaskan North Slope oil could deliver the oil for about the same price per barrel as the proposed trans-Alaska pipeline with only one-third of the capital investment. The report includes the description of the conceptual system and its operation; preliminary cost estimates; an appraisal of ACV tanker development; and a comparison of system costs, versatility, vulnerability, and ecological effect with those of the trans-Alaska pipeline.

  14. Aerobic Methane Oxidation in Alaskan Lakes Along a Latitudinal Transect

    NASA Astrophysics Data System (ADS)

    Martinez-Cruz, K. C.; Sepulveda-Jauregui, A.; Walter Anthony, K. M.; Anthony, P.; Thalasso, F.

    2013-12-01

    Karla Martinez-Cruz* **, Armando Sepulveda-Jauregui*, Katey M. Walter Anthony*, Peter Anthony*, and Frederic Thalasso**. * Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, Alaska. ** Biotechnology and Bioengineering Department, Cinvestav, Mexico city, D. F., Mexico. Methane (CH4) is the third most important greenhouse gas in the atmosphere, after carbon dioxide and water vapor. Boreal lakes play an important role in the current global warming by contributing as much as 6% of global atmospheric CH4 sources annually. On the other hand, aerobic methane oxidation (methanotrophy) in lake water is a fundamental process in global methane cycling that reduces the amount of CH4 emissions to the atmosphere. Several environmental factors affect aerobic methane oxidation in the water column both directly and indirectly, including concentration of CH4 and O2, temperature and carbon budgets of lakes. We analyzed the potential of aerobic methane oxidation (PMO) rates in incubations of water collected from 30 Alaskan lakes along a north-south transect during winter and summer 2011. Our findings showed an effect of CH4 and O2 concentrations, temperature and yedoma thawing permafrost on PMO activity in the lake water. The highest PMO rates were observed in summer by lakes situated on thawing yedoma permafrost, most of them located in the interior of Alaska. We also estimated that 60-80% of all CH4 produced in Alaskan lakes could be taken up by methanotrophs in the lake water column, showing the significant influence of aerobic methane oxidation of boreal lakes to the global CH4 budget.

  15. Linkage among Vegetation, Microbes and Methanogenic Pathways in Alaskan Peatlands

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Sidelinger, W.; Shu, H.; Varner, R. K.; Hines, M. E.

    2014-12-01

    Northern wetlands are thought to account for one third of the naturally emitted CH4. However, methane production pathways in northern peatlands are poorly understood, yet are predicted to change in response to vegetation shifts due to warming. Previous studies noted that acetate conversion to methane (acetoclastic methanogenesis, AM) in northern wetlands is largely impeded and acetate accumulates, however AM tends to increase with minerotrophy. To understand methanogenic pathways and to provide linkage among pathways, we studied Alaskan wetlands in 2013 and 2014. In 2013, laboratory incubations were conducted in three peatlands representing trophic gradients from bogs to fens. During 2014, 37 different sites in Fairbanks and Anchorage were studied that represented wetlands with pH values from 3.5 to 5.5 and vegetation from primarily Sphagnum to sedges. Measurements in 2014 included vegetation composition, gases (CH4, CO2, H2, and CO), 13CH4 and 13CO2, volatile fatty acids, DOC, other electron acceptors. Further incubation studies are being conducted to decipher controls on decomposition pathways. Gene sequencing was used to characterize microbial community composition, and metagenomic and transcriptomics were conducted to describe community activity. Results showed that methanogenesis was higher in fens than bogs, but hydrogenotrophic methanogenesis (HM) was dominant at all sites. End product ratios showed that AM was occurring in fens, albeit slowly. Fermentation was an important end-point in decomposition and microbial syntrophy was weak. These data, regardless of trophic status, differed greatly from data obtained from temperate wetlands in which terminal respiratory processes were strong and C flow through syntrophy was important. Trophic status influenced C flow in the Alaskan sites, but terminal processes were weak and end product formation tended to end at primary fermentation, which dominated as the terminal step in decomposition.

  16. A recurrent regulatory change underlying altered expression and Wnt response of the stickleback armor plates gene EDA

    PubMed Central

    O'Brown, Natasha M; Summers, Brian R; Jones, Felicity C; Brady, Shannon D; Kingsley, David M

    2015-01-01

    Armor plate changes in sticklebacks are a classic example of repeated adaptive evolution. Previous studies identified ectodysplasin (EDA) gene as the major locus controlling recurrent plate loss in freshwater fish, though the causative DNA alterations were not known. Here we show that freshwater EDA alleles have cis-acting regulatory changes that reduce expression in developing plates and spines. An identical T → G base pair change is found in EDA enhancers of divergent low-plated fish. Recreation of the T → G change in a marine enhancer strongly reduces expression in posterior armor plates. Bead implantation and cell culture experiments show that Wnt signaling strongly activates the marine EDA enhancer, and the freshwater T → G change reduces Wnt responsiveness. Thus parallel evolution of low-plated sticklebacks has occurred through a shared DNA regulatory change, which reduces the sensitivity of an EDA enhancer to Wnt signaling, and alters expression in developing armor plates while preserving expression in other tissues. DOI: http://dx.doi.org/10.7554/eLife.05290.001 PMID:25629660

  17. Hybrid male sterility between the fresh- and brackish-water types of ninespine stickleback Pungitius pungitius (Pisces, Gasterosteidae).

    PubMed

    Takahashi, Hiroshi; Nagai, Terumi; Goto, Akira

    2005-01-01

    Two ecologically distinct forms, fresh- and brackish-water types, of ninespine stickleback co-exist in several freshwater systems on the coast of eastern Hokkaido. Recent genetic analyses of 13 allozyme loci revealed genetic separation between the two types even though their spawning grounds were in close proximity. On the other hand, there is only a small difference in mitochondrial DNA (mtDNA) sequence between the two types suggesting that they diverged quite recently or that mtDNA introgression occurred between them. To test for postzygotic reproductive isolating mechanisms and hybrid mediated gene flow, we examined the viability and reproductive performance of reciprocal F1 hybrids. The hybrids grew to the adult size normally and both sexes expressed secondary sexual characters in the reciprocal crosses. The female hybrids were reciprocally fertile, while the male hybrids were reciprocally sterile. Histological and flow-cytometric analyses of the hybrid testis revealed that the sterility pattern was classified as 'gametic sterility,' with gonads of normal size but abnormal spermatogenesis. To our knowledge, the present finding is a novel example of one sex hybrid sterility in the stickleback family (Gasterosteidae).

  18. A 190 base pair, TGF-β responsive tooth and fin enhancer is required for stickleback Bmp6 expression

    PubMed Central

    Erickson, Priscilla A.; Cleves, Phillip A.; Ellis, Nicholas A.; Schwalbach, Kevin T.; Hart, James C.; Miller, Craig T.

    2015-01-01

    The ligands of the Bone Morphogenetic Protein (BMP) family of developmental signaling molecules are often under the control of complex cis-regulatory modules and play diverse roles in vertebrate development and evolution. Here, we investigated the cis-regulatory control of stickleback Bmp6. We identified a 190 bp enhancer ~2.5 kilobases 5’ of the Bmp6 gene that recapitulates expression in developing teeth and fins, with a core 72 bp sequence that is sufficient for both domains. By testing orthologous enhancers with varying degrees of sequence conservation from outgroup teleosts in transgenic reporter gene assays in sticklebacks and zebrafish, we found that the function of this regulatory element appears to have been conserved for over 250 million years of teleost evolution. We show that a predicted binding site for the TGFβ effector Smad3 in this enhancer is required for enhancer function and that pharmacological inhibition of TGFβ signaling abolishes enhancer activity and severely reduces endogenous Bmp6 expression. Finally, we used TALENs to disrupt the enhancer in vivo and find that Bmp6 expression is dramatically reduced in teeth and fins, suggesting this enhancer is necessary for expression of the Bmp6 locus. This work identifies a relatively short regulatory sequence that is required for expression in multiple tissues and, combined with previous work, suggests that shared regulatory networks control limb and tooth development. PMID:25732776

  19. Habitat-dependent and -independent plastic responses to social environment in the nine-spined stickleback (Pungitius pungitius) brain

    PubMed Central

    Gonda, Abigél; Herczeg, Gábor; Merilä, Juha

    2009-01-01

    The influence of environmental complexity on brain development has been demonstrated in a number of taxa, but the potential influence of social environment on neural architecture remains largely unexplored. We investigated experimentally the influence of social environment on the development of different brain parts in geographically and genetically isolated and ecologically divergent populations of nine-spined sticklebacks (Pungitius pungitius). Fish from two marine and two pond populations were reared in the laboratory from eggs to adulthood either individually or in groups. Group-reared pond fish developed relatively smaller brains than those reared individually, but no such difference was found in marine fish. Group-reared fish from both pond and marine populations developed larger tecta optica and smaller bulbi olfactorii than individually reared fish. The fact that the social environment effect on brain size differed between marine and pond origin fish is in agreement with the previous research, showing that pond fish pay a high developmental cost from grouping while marine fish do not. Our results demonstrate that social environment has strong effects on the development of the stickleback brain, and on the brain's sensory neural centres in particular. The potential adaptive significance of the observed brain-size plasticity is discussed. PMID:19324759

  20. Modelling guided waves in the Alaskan-Aleutian subduction zone

    NASA Astrophysics Data System (ADS)

    Coulson, Sophie; Garth, Thomas; Reitbrock, Andreas

    2016-04-01

    Subduction zone guided wave arrivals from intermediate depth earthquakes (70-300 km depth) have a huge potential to tell us about the velocity structure of the subducting oceanic crust as it dehydrates at these depths. We see guided waves as the oceanic crust has a slower seismic velocity than the surrounding material, and so high frequency energy is retained and delayed in the crustal material. Lower frequency energy is not retained in this crustal waveguide and so travels at faster velocities of the surrounding material. This gives a unique observation at the surface with low frequency energy arriving before the higher frequencies. We constrain this guided wave dispersion by comparing the waveforms recorded in real subduction zones with simulated waveforms, produced using finite difference full waveform modelling techniques. This method has been used to show that hydrated minerals in the oceanic crust persist to much greater depths than accepted thermal petrological subduction zone models would suggest in Northern Japan (Garth & Rietbrock, 2014a), and South America (Garth & Rietbrock, in prep). These observations also suggest that the subducting oceanic mantle may be highly hydrated at intermediate depth by dipping normal faults (Garth & Rietbrock 2014b). We use this guided wave analysis technique to constrain the velocity structure of the down going ~45 Ma Pacific plate beneath Alaska. Dispersion analysis is primarily carried out on guided wave arrivals recorded on the Alaskan regional seismic network. Earthquake locations from global earthquake catalogues (ISC and PDE) and regional earthquake locations from the AEIC (Alaskan Earthquake Information Centre) catalogue are used to constrain the slab geometry and to identify potentially dispersive events. Dispersed arrivals are seen at stations close to the trench, with high frequency (>2 Hz) arrivals delayed by 2 - 4 seconds. This dispersion is analysed to constrain the velocity and width of the proposed waveguide

  1. Rapid body size decline in Alaskan Pleistocene horses before extinction.

    PubMed

    Guthrie, R Dale

    2003-11-13

    About 70% of North American large mammal species were lost at the end of the Pleistocene epoch. The causes of this extinction--the role of humans versus that of climate--have been the focus of much controversy. Horses have figured centrally in that debate, because equid species dominated North American late Pleistocene faunas in terms of abundance, geographical distribution, and species variety, yet none survived into the Holocene epoch. The timing of these equid regional extinctions and accompanying evolutionary changes are poorly known. In an attempt to document better the decline and demise of two Alaskan Pleistocene equids, I selected a large number of fossils from the latest Pleistocene for radiocarbon dating. Here I show that horses underwent a rapid decline in body size before extinction, and I propose that the size decline and subsequent regional extinction at 12,500 radiocarbon years before present are best attributed to a coincident climatic/vegetational shift. The present data do not support human overkill and several other proposed extinction causes, and also show that large mammal species responded somewhat individualistically to climate changes at the end of the Pleistocene.

  2. Ice loss and sea level rise contribution from Alaskan glaciers

    NASA Astrophysics Data System (ADS)

    Berthier, E.; Schiefer, E.; Clarke, G. K.; Menounos, B.; Rémy, F.; Cazenave, A. A.

    2009-12-01

    Over the last 50 years, retreating glaciers and ice caps (GIC) contributed 0.5 mm/yr to SLR, and one third is believed to originate from ice masses bordering the Gulf of Alaska. However, these estimates of ice wastage in Alaska are based on methods that directly measure mass changes from a limited number of glaciers and extrapolate the results to estimate ice loss for the many thousands of others. Here, using a new glacier inventory with elevation changes derived from sequential digital elevation models (DEMs), we found that, between 1962 and 2006, Alaskan glaciers lost 41.9 ± 8.6 km**3/yr water equivalent (w.e.) and contributed 0.12 ± 0.02 mm/yr to SLR. Our ice loss is 34% lower than previous estimates. Reasons for our lower values include the higher spatial resolution of the glacier inventory used in our study and the complex pattern of ice elevation changes at the scale of individual glaciers and mountain ranges which was not resolved in earlier work. Our ice elevation changes reveal that glacier dynamics (surges, phase of the tidewater cycle, etc...) have a profound effect on the wastage of Alaska glaciers. 3D satellite view of Columbia glacier, Chugach Mountains, Alaska. (Copyright CNES 2007, Distribution Spot Image, processing E. Berthier CNRS)

  3. Quantifying seismic survey reverberation off the Alaskan North Slope.

    PubMed

    Guerra, Melania; Thode, Aaron M; Blackwell, Susanna B; Michael Macrander, A

    2011-11-01

    Shallow-water airgun survey activities off the North Slope of Alaska generate impulsive sounds that are the focus of much regulatory attention. Reverberation from repetitive airgun shots, however, can also increase background noise levels, which can decrease the detection range of nearby passive acoustic monitoring (PAM) systems. Typical acoustic metrics for impulsive signals provide no quantitative information about reverberation or its relative effect on the ambient acoustic environment. Here, two conservative metrics are defined for quantifying reverberation: a minimum level metric measures reverberation levels that exist between airgun pulse arrivals, while a reverberation metric estimates the relative magnitude of reverberation vs expected ambient levels in the hypothetical absence of airgun activity, using satellite-measured wind data. The metrics are applied to acoustic data measured by autonomous recorders in the Alaskan Beaufort Sea in 2008 and demonstrate how seismic surveys can increase the background noise over natural ambient levels by 30-45 dB within 1 km of the activity, by 10-25 dB within 15 km of the activity, and by a few dB at 128 km range. These results suggest that shallow-water reverberation would reduce the performance of nearby PAM systems when monitoring for marine mammals within a few kilometers of shallow-water seismic surveys.

  4. ERTS imagery applied to Alaskan coastal problems. [surface water circulation

    NASA Technical Reports Server (NTRS)

    Wright, F. F.; Sharma, G. D.; Burbank, D. C.; Burns, J. J.

    1974-01-01

    Along the Alaska coast, surface water circulation is relatively easy to study with ERTS imagery. Highly turbid river water, sea ice, and fluvial ice have proven to be excellent tracers of the surface waters. Sea truth studies in the Gulf of Alaska, Cook Inlet, Bristol Bay, and the Bering Strait area have established the reliability of these tracers. ERTS imagery in the MSS 4 and 5 bands is particularly useful for observing lower concentrations of suspended sediment, while MSS 6 data is best for the most concentrated plumes. Ice features are most clearly seen on MSS 7 imagery; fracture patterns and the movement of specific floes can be used to map circulation in the winter when runoff is restricted, if appropriate allowance is made for wind influence. Current patterns interpreted from satellite data are only two-dimensional, but since most biological activity and pollution are concentrated near the surface, the information developed can be of direct utility. Details of Alaska inshore circulation of importance to coastal engineering, navigation, pollution studies, and fisheries development have been clarified with satellite data. ERTS has made possible the analysis of circulation in many parts of the Alaskan coast.

  5. Soluble trace elements and total mercury in Arctic Alaskan snow

    USGS Publications Warehouse

    Snyder-Conn, E.; Garbarino, J.R.; Hoffman, G.L.; Oelkers, A.

    1997-01-01

    Ultraclean field and laboratory procedures were used to examine trace element concentrations in northern Alaskan snow. Sixteen soluble trace elements and total mercury were determined in snow core samples representing the annual snowfall deposited during the 1993-94 season at two sites in the Prudhoe Bay oil field and nine sites in the Arctic National Wildlife Refuge (Arctic NWR). Results indicate there were two distinct point sources for trace elements in the Prudhoe Bay oil field - a source associated with oil and gas production and a source associated with municipal solid-waste incineration. Soluble trace element concentrations measured in snow from the Arctic NWR resembled concentrations of trace elements measured elsewhere in the Arctic using clean sample-collection and processing techniques and were consistent with deposition resulting from widespread arctic atmospheric contamination. With the exception of elements associated with sea salts, there were no orographic or east-west trends observed in the Arctic NWR data, nor were there any detectable influences from the Prudhoe Bay oil field, probably because of the predominant easterly and northeasterly winds on the North Slope of Alaska. However, regression analysis on latitude suggested significant south-to-north increases in selected trace element concentrations, many of which appear unrelated to the sea salt contribution.

  6. Ecology of invasive Melilotus albus on Alaskan glacial river floodplains

    USGS Publications Warehouse

    Conn, Jeff S.; Werdin-Pfisterer, Nancy R.; Beattie, Katherine L.; Densmore, Roseann V.

    2011-01-01

    Melilotus albus (white sweetclover) has invaded Alaskan glacial river floodplains. We measured cover and density of plant species and environmental variables along transects perpendicular to the Nenana, Matanuska, and Stikine Rivers to study interactions between M. albus and other plant species and to characterize the environment where it establishes. Melilotus albus was a pioneer species on recently disturbed sites and did not persist into closed canopy forests. The relationships between M. albus cover and density and other species were site-specific.Melilotus albus was negatively correlated with native species Elaeagnus commutata at the Nenana River, but not at the Matanuska River. Melilotus albus was positively correlated with the exotic species Crepis tectorumand Taraxacum officinale at the Matanuska River and T. officinale on the upper Stikine River. However, the high density of M. albus at a lower Stikine River site was negatively correlated with T. officinale and several native species including Lathyrus japonicus var. maritimus and Salix alaxensis. Glacial river floodplains in Alaska are highly disturbed and are corridors for exotic plant species movement. Melilotus albus at moderate to low densities may facilitate establishment of exotic species, but at high densities can reduce the cover and density of both exotic and native species.

  7. Emissions of biogenic sulfur gases from Alaskan tundra

    NASA Technical Reports Server (NTRS)

    Hines, Mark E.; Morrison, Michael C.

    1992-01-01

    Results of sulfur emission measurements made in freshwater and marine wetlands in Alaskan tundra during the Arctic Boundary Layer Expedition 2A (ABLE 3A) in July 1988 are presented. The data indicate that this type of tundra emits very small amounts of gaseous sulfur and, when extrapolated globally, accounts for a very small percentage of the global flux of biogenic sulfur to the atmosphere. Sulfur emissions from marine sites are up to 20-fold greater than fluxes from freshwater habitats and are dominated by dimethyl sulfide (DMS). Highest emissions, with a mean of 6.0 nmol/sq m/h, occurred in water-saturated wet meadow areas. In drier upland tundra sites, highest fluxes occurred in areas inhabited by mixed vegetation and labrador tea at 3.0 nmol/sq m/h and lowest fluxes were from lichen-dominated areas at 0.9 nmol/sq m/h. DMS was the dominant gas emitted from all these sites. Emissions of DMS were highest from intertidal soils inhabited by Carex subspathacea.

  8. A Formal Messaging Notation for Alaskan Aviation Data

    NASA Technical Reports Server (NTRS)

    Rios, Joseph L.

    2015-01-01

    Data exchange is an increasingly important aspect of the National Airspace System. While many data communication channels have become more capable of sending and receiving data at higher throughput rates, there is still a need to use communication channels efficiently with limited throughput. The limitation can be based on technological issues, financial considerations, or both. This paper provides a complete description of several important aviation weather data in Abstract Syntax Notation format. By doing so, data providers can take advantage of Abstract Syntax Notation's ability to encode data in a highly compressed format. When data such as pilot weather reports, surface weather observations, and various weather predictions are compressed in such a manner, it allows for the efficient use of throughput-limited communication channels. This paper provides details on the Abstract Syntax Notation One (ASN.1) implementation for Alaskan aviation data, and demonstrates its use on real-world aviation weather data samples as Alaska has sparse terrestrial data infrastructure and data are often sent via relatively costly satellite channels.

  9. Quantifying seismic survey reverberation off the Alaskan North Slope.

    PubMed

    Guerra, Melania; Thode, Aaron M; Blackwell, Susanna B; Michael Macrander, A

    2011-11-01

    Shallow-water airgun survey activities off the North Slope of Alaska generate impulsive sounds that are the focus of much regulatory attention. Reverberation from repetitive airgun shots, however, can also increase background noise levels, which can decrease the detection range of nearby passive acoustic monitoring (PAM) systems. Typical acoustic metrics for impulsive signals provide no quantitative information about reverberation or its relative effect on the ambient acoustic environment. Here, two conservative metrics are defined for quantifying reverberation: a minimum level metric measures reverberation levels that exist between airgun pulse arrivals, while a reverberation metric estimates the relative magnitude of reverberation vs expected ambient levels in the hypothetical absence of airgun activity, using satellite-measured wind data. The metrics are applied to acoustic data measured by autonomous recorders in the Alaskan Beaufort Sea in 2008 and demonstrate how seismic surveys can increase the background noise over natural ambient levels by 30-45 dB within 1 km of the activity, by 10-25 dB within 15 km of the activity, and by a few dB at 128 km range. These results suggest that shallow-water reverberation would reduce the performance of nearby PAM systems when monitoring for marine mammals within a few kilometers of shallow-water seismic surveys. PMID:22087932

  10. 33 CFR 334.1290 - In Bering Sea, Shemya Island Area, Alaska; meteorological rocket launching facility, Alaskan Air...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., Alaska; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. 334.1290 Section...; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. (a) The danger zone. An arc of a...) Rockets will normally be launched one each day Monday through Friday between 9 a.m. and 3 p.m....

  11. 33 CFR 334.1290 - In Bering Sea, Shemya Island Area, Alaska; meteorological rocket launching facility, Alaskan Air...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., Alaska; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. 334.1290 Section...; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. (a) The danger zone. An arc of a...) Rockets will normally be launched one each day Monday through Friday between 9 a.m. and 3 p.m....

  12. 33 CFR 334.1290 - In Bering Sea, Shemya Island Area, Alaska; meteorological rocket launching facility, Alaskan Air...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., Alaska; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. 334.1290 Section...; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. (a) The danger zone. An arc of a...) Rockets will normally be launched one each day Monday through Friday between 9 a.m. and 3 p.m....

  13. 33 CFR 334.1290 - In Bering Sea, Shemya Island Area, Alaska; meteorological rocket launching facility, Alaskan Air...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., Alaska; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. 334.1290 Section...; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. (a) The danger zone. An arc of a...) Rockets will normally be launched one each day Monday through Friday between 9 a.m. and 3 p.m....

  14. 33 CFR 334.1290 - In Bering Sea, Shemya Island Area, Alaska; meteorological rocket launching facility, Alaskan Air...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., Alaska; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. 334.1290 Section...; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. (a) The danger zone. An arc of a...) Rockets will normally be launched one each day Monday through Friday between 9 a.m. and 3 p.m....

  15. 25 CFR 243.6 - Which sales or transfers of Alaskan reindeer do not require a permit?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Which sales or transfers of Alaskan reindeer do not... AND WILDLIFE REINDEER IN ALASKA § 243.6 Which sales or transfers of Alaskan reindeer do not require a... reindeer or reindeer products; and (b) Sale of transfer of live reindeer between Alaska Natives or...

  16. 25 CFR 243.6 - Which sales or transfers of Alaskan reindeer do not require a permit?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Which sales or transfers of Alaskan reindeer do not... AND WILDLIFE REINDEER IN ALASKA § 243.6 Which sales or transfers of Alaskan reindeer do not require a... reindeer or reindeer products; and (b) Sale of transfer of live reindeer between Alaska Natives or...

  17. 25 CFR 243.6 - Which sales or transfers of Alaskan reindeer do not require a permit?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Which sales or transfers of Alaskan reindeer do not... AND WILDLIFE REINDEER IN ALASKA § 243.6 Which sales or transfers of Alaskan reindeer do not require a... reindeer or reindeer products; and (b) Sale of transfer of live reindeer between Alaska Natives or...

  18. 25 CFR 243.6 - Which sales or transfers of Alaskan reindeer do not require a permit?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Which sales or transfers of Alaskan reindeer do not... AND WILDLIFE REINDEER IN ALASKA § 243.6 Which sales or transfers of Alaskan reindeer do not require a... reindeer or reindeer products; and (b) Sale of transfer of live reindeer between Alaska Natives or...

  19. 25 CFR 243.6 - Which sales or transfers of Alaskan reindeer do not require a permit?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Which sales or transfers of Alaskan reindeer do not... AND WILDLIFE REINDEER IN ALASKA § 243.6 Which sales or transfers of Alaskan reindeer do not require a... reindeer or reindeer products; and (b) Sale of transfer of live reindeer between Alaska Natives or...

  20. Bayesian analysis of size-dependent overwinter mortality from size-frequency distributions.

    PubMed

    Carlson, Stephanie M; Kottas, Athanasios; Mangel, Marc

    2010-04-01

    Understanding the relationship between body size and mortality is an important problem in ecology. We introduce a novel Bayesian method that can be used to quantify this relationship when the only data available are size-frequency distributions of unmarked individuals measured at two successive time periods. The inverse Gaussian distribution provides a parametric form for the statistical model development, and we use Markov chain Monte Carlo methods to evaluate posterior distributions. We illustrate the method using data on threespine stickleback (Gasterosteus aculeatus) collected before and after the winter season in an Alaskan lake. Our method allows us to compare the intensity of size-biased mortality in different years. We discuss generalizations that include more complicated relationships between size and survival as well as time-series modeling.

  1. Ventilation of North Pacific Intermediate Waters - The role of the Alaskan Gyre

    NASA Technical Reports Server (NTRS)

    Van Scoy, Kim A.; Olson, Donald B.; Fine, Rana A.

    1991-01-01

    Hydrographic data, tritium data, and potential vorticity calculations suggest that although North Pacific Intermediate Water is formed in the northwest, the Alaskan Gyre might be an additional ventilation site. The proposed ventilation is quantified by a vertical column tritium inventory, which indicates an excess of 0.08 kg of tritium in the Alaskan Gyre. An evaluation of the energy stored in the water column and of wind and buoyancy forcing shows that during winter conditions enough energy can be pumped into the system to force 26.80 sigma(theta) to outcrop in the Alaskan Gyre. Model results suggest that relatively limited outcrops in time and space (tens of days and several hundred kilometers in diameter) can account for the excess tritium.

  2. Histopathologic biomarkers in three spined sticklebacks, Gasterosteus aculeatus, from several rivers in Southern England that meet the freshwater fisheries directive.

    PubMed

    Handy, R D; Runnalls, T; Russell, P M

    2002-12-01

    This study demonstrates the utility and sensitivity of histopathologic biomarkers by recording lesions to the gill, liver and spleen in three spined sticklebacks (Gasterosteus aculeatus) from several rivers in Southern England which broadly comply with the water quality directives to protect fish health. The main study site was the Letcombe Brook system near Wantage, graded 1 (good) to 3 (fair) by the Environment Agency, using the River Ecosystem (RE) Class system. Sites with similar grades on the rivers Erme, Clyst, Exe and Plym were also selected in Devon. A normal condition factor (0.9 +/- 0.02, mean +/- S.E., n = 90), the presence of food in the stomach, and the whole body ionic composition (Na, K, Mg, Ca, Cu, Zn) suggested that fish were generally healthy. All fish showed some minor incidence of gill and liver lesions, even in the best (grade RE1) river water quality. Scoring the percentage of branchial secondary lamellae showing lesions did not reflect water quality because of biotic factors such as parasite load. However, fatness of secondary lamellae (length/width) increased in lower class rivers. Hepatic fatty change and focal necrosis was related to river quality grades with fatty change increasing from 0.8% to 12% of total liver area in grade RE1 and RE2 rivers, respectively. The gross anatomy of the spleen showed normal red and white pulp, and sinusoid space varied between 11% and 34% of the tissue area, but was not correlated with river grade. Overall, we conclude that histopathologic lesions are present in fish even when water quality meets the Freshwater Fisheries Directive. The Directive therefore only partly protects fish health. The incidence of fatty change in the liver, or fatness of secondary lamellae, in adult three spined sticklebacks are suggested as simple but sensitive histopathologic biomarkers which may be used to protect freshwater fishes as a novel alternative approach to water quality based Directives. We propose histopathologic

  3. Alaskan malamute chondrodysplasia IV. Concentrations of zinc, copper and iron in various tissues.

    PubMed

    Brown, R G; Hoag, G N; Smart, M E; Boechner, G; Subden, R E

    1977-09-01

    Trace mineral concentrations in various tissues of the chondrodysplastic (dwarf) Alaskan Malamute are remarkably different as compared to normal. The zinc level in heart tissue was depressed in dwarf animals (26 weeks). Copper concentration in the liver is elevated two to four fold in 26 week old dwarf animals and iron levels are significantly elevated in kidney, liver and pancreas of these animals. These observations suggest that the dwarf Alaskan Malamutes suffer from a genetic defect in trace mineral metabolism. If this is the case, then many of the skeletal lesions reported for these animals may be attributed to disorders in either zinc or copper metabolism.

  4. Contaminants in arctic snow collected over northwest Alaskan sea ice

    USGS Publications Warehouse

    Garbarino, J.R.; Snyder-Conn, E.; Leiker, T.J.; Hoffman, G.L.

    2002-01-01

    Snow cores were collected over sea ice from four northwest Alaskan Arctic estuaries that represented the annual snowfall from the 1995-1996 season. Dissolved trace metals, major cations and anions, total mercury, and organochlorine compounds were determined and compared to concentrations in previous arctic studies. Traces (<4 nanograms per liter, ng L-1) of cis- and trans-chlordane, dimethyl 2,3,5,6-tetrachloroterephthalate, dieldrin, endosulfan II, and PCBs were detected in some samples, with endosulfan I consistently present. High chlorpyrifos concentrations (70-80 ng L-1) also were estimated at three sites. The snow was highly enriched in sulfates (69- 394 mg L-1), with high proportions of nonsea salt sulfates at three of five sites (9 of 15 samples), thus indicating possible contamination through long-distance transport and deposition of sulfate-rich atmospheric aerosols. Mercury, cadmium, chromium, molybdenum, and uranium were typically higher in the marine snow (n = 15) in relation to snow from arctic terrestrial studies, whereas cations associated with terrigenous sources, such as aluminum, frequently were lower over the sea ice. One Kasegaluk Lagoon site (Chukchi Sea) had especially high concentrations of total mercury (mean = 214 ng L-1, standard deviation = 5 ng L-1), but no methyl mercury was detected above the method detection limit (0.036 ng L-1) at any of the sites. Elevated concentrations of sulfate, mercury, and certain heavy metals might indicate mechanisms of contaminant loss from the arctic atmosphere over marine water not previously reported over land areas. Scavenging by snow, fog, or riming processes and the high content of deposited halides might facilitate the loss of such contaminants from the atmosphere. Both the mercury and chlorpyrifos concentrations merit further investigation in view of their toxicity to aquatic organisms at low concentrations.

  5. Quantifying and comparing size selectivity among Alaskan sockeye salmon fisheries.

    PubMed

    Kendall, Neala W; Quinn, Thomas P

    2012-04-01

    Quantifying long-term size-selective harvest patterns is necessary for understanding the potential evolutionary effects on exploited species. The comparison of fishery selection patterns on the same species subject to different gear types, in different areas, and over multi-decadal periods can reveal the factors influencing selection. In this study we quantified and compared size-selective harvest by nine Alaskan sockeye salmon (Oncorhynchus nerka) fisheries to understand overall patterns. We calculated length-specific linear selection differentials (the difference in average length of fish before vs. after fishing), which are produced by different combinations of exploitation rates and length-selectivity values, and nonlinear standardized differentials, describing disruptive selection, across all years for each fishery. Selection differentials varied among years, but larger fish were caught in 73% of years for males and 84% of years for females, leaving smaller fish to spawn. Disruptive selection was observed on female and male fish in 84% and 92% of years, respectively. Linear selection was stronger on females than males in 77% of years examined, and disruptive selection was stronger on males in 71% of years. Selection pressure was influenced by a combination of factors under and beyond management control; analyses using mixed-effects models indicated that fisheries were less size selective in years when fish were larger than average and had lower exploitation rates. The observed harvest of larger than average sockeye salmon is consistent with the hypothesis that size-selective fishing contributes to decreasing age and length at maturation trends over time, but temporal variability in selection and strong disruptive selection suggests that the overall directional pressure is weaker than is often assumed in evolutionary models.

  6. Inorganic and organic contaminants in Alaskan shorebird eggs.

    PubMed

    Saalfeld, David T; Matz, Angela C; McCaffery, Brian J; Johnson, Oscar W; Bruner, Phil; Lanctot, Richard B

    2016-05-01

    Many shorebird populations throughout North America are thought to be declining, with potential causes attributed to habitat loss and fragmentation, reduced prey availability, increased predation, human disturbance, and increased exposure to environmental pollutants. Shorebirds may be particularly vulnerable to contaminant exposure throughout their life cycle, as they forage primarily on invertebrates in wetlands, where many contaminants accumulate disproportionately in the sediments. Therefore, it is important to document and monitor shorebird populations thought to be at risk and assess the role that environmental contaminants may have on population declines. To investigate potential threats and provide baseline data on shorebird contaminant levels in Alaskan shorebirds, contaminant concentrations were evaluated in shorebird eggs from 16 species residing in seven geographic distinct regions of Alaska. Similar to previous studies, low levels of most inorganic and organic contaminants were found, although concentrations of several inorganic and organic contaminants were higher than those of previous studies. For example, elevated strontium levels were observed in several species, especially black oystercatcher (Haematopus bachmani) sampled in Prince William Sound, Alaska. Additionally, contaminant concentrations varied among species, with significantly higher concentrations of inorganic contaminants found in eggs of pectoral sandpiper (Calidris melanotos), semipalmated sandpiper (Calidris pusilla), black oystercatcher, and bar-tailed godwit (Limosa lapponica). Similarly, significantly higher concentrations of some organic contaminants were found in the eggs of American golden plover (Pluvialis dominica), black-bellied plover (Pluvialis squatarola), pacific golden plover (Pluvialis fulva), bar-tailed godwit, and semipalmated sandpiper. Despite these elevated levels, current concentrations of contaminants in shorebird eggs suggest that breeding environments are

  7. Mechanisms influencing changes in lake area in Alaskan boreal forest

    USGS Publications Warehouse

    Roach, Jennifer K.; Griffith, Brad; Verbyla, David; Jones, Jeremy B.

    2011-01-01

    During the past ∼50 years, the number and area of lakes have declined in several regions in boreal forests. However, there has been substantial finer-scale heterogeneity; some lakes decreased in area, some showed no trend, and others increased. The objective of this study was to identify the primary mechanisms underlying heterogeneous trends in closed-basin lake area. Eight lake characteristics (δ18O, electrical conductivity, surface : volume index, bank slope, floating mat width, peat depth, thaw depth at shoreline, and thaw depth at the forest boundary) were compared for 15 lake pairs in Alaskan boreal forest where one lake had decreased in area since ∼1950, and the other had not. Mean differences in characteristics between paired lakes were used to identify the most likely of nine mechanistic scenarios that combined three potential mechanisms for decreasing lake area (talik drainage, surface water evaporation, and terrestrialization) with three potential mechanisms for nondecreasing lake area (subpermafrost groundwater recharge through an open talik, stable permafrost, and thermokarst). A priori expectations of the direction of mean differences between decreasing and nondecreasing paired lakes were generated for each scenario. Decreasing lakes had significantly greater electrical conductivity, greater surface : volume indices, shallower bank slopes, wider floating mats, greater peat depths, and shallower thaw depths at the forest boundary. These results indicated that the most likely scenario was terrestrialization as the mechanism for lake area reduction combined with thermokarst as the mechanism for nondecreasing lake area. Terrestrialization and thermokarst may have been enhanced by recent warming which has both accelerated permafrost thawing and lengthened the growing season, thereby increasing plant growth, floating mat encroachment, transpiration rates, and the accumulation of organic matter in lake basins. The transition to peatlands associated

  8. Inorganic and organic contaminants in Alaskan shorebird eggs.

    PubMed

    Saalfeld, David T; Matz, Angela C; McCaffery, Brian J; Johnson, Oscar W; Bruner, Phil; Lanctot, Richard B

    2016-05-01

    Many shorebird populations throughout North America are thought to be declining, with potential causes attributed to habitat loss and fragmentation, reduced prey availability, increased predation, human disturbance, and increased exposure to environmental pollutants. Shorebirds may be particularly vulnerable to contaminant exposure throughout their life cycle, as they forage primarily on invertebrates in wetlands, where many contaminants accumulate disproportionately in the sediments. Therefore, it is important to document and monitor shorebird populations thought to be at risk and assess the role that environmental contaminants may have on population declines. To investigate potential threats and provide baseline data on shorebird contaminant levels in Alaskan shorebirds, contaminant concentrations were evaluated in shorebird eggs from 16 species residing in seven geographic distinct regions of Alaska. Similar to previous studies, low levels of most inorganic and organic contaminants were found, although concentrations of several inorganic and organic contaminants were higher than those of previous studies. For example, elevated strontium levels were observed in several species, especially black oystercatcher (Haematopus bachmani) sampled in Prince William Sound, Alaska. Additionally, contaminant concentrations varied among species, with significantly higher concentrations of inorganic contaminants found in eggs of pectoral sandpiper (Calidris melanotos), semipalmated sandpiper (Calidris pusilla), black oystercatcher, and bar-tailed godwit (Limosa lapponica). Similarly, significantly higher concentrations of some organic contaminants were found in the eggs of American golden plover (Pluvialis dominica), black-bellied plover (Pluvialis squatarola), pacific golden plover (Pluvialis fulva), bar-tailed godwit, and semipalmated sandpiper. Despite these elevated levels, current concentrations of contaminants in shorebird eggs suggest that breeding environments are

  9. Exporting Alaskan North Slope crude oil: Benefits and costs

    SciTech Connect

    Not Available

    1994-06-01

    The Department of Energy study examines the effects of lifting the current prohibitions against the export of Alaskan North Slope (ANS) crude. The study concludes that permitting exports would benefit the US economy. First, lifting the ban would expand the markets in which ANS oil can be sold, thereby increasing its value. ANS oil producers, the States of California and Alaska, and some of their local governments all would benefit from increased revenues. Permitting exports also would generate new economic activity and employment in California and Alaska. The study concludes that these economic benefits would be achieved without increasing gasoline prices (either in California or in the nation as a whole). Lifting the export ban could have important implications for US maritime interests. The Merchant Marine Act of 1970 (known as the Jones Act) requires all inter-coastal shipments to be carried on vessels that are US-owned, US-crewed, and US-built. By limiting the shipment of ANS crude to US ports only, the export ban creates jobs for the seafarers and the builders of Jones Act vessels. Because the Jones Act does not apply to exports, however, lifting the ban without also changing US maritime law would jeopardize the jobs associated with the current fleet of Jones Act tankers. Therefore the report analyzes selected economic impacts of several maritime policy alternatives, including: Maintaining current law, which allows foreign tankers to carry oil where export is allowed; requiring exports of ANS crude to be carried on Jones Act vessels; and requiring exports of ANS crude to be carried on vessels that are US-owned and US-crewed, but not necessarily US-built. Under each of these options, lifting the export ban would generate economic benefits.

  10. Quantitative genetics of behavioural reaction norms: genetic correlations between personality and behavioural plasticity vary across stickleback populations.

    PubMed

    Dingemanse, N J; Barber, I; Wright, J; Brommer, J E

    2012-03-01

    Behavioural ecologists have proposed various evolutionary mechanisms as to why different personality types coexist. Our ability to understand the evolutionary trajectories of personality traits requires insights from the quantitative genetics of behavioural reaction norms. We assayed > 1000 pedigreed stickleback for initial exploration behaviour of a novel environment, and subsequent changes in exploration over a few hours, representing their capacity to adjust their behaviour to changes in perceived novelty and risk. We found heritable variation in both the average level of exploration and behavioural plasticity, and population differences in the sign of the genetic correlation between these two reaction norm components. The phenotypic correlation was not a good indicator of the genetic correlation, implying that quantitative genetics are necessary to appropriately evaluate evolutionary hypotheses in cases such as these. Our findings therefore have important implications for future studies concerning the evolution of personality and plasticity.

  11. Differences in the metabolic response to temperature acclimation in nine-spined stickleback (Pungitius pungitius) populations from contrasting thermal environments.

    PubMed

    Bruneaux, Matthieu; Nikinmaa, Mikko; Laine, Veronika N; Lindström, Kai; Primmer, Craig R; Vasemägi, Anti

    2014-12-01

    Metabolic responses to temperature changes are crucial for maintaining the energy balance of an individual under seasonal temperature fluctuations. To understand how such responses differ in recently isolated populations (<11,000 years), we studied four Baltic populations of the nine-spined stickleback (Pungitius pungitius L.) from coastal locations (seasonal temperature range, 0-29°C) and from colder, more thermally stable spring-fed ponds (1-19°C). Salinity and predation pressure also differed between these locations. We acclimatized wild-caught fish to 6, 11, and 19°C in common garden conditions for 4-6 months and determined their aerobic scope and hepatosomatic index (HSI). The freshwater fish from the colder (2-14°C), predator-free pond population exhibited complete temperature compensation for their aerobic scope, whereas the coastal populations underwent metabolic rate reduction during the cold treatment. Coastal populations had higher HSI than the colder pond population at all temperatures, with cold acclimation accentuating this effect. The metabolic rates and HSI for freshwater fish from the pond with higher predation pressure were more similar to those of the coastal ones. Our results suggest that ontogenic effects and/or genetic differentiation are responsible for differential energy storage and metabolic responses between these populations. This work demonstrates the metabolic versatility of the nine-spined stickleback and the pertinence of an energetic framework to better understand potential local adaptations. It also demonstrates that instead of using a single acclimation temperature thermal reaction norms should be compared when studying individuals originating from different thermal environments in a common garden setting.

  12. Differences in the metabolic response to temperature acclimation in nine-spined stickleback (Pungitius pungitius) populations from contrasting thermal environments.

    PubMed

    Bruneaux, Matthieu; Nikinmaa, Mikko; Laine, Veronika N; Lindström, Kai; Primmer, Craig R; Vasemägi, Anti

    2014-12-01

    Metabolic responses to temperature changes are crucial for maintaining the energy balance of an individual under seasonal temperature fluctuations. To understand how such responses differ in recently isolated populations (<11,000 years), we studied four Baltic populations of the nine-spined stickleback (Pungitius pungitius L.) from coastal locations (seasonal temperature range, 0-29°C) and from colder, more thermally stable spring-fed ponds (1-19°C). Salinity and predation pressure also differed between these locations. We acclimatized wild-caught fish to 6, 11, and 19°C in common garden conditions for 4-6 months and determined their aerobic scope and hepatosomatic index (HSI). The freshwater fish from the colder (2-14°C), predator-free pond population exhibited complete temperature compensation for their aerobic scope, whereas the coastal populations underwent metabolic rate reduction during the cold treatment. Coastal populations had higher HSI than the colder pond population at all temperatures, with cold acclimation accentuating this effect. The metabolic rates and HSI for freshwater fish from the pond with higher predation pressure were more similar to those of the coastal ones. Our results suggest that ontogenic effects and/or genetic differentiation are responsible for differential energy storage and metabolic responses between these populations. This work demonstrates the metabolic versatility of the nine-spined stickleback and the pertinence of an energetic framework to better understand potential local adaptations. It also demonstrates that instead of using a single acclimation temperature thermal reaction norms should be compared when studying individuals originating from different thermal environments in a common garden setting. PMID:25389079

  13. Projected future duration of the sea-ice-free season in the Alaskan Arctic

    NASA Astrophysics Data System (ADS)

    Wang, Muyin; Overland, James E.

    2015-08-01

    Global warming and continued reduction in sea ice cover will result in longer open water duration in the Arctic, which is important for the shipping industry, marine mammals, and other components of the regional ecosystem. In this study we assess the length of open water duration in the Alaskan Arctic over the next few decades using the set of latest coupled climate models (CMIP5). The Alaskan Arctic, including the Chukchi and the Beaufort Sea, has been a major region of summer sea ice retreat since 2007. Thirty five climate models from CMIP5 are evaluated and twelve are selected for composite projections based on their historical simulation performance. In the regions north of the Bering Strait (north of 70° N), future open-water duration shifts from a current 3-4 months to a projected near 5 months by 2040 based on the mean of the twelve selected climate models. There is considerable north-south gradient in projected durations. Open water duration is about 1 month shorter along the same latitudes in the Beaufort Sea compared with that in the Chukchi Sea. Uncertainty is generally ±1 month estimated from the range of model results. Open-water duration in the Alaskan Arctic expands quickly in these models over the next decades which will impact regional economic access and potentially alter ecosystems. Yet the northern Alaskan Arctic from January through May will remain sea ice covered into the second half of the century due to normal lack of sunlight.

  14. CYCLING OF DISSOLVED ELEMENTAL MERCURY IN ARCTIC ALASKAN LAKES. (R829796)

    EPA Science Inventory

    Aqueous production and water-air exchange of elemental mercury (Hg0) are important features of the environmental cycling of Hg. We investigated Hg0 cycling in ten Arctic Alaskan lakes that spanned a wide range in physicochemical characteristics. Dissolved...

  15. AlaskaAdvantage[R] Programs Annual Report to Alaskans, Year Ending June 30, 2007

    ERIC Educational Resources Information Center

    Alaska Commission on Postsecondary Education, 2007

    2007-01-01

    Through its AlaskAdvantage[R] Programs, the Alaska Commission on Postsecondary Education promotes, supports, and provides access to postsecondary education for Alaskans and in Alaska. This publication reports on another year of success for the state's higher education assistance agency. Among the accomplishments this year to make higher…

  16. Radiocarbon evidence of mid-Holocene mammoths stranded on an Alaskan Bering Sea island.

    PubMed

    Guthrie, R Dale

    2004-06-17

    Island colonization and subsequent dwarfing of Pleistocene proboscideans is one of the more dramatic evolutionary and ecological occurrences, especially in situations where island populations survived end-Pleistocene extinctions whereas those on the nearby mainland did not. For example, Holocene mammoths have been dated from Wrangel Island in northern Russia. In most of these cases, few details are available about the dynamics of how island colonization and extinction occurred. As part of a large radiocarbon dating project of Alaskan mammoth fossils, I addressed this question by including mammoth specimens from Bering Sea islands known to have formed during the end-Pleistocene sea transgression. One date of 7,908 +/- 100 yr bp (radiocarbon years before present) established the presence of Holocene mammoths on St Paul Island, a first Holocene island record for the Americas. Four lines of evidence--265 accelerator mass spectrometer (AMS) radiocarbon dates from Alaskan mainland mammoths, 13 new dates from Alaskan island mammoths, recent reconstructions of bathymetric plots and sea transgression rates from the Bering Sea--made it possible to reconstruct how mammoths became stranded in the Pribilofs and why this apparently did not happen on other Alaskan Bering Sea islands.

  17. American Indian/Alaskan Native Grandparents Raising Grandchildren: Findings from the Census 2000 Supplementary Survey

    ERIC Educational Resources Information Center

    Fuller-Thomson, Esme; Minkler, Meredith

    2005-01-01

    This article documents the prevalence and national profile of American Indian/Alaskan Native (AI/AN) grandparents who are raising their grandchildren, based on data from the American Community Survey/Census 2000 Supplementary Survey. In 2000 there were estimated to be nearly 53,000 AI/AN grandparent caregivers age 45 and older in the United…

  18. 36 CFR 223.10 - Free use to Alaskan settlers, miners, residents, and prospectors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... SERVICE, DEPARTMENT OF AGRICULTURE SALE AND DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER, SPECIAL FOREST... may take free of charge green or dried timber from the National Forests in Alaska for personal use but... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false Free use to Alaskan...

  19. 36 CFR 223.10 - Free use to Alaskan settlers, miners, residents, and prospectors.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... SERVICE, DEPARTMENT OF AGRICULTURE SALE AND DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER, SPECIAL FOREST... may take free of charge green or dried timber from the National Forests in Alaska for personal use but... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Free use to Alaskan...

  20. 36 CFR 223.10 - Free use to Alaskan settlers, miners, residents, and prospectors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... SERVICE, DEPARTMENT OF AGRICULTURE SALE AND DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER, SPECIAL FOREST... may take free of charge green or dried timber from the National Forests in Alaska for personal use but... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Free use to Alaskan...

  1. Alaskan Native Social Adjustment and the Role of Eskimo and Indian Music

    ERIC Educational Resources Information Center

    Johnston, Thomas F.

    1976-01-01

    Suggests that research into the social and psychological implications of Alaskan Eskimo and Indian musical behavior will continue to provide useful clues to solving current inter-cultural and intra-cultural problems in changing Alaska, particularly within the real of Eskimo and Indian preschool and primary education. (Author/AM)

  2. College Orientation Program for Alaskan Natives (COPAN Program - Education for Survival). Final Report.

    ERIC Educational Resources Information Center

    Salisbury, Lee H.

    Of the original number of Alaskan natives entering the University of Alaska from rural and urban areas, 50% drop out at the end of their freshman year, and less than 2% are likely to receive a degree at the end of 4 years. This high attrition rate is caused by poor elementary and secondary school preparation, and strong personal feelings of…

  3. Poly(hydroxyalkanoate) Biosynthesis from Crude Alaskan Pollock (Theragra chalcogramma) Oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Six strains of Pseudomonas were tested for their abilities to synthesize poly(hydroxyalkanoate) (PHA) polymers from crude Pollock oil, a large volume byproduct of the Alaskan fishing industry. All six strains were found to produce PHA polymers from hydrolyzed Pollock oil with productivities (P; the...

  4. Alaskan Fish Gelatin Films: Thermal, Tensile, and Barrier Properties and Effects of Cross-linking

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gelatin was extracted from the skins of Alaska pollock (Theragra chalcogramma) and Alaska pink salmon (Oncorhynchus gorbuscha). These skins were by-products generated from the Alaskan fishing industry. Films were then cast from the fish gelatin and their thermal, tensile, water vapor permeability, o...

  5. Understanding the Complex Dimensions of the Digital Divide: Lessons Learned in the Alaskan Arctic

    ERIC Educational Resources Information Center

    Subramony, Deepak Prem

    2007-01-01

    An ethnographic case study of Inupiat Eskimo in the Alaskan Arctic has provided insights into the complex nature of the sociological issues surrounding equitable access to technology tools and skills, which are referred to as the digital divide. These people can overcome the digital divide if they get the basic ready access to hardware and…

  6. Alaska Is Our Home--Book 2: A Natural Science Handbook for Alaskan Students.

    ERIC Educational Resources Information Center

    Bury, John; Bury, Susan

    A natural science resource booklet for teachers and students contains detailed materials for teaching and learning about Alaskan wildlife. Each of nine chapters provides background subject information, suggested learning activities, tear-out pages of review questions for students to answer, and supplementary notes for teachers which include…

  7. Intensive Evaluation of Satellite TV Impact on Four Alaskan Villages. Supplement to Basic ESCD Evaluation Design.

    ERIC Educational Resources Information Center

    Practical Concepts, Inc., Washington, DC.

    A supplement to the final report, "Design for an Analysis and Assessment of the Education Satellite Communications Demonstration (ESCD)," this document is both: (1) a separable, sociologically oriented evaluation of the ESCD impact on Alaskan native villages; and (2) a direct extension of the work described in sections 4 and 5 in the Practical…

  8. It Happens When We Get There. Conversations With Teachers in Alaskan Villages.

    ERIC Educational Resources Information Center

    Beers, C. David

    Developed through in-depth interviews with experienced "bush" teachers from interior Alaska, this booklet is the product of a five-day workshop in the design of vocational education curriculum materials for rural Alaskan secondary schools. The statements in this booklet represent the edited responses of experienced teachers to the following…

  9. Studies of the Northern Alaskan Coastal System: Ongoing project work and synthesis activities

    NASA Astrophysics Data System (ADS)

    Douglas, T. A.; Sturm, M.; Ashjian, C. J.; Jorgensen, T.; Oechel, W. C.; Ping, C.; Rhew, R. C.; Stieglitz, M.

    2006-12-01

    Six ongoing projects focus on a better understanding of processes occurring along the Arctic Alaskan Coast. These projects, grouped as "Studies of the Northern Alaskan Coastal System", or SNACS, combine field, laboratory, modeling and human dimensions research. They include: 1) an investigation of climate variability, ocean processes, sea ice, bowhead whales, and Inupiat subsistence whaling, 2) research on the impact of variability within the ocean and atmosphere on terrestrial fluxes of carbon dioxide, dissolved organic matter and energy, 3) an inventory and description of soil organic carbon fluxes and ground ice in the coastal environment, 4) a determination of whether arctic coastal terrestrial ecosystems are significant sources or sinks of atmospheric methyl halides, chloroform and methane, 5) development of generalized discharge- constituent relationships for arctic basins, and 6) an investigation of the processes controlling mercury deposition to the coastal system. Three broad themes unite the projects: 1) nutrient fluxes from rivers and shoreline erosion in the Arctic coastal zone, 2) impacts of cryospheric changes on the Alaskan Arctic Coast, and 3) potential rapid regime shifts controlled by atmospheric and meteorological processes that could affect the Alaskan Arctic Coast. Warming of the Arctic, particularly its impact on sea ice and nutrient transport in arctic rivers is already affecting fundamental coastal system processes. The six SNACS projects are helping to understand how these impacts will evolve and what their ramifications will be both within and outside of the Arctic.

  10. EXAMINATION OF THE FEASIBILITY FOR DEMONSTRATION AND USE OF RADIOLUMINESCENT LIGHTS FOR ALASKAN REMOTE RUNWAY LIGHTING

    SciTech Connect

    Jensen, G.; Perrigo, L.; Leonard, L.; Hegdal, L

    1984-01-01

    This report examines the feasibility of radioluminescent light applications for rural Alaskan airports. The work presented in this report covers four tasks: State of the Art Evaluation of Radioluminescent Lights, Environmental, Radiological, and Regulatory Evaluations, Engineering Evaluations, and Demonstration Plan Development.

  11. Petroleum systems of the Alaskan North Slope: a numerical journey from source to trap

    USGS Publications Warehouse

    Lampe, C.; Peters, K.E.; Magoon, L.B.; Bird, K.J.; Lillis, P.G.

    2003-01-01

    The complex petroleum province of the Alaskan North Slope contains six petroleum systems (Magoon and others, this session). Source rocks for four of these systems include the Hue-gamma ray zone (Hue-GRZ), pebble shale unit, Kingak Shale, and Shublik Formation. Geochemical data for these source rocks are investigated in greater detail and provide the basis for numerical petroleum migration models.

  12. Alaskan glaciers: Recent observations in respect to the earthquake-advance theory

    USGS Publications Warehouse

    Post, A.S.

    1965-01-01

    Preliminary aerial photographic studies indicate that the Alaskan earthquake produced some rockfalls but no significant snow and ice avalanches on glaciers. No rapid, short-lived glacier advances (surges) are conclusively associated with this earthquake. Recent evidence fails to support the earthquake-advance theory of Tarr and Martin.

  13. Shaping the Landscape: A Journal of Writing by Alaskan Teachers 1992.

    ERIC Educational Resources Information Center

    Longenbaugh, Betsy, Ed.

    Intended to encourage Alaska teachers to write, to provide an honest sounding board for those submitting work, and to be a pleasure to read, this booklet presents a collection of 20 pieces of writing (short stories, poems, and life experiences) by Alaskan teachers. The pieces and their authors are as follows: "The First Haiku" (Dan Walker);…

  14. Implications of lifting the ban on the export of Alaskan crude oil

    SciTech Connect

    Not Available

    1990-03-26

    Present legislation effectively bans the export of crude oil produced in the United States. The ban has been in effect for years and is particularly stringent with respect to crude oil produced in Alaska, particularly on the North Slope. The Alaska crude export ban is specifically provided for in the Trans-Alaska Pipeline Authorization Act of 1973 and in other legislation. It was imposed for two reasons. The first was to reduce US dependence on imported crude oil. The Arab oil embargo had been imposed shortly before the Act was passed and a greater measure of energy independence was considered imperative at that time. The second reason was to assure that funds expended in building an Alaskan pipeline would benefit domestic users rather than simply employed to facilitate shipments to other countries. The main objective of this report is to estimate the potential impacts on crude oil prices that would result from lifting the export ban Alaskan crude oil. The report focuses on the Japanese market and the US West Coast market. Japan is the principal potential export market for Alaskan crude oil. Exports to that market would also affect the price of Alaskan crude oil as well as crude oil and product prices on the West Coast and the volume of petroleum imported in that area. 3 figs., 8 tabs.

  15. 77 FR 45921 - Alaskan Fuel Hauling as a Restricted Category Special Purpose Flight Operation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-02

    ... the Federal Register (74 FR 39242) in which the FAA proposed to specify Alaskan fuel hauling as a... Purpose Flight Operation AGENCY: Federal Aviation Administration (FAA), (DOT). ACTION: Notice of policy... submitted was, ``The transport of the fuel could be made safer by limiting the payload on each flight to...

  16. Alaskan Native Games--A Cross-Cultural Addition to the Physical Education Curriculum.

    ERIC Educational Resources Information Center

    Frey, Richard D.; Allen, Mike

    1989-01-01

    Importing traditional, yet unknown, physical activities from different cultures is an exciting way to add creativity and imagination to the physical education curriculum. Explanations, accompanied by teaching hints, are given of several traditional Alaskan native games which have been successfully used with K-Six students in the Anchorage School…

  17. Controls on Ecosystem and Root Respiration in an Alaskan Peatland

    NASA Astrophysics Data System (ADS)

    McConnell, N. A.; McGuire, A. D.; Harden, J. W.; Kane, E. S.; Turetsky, M. R.

    2010-12-01

    Boreal ecosystems cover 14% of the vegetated surface on earth and account for 25-30% of the world’s soil carbon (C), mainly due to large carbon stocks in deep peat and frozen soil layers. While peatlands have served as historical sinks of carbon, global climate change may trigger re-release of C to the atmosphere and may turn these ecosystems into net C sources. Rates of C release from a peatland are determined by regional climate and local biotic and abiotic factors such as vegetation cover, thaw depth, and peat thickness. Soil CO2 fluxes are driven by both autotrophic (plant) respiration and heterotrophic (microbial) respiration. Thus, changes in plant and microbial activity in the soil will impact CO2 emissions from peatlands. In this study, we explored environmental and vegetation controls on ecosystem respiration and root respiration in a variety of wetland sites. The study was conducted at the Alaskan Peatland Experiment (APEX; www.uoguelph.ca/APEX) sites in the Bonanza Creek Experimental Forest located 35 km southwest of Fairbanks Alaska. We measured ecosystem respiration, root respiration, and monitored a suite of environmental variables along a vegetation and soil moisture gradient including a black spruce stand with permafrost, a shrubby site with permafrost, a tussock grass site, and a herbaceous open rich fen. Within the rich fen, we have been conducting water table manipulations including a control, lowered, and raised water table treatment. In each of our sites, we measured total ecosystem respiration using static chambers and root respiration by harvesting roots from the uppermost 20 cm and placing them in a root cuvette to obtain a root flux. Ecosystem respiration (ER) on a μmol/m2/sec basis varied across sites. Water table was a significant predictor of ER at the lowered manipulation site and temperature was a strong predictor at the control site in the rich fen. Water table and temperature were both significant predictors of ER at the raised

  18. Seasonal Variations of Biomass Burning Tracers in Alaskan Aerosols

    NASA Astrophysics Data System (ADS)

    Haque, M. M.; Kawamura, K.; Kim, Y.

    2015-12-01

    Biomass burning (BB) is a large source of atmospheric trace gases and aerosols. During the burning, several organic and inorganic gases and particles are emitted into the atmosphere. Here, we present seasonal variations of specific BB tracers such as levoglucosan, mannosan and galactosan, which are produced by pyrolysis of cellulose and hemicelluloses. We collected TSP aerosol samples (n= 32) from Fairbanks, Alaska in June 2008 to June 2009. Levoglucosan was detected as the dominant anhydrosugar followed by its isomers, mannosan and galactosan. The result of levoglucosan showed clear seasonal trends with winter maximum (ave.145 ng m-3) and spring minimum (12.3 ng m-3). The analyses of air mass back trajectories and fire spots demonstrated that anhydrosugars may be associated from residential heating and cooking in local region and Siberia in winter time. Levoglucosan showed significant positive correlation with EC (r= 0.67, p= 0.001) and OC (r= 0.51, p= 0.002) but there was no correlation with nss-K+ (r= -0.16, p= 0.37). The emission of K+ from biomass burning depends on burning condition and types of material burned. There are two possible reasons, which can be explained for the lack of correlation between levoglucosan and K+. First, specific burning materials may be used for residential heating, which can't produce K+. Secondly, K+ could be deposit on the surface of chimney breast and it can't emit into the atmosphere. Anhydrosugars contributed 4.4% to water-soluble organic carbon (WSOC) and 2.4% to organic carbon (OC). Their highest values of WSOC (8.1%) and OC (4.9%) in wintertime indicate that contribution of BB to Alaskan aerosols is important in winter period. The current study presents for the first time one-year observation on BB tracers in the subarctic region, which provide useful information to better understand the effect of biomass burning on subarctic atmosphere. It will also be helpful for further long-term climate studies in this region.

  19. Rheological conditions for emplacement of Ural-Alaskan-type ultramafic complexes

    NASA Astrophysics Data System (ADS)

    Guillou-Frottier, Laurent; Burov, Evgueni; Augé, Thierry; Gloaguen, Eric

    2014-09-01

    Ural-Alaskan- (or Alaskan-) type complexes correspond to a particular class of ultramafic intrusions that attract particular attention due to their deep mantle origin and their platinum-group element (PGE) mineralization. When defined as massifs of dunite-clinopyroxenite, only forty-six complexes are reported in the literature. These large-scale dunite pipe-like structures are rarely isolated and they even can appear in clusters. To better understand genesis of these relatively young (< 460 Ma) complexes, a worldwide compilation has been built, and three categories have been defined: single circular or elliptical bodies, twin bodies with similar shapes, and dismembered dunite bodies. PGE enrichment in Alaskan-type complexes is highest for the second category, where twin bodies are interpreted as horizontal sections of Y-shaped dunite pipes. To constrain mechanical properties of the lithosphere allowing emplacement of the Alaskan-type complexes, the forceful diapiric ascent hypothesis is investigated through numerical thermo-mechanical models. One hundred high resolution experiments accounting for realistic phase changes and softening mechanisms have been performed. The experiments show that with no rheological softening of the host rock and in case of a relatively weak ductile lower crust, the uprising magma tends to spread laterally without reaching the surface. To account for the forceful ascent of deep magmas, it is hence necessary to assume a strong lower crust rheology and strong local softening mechanisms. Besides reproducing the clustered distribution of the weakness zones representing magma pathways, these latter experiments reproduce large-scale pipe-like (cylindrical) structures, Y-shaped and funnel-shaped bodies, and laterally-shifted structures. Interestingly, zones of highest strain rates are located at the bottom parts of the inclined edges of Y-shaped and funnel-shaped bodies. The restricted age range of Alaskan-type complexes (< 460 Ma) would mean

  20. Bet hedging in a warming ocean: predictability of maternal environment shapes offspring size variation in marine sticklebacks.

    PubMed

    Shama, Lisa N S

    2015-12-01

    Bet hedging at reproduction is expected to evolve when mothers are exposed to unpredictable cues for future environmental conditions, whereas transgenerational plasticity (TGP) should be favoured when cues reliably predict the environment offspring will experience. Since climate predictions forecast an increase in both temperature and climate variability, both TGP and bet hedging are likely to become important strategies to mediate climate change effects. Here, the potential to produce variably sized offspring in both warming and unpredictable environments was tested by investigating whether stickleback (Gasterosteus aculeatus) mothers adjusted mean offspring size and within-clutch variation in offspring size in response to experimental manipulation of maternal thermal environment and predictability (alternating between ambient and elevated water temperatures). Reproductive output traits of F1 females were influenced by both temperature and environmental predictability. Mothers that developed at ambient temperature (17 °C) produced larger, but fewer eggs than mothers that developed at elevated temperature (21 °C), implying selection for different-sized offspring in different environments. Mothers in unpredictable environments had smaller mean egg sizes and tended to have greater within-female egg size variability, especially at 21 °C, suggesting that mothers may have dynamically modified the variance in offspring size to spread the risk of incorrectly predicting future environmental conditions. Both TGP and diversification influenced F2 offspring body size. F2 offspring reared at 21 °C had larger mean body sizes if their mother developed at 21 °C, but this TGP benefit was not present for offspring of 17 °C mothers reared at 17 °C, indicating that maternal TGP will be highly relevant for ocean warming scenarios in this system. Offspring of variable environment mothers were smaller but more variable in size than offspring from constant environment

  1. Population variation in brain size of nine-spined sticklebacks (Pungitius pungitius) - local adaptation or environmentally induced variation?

    PubMed Central

    2011-01-01

    Background Most evolutionary studies on the size of brains and different parts of the brain have relied on interspecific comparisons, and have uncovered correlations between brain architecture and various ecological, behavioural and life-history traits. Yet, similar intraspecific studies are rare, despite the fact that they could better determine how selection and phenotypic plasticity influence brain architecture. We investigated the variation in brain size and structure in wild-caught nine-spined sticklebacks (Pungitius pungitius) from eight populations, representing marine, lake, and pond habitats, and compared them to data from a previous common garden study from a smaller number of populations. Results Brain size scaled hypo-allometrically with body size, irrespective of population origin, with a common slope of 0.5. Both absolute and relative brain size, as well as relative telencephalon, optic tectum and cerebellum size, differed significantly among the populations. Further, absolute and relative brain sizes were larger in pond than in marine populations, while the telencephalon tended to be larger in marine than in pond populations. These findings are partly incongruent with previous common garden results. A direct comparison between wild and common garden fish from the same populations revealed a habitat-specific effect: pond fish had relatively smaller brains in a controlled environment than in the wild, while marine fish were similar. All brain parts were smaller in the laboratory than in the wild, irrespective of population origin. Conclusion Our results indicate that variation among populations is large, both in terms of brain size and in the size of separate brain parts in wild nine-spined sticklebacks. However, the incongruence between the wild and common garden patterns suggests that much of the population variation found in the wild may be attributable to environmentally induced phenotypic plasticity. Given that the brain is among the most plastic

  2. Bet hedging in a warming ocean: predictability of maternal environment shapes offspring size variation in marine sticklebacks.

    PubMed

    Shama, Lisa N S

    2015-12-01

    Bet hedging at reproduction is expected to evolve when mothers are exposed to unpredictable cues for future environmental conditions, whereas transgenerational plasticity (TGP) should be favoured when cues reliably predict the environment offspring will experience. Since climate predictions forecast an increase in both temperature and climate variability, both TGP and bet hedging are likely to become important strategies to mediate climate change effects. Here, the potential to produce variably sized offspring in both warming and unpredictable environments was tested by investigating whether stickleback (Gasterosteus aculeatus) mothers adjusted mean offspring size and within-clutch variation in offspring size in response to experimental manipulation of maternal thermal environment and predictability (alternating between ambient and elevated water temperatures). Reproductive output traits of F1 females were influenced by both temperature and environmental predictability. Mothers that developed at ambient temperature (17 °C) produced larger, but fewer eggs than mothers that developed at elevated temperature (21 °C), implying selection for different-sized offspring in different environments. Mothers in unpredictable environments had smaller mean egg sizes and tended to have greater within-female egg size variability, especially at 21 °C, suggesting that mothers may have dynamically modified the variance in offspring size to spread the risk of incorrectly predicting future environmental conditions. Both TGP and diversification influenced F2 offspring body size. F2 offspring reared at 21 °C had larger mean body sizes if their mother developed at 21 °C, but this TGP benefit was not present for offspring of 17 °C mothers reared at 17 °C, indicating that maternal TGP will be highly relevant for ocean warming scenarios in this system. Offspring of variable environment mothers were smaller but more variable in size than offspring from constant environment

  3. Impact of disability and other physical health issues on academic outcomes among American Indian and Alaskan Native college students: an exploratory analysis.

    PubMed

    Patterson Silver Wolf Adelv Unegv Waya, David A; Vanzile-Tamsen, Carol; Black, Jessica; Billiot, Shanondora M; Tovar, Molly

    2015-01-01

    This study investigated whether self-identified disabilities among American Indian and Alaskan Native college students impact academic performance and persistence to graduation and explored the differences in health and academic grades between American Indian and Alaskan Native students and students of other racial and ethnic identities using the National College Health Assessment. Findings indicate that American Indian or Alaskan Native students have significantly lower grades than White and Asian students, and American Indian and Alaskan Native women report the highest incidence of health problems of any demographic group. Exploratory results point to future research to determine the full impact of disabilities and poor health on academic success.

  4. REPETITIVE DIGITAL NOAA-AVHRR DATA FOR ALASKAN ENGINEERING AND SCIENTIFIC APPLICATIONS.

    USGS Publications Warehouse

    Christie, William M.; Pawlowski, Robert J.; Fleming, Michael D.

    1986-01-01

    Selected digitally enhanced NOAA - Advanced Very High Resolution Radiometer (AVHRR) images taken by the NOAA 6, 7, 8 and 9 Polar Orbiting Satellites demonstrate the capability and application of repetitive low-resolution satellite data to Alaska's engineering and science community. Selected cloud-free visible and thermal infrared images are enhanced to depict distinct oceanographic and geologic processes along Alaska's west coast and adjacent seas. Included are the advance of the Bering Sea ice field, transport of Yukon River sediment into Norton Sound, and monitoring of plume trajectories from the Mount Augustine volcanic eruptions. Presented illustrations are representative of the 94 scenes in a cooperative USGS EROS/NOAA Alaskan AVHRR Digital Archive. This paper will discuss the cooperative efforts in establishing the first year data set and identifying Alaskan applications.

  5. Preliminary evidence for the involvement of budding bacteria in the origin of Alaskan placer gold

    USGS Publications Warehouse

    Watterson, J.R.

    1992-01-01

    Lacelike networks of micrometre-size filiform gold associated wtih Alaskan placer gold particles are interpreted as low-temperature pseudomorphs of a Pedomicrobium-like budding bacterium. Submicron reproductive structures (hyphae) and other morphological features similar to those of Pedomicrobium manganicum occur as detailed three-dimensional facsimiles in high purity gold in and on placer gold particles from Lillian Creek, Alaska. In a scanning electron microscope survey, the majority of gold particles at nine Alaskan placer deposits appear to include gold that has accumulated chemically at low temperatures in and on the cells of P. manganicum. Similar bacterioform gold from a Paleozoic deposit in China and from the Precambrian Witwatersrand deposit in South Africa may indicate that bacterioform gold is widespread. -Author

  6. Clinical pathology and assessment of pathogen exposure in southern and Alaskan sea otters.

    PubMed

    Hanni, Krista D; Mazet, Jonna A K; Gulland, Frances M D; Estes, James; Staedler, Michelle; Murray, Michael J; Miller, Melissa; Jessup, David A

    2003-10-01

    The southern sea otter (Enhydra lutris nereis) population in California (USA) and the Alaskan sea otter (E. lutris kenyoni) population in the Aleutian Islands (USA) chain have recently declined. In order to evaluate disease as a contributing factor to the declines, health assessments of these two sea otter populations were conducted by evaluating hematologic and/or serum biochemical values and exposure to six marine and terrestrial pathogens using blood collected during ongoing studies from 1995 through 2000. Samples from 72 free-ranging Alaskan, 78 free-ranging southern, and (for pathogen exposure only) 41 debilitated southern sea otters in rehabilitation facilities were evaluated and compared to investigate regional differences. Serum chemistry and hematology values did not indicate a specific disease process as a cause for the declines. Statistically significant differences were found between free-ranging adult southern and Alaskan population mean serum levels of creatinine kinase, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, calcium, cholesterol, creatinine, glucose, phosphorous, total bilirubin, blood urea nitrogen, and sodium. These were likely due to varying parasite loads, contaminant exposures, and physiologic or nutrition statuses. No free-ranging sea otters had signs of disease at capture, and prevalences of exposure to calicivirus, Brucella spp., and Leptospira spp. were low. The high prevalence (35%) of antibodies to Toxoplasma gondii in free-ranging southern sea otters, lack of antibodies to this parasite in Alaskan sea otters, and the pathogen's propensity to cause mortality in southern sea otters suggests that this parasite may be important to sea otter population dynamics in California but not in Alaska. The evidence for exposure to pathogens of public health importance (e.g., Leptospira spp., T. gondii) in the southern sea otter population, and the naïveté of both populations to other pathogens (e.g., morbillivirus

  7. Clinical pathology and assessment of pathogen exposure in southern and Alaskan sea otters

    USGS Publications Warehouse

    Hanni, K.D.; Mazet, J.A.K.; Gulland, F.M.D.; Estes, James; Staedler, M.; Murray, M.J.; Miller, M.; Jessup, David A.

    2003-01-01

    The southern sea otter (Enhydra lutris nereis) population in California (USA) and the Alaskan sea otter (E. lutris kenyoni) population in the Aleutian Islands (USA) chain have recently declined. In order to evaluate disease as a contributing factor to the declines, health assessments of these two sea otter populations were conducted by evaluating hematologic and/or serum biochemical values and exposure to six marine and terrestrial pathogens using blood collected during ongoing studies from 1995 through 2000. Samples from 72 free-ranging Alaskan, 78 free-ranging southern, and (for pathogen exposure only) 41 debilitated southern sea otters in rehabilitation facilities were evaluated and compared to investigate regional differences. Serum chemistry and hematology values did not indicate a specific disease process as a cause for the declines. Statistically significant differences were found between free-ranging adult southern and Alaskan population mean serum levels of creatinine kinase, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, calcium, cholesterol, creatinine, glucose, phosphorous, total bilirubin, blood urea nitrogen, and sodium. These were likely due to varying parasite loads, contaminant exposures, and physiologic or nutrition statuses. No free-ranging sea otters had signs of disease at capture, and prevalences of exposure to calicivirus, Brucella spp., and Leptospira spp. were low. The high prevalence (35%) of antibodies to Toxoplasma gondii in free-ranging southern sea otters, lack of antibodies to this parasite in Alaskan sea otters, and the pathogen's propensity to cause mortality in southern sea otters suggests that this parasite may be important to sea otter population dynamics in California but not in Alaska. The evidence for exposure to pathogens of public health importance (e.g., Leptospira spp., T. gondii) in the southern sea otter population, and the nai??vete?? of both populations to other pathogens (e

  8. Characteristics and petrogenesis of Alaskan-type ultramafic-gabbro intrusions, southeastern Alaska

    SciTech Connect

    Loney, R.A. ); Himmelberg, G.R. Univ. of Missouri, Columbia, MO )

    1993-04-01

    Alaskan-type ultramafic-gabbro intrusions occur along a belt that extends from Duke Island to Klukwan in southeastern Alaska and fall into two age groups, 400 to 440 Ma and 100 to 110 Ma. Most of the smaller bodies are magnetite-bearing hornblende clinopyroxenite; the larger ones consist of dunite, wehrlite, olivine clinopyroxenite, with some gabbro, in addition to hornblende clinopyroxenite and hornblendite. Textural, mineralogical, and chemical characteristics of the Alaskan-type ultramafic bodies indicate that they originated by fractional crystallization of a basaltic magma and accumulation in a crustal magma chamber. The Al[sub 2]O[sub 3] content of clinopyroxene shows a marked enrichment with differentiation, suggesting crystallization from progressively more hydrous melts like those characteristics of arc magmas. REE abundance levels and patterns are markedly similar for given rock units in all the bodies studied suggesting that all the bodies were derived by differentiation of closely similar parent magmas under near identical conditions. The exact composition of the primary melt is uncertain but the authors' preferred interpretation is that the parental magma of most Alaskan-type bodies was a subalkaline hydrous basalt. The striking similarity between the REE abundance levels and patterns of the Alaskan-type clinopyroxenites and gabbros, and the clinopyroxenite xenoliths and plutonic gabbros associated with Aleutian Island Arc volcanism, further suggests that the primary magma was probably a hydrous olivine basalt similar to the primary magma proposed for the Aleutian arc lavas. The mineral chemistry and phase equilibria of the ultramafic bodies suggest that they crystallized in magma chambers at depths greater than about 9 km. Except for the Duke Island body, which has sedimentary structures and shows evidence of ubiquitous current activity, most of the other bodies appear to have accumulated under static conditions.

  9. Projected Duration of the Sea-Ice-Free Season in the Future Alaskan Arctic

    NASA Astrophysics Data System (ADS)

    Wang, M.; Overland, J. E.

    2014-12-01

    The change in the Arctic climate is fast and broad. Among many changes that have been observed, the reduction of sea ice coverage has been one of the most significant factors. Continued reduction in sea ice cover will probably result in longer open water duration, which is important for the shipping industry, marine mammals as well as other component of the local ecosystem. In this study we are to assess future sea ice conditions, particularly the length of open water duration in the Alaskan Arctic over the next few decades using the latest coupled climate models (CMIP5). The Alaskan Arctic, including the Chukchi and the Beaufort Sea, has been a major region of summer sea ice retreat since 2007. Based on the mean of 12 climate models, for the region north of the Bering Strait (70° N), future open-water duration may extend from a current 3-4 months to around five months by 2050. It is about one month shorter along the same latitude over the Beaufort Sea. The difference in the length of ice-free season between the north and the south will remain, but will be smaller in the 21st century compared with current condition. Open-water duration in the Alaskan Arctic expands quickly in these models over the next decades, in contrast to model under-predictions of sea ice loss for the summer minimum over the Arctic wide domain. Uncertainty is generally ±one month estimated from the range of model results. Continued increases in open-water duration over the next two decades will impact regional economic access and potentially alter ecosystems, yet we need to keep in mind that from December through May most of the northern Alaskan Arctic will remain sea ice covered into the second half of the century.

  10. Juvenile laryngeal paralysis in three Siberian husky x Alaskan malamute puppies.

    PubMed

    Polizopoulou, Z S; Koutinas, A F; Papadopoulos, G C; Saridomichelakis, M N

    2003-11-15

    Three three-month-old Siberian husky x Alaskan malamute crossbreds had suffered episodic inspiratory dyspnoea and stridor for four to eight weeks and their endurance had decreased. In two of them bilateral, and in the other unilateral, laryngeal paralysis was diagnosed by laryngoscopy. In the nucleus ambiguus of the dogs there was a depletion of motor neurons, neuronal degeneration and mild gliosis, but there were no lesions in the root and peripheral segments of the recurrent laryngeal nerves.

  11. Viability of the Alaskan breeding population of Steller’s eiders

    USGS Publications Warehouse

    Dunham, Kylee; Grand, James B.

    2016-10-11

    The U.S. Fish and Wildlife Service is tasked with setting objective and measurable criteria for delisting species or populations listed under the Endangered Species Act. Determining the acceptable threshold for extinction risk for any species or population is a challenging task, particularly when facing marked uncertainty. The Alaskan breeding population of Steller’s eiders (Polysticta stelleri) was listed as threatened under the Endangered Species Act in 1997 because of a perceived decline in abundance throughout their nesting range and geographic isolation from the Russian breeding population. Previous genetic studies and modeling efforts, however, suggest that there may be dispersal from the Russian breeding population. Additionally, evidence exists of population level nonbreeding events. Research was conducted to estimate population viability of the Alaskan breeding population of Steller’s eiders, using both an open and closed model of population process for this threatened population. Projections under a closed population model suggest this population has a 100 percent probability of extinction within 42 years. Projections under an open population model suggest that with immigration there is no probability of permanent extinction. Because of random immigration process and nonbreeding behavior, however, it is likely that this population will continue to be present in low and highly variable numbers on the breeding grounds in Alaska. Monitoring the winter population, which includes both Russian and Alaskan breeding birds, may offer a more comprehensive indication of population viability.

  12. Task 27 -- Alaskan low-rank coal-water fuel demonstration project

    SciTech Connect

    1995-10-01

    Development of coal-water-fuel (CWF) technology has to-date been predicated on the use of high-rank bituminous coal only, and until now the high inherent moisture content of low-rank coal has precluded its use for CWF production. The unique feature of the Alaskan project is the integration of hot-water-drying (HWD) into CWF technology as a beneficiation process. Hot-water-drying is an EERC developed technology unavailable to the competition that allows the range of CWF feedstock to be extended to low-rank coals. The primary objective of the Alaskan Project, is to promote interest in the CWF marketplace by demonstrating the commercial viability of low-rank coal-water-fuel (LRCWF). While commercialization plans cannot be finalized until the implementation and results of the Alaskan LRCWF Project are known and evaluated, this report has been prepared to specifically address issues concerning business objectives for the project, and outline a market development plan for meeting those objectives.

  13. Long-term climate patterns in Alaskan surface temperature and precipitation and their biological consequences

    USGS Publications Warehouse

    Simpson, James J.; Hufford, Gary L.; Fleming, Michael D.; Berg, Jared S.; Ashton, J.B.

    2002-01-01

    Mean monthly climate maps of Alaskan surface temperature and precipitation produced by the parameter-elevation regression on independent slopes model (PRISM) were analyzed. Alaska is divided into interior and coastal zones with consistent but different climatic variability separated by a transition region; it has maximum interannual variability but low long-term mean variability. Pacific decadal oscillation (PDO)- and El Nin??o southern oscillation (ENSO)-type events influence Alaska surface temperatures weakly (1-2 ??C) statewide. PDO has a stronger influence than ENSO on precipitation but its influence is largely localized to coastal central Alaska. The strongest influence of Arctic oscillation (AO) occurs in northern and interior Alaskan precipitation. Four major ecosystems are defined. A major eco-transition zone occurs between the interior boreal forest and the coastal rainforest. Variability in insolation, surface temperature, precipitation, continentality, and seasonal changes in storm track direction explain the mapped ecosystems. Lack of westward expansion of the interior boreal forest into the western shrub tundra is influenced by the coastal marine boundary layer (enhanced cloud cover, reduced insolation, cooler surface and soil temperatures). In this context, the marine boundary layer acts in an analogous fashion to the orographic features which form the natural boundaries of other Alaskan ecosystems. Variability in precipitation may play a secondary role.

  14. Morphological differences between habitats are associated with physiological and behavioural trade-offs in stickleback (Gasterosteus aculeatus)

    PubMed Central

    Seebacher, Frank; Webster, Mike M.; James, Rob S.; Tallis, Jason; Ward, Ashley J. W.

    2016-01-01

    Local specialization can be advantageous for individuals and may increase the resilience of the species to environmental change. However, there may be trade-offs between morphological responses and physiological performance and behaviour. Our aim was to test whether habitat-specific morphology of stickleback (Gasterosteus aculeatus) interacts with physiological performance and behaviour at different salinities. We rejected the hypothesis that deeper body shape of fish from habitats with high predation pressure led to decreases in locomotor performance. However, there was a trade-off between deeper body shape and muscle quality. Muscle of deeper-bodied fish produced less force than that of shallow-bodied saltmarsh fish. Nonetheless, saltmarsh fish had lower swimming performance, presumably because of lower muscle mass overall coupled with smaller caudal peduncles and larger heads. Saltmarsh fish performed better in saline water (20 ppt) relative to freshwater and relative to fish from freshwater habitats. However, exposure to salinity affected shoaling behaviour of fish from all habitats and shoals moved faster and closer together compared with freshwater. We show that habitat modification can alter phenotypes of native species, but local morphological specialization is associated with trade-offs that may reduce its benefits. PMID:27429785

  15. Quantitative genetic inheritance of morphological divergence in a lake-stream stickleback ecotype pair: implications for reproductive isolation.

    PubMed

    Berner, D; Kaeuffer, R; Grandchamp, A-C; Raeymaekers, J A M; Räsänen, K; Hendry, A P

    2011-09-01

    Ecological selection against hybrids between populations occupying different habitats might be an important component of reproductive isolation during the initial stages of speciation. The strength and directionality of this barrier to gene flow depends on the genetic architecture underlying divergence in ecologically relevant phenotypes. We here present line cross analyses of inheritance for two key foraging-related morphological traits involved in adaptive divergence between stickleback ecotypes residing parapatrically in lake and stream habitats within the Misty Lake watershed (Vancouver Island, Canada). One main finding is the striking genetic dominance of the lake phenotype for body depth. Selection associated with this phenotype against first- and later-generation hybrids should therefore be asymmetric, hindering introgression from the lake to the stream population but not vice versa. Another main finding is that divergence in gill raker number is inherited additively and should therefore contribute symmetrically to reproductive isolation. Our study suggests that traits involved in adaptation might contribute to reproductive isolation qualitatively differently, depending on their mode of inheritance. PMID:21649765

  16. Morphological differences between habitats are associated with physiological and behavioural trade-offs in stickleback (Gasterosteus aculeatus).

    PubMed

    Seebacher, Frank; Webster, Mike M; James, Rob S; Tallis, Jason; Ward, Ashley J W

    2016-06-01

    Local specialization can be advantageous for individuals and may increase the resilience of the species to environmental change. However, there may be trade-offs between morphological responses and physiological performance and behaviour. Our aim was to test whether habitat-specific morphology of stickleback (Gasterosteus aculeatus) interacts with physiological performance and behaviour at different salinities. We rejected the hypothesis that deeper body shape of fish from habitats with high predation pressure led to decreases in locomotor performance. However, there was a trade-off between deeper body shape and muscle quality. Muscle of deeper-bodied fish produced less force than that of shallow-bodied saltmarsh fish. Nonetheless, saltmarsh fish had lower swimming performance, presumably because of lower muscle mass overall coupled with smaller caudal peduncles and larger heads. Saltmarsh fish performed better in saline water (20 ppt) relative to freshwater and relative to fish from freshwater habitats. However, exposure to salinity affected shoaling behaviour of fish from all habitats and shoals moved faster and closer together compared with freshwater. We show that habitat modification can alter phenotypes of native species, but local morphological specialization is associated with trade-offs that may reduce its benefits.

  17. Comparative transcriptomics of stickleback immune gene responses upon infection by two helminth parasites, Diplostomum pseudospathaceum and Schistocephalus solidus.

    PubMed

    Haase, David; Rieger, Jenny K; Witten, Anika; Stoll, Monika; Bornberg-Bauer, Erich; Kalbe, Martin; Schmidt-Drewello, Alexander; Scharsack, Jörn P; Reusch, Thorsten B H

    2016-08-01

    Immune systems of vertebrates are much more diverse than previously thought, in particular at the base of the vertebrate clade. RNA-seq was used to describe in detail the transcriptomic response of stickleback hosts to infection by two helminth parasites, the trematode Diplostomum pseudospathaceum (2 genotypes plus a genotype mix) and the cestode Schistocephalus solidus. Based on a global transcription profiling, we present immune genes that are active during chronic or multiple repeated infection. We found that the transcription profiles of D. pseudospathaceum genotypes were as divergent as those of the two parasite species. When comparing the host immune response, only 5 immune genes were consistently upregulated upon infection by both species. These genes indicated a role for enhanced toll like receptor (TLR) activity (CTSK, CYP27B1) and an associated positive regulation of macrophages (CYP27B1, THBS1) for general helminth defense. We interpret the largely differentiated gene expression response among parasite species as general redundancy of the vertebrate immune system, which was also visible in genotype-specific responses among the different D. pseudospathaceum infections. The present study provides the first evidence that IL4-mediated activation of T-helper lymphocyte cells is also important in anti-helminthic immune responses of teleost fish.

  18. Universal scaling rules predict evolutionary patterns of myogenesis in species with indeterminate growth

    PubMed Central

    Johnston, Ian A.; Kristjánsson, Bjarni K.; Paxton, Charles G. P.; Vieira, Vera L. A.; Macqueen, Daniel J.; Bell, Michael A.

    2012-01-01

    Intraspecific phenotypic variation is ubiquitous and often associated with resource exploitation in emerging habitats. For example, reduced body size has evolved repeatedly in Arctic charr (Salvelinus alpinus L.) and threespine stickleback (Gasterosteus aculeatus L.) across post-glacial habitats of the Northern Hemisphere. Exploiting these models, we examined how body size and myogenesis evolve with respect to the ‘optimum fibre size hypothesis’, which predicts that selection acts to minimize energetic costs associated with ionic homeostasis by optimizing muscle fibre production during development. In eight dwarf Icelandic Arctic charr populations, the ultimate production of fast-twitch muscle fibres (FNmax) was only 39.5 and 15.5 per cent of that in large-bodied natural and aquaculture populations, respectively. Consequently, average fibre diameter (FD) scaled with a mass exponent of 0.19, paralleling the relaxation of diffusional constraints associated with mass-specific metabolic rate scaling. Similar reductions in FNmax were observed for stickleback, including a small-bodied Alaskan population derived from a larger-bodied oceanic stock over a decadal timescale. The results suggest that in species showing indeterminate growth, body size evolution is accompanied by strong selection for fibre size optimization, theoretically allowing resources saved from ionic homeostasis to be allocated to other traits affecting fitness, including reproduction. Gene flow between small- and large-bodied populations residing in sympatry may counteract the evolution of this trait. PMID:22237905

  19. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. 334.1280 Section 334.1280 Navigation and Navigable... REGULATIONS § 334.1280 Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force....

  20. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. 334.1280 Section 334.1280 Navigation and Navigable... REGULATIONS § 334.1280 Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force....

  1. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. 334.1280 Section 334.1280 Navigation and Navigable... REGULATIONS § 334.1280 Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force....

  2. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. 334.1280 Section 334.1280 Navigation and Navigable... REGULATIONS § 334.1280 Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force....

  3. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. 334.1280 Section 334.1280 Navigation and Navigable... REGULATIONS § 334.1280 Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force....

  4. Earthquake triggering at alaskan volcanoes following the 3 November 2002 denali fault earthquake

    USGS Publications Warehouse

    Moran, S.C.; Power, J.A.; Stihler, S.D.; Sanchez, J.J.; Caplan-Auerbach, J.

    2004-01-01

    The 3 November 2002 Mw 7.9 Denali fault earthquake provided an excellent opportunity to investigate triggered earthquakes at Alaskan volcanoes. The Alaska Volcano Observatory operates short-period seismic networks on 24 historically active volcanoes in Alaska, 247-2159 km distant from the mainshock epicenter. We searched for evidence of triggered seismicity by examining the unfiltered waveforms for all stations in each volcano network for ???1 hr after the Mw 7.9 arrival time at each network and for significant increases in located earthquakes in the hours after the mainshock. We found compelling evidence for triggering only at the Katmai volcanic cluster (KVC, 720-755 km southwest of the epicenter), where small earthquakes with distinct P and 5 arrivals appeared within the mainshock coda at one station and a small increase in located earthquakes occurred for several hours after the mainshock. Peak dynamic stresses of ???0.1 MPa at Augustine Volcano (560 km southwest of the epicenter) are significantly lower than those recorded in Yellowstone and Utah (>3000 km southeast of the epicenter), suggesting that strong directivity effects were at least partly responsible for the lack of triggering at Alaskan volcanoes. We describe other incidents of earthquake-induced triggering in the KVC, and outline a qualitative magnitude/distance-dependent triggering threshold. We argue that triggering results from the perturbation of magmatic-hydrothermal systems in the KVC and suggest that the comparative lack of triggering at other Alaskan volcanoes could be a result of differences in the nature of magmatic-hydrothermal systems.

  5. The Apparent Periodicity of Felt Reports in the Alaskan Earthquake Record

    NASA Astrophysics Data System (ADS)

    Hafner, L. A.; McNutt, S. R.

    2004-12-01

    Felt reports for Alaskan earthquakes were found to be non-uniformly distributed throughout the year. With a predominantly tourist economy, the Alaskan population nearly triples in the summer months, possibly affecting the reporting of earthquakes in the historical record. Using published felt reports from the National Earthquake Information Center and the Alaska Earthquake Information Center, the percentage of events felt each month in central mainland Alaska were tabulated and compared between the summer and winter seasons. Earthquakes were selected from January 1, 1990 to October 31, 2002, from latitudes 58 to 70 degrees N and longitudes 140 to 160 degrees W, and depths 0 to 200 km. 408 events were felt out of a total of 695 that occurred. A number of parameters, including time of day, latitude, longitude, and magnitude, were additionally compared to specify possible limiting factors within each season. While a strong seasonal effect was not found in magnitude 4.0 ML events and greater, the months of May and June were consistently found to have the highest percentage of felt events with a steep drop occurring in the month of July. We ascribe this effect to the summer melting of the top layer of frozen ground to a depth of about 1.5 meters. Additionally, smaller events from magnitude 1.0 to 4.0 ML were also examined. 396 events were felt out of a total of 7,451 that occurred. We found that small earthquakes were felt, with a significant difference, more readily during summer months than in winter. This is likely an effect of the higher summer population of tourists and greater distribution of open businesses. Together these observations suggest that the historical Alaskan earthquake record is likely biased in favor of more frequent reporting of events occurring in summer months as opposed to winter.

  6. Implications of lifting the ban on the export of Alaskan crude oil: Price and trade impacts

    SciTech Connect

    Not Available

    1990-06-26

    This study addresses the issue of the ban on exports of Alaskan crude oil. At present almost all crude oil production from Alaska must be sold in the United States, i.e., it may not be exported. This study examines the impact, mainly on the West Coast, of eliminating this export restraint. The study concentrates on two time periods. These are 1988, the most recent year for which complete data are available, and 1995, a year in which Alaskan production is projected to be substantially less than at present. This is the Energy Information Administration's (EIA's) second report on this subject. The first was released earlier in 1990. They differ principally in the years for which results are presented and in the models used to generate quantitative results. The first report was limited to 1988. The quantitative results for that year were based on use of a single region model and therefore did not take into account petroleum interactions among all areas of the world. Because of this limitation, quantitative results were limited to Alaskan crude oil prices. All other price and trade flow results were qualitative. In contrast, the present report covers both 1988 and 1995. The quantitative results are generated with use of a more comprehensive model, one which does take into account petroleum interactions among all areas of the world. The model-generated results cover both crude and product prices as well as petroleum trade flows. The quantitative results in the present report therefore supersede those in the first, although both sets are generally consistent.

  7. Alaskan marine mammal tissue archival project: a project description including collection protocols

    SciTech Connect

    Becker, P.R.; Wise, S.A.; Koster, B.J.; Zeisler, R.

    1988-03-01

    The Alaskan Marine Mammal Tissue Archival Project was initiated in 1987. Although the emphasis is on the collection of tissues for analysis of contaminants that may be associated with the petroleum industry, the development of an archive of marine mammal tissues collected and stored using carefully controlled procedures provides an important resource addressing questions concerning the transport of elements and compounds (contaminants and non-contaminants) throughout the polar ecosystem. The document provides the basic information on Project objectives and management, justification for the species, tissues, and contaminants of interest, and specific instructions for collecting, handling, and storing samples.

  8. First Alaskan records and a significant northern range extension for two species of Diplura (Diplura, Campodeidae)

    PubMed Central

    Sikes, Derek S.; Allen, Robert T.

    2016-01-01

    Abstract Species in the class Diplura are recorded from Alaska for the first time. Two species, Tricampa rileyi Silvestri from Dall and Prince of Wales Islands in the Alexander Archipelago of Southeast Alaska and Metriocampa allocerca Conde & Geeraert from near Quartz Lake, southeast of Fairbanks, both in the family Campodeidae, are documented based on recently collected specimens deposited in the University of Alaska Museum Insect Collection. A brief review of the history of the documentation of the Alaskan soil microarthropod fauna is provided, as well as discussion of possible glacial refugia. PMID:27047242

  9. Anti-infective Discorhabdins from a Deep-Water Alaskan Sponge of the Genus Latrunculia†

    PubMed Central

    Na, MinKyun; Ding, Yuanqing; Wang, Bin; Tekwani, Babu L.; Schinazi, Raymond F.; Franzblau, Scott; Kelly, Michelle; Stone, Robert; Li, Xing-Cong; Ferreira, Daneel; Hamann, Mark T.

    2016-01-01

    Bioassay- and LC-MS-guided fractionation of a methanol extract from a new deep-water Alaskan sponge species of the genus Latrunculia resulted in the isolation of two new brominated pyrroloiminoquinones, dihydrodiscorhabdin B (1) and discorhabdin Y (2), along with six known pyrroloiminoquinone alkaloids, discorhabdins A (3), C (4), E (5), and L (6), dihydrodiscorhabdin C (7), and the benzene derivative 8. Compounds 3, 4, and 7 exhibited anti-HCV activity, antimalarial activity, and selective antimicrobial activity. Although compounds 3 and 7 displayed potent and selective in vitro antiprotozoal activity, Plasmodium berghei-infected mice did not respond to these metabolites due to their toxicity in vivo. PMID:20337497

  10. Enhanced removal of Exxon Valdez spilled oil Alaskan gravel by a microbial surfactant

    SciTech Connect

    Harvey, S.; Elashvili, I.; Valdes, J.J.; Kamely, D.; Chakrabarty, A.M. )

    1990-03-01

    Remediation efforts for the oil spill from the Exxon Valdez tanker in Alaska have focused on the use of pressurized water at high temperature to remove oil from the beaches. We have tested a biological surfactant from Pseudomonas aeruginosa for its ability to remove oil from contaminated Alaskan gravel samples under various conditions, including concentration of the surfactant, time of contact, temperature of the wash, and presence or absence of xanthan gum. The results demonstrate the ability of the microbial surfactant to release oil to a significantly greater extent (2 to 3 times) than water alone, particularly at temperatures of 30{degree}C and above.

  11. Enhanced removal of Exxon Valdez spilled oil from Alaskan gravel by a microbial surfactant.

    PubMed

    Harvey, S; Elashvili, I; Valdes, J J; Kamely, D; Chakrabarty, A M

    1990-03-01

    Remediation efforts for the oil spill from the Exxon Valdez tanker in Alaska have focused on the use of pressurized water at high temperature to remove oil from the beaches. We have tested a biological surfactant from Pseudomonas aeruginosa for its ability to remove oil from contaminated Alaskan gravel samples under various conditions, including concentration of the surfactant, time of contact, temperature of the wash, and presence or absence of xanthan gum. The results demonstrate the ability of the microbial surfactant to release oil to a significantly greater extent (2 to 3 times) than water alone, particularly at temperatures of 30 degrees C and above. PMID:1367420

  12. Enhanced removal of Exxon Valdez spilled oil from Alaskan gravel by a microbial surfactant.

    PubMed

    Harvey, S; Elashvili, I; Valdes, J J; Kamely, D; Chakrabarty, A M

    1990-03-01

    Remediation efforts for the oil spill from the Exxon Valdez tanker in Alaska have focused on the use of pressurized water at high temperature to remove oil from the beaches. We have tested a biological surfactant from Pseudomonas aeruginosa for its ability to remove oil from contaminated Alaskan gravel samples under various conditions, including concentration of the surfactant, time of contact, temperature of the wash, and presence or absence of xanthan gum. The results demonstrate the ability of the microbial surfactant to release oil to a significantly greater extent (2 to 3 times) than water alone, particularly at temperatures of 30 degrees C and above.

  13. Paleoclimatic forcing of magnetic susceptibility variations in Alaskan loess during the late Quaternary

    SciTech Connect

    Beget, J.E.; Stone, D.B.; Hawkins, D.B. )

    1990-01-01

    Visual matches and statistical tests suggest correlations between marine isotope curves, retrodictive solar insolation at lat 65{degree}N, and magnetic susceptibility profiles through late Quaternary age Alaskan loess sections. The susceptibility changes largely appear to reflect variability in magnetite content due to climatically controlled changes in wind intensity and competence. Magnetic susceptibility profiles through massive loess can provide stratigraphic context for intercalated paleosols and tephras. A prominent paleosol correlated with marine isotope stage 5 occurs several metres above the Old Crow ash in loess sections, indicating that this important tephra is older than suggested by thermoluminescence dates, and may have been deposited ca. 215 {plus minus}25 ka.

  14. The Changing Alaskan Experience—Health Care Services and Cultural Identity

    PubMed Central

    Dixon, Mim; Myers, Wayne W.; Book, Patricia A.; Nice, Philip O.

    1983-01-01

    Before Western contact, Alaskan Native populations were self-sufficient in their health practices. Slowly, the Native health care system was replaced by a Western one which was highly effective in treating infectious diseases. As infectious diseases were brought under control by the Indian Health Service, the emergent leading health problems were related to violence, attributed in part to cultural disintegration. New types of Native health providers and new Native-controlled institutions evolved to provide culturally appropriate health and mental health services and to promote a stronger cultural identity. PMID:6666110

  15. TRANSPORTATION ISSUES IN THE DELIVERY OF GTL PRODUCTS FROM ALASKAN NORTH SLOPE TO MARKET

    SciTech Connect

    Godwin Chukwu

    2004-01-01

    The Alaskan North Slope (ANS) is one of the largest hydrocarbon reserves in the United States where Gas-to-Liquids (GTL) technology can be successfully implemented. The proven and recoverable reserves of conventional natural gas in the developed and undeveloped fields in the Alaskan North Slope (ANS) are estimated to be 38 trillion standard cubic feet (TCF) and estimates of additional undiscovered gas reserves in the Arctic field range from 64 TCF to 142 TCF. Because the domestic gas market in the continental United States is located thousands of miles from the ANS, transportation of the natural gas from the remote ANS to the market is the key issue in effective utilization of this valuable and abundant resource. The focus of this project is to study the operational challenges involved in transporting the gas in converted liquid (GTL) form through the existing Trans Alaska Pipeline System (TAPS). A three-year, comprehensive research program was undertaken by the Petroleum Development Laboratory, University of Alaska Fairbanks, under cooperative agreement No. DE-FC26-98FT40016 to study the feasibility of transporting GTL products through TAPS. Cold restart of TAPS following an extended winter shutdown and solids deposition in the pipeline were identified as the main transportation issues in moving GTL products through the pipeline. The scope of work in the current project (Cooperative Agreement No. DE-FC26-01NT41248) included preparation of fluid samples for the experiments to be conducted to augment the comprehensive research program.

  16. Atmospheric methane sources - Alaskan tundra bogs, an alpine fen, and a subarctic boreal marsh

    NASA Technical Reports Server (NTRS)

    Sebacher, D. I.; Harriss, R. C.; Grice, S. S.; Bartlett, K. B.; Sebacher, S. M.

    1986-01-01

    Methane (CH4) flux measurements from Alaska tundra bogs, an alpine fen, and a subarctic boreal marsh were obtained at field sites ranging from Prudhoe Bay on the coast of the Arctic Ocean to the Alaskan Range south of Fairbanks during August 1984. In the tundra, average CH4 emission rates varied from 4.9 mg CH4 per sq m per day (moist tundra) to 119 mg CH4 per sq m per day (waterlogged tundra). Fluxes averaged 40 mg CH4 per sq m per day from wet tussock meadows in the Brooks Range and 289 mg Ch4 per sq m per day from an alpine fen in the Alaskan Range. The boreal marsh had an average CH4 emission rate of 106 mg CH4 per sq m per day. Significant emissions were detected in tundra areas where peat temperatures were as low as 4 C, and permafrost was only 25 cm below the ground surface. Emission rates from the 17 sites sampled were found to be logarithmically related to water levels at the sites. Extrapolation of the data to an estimate of the total annual CH4 emission from all arctic and boreal wetlands suggests that these ecosystems are a major source of atmospheric CH4 and could account for up to 23 percent of global CH4 emissions from wetlands.

  17. Seasonal Storminess in the North Pacific, Bering Sea, and Alaskan Regions

    NASA Astrophysics Data System (ADS)

    Shippee, N. J.; Atkinson, D. E.; Walsh, J. E.; Partain, J.; Gottschalck, J.; Marra, J.

    2012-12-01

    Annually, extra-tropical cyclones present a high impact natural hazard to the North Pacific, Bering Sea, and Alaskan regions. In these regions, extensive subsistence and commercial fishing, new oil and gas field development, tourism, growing interest in and exploitation of new commercial shipping potential, and increasing military and Coast Guard activity, all represent potential parties impacted by storms in these waters. It is of interest to many parties to begin developing capacity to provide some indication of storm activity at a monthly- to seasonal-outlook (30 to 90 days) timeframe. Using storm track data from NOAA's Climate Prediction Center for the North Pacific and Alaskan region, an experimental seasonal storminess outlook product, using eigen-based methods similar to the operational seasonal temperature and precipitation products currently produced at NOAA CPC, has been created and tested in hindcast mode using predicted states of ENSO, the Pacific Decadal Oscillation (PDO), the Pacific-North American Pattern (PNA), and the Arctic Oscillation (AO). A sample of the seasonal storminess outlook product will be shown along with a discussion of the utility of individual teleconnection patterns in the generation of the product.

  18. Spatial variability and landscape controls of near-surface permafrost within the Alaskan Yukon River Basin

    USGS Publications Warehouse

    Pastick, Neal J.; Jorgenson, M. Torre; Wylie, Bruce K.; Rose, Joshua R.; Rigge, Matthew; Walvoord, Michelle A.

    2014-01-01

    The distribution of permafrost is important to understand because of permafrost's influence on high-latitude ecosystem structure and functions. Moreover, near-surface (defined here as within 1 m of the Earth's surface) permafrost is particularly susceptible to a warming climate and is generally poorly mapped at regional scales. Subsequently, our objectives were to (1) develop the first-known binary and probabilistic maps of near-surface permafrost distributions at a 30 m resolution in the Alaskan Yukon River Basin by employing decision tree models, field measurements, and remotely sensed and mapped biophysical data; (2) evaluate the relative contribution of 39 biophysical variables used in the models; and (3) assess the landscape-scale factors controlling spatial variations in permafrost extent. Areas estimated to be present and absent of near-surface permafrost occupy approximately 46% and 45% of the Alaskan Yukon River Basin, respectively; masked areas (e.g., water and developed) account for the remaining 9% of the landscape. Strong predictors of near-surface permafrost include climatic indices, land cover, topography, and Landsat 7 Enhanced Thematic Mapper Plus spectral information. Our quantitative modeling approach enabled us to generate regional near-surface permafrost maps and provide essential information for resource managers and modelers to better understand near-surface permafrost distribution and how it relates to environmental factors and conditions.

  19. Using smooth sheets to describe groundfish habitat in Alaskan waters, with specific application to two flatfishes

    NASA Astrophysics Data System (ADS)

    Zimmermann, Mark; Reid, Jane A.; Golden, Nadine

    2016-10-01

    In this analysis we demonstrate how preferred fish habitat can be predicted and mapped for juveniles of two Alaskan groundfish species - Pacific halibut (Hippoglossus stenolepis) and flathead sole (Hippoglossoides elassodon) - at five sites (Kiliuda Bay, Izhut Bay, Port Dick, Aialik Bay, and the Barren Islands) in the central Gulf of Alaska. The method involves using geographic information system (GIS) software to extract appropriate information from National Ocean Service (NOS) smooth sheets that are available from NGDC (the National Geophysical Data Center). These smooth sheets are highly detailed charts that include more soundings, substrates, shoreline and feature information than the more commonly-known navigational charts. By bringing the information from smooth sheets into a GIS, a variety of surfaces, such as depth, slope, rugosity and mean grain size were interpolated into raster surfaces. Other measurements such as site openness, shoreline length, proportion of bay that is near shore, areas of rocky reefs and kelp beds, water volumes, surface areas and vertical cross-sections were also made in order to quantify differences between the study sites. Proper GIS processing also allows linking the smooth sheets to other data sets, such as orthographic satellite photographs, topographic maps and precipitation estimates from which watersheds and runoff can be derived. This same methodology can be applied to larger areas, taking advantage of these free data sets to describe predicted groundfish essential fish habitat (EFH) in Alaskan waters.

  20. Fine-scale population genetic structure in Alaskan Pacific halibut (Hippoglossus stenolepis)

    USGS Publications Warehouse

    2010-01-01

    Pacific halibut collected in the Aleutian Islands, Bering Sea and Gulf of Alaska were used to test the hypothesis of genetic panmixia for this species in Alaskan marine waters. Nine microsatellite loci and sequence data from the mitochondrial (mtDNA) control region were analyzed. Eighteen unique mtDNA haplotypes were found with no evidence of geographic population structure. Using nine microsatellite loci, significant heterogeneity was detected between Aleutian Island Pacific halibut and fish from the other two regions (FST range = 0.007–0.008). Significant FST values represent the first genetic evidence of divergent groups of halibut in the central and western Aleutian Archipelago. No significant genetic differences were found between Pacific halibut in the Gulf of Alaska and the Bering Sea leading to questions about factors contributing to separation of Aleutian halibut. Previous studies have reported Aleutian oceanographic conditions at deep inter-island passes leading to ecological discontinuity and unique community structure east and west of Aleutian passes. Aleutian Pacific halibut genetic structure may result from oceanographic transport mechanisms acting as partial barriers to gene flow with fish from other Alaskan waters.

  1. TISSUE DISTRIBUTION OF PCBS AND ORGANOCHLORINE PESTICIDES IN ALASKAN NORTHERN FUR SEALS: COMPARISON OF VARIOUS CONGENER CLASSIFICATION SCHEMES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) are believed to adversely affect reproduction and cause health problems in Pinnipeds 1-4. In this study, 145 PCB congeners and OCPs were analyzed in 10 juvenile male northern fur seals, Callorhinus ursinus, collected from Alaskan...

  2. Long-Term Effects of Otitis Media a Ten-Year Cohort Study of Alaskan Eskimo Children

    ERIC Educational Resources Information Center

    Kaplan, Gary J.; And Others

    1973-01-01

    Histories of ear disease, otoscopic examinations, and audiologic, intelligence, and achievement tests were obtained from a cohort of 489 Alaskan Eskimo children, followed through the first 10 years of life, to determine whether otitis media (middle ear inflammation) deleteriously affected intellectual functioning and achievement in school.…

  3. Urban American Indian/Alaskan Natives Compared to Non-Indians in Out-of-Home Care

    ERIC Educational Resources Information Center

    Carter, Vernon B.

    2011-01-01

    Historically, American Indian/Alaskan Native (AI/AN) children have been disproportionately represented in the foster care system. In this study, nationally representative child welfare data from October 1999 was used to compare urban AI/AN children to non-Indian children placed into out-of-home care. Compared to non-Indian children, urban AI/AN…

  4. Population structure over a broad spatial scale driven by nonanthropogenic factors in a wide-ranging migratory mammal, Alaskan caribou.

    PubMed

    Mager, Karen H; Colson, Kevin E; Groves, Pam; Hundertmark, Kris J

    2014-12-01

    Wide-ranging mammals face significant conservation threats, and knowledge of the spatial scale of population structure and its drivers is needed to understand processes that maintain diversity in these species. We analysed DNA from 655 Alaskan caribou (Rangifer tarandus granti) from 20 herds that vary in population size, used 19 microsatellite loci to document genetic diversity and differentiation in Alaskan caribou, and examined the extent to which genetic differentiation was associated with hypothesized drivers of population subdivision including landscape features, population size and ecotype. We found that Alaskan caribou are subdivided into two hierarchically structured clusters: one group on the Alaska Peninsula containing discrete herds and one large group on the Mainland lacking differentiation between many herds. Population size, geographic distance, migratory ecotype and the Kvichak River at the nexus of the Alaska Peninsula were associated with genetic differentiation. Contrary to previous hypotheses, small Mainland herds were often differentiated genetically from large interconnected herds nearby, and genetic drift coupled with reduced gene flow may explain this pattern. Our results raise the possibility that behaviour helps to maintain genetic differentiation between some herds of different ecotypes. Alaskan caribou show remarkably high diversity and low differentiation over a broad geographic scale. These results increase information for the conservation of caribou and other migratory mammals threatened by population reductions and landscape barriers and may be broadly applicable to understanding the spatial scale and ecological drivers of population structure in widespread species. PMID:25403098

  5. Population structure over a broad spatial scale driven by nonanthropogenic factors in a wide-ranging migratory mammal, Alaskan caribou.

    PubMed

    Mager, Karen H; Colson, Kevin E; Groves, Pam; Hundertmark, Kris J

    2014-12-01

    Wide-ranging mammals face significant conservation threats, and knowledge of the spatial scale of population structure and its drivers is needed to understand processes that maintain diversity in these species. We analysed DNA from 655 Alaskan caribou (Rangifer tarandus granti) from 20 herds that vary in population size, used 19 microsatellite loci to document genetic diversity and differentiation in Alaskan caribou, and examined the extent to which genetic differentiation was associated with hypothesized drivers of population subdivision including landscape features, population size and ecotype. We found that Alaskan caribou are subdivided into two hierarchically structured clusters: one group on the Alaska Peninsula containing discrete herds and one large group on the Mainland lacking differentiation between many herds. Population size, geographic distance, migratory ecotype and the Kvichak River at the nexus of the Alaska Peninsula were associated with genetic differentiation. Contrary to previous hypotheses, small Mainland herds were often differentiated genetically from large interconnected herds nearby, and genetic drift coupled with reduced gene flow may explain this pattern. Our results raise the possibility that behaviour helps to maintain genetic differentiation between some herds of different ecotypes. Alaskan caribou show remarkably high diversity and low differentiation over a broad geographic scale. These results increase information for the conservation of caribou and other migratory mammals threatened by population reductions and landscape barriers and may be broadly applicable to understanding the spatial scale and ecological drivers of population structure in widespread species.

  6. American Indian/Alaskan Native Undergraduate Retention at Predominantly White Institutions: An Elaboration of Tinto's Theory of College Student Departure

    ERIC Educational Resources Information Center

    Lee, Junghee; Donlan, William; Brown, Eddie F.

    2011-01-01

    This article reports findings from a major public university sponsored study undertaken with the intention of (a) improving university understanding of factors affecting American Indian/Alaskan Native (AI/AN) undergraduates' persistence at this institution, and (b) identifying in what areas, and in what manner, this institution could improve…

  7. Social Disruption and Psychological Stress in an Alaskan Fishing Community: The Impact of the Exxon Valdez Oil Spill.

    ERIC Educational Resources Information Center

    Picou, J. Steven; And Others

    Technological accidents such as the Exxon Valdez oil spill in 1989 create man-made disaster situations that threaten community survival and the well-being and quality of life of community residents. This paper focuses on the social and psychological impact of the 1989 oil spill on Cordova, an isolated Alaskan community with high economic…

  8. STARCH/PULP-FIBER BASED PACKAGING FOAMS AND CAST FILMS CONTAINING ALASKAN FISH BY-PRODUCTS (WASTE)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Baked starch/pulp foams were prepared from formulations containing 0-25% (wt%) of processed Alaskan fish by-products that consisted mostly of salmon heads, pollock heads and pollock frames (bones and associated remains produced in the filleting operation). Fish by-products thermoformed well along wi...

  9. Late nineteenth to early twenty-first century behavior of Alaskan glaciers as indicators of changing regional climate

    USGS Publications Warehouse

    Molnia, B.F.

    2007-01-01

    Alaska's climate is changing and one of the most significant indications of this change has been the late 19th to early 21st century behavior of Alaskan glaciers. Weather station temperature data document that air temperatures throughout Alaska have been increasing for many decades. Since the mid-20th century, the average change is an increase of ?????2.0????C. In order to determine the magnitude and pattern of response of glaciers to this regional climate change, a comprehensive analysis was made of the recent behavior of hundreds of glaciers located in the eleven Alaskan mountain ranges and three island areas that currently support glaciers. Data analyzed included maps, historical observations, thousands of ground-and-aerial photographs and satellite images, and vegetation proxy data. Results were synthesized to determine changes in length and area of individual glaciers. Alaskan ground photography dates from 1883, aerial photography dates from 1926, and satellite photography and imagery dates from the early 1960s. Unfortunately, very few Alaskan glaciers have any mass balance observations. In most areas analyzed, every glacier that descends below an elevation of ?????1500??m is currently thinning and/or retreating. Many glaciers have an uninterrupted history of continuous post-Little-Ice-Age retreat that spans more than 250??years. Others are characterized by multiple late 19th to early 21st century fluctuations. Today, retreating and/or thinning glaciers represent more than 98% of the glaciers examined. However, in the Coast Mountains, St. Elias Mountains, Chugach Mountains, and the Aleutian Range more than a dozen glaciers are currently advancing and thickening. Many currently advancing glaciers are or were formerly tidewater glaciers. Some of these glaciers have been expanding for more than two centuries. This presentation documents the post-Little-Ice-Age behavior and variability of the response of many Alaskan glaciers to changing regional climate. ?? 2006.

  10. Potential effects of oil spills and other chemical pollutants on marine mammals occurring in Alaskan waters

    SciTech Connect

    Hansen, D.J.

    1985-01-01

    The outer continental shelf report describes and assesses the potential effects of oil spills and other contaminants on marine mammals that occur in Alaskan waters, assuming that a spill or contamination occurs. The report focuses primarily on the potential direct and indirect effects of oil spills on marine mammals and addresses both short-term effects that may occur at the time of contact with oil, and long-term effects that may occur long after contact with oil. The report also briefly reviews the literature on the potential effects of other contaminants such as heavy metals and organochlorines (DDT and PCB's) on marine mammals. The assessment concludes that sea otters, polar bears, fur seals, and very young seal pups could suffer serious or lethal effects if contact with oil occurred.

  11. Recent physical connections may explain weak genetic structure in western Alaskan chum salmon (Oncorhynchus keta) populations

    PubMed Central

    Garvin, Michael R; Kondzela, Christine M; Martin, Patrick C; Finney, Bruce; Guyon, Jeffrey; Templin, William D; DeCovich, Nick; Gilk-Baumer, Sara; Gharrett, Anthony J

    2013-01-01

    Low genetic divergence at neutral loci among populations is often the result of high levels of contemporary gene flow. Western Alaskan summer-run chum salmon (Oncorhynchus keta) populations demonstrate weak genetic structure, but invoking contemporary gene flow as the basis for the low divergence is problematic because salmon home to their natal streams and some of the populations are thousands of kilometers apart. We used genotypes from microsatellite and single nucleotide polymorphism loci to investigate alternative explanations for the current genetic structure of chum salmon populations from western Alaska. We also estimated current levels of gene flow among Kuskokwim River populations. Our results suggest that weak genetic structure is best explained by physical connections that occurred after the Holocene Thermal Maximum among the Yukon, Kuskokwim, and Nushagak drainages that allowed gene flow to occur among now distant populations. PMID:23919176

  12. All-weather ice information system for Alaskan arctic coastal shipping

    NASA Technical Reports Server (NTRS)

    Gedney, R. T.; Jirberg, R. J.; Schertler, R. J.; Mueller, R. A.; Chase, T. L.; Kramarchuk, I.; Nagy, L. A.; Hanlon, R. A.; Mark, H.

    1977-01-01

    A near real-time ice information system designed to aid arctic coast shipping along the Alaskan North Slope is described. The system utilizes a X-band Side Looking Airborne Radar (SLAR) mounted aboard a U.S. Coast Guard HC-130B aircraft. Radar mapping procedures showing the type, areal distribution and concentration of ice cover were developed. In order to guide vessel operational movements, near real-time SLAR image data were transmitted directly from the SLAR aircraft to Barrow, Alaska and the U.S. Coast Guard icebreaker Glacier. In addition, SLAR image data were transmitted in real time to Cleveland, Ohio via the NOAA-GOES Satellite. Radar images developed in Cleveland were subsequently facsimile transmitted to the U.S. Navy's Fleet Weather Facility in Suitland, Maryland for use in ice forecasting and also as a demonstration back to Barrow via the Communications Technology Satellite.

  13. Issues facing the future use of Alaskan NorthSlope natural gas

    SciTech Connect

    Bowsher, C.A.

    1983-05-12

    The North Slope of Alaska contains over 26 trillion cubic feet of natural gas. In 1977, the President and the Congress approved construction of a 4800-mile gas pipeline to bring this gas to US consumers by 1983. However, completion of the project is not now expected until late 1989 at the earliest. This report examines the status and outlook for the Alaskan gas pipeline (the Alaska Natural Gas Transportation System). It also evaluates the pros and cons of (1) alternative systems to deliver this gas to market, including a gas pipeline with Alaska for export of liquefied natural gas; (2) processing the gas in Alaska by converting it to methanol and petrochemicals for export; and (3) using the gas within Alaska.

  14. The influence of the Alaskan Gyre on the coastal circulation in the Gulf of Alaska

    NASA Technical Reports Server (NTRS)

    Heim, Paul K., II; Johnson, Mark A.; O'Brien, James J.

    1992-01-01

    The circulation of the northeast Pacific Ocean and the Gulf of Alaska is simulated by means of a reduced-gravity wind-driven model to study seasonal and interannual flow variability. The circulation in the NE Pacific is discussed emphasizing its ramifications for the physical domain, equations, and boundary conditions of the numerical model. The pseudostress fields used to drive the model are based on 20 years of data from the Comprehensive Ocean-Atmosphere Data Set and are analyzed with empirical orthogonal function analysis. The monthly stresses from 1986-89 are used to drive the model, and regional oceanographic features are reproduced including the Alaskan Gyre, Coastal Current, the Sitka eddy, and a severe cyclonic eddy. Comparisons with experimental data show that the high-resolution baroclinic model is valid and demonstrates the applicability of reduced-gravity models.

  15. Bowhead whale behavior in relation to seismic exploration, Alaskan Beaufort Sea, Autumn 1981. Study report (Final)

    SciTech Connect

    Fraker, M.A.; Ljungblad, D.K.; Richardson, W.J.; Van Schoik, D.R.

    1985-10-01

    Behavior of bowhead whales (Balsena mysticetus) in the eastern part of the Alaskan Beaufort Sea or near the Alaska/Yukon border was observed from a circling turbine-powered Goose aircraft on 10 dates from 12 September to 5 October 1981. On three of these dates, the whales were exposed t, noise impulses from seismic vessels 13 km or more away. Some behavioral data were acquired. In both the presence and the absence of seismic impulses, most bowheads appeared to be feeding in the water column, although slow travel and active socializing were sometimes detected. Sonobuoys detected bowhead calls both in the presence and the absence of seismic impulses. There was no clear evidence of unusual behavior in the presence of seismic impulses.

  16. Digital depth horizon compilations of the Alaskan North Slope and adjacent Arctic regions

    USGS Publications Warehouse

    Saltus, Richard W.; Bird, Kenneth J.

    2003-01-01

    Data have been digitized and combined to create four detailed depth horizon grids spanning the Alaskan North Slope and adjacent offshore areas. These map horizon compilations were created to aid in petroleum system modeling and related studies. Topography/bathymetry is extracted from a recent Arctic compilation of global onshore DEM and satellite altimetry and ship soundings offshore. The Lower Cretaceous Unconformity (LCU), the top of the Triassic Shublik Formation, and the pre-Carboniferous acoustic basement horizon grids are created from numerous seismic studies, drill hole information, and interpolation. These horizons were selected because they mark critical times in the geologic evolution of the region as it relates to petroleum. The various horizons clearly show the major tectonic elements of this region including the Brooks Range, Colville Trough, Barrow Arch, Hanna Trough, Chukchi Platform, Nuwuk Basin, Kaktovik Basin, and Canada Basin. The gridded data are available in a variety of data formats for use in regional studies.

  17. Quantifying the historic and future distribution of fire in Alaskan tundra ecosystems

    NASA Astrophysics Data System (ADS)

    Young, A. M.; Higuera, P. E.; Duffy, P. A.

    2012-12-01

    During the past 60 years fire has been relatively rare and small in size within tundra ecosystems. However, historical observations and paleoecological evidence indicates that fire regimes vary widely across Alaskan tundra, in both space and time. These lines of evidence suggest that fire occupies a highly specified niche or ecological space in Alaskan tundra, which may change significantly with future climate warming. The objective of this research was to quantify the relationships between fire occurrence and different seasonal climate variables, and to begin to make inferences about future distributions of fire across the tundra landscape. The results of this research will ultimately contribute to the goal of summarizing the linkages that exist among climate, vegetation, and fire in the historical record, and for making predictions concerning fire disturbance in tundra ecosystems throughout the next century. Historic tundra fires occurred non-randomly across space, and a relationship exists between fire occurrence and warm, dry climates. We quantified this relationship with generalized boosting models (GBM) using datasets of downscaled temperature and precipitation (2 km, 1971-2000), and historic records of tundra area burned (1950-2010). The GBM used six seasonal climate variables, focused on growing season temperature and precipitation, to predict the probability of fire occurrence over the 1950-2010 time period. To understand implications of these historic relationships given ongoing climate warming, we constructed future climatologies of temperature and precipitation for the five GCMs which performed best in Alaska under the IPCC AR4 A1B (middle-of-the-road) emissions scenario for the time period 2021-2050. The GBM performed well predicting the observed spatial distribution of tundra area burned, capturing key regions which experienced the most fire activity from 1950-2010. The mean temperature of the warmest month (MeanMaxTemp) was the most influential

  18. Frequency of genes in aromatic and aliphatic hydrocarbon biodegradation pathways within bacterial populations from Alaskan sediments.

    PubMed

    Sotsky, J B; Greer, C W; Atlas, R M

    1994-11-01

    A significant proportion of the naturally occurring hydrocarbon-degrading populations within Alaskan sediments affected by the Exxon Valdez oil spill had both the xylE and alkB genes and could convert hexadecane and naphthalene to carbon dioxide; a greater proportion of the population had xylE than had alkB, reflecting the composition of the residual oil at the time of sampling; nearly equal populations with xylE alone, alkB alone, and xylE + alkB genes together were found after exposure to fresh crude oil; populations with xylE lacking alkB increased after enrichment on naphthalene. Thus, the genotypes of hydrocarbon-degrading populations reflected the composition of the hydrocarbons to which they were exposed. PMID:7804909

  19. Pleiotropic effects on subclasses of HDL, adiposity and glucose metabolism in adult Alaskan Eskimos

    PubMed Central

    Tejero, ME; Voruganti, VS; Cai, G; Cole, SA; Laston, S; Wenger, CR; MacCluer, JW; Dyke, B; Devereux, R; Ebbesson, SO; Fabsitz, RR; Howard, BV; Comuzzie, AG

    2012-01-01

    The aim of the present study was to analyze the heritability and the presence of pleiotropic effects on subfractions of high density lipoproteins (HDLs) as measured by nuclear magnetic resonance (NMR), parameters for adiposity and glucose metabolism in adult Alaskan Eskimos. The present family study included 1214 adult Alaskan Eskimos (537 male/677 female). Body weight, height, circumferences, selected skinfolds and blood pressure were measured in all participants. Blood samples were collected under fasting conditions for isolation of plasma. Glucose, insulin, subclasses and size of lipoproteins, triglycerides, total and HDL cholesterol and lipoprotein (a) were measured in plasma. HbA1c was measured in total blood. Univariate and bivariate quantitative genetic analyses were conducted between HDL subclasses and size and the anthropometric and biochemical measures using the variance decomposition approach. Variation in all the analyzed traits exhibits a significant genetic component. Heritabilities ranged between 0.18 ± 0.11 for LDL2 (intermediate) to 0.89 ± 0.07 for small HDL. No common genetic effects were found on the HDL subclasses (small, intermediate and large). Small HDL particles were genetically correlated with LDL particles and HbA1c. Negative genetic correlations were observed between intermediate and large HDL subfractions and HDL size and measures of adiposity, LDL and parameters for glucose metabolism (HbA1, insulin). These observations confirm the presence of possible pleiotropic effects on HDL, adiposity and cardiovascular risk factors and provide novel insight on the relationship between HDL subclasses, adiposity and glucose regulation. PMID:19950191

  20. Placer and lode platinum-group minerals in south Kalimantan, Indonesia: evidence for derivation from Alaskan-type ultramafic intrusions

    USGS Publications Warehouse

    Zientek, M.L.

    1992-01-01

    Platinum-group minerals occur in significant proportions in placer deposits in several localities in South Kalimantan. They consist of Pt-Fe alloy that may be intergrown with or contain inclusions of Ir-Os-Ru alloy, laurite and chromite. Alluvial PGM found along Sungai Tambanio are in part derived from chromatite schlieren in dunitic bodies intruded into clinopyroxene cumulates that may be part of an Alaskan-type ultramafic complex. A chromitite schlieren in serpentinite from one of these dunitic bodies is anomalous in PGE. The chondrite-normalized PGE pattern for this rock, pan concentrates from this area, and PGM concentrates from diamond-Au-PGM placer deposits have an "M'-shaped pattern enriched in Ir and Pt that is typical of PGE-mineralization associated with Alaskan-type ultramafic complexes. -Authors