Nine hemoglobins have been isolated from the blood of cutthroat trout. All nine hemoglobins bind oxygen cooperatively and appear to be tetramers with molecular weights of -64,000. The oxygen equilibria and subunit structures of the purified hemoglobins were studied. In addition, the red blood cells of cutthroat trout were examined for the presence of ATP and GTP, which are known to be physiological modulators of hemoglobins in fishes. Five hemoglobins with isoelectric points from 9.1 to 7.0 are classified as cathodal hemoglobins. These five hemoglobins have identical oxygen binding properties by the criteria tested. All have oxygen equilibria which are unaffected by protons and ATP and essentially independent of temperature, with overall enthalpies of oxygenation ~0. Two hemoglobins with isoelectric points near 6.5, classified as a nodal hemoglobins, have oxygen binding properties distinctly different from those of the cathodal hemoglobins. Both are characterized by a Root effect, displaying non-cooperative oxygen binding and low oxygen affinity at pH 6.2. ATP causes a large reduction in the oxygen affinity without affecting the cooperativity of oxygen binding. GTP has a similar but slightly larger effect on both hemoglobins. The oxygen equilibria of the anodal hemoglobins are temperature dependent, with the oxygen affinity being reduced as temperature increases. The overall enthalpy of oxygenation is -14 kcal/mol for both hemoglobins. The two remaining hemoglobins represent only a small percentage of the total hemoglobin. These hemoglobins are tentatively designated as embryonic hemoglobins based primarily on a comparison of their properties to those observed for hemoglobins from newly-hatched rainbow trout (Iuchi, I. (1973) Comp. Biochem. Physiol. 44B, 1087-1101). These two hemoglobins have isoelectric points near 5.9 and oxygen binding properties similar to those of the cathodal hemoglobins. With the possible exception of one of the embryonic hemoglobins (for which globins were not obtained), all the hemoglobins are composed of two different types of globin chains. Six are ∝_2 β_2 tetramers, while two of the cathodal hemoglobins are hybrid tetramers of the type 〖∝∝'β〗_2 and ∝∝'ββ. Red blood cells of cutthroat trout contain both ATP and GTP, suggesting that, in contrast to rainbow trout, both nucleotides may be important physiological modulators of hemoglobin oxygen affinity in this fish.

The purposes of this paper are threefold: 1) To provide a justification for the increased use of native plants in mountain land development, not only in northeastern Utah, but in the entire western United States. 2) To investigate and delineate what the physical needs of a plant materials list are. 3) To provide a nearly comprehensive list of basically unused plants native to northeastern Utah and to highlight their landscaping potentials based on the earlier investigation. Also touched upon, to help landscape architectural students and professionals alike, are two cursory case studies and a chapter which deals briefly with the problems of nursery supply of native plants and the potential and future research.

Due to the significant threats posed by nonnative fish species worldwide, it is important to understand how life-history strategies of individual species interact with environmental conditions to explain the success or failure of nonnative fish invasions. Brown trout are prolific invaders, but often exhibit upstream distributional limits in Intermountain West streams, potentially due to a maladaptive reproductive life-history strategy influenced by hydrologic conditions in high-elevation areas. We used redd counts, egg survival experiments, and temperature modeling to investigate the reproductive life-history strategy of brown trout and its potential for success along an elevational stream gradient. We documented brown trout spawning in stream reaches at elevations higher than where we typically encounter brown trout during summer electrofishing surveys, indicating the potential for upstream invasion. We observed a decline in egg survival at higher elevation, cooler water sites, but did not document complete recruitment failure at these sites, again indicating the potential for successful invasion at this life-stage. Temperature data indicate that during most years, incubating brown trout eggs would likely fail to emerge from the gravel prior to peak spring flows in these high-elevation stream reaches, suggesting that damaging spring floods may cause significant egg and sac-fry mortality at high elevations, and may determine invasion success in these areas. Our results highlight the importance of identifying specific mechanisms of recruitment failure in order to better predict nonnative fish invasions in the future.

Devido ao consumo predatório e ao risco inerente de extinção de várias espécies de peixes, pesquisadores têm buscado técnicas alternativas de reprodução para viabilizar tanto o cultivo como a conservação ex situ. Os transplantes xenogênicos de gônadas representam uma técnica reprodutiva inovadora e já existem resultados promissores em diversas espécies de mamíferos, aves, insetos e também de peixes. No entanto, a baixa eficiência na geração de gametas alógenos consiste em uma das limitações desta técnica. Um dos possíveis motivos seria o desencadeamento de reações de rejeição por parte do hospedeiro, comum em transplante de órgãos e tecidos humanos. Dentro deste contexto, visamos identificar e avaliar a interferência destes mecanismos durante o processo de enxerto de gônada de truta arco-íris entre linhagens diferentes e salmão do Atlântico, identificando possíveis graus de respostas imunológicas utilizando enxertos autógenos, isógenos, alógenos e xenógenos. Tais avaliações foram feitas pela análise histopatológica dos tecidos transplantados e dos locais dos implantes. Com os resultados obtidos, pudemos avaliar que a resposta imunológica em implantes de tecidos alogênicos e xenogênicos é bem evidente. Já no enxerto de células germinativas dissociadas houve apenas um discreto processo inflamatório em todas as variações dos enxertos, o que pode representar uma adaptação técnica viável e mais eficaz para a obtenção de gametas. / Due the predatory consumption and the inherent risk of extinction of various species of the fish, investigate the alternatives of reproduction to make viable the cultivation as an ex situ. Xenogeneic transplants of gonads represent an innovative reproductive technique and those that can already be found in various species of animals, birds, insects and fish. However, a low efficiency in the range of allogenic gametes is one of the limitation of this technique. A probable cause would be related to an immune response process that would lead to rejection of the transplanted tissue, as observed in organs and tissues transplantation in human. In this context, we aimed to identify and to evaluate the presence of immune rejection mechanisms during the process of gonads tissues transplantation among different rainbow trout lineages and to Atlantic salmon, observing possible response degrees according to the nature of the graft: autogenic, isogenic, allogeneic or xenogeneic transplantations. Histopathological analysis of the transplanted tissues and of the implanted sites were conducted. Results showed a clear evidence of an immune response in allogeneic and xenogeneic implants. Dissociated gonad cells grafts showed a discrete inflammatory process disregarding the graft nature, that may be an indication of a feasible and more efficient technique adaption to obtain viable gametes.

Object - oriented ecosystem modelling was introduced in the early of 1990s ( Silvert, 1992 ). From that time on, ecosystem models using object - oriented programming ( OOP ) has earned significant achievements with increasing upgraded information technology. The common purposes of ecosystem modellers are to build a model with flexible structure, which allow continuous modifications on the model content. In last decade, ecosystem modellers have put a large number of efforts to practice the OOP approaches in order to implement a true object - oriented ecosystem model. However, these previous work have not fully take advantage of object - orientation because of misusing more or less this technique. This paper explains the shortcoming of these previous endeavours therewith points out a practical solution that using the methodology of object - oriented software engineering and some relative novel information techniques. A case study SALMO - OO will be presented in this paper to prove Silvert ' s assumption that OOP play an important role on ecosystem modelling approaches. Moreover, the results of SALMO - OO convince that object - oriented ecosystem modelling can be achieved by using object - oriented software engineering associating with a true object - oriented programming language ( Java in this case ). / Thesis (M.Sc.)--School of Earth and Environmental Sciences, 2006.

<p>The effect of water temperature prey capture success and foraging behavior of drift-feeding juvenile brown trout (<em>Salmo trutta</em>) was examined in a laboratory stream. Water temperature treatments were 5.7, 6.7, 8.0, 10, 12 and 14°C. Five wild brown trout, age 1+ and collected by electrofishing from a stream in Western Sweden, were used in the experiments. There was a significant effect of water temperature on both prey capture probability and the percentage of time spent resting on the substrate while drift-feeding. At low water temperatures the fish suffered a reduced prey capture capability and spent more time resting on the substrate in between the excursions to capture drifting prey. Temperature did not significantly affect the amount of time fish spent foraging holding a station in the current versus active searching. Significant positive correlations were found between holding a station and prey capture probability at four out of the six different water temperature treatments.</p><p> </p>

The number of species extinctions is increasing at an alarming rate. Long-lived freshwater mussels of the order Unionoida, which include a parasitic stage on a host fish, are highly threatened. Habitat degradation by turbidity and sedimentation is thought to be one major reason for their decline. The objective of this thesis was to examine recruitment patterns and identify the causes of the lack of recruitment in the threatened unionoid freshwater pearl mussel (Margaritifera margaritifera). In addition, I investigated the effects of turbidity on non-endangered dreissenid mussels, where turbidity was manipulated through use of bioturbating mayflies. In a survey of 107 Swedish streams, mussel population size and trout density were both positively correlated to recruitment probability of M. margaritifera. A more in-depth study of the age-structure of nine populations revealed that four of these populations showed no signs of recruitment over the last ten years. Within-stream variation in recruitment was high as both mussels and trout had patchy distribution, and may be important for population regulation. Moreover, examination of different life stages revealed no differences in the gravid mussel stage or the stage when mussels infect salmonid fish. Instead, differences were observed for the juvenile, benthic stage, presumably related to differences in turbidity and sedimentation. High turbidity may affect filter-feeding efficiency of mussels and high sedimentation may reduce survival by clogging sediments, thereby altering, for example, oxygen and food conditions. In the study of the effects of turbidity, bioturbating mayflies increased turbidity and filter-feeding dreissenid mussels reduced turbidity. Mussel growth both decreased and increased with increasing turbidity, depending on sediment type. Turbidity and sedimentation often impact entire stream systems, and a holistic, catchment-based management strategy may be needed to reduce the effects of sedimentation on freshwater pearl mussels. The effects of restoration take a long time and must start soon if recruitment of mussels is to be re-established. Restoration may also be more urgent in some streams than in others, as the maximum age of M. margaritifera populations in my study differed by as much as 60 years. As mussel and trout densities seem to be important for recruitment success, one conservation method may be to concentrate mussels into sites where trout density is high.

Flodpärlmusslan (Margaritifera margaritifera. L) har en obligatorisk fas i sin komplexa livcykel där den lever som parasit på antingen öringens (Salmo trutta, L) eller laxens (Salmo salar, L) gälar. För värdfisken skulle detta kunna innebära en ökad energikostnad när den födosöker i rinnande vatten. Öringens furagering består i att den finner en utgångspunkt (eng. focal point) i strömmen utifrån vilken den fångar sina byten. I denna studie undersöks det om en infektion av flodpärlmusslans glochidielarver på öring påverkar öringens födointag och hantering av födan. Sextio årsungar av öring infekterades med glochidielarver av känd koncentration, och deras födosökning mättes över en 10-veckors period för att bedöma effekten av den växande mussellarven i jämförelse med en icke-infekterad (kontrollgrupp) grupp fiskar. Individuella födoförsök, tio försök per mätningstillfällena, utfördes i ett strömakvarium där en enskild öring matades med drivande föda i fem minuter. Bytet släpptes ned i strömmen med två sekunders intervall, antalet byten räknades och furageringsbeteendet observerades. Födoförsöken genomfördes med två veckors intervall. Vid försöken hittades inga signifikanta skillnader med avseende på: 1) antalet fångade byten, 2) proportionen av fångade byten av försökets första tre minuter, eller 3) de rumsliga aspekterna av öringens utgångspunkt. Vidare uppmättes ingen signifikant effekt av tid på furageringsframgången på den infekterade gruppen jämfört med kontrollgruppen. Däremot var det ett högre antal infekterade individer som spottade ut byten jämfört med kontrollgruppen. Skillnaden i utspottade byten pekar på att infektionen har en negativ påverkan på fiskarnas furageringsförmåga. Dock visade försöken inga resultat som stödjer tidigare studier där signifikant skillnad erhållits med avseende på födointag. Förklaring till detta kan finnas i metodskillnader mellan denna och tidigare studier, inklusive skillnad i typ av byte, strömakvarier, ursprungsström för musslorna och öringen och infektionsgrad hos de infekterade fiskarna samt kontrollgruppen. / The freshwater pearl mussel (Margaritifera margaritifera, L) has a mandatory phase of its complex life cycle where it lives as a parasite on the gills of either trout (Salmo trutta, L) or salmon (Salmo salar, L). For the host fish this could mean an increased cost when it forages in running water. The trout´s foraging consists of finding a focal point in the stream from where it catches its prey. This study examines whether an infection of the freshwater pearl mussel´s glochidium larva on the gills of brown trout affect trout foraging. Sixty juvenile (0+) brown trout were infected with glochidium larva of a known concentration, and trout foraging behaviour was measured over a 10-week period to assess the effects of the growing mussel larvae of the fish compared to non-infected (control) fish.  Individual feeding trials, ten replicates for each session, were conducted in a stream aquarium where a single trout was fed drifting prey for five minutes. The prey were released into the stream every two seconds, the number of prey captured was counted, and the foraging behavior was characterized. Feeding trials were conducted at two-week intervals. No significant differences between the infected and control groups were found for: 1) the number of prey eaten, 2) the proportion of prey eaten during the first three minutes of the trial, or 3) location of the focal points. Furthermore, there was no significant effect of time on foraging success of the infected group compared to the control group. However, there was a higher number of infected individuals who spat out the prey compared with the control group. The difference in rejected prey suggests that the infection has a negative impact on the fish’s foraging ability. However, the results of this experiment do not support previous studies, where a significant difference was obtained with respect to food intake. This might be explained by differences in experimental protocol between this and previous studies, including differences in prey type, stream aquaria, stream origins of mussels and trout, and the infection status of infected and control fish.

Leptin is a peripheral adiposity signal and a key hormone in energy balance regulation in mammals, acting as a link between nutritional status and the endocrine reproductive axis. If this is also the role of leptin in fish is not fully understood. This thesis investigates how different components of the leptin system are affected by sexual maturation and seasonal changes in energy balance in male Atlantic salmon (Salmo salar L.) parr under fully fed and feed-restricted conditions. Moreover, the role of sex steroids as being one of the possible mechanisms by which sexual maturation interacts with leptin is explored. The salmon leptin-a genes, lepa1 and lepa2, were expressed mainly in liver and the leptin receptor (lepr) in brain and ubiquitously in peripheral tissues. Seasonal characterization of the lepa genes and lepr during the growth and reproductive season in one-year old males showed that hepatic lepa1 and lepa2 mRNA levels and plasma leptin levels were down-regulated concomitantly with an increase in weight and body fat. Feed restriction up-regulated hepatic leptin, and pituitary lepr expression as well as plasma leptin levels. Correlation between leptin levels and body lipid stores were either lacking or negative. These findings show that leptin and lepr are sensitive to changes in energy balance, but that leptin might not reflect adiposity in juvenile salmon. Hepatic lepa1 and lepa2, and testicular lepr expression increased during mid- to late spermatogenesis in early maturing males. This up-regulation was preceded by rapid gonadal growth and elevated pituitary follicle-stimulating hormone gene expression levels, whereas peak leptin levels coincided with peak pituitary luteinizing hormone expression and the presence of running milt in the testes. The sex steroids testosterone (T), 11-ketotestosterone and 17-β estradiol stimulated lepa1 and lepa2 gene expression in Atlantic salmon hepatocytes in vitro differentially depending on developmental stage. T was also able to stimulate hepatic lepa1 and pituitary lepa1 and lepr gene expression in immature male salmon in vivo. These results suggest that leptin plays a role in male fish reproduction during later stages of the maturational process and that the elevation of leptin expression during spermatogenesis could be caused by androgen stimulation.

L'article 2 de la tesi enviat a la revista Conservation Biology, finalment va ser publicat a la revistat Conservation Genetics 3:385:400, 2002 / L'estudi de la diversitat i la diferenciació genètiques de les poblacions de truita comuna (Salmo trutta L.) a la Península Ibèrica ha confirmat l'elevada diferenciació observada en treballs previs i la divergència, ja descrita, entre les poblacions de la vessant atlàntica i la mediterrània. El resultats obtinguts, però, ens permeten observar patrons d'estructura poblacional tant en les poblacions atlàntiques com les mediterrànies. A l'Atlàntic s'observa un marcat patró hidrogràfic en la distribució de la diferenciació genètica, que contrasta fortament amb la distribució d'aquesta diferenciació en les poblacions mediterrànies, caracteritzades pels contactes secundaris entre llinatges durant les expansions pleniglacials i una forta divergència local conseqüència de la seva marginalitat i aïllament en els períodes interglacials. El manteniment d'aquesta diferenciació i individualitat descrites en les poblacions de truita de la Península, es veu seriosament compromès per les contínues repoblacions dels rius amb exemplars exògens d'origen nord europeu. La substitució dels genomes autòctons per la introducció de gens al.lòctons provoca una erosió dels patrimonis genètics natius i una homogeneïtzació de les poblacions, destruint els patrons de diferenciació existents. Al mateix temps, els nostres resultats indiquen que les conseqüències de les repoblacions no són sempre les mateixes. Concretament, es constata un fracàs de les repoblacions en rius intensament repoblats i sotmesos a pesca intensiva, que contrasta amb una enorme erosió de les poblacions quan les repoblacions s'efectuen sobre àrees protegides i sense cap mena de pressió pesquera. Això suggereix que múltiples factors com la gestió dels rius posterior a les repoblacions, l'estat de les poblacions o les condicions de l'hàbitat són determinants de la introducció efectiva dels exemplars alliberats; fet que dificulta la predicció sobre actuacions particulars. Malgrat aquesta introgressió de gens exògens que es detecta en moltes de les poblacions analitzades, els gens natius predominen en gairebé tots els rius de la Península. La conservació d'aquesta elevada riquesa genètica que encara resta en les poblacions de truita de la Península Ibèrica ha de ser l'objectiu final de qualsevol programa de gestió. Per això, defensem una gestió basada en el propi riu mitjançant una pesca sostinguda per la reproducció natural de les poblacions salvatges, acompanyada d'una millora i recuperació d'hàbitats adequats per la truita, i evitant, per sobre de tot, la introducció en els rius d'exemplars exògens, degut als efectes nocius i incontrolables que comporta aquest procés. / Our study on the genetic diversity and differentiation of brown trout (Salmo trutta L.) population of the Iberian Peninsula confirmed the high levels of differentiation and the divergence between Atlantic and Mediterranean populations previously described. However, additional substructuring among Atlantic rivers and among Mediterranean ones has been detected. In the Atlantic, genetic diversity is related with the river network, producing a marked hydrographical pattern in sharp contrast with a mosaic distribution of genetic variation among the Mediterranean collections. In this later area, genetic resources distributed as a result of distinct colonization episodes during pleniglacial expansions, secondary contacts, and local divergence due to its marginality and isolation in the interglacial periods. Continuous stocking with hatchery-reared fish of north European origin, seriously compromises the conservation of this differentiation and individuality described in brown trout populations of the Iberian Peninsula. Replacement of the autochthonous genome due to introduction of exogenous genes is leading to an erosion of the native gene pools, a homogenisation of populations, and a destruction of the ancestral patterns of differentiation. At the same time, our results indicated that successful stocking appears to be limited to wild populations subjected to occasional releases in protected or unfished areas. Extensive stocking in fished areas result in a more limited impact on the recipient native population. These results suggest that stocking success is unpredictable and controlled by different factors including habitat and population conditions at the time of stocking, as well as post-release management actuations. Although many of the analysed populations are introgressed with exogenous genes, native gene pools predominate in almost all the Iberian rivers. Conservation of this high genetic richness that still remains in brown trout Iberian populations must be the final goal of any management program. So, our management proposal is based on fisheries sustained by natural reproduction of the respective wild populations, coupled with an improvement and recovery of habitat suitable for brown trout; avoiding stocking with exogenous fish due to the harmful and incontrollable risks that this process involves for the genetic resources of the species.