Digitala Vetenskapliga Arkivet

Change search
Refine search result
1 - 32 of 32
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Almqvist, Gustaf
    et al.
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Strandmark, Alma K.
    Appelberg, Magnus
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Has the invasive round goby caused new links in Baltic food webs?2010In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 89, no 1, p. 79-93Article in journal (Refereed)
    Abstract [en]

    The Ponto-Caspian round goby (Neogobius melanostomus, Pallas 1814) most probably was established in the Gulf of GdaA""sk, Baltic Sea, in the late 1980's and has since become one of the dominant species in the region. In this study we assess the role of round gobies as prey for two important fish species in the Gulf of GdaA""sk, cod (Gadus morhua) and perch (Perca fluviatilis). We compared their present diet with stomach analyses from the area prior the round goby establishment, as well as with diet analysis from Baltic regions where round gobies are absent. There were large differences in the diet between cods from the Gulf of GdaA""sk 2003-2006 compared to cods in earlier studies (1977-1981) from the Southern Baltic Sea. There were also large differences in cod and perch diets from areas with and without round goby. Presently, round goby constitutes the most important prey for medium sized cods in Gulf of GdaA""sk, and perch from the same area almost exclusively feed on gobiids. Stomach analysis, trophic level estimates, and stable isotope analyses all indicated that cod and perch in Gulf of GdaA""sk after the round goby establishment belonged to a similar trophic level. Beside round goby, no mussel feeding fish contributed much to the diet of cod or at all to the diet of perch. Thus, it is likely that round gobies constitute a new energetic pathway from mussels to top predators. However, due to the short time elapsed after round goby establishment, we can only speculate on the species future impacts on Baltic food webs.

  • 2.
    Amcoff, Mirjam
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Kolm, Niclas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    A test of sensory exploitation in the swordtail characin (Corynopoma riisei) based on colour matchingbetween female prey and a male ornament2014In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 97, no 3, p. 247-254Article in journal (Refereed)
    Abstract [en]

    The sensory exploitation hypothesis states that pre-existing biases in female sensory systems may generate strong selection on male signals to match such biases. As environmental conditions differ between populations, sexual preferences resulting from natural selection are expected to vary as well. The swordtail characin (Corynopoma riisei) is a species in which males carry a flag-like ornament growing from the operculum that has been proposed to function as a prey mimic to attract females. Here, we investigated if female plasticity in feeding preferences is associated with plasticity in preference for an artificial male ornament in this species. Females were trained for 10 days by offering them differently coloured food items and were then tested for changes in preferences for differently coloured artificial male ornaments according to foraging experience. We found a rapid and pronounced change in female preference for the colouration of the artificial ornament according to food training. Thus our results support the possibility that sensory exploitation may act as a driving force for female preferences for male ornaments in this species.

  • 3.
    Amcoff, Mirjam
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Kolm, Niclas
    Multiple male sexual signals and female responsiveness in the swordtail characin, Corynopoma riisei2015In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 98, no 7, p. 1731-1740Article in journal (Refereed)
    Abstract [en]

    In the courtship process, multiple signals are often used between the signaller and the receiver. Here we describe female response to multiple male visual morphological and behavioural signals in the swordtail characin, Corynopoma riisei. The swordtail characin is a species in which males display several morphological ornaments as well as a rich courtship repertoire. Our results show that high courtship intensity was associated with an increased female response towards the male ornament, increased number of mating attempts and a reduction in female aggression. The morphological aspects investigated here did not seem to correlate with female response. This may indicate that, when both behaviour and morphology are considered simultaneously, courtship behaviour may have priority over morphological cues in this species.

  • 4.
    Amcoff, Mirjam
    et al.
    Uppsala University, Sweden.
    Kolm, Niclas
    Stockholm University, Faculty of Science, Department of Zoology.
    Multiple male sexual signals and female responsiveness in the swordtail characin, Corynopoma riisei2015In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 98, no 7, p. 1731-1740Article in journal (Refereed)
    Abstract [en]

    In the courtship process, multiple signals are often used between the signaller and the receiver. Here we describe female response to multiple male visual morphological and behavioural signals in the swordtail characin, Corynopoma riisei. The swordtail characin is a species in which males display several morphological ornaments as well as a rich courtship repertoire. Our results show that high courtship intensity was associated with an increased female response towards the male ornament, increased number of mating attempts and a reduction in female aggression. The morphological aspects investigated here did not seem to correlate with female response. This may indicate that, when both behaviour and morphology are considered simultaneously, courtship behaviour may have priority over morphological cues in this species.

  • 5. Backstrom, Tobias
    et al.
    Heynen, Martina
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Brannas, Eva
    Nilsson, Jan
    Winberg, Svante
    Magnhagen, Carin
    Anaesthesia and handling stress effects on pigmentation and monoamines in Arctic charr2017In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 100, no 5, p. 471-480Article in journal (Refereed)
    Abstract [en]

    Stress responsiveness differs between individuals and is often categorized into different stress coping styles. Using these stress coping styles for selection in fish farming could be beneficial, since stress is one main factor affecting welfare. In Arctic charr (Salvelinus alpinus) carotenoid pigmentation is associated with stress responsiveness and stress coping styles. Thus this could be an important tool to use for selection of stress resilient charr. However, anaesthetics seem to affect carotenoid pigmentation, and it would be better if the method for selection could be implemented during normal maintenance, which usually includes anaesthetics. Therefore, this study investigated how the use of anaesthetics affected carotenoid pigmentation, i.e. number of spots, over time compared to no-anaesthetic treatment. Additionally, the stress indicators monoamines and glucocorticoids were investigated. The results indicate that the anaesthetic MS-222 affects number of spots on the right side. This anaesthetic also increased dopaminergic activity in the telencephalon. Both brain dopaminergic and serotonergic activity was associated with spottiness. Further, behaviour during anaesthetization was associated with spots on the left side, but not the right side. Repetition of the same treatment seemed to affect spot numbers on the right side. In conclusion, this study shows that inducing stress in charr affects the carotenoid spots. Thus, it is possible to use anaesthetics when evaluating spottiness although careful planning is needed.

    Download full text (pdf)
    fulltext
  • 6.
    Backström, Tobias
    et al.
    Swedish Univ Agr Sci, Dept Wildlife Fish & Environm Studies, Umea, Sweden..
    Heynen, Martina
    Dept Ecol & Environm Sci, Umea, Sweden..
    Brännäs, Eva
    Swedish Univ Agr Sci, Dept Wildlife Fish & Environm Studies, Umea, Sweden..
    Nilsson, Jan
    Swedish Univ Agr Sci, Dept Wildlife Fish & Environm Studies, Umea, Sweden..
    Winberg, Svante
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Magnhagen, Carin
    Swedish Univ Agr Sci, Dept Wildlife Fish & Environm Studies, Umea, Sweden..
    Anaesthesia and handling stress effects on pigmentation and monoamines in Arctic charr2017In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 100, no 5, p. 471-480Article in journal (Refereed)
    Abstract [en]

    Stress responsiveness differs between individuals and is often categorized into different stress coping styles. Using these stress coping styles for selection in fish farming could be beneficial, since stress is one main factor affecting welfare. In Arctic charr (Salvelinus alpinus) carotenoid pigmentation is associated with stress responsiveness and stress coping styles. Thus this could be an important tool to use for selection of stress resilient charr. However, anaesthetics seem to affect carotenoid pigmentation, and it would be better if the method for selection could be implemented during normal maintenance, which usually includes anaesthetics. Therefore, this study investigated how the use of anaesthetics affected carotenoid pigmentation, i.e. number of spots, over time compared to no-anaesthetic treatment. Additionally, the stress indicators monoamines and glucocorticoids were investigated. The results indicate that the anaesthetic MS-222 affects number of spots on the right side. This anaesthetic also increased dopaminergic activity in the telencephalon. Both brain dopaminergic and serotonergic activity was associated with spottiness. Further, behaviour during anaesthetization was associated with spots on the left side, but not the right side. Repetition of the same treatment seemed to affect spot numbers on the right side. In conclusion, this study shows that inducing stress in charr affects the carotenoid spots. Thus, it is possible to use anaesthetics when evaluating spottiness although careful planning is needed.

    Download full text (pdf)
    fulltext
  • 7. Blom, Eva-Lotta
    et al.
    Mueck, Isabel
    Heubel, Katja
    Svensson, Ola
    Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, Gothenburg, SE-405 30, Sweden.
    Acoustic and visual courtship traits in two sympatric marine Gobiidae species - Pomatoschistus microps and Pomatoschistus minutus2016In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 99, no 12, p. 999-1007Article in journal (Refereed)
    Abstract [en]

    Divergence in courtship traits across species can evolve as adaptations to different environments, and also through avoidance of reproductive interference and character displacement. Differences may also be explained by phylogenetic relationships. We compared different courtship traits, including male courtship sounds, in two sympatric Pomatoschistus species. Both species are characterised by having male and female courtship, and paternal care of eggs in nests under mussel shells and rocks. In addition to presenting novel observations, we reviewed the literature on courtship traits for both species and complemented it with new observations. We found that courting males of the common goby P. microps sing louder and produce sounds of shorter duration than males of the sand goby P. minutus. Furthermore, males of P. microps swim faster towards females during courtship than males of P. minutus. The eyes of P. minutus females turn black during courtship attempts, whereas this is not the case for females of P. microps. Species-specific differences in courtship sounds and behavior may lead to different susceptibility of the two species to environmental change such as noise pollution and turbidity.

  • 8.
    Costalago, David
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Nelson Mandela Metropolitan University, South Africa.
    Potter, Paige
    Pattrick, Paula
    Strydom, Nadine A.
    Influence of environmental variables on the larval stages of anchovy, Engraulis encrasicolus, and sardine, Sardinops sagax, in Algoa Bay, South Africa2018In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 101, no 2, p. 225-236Article in journal (Refereed)
    Abstract [en]

    We investigated the environmental drivers of larval abundance of anchovy Engraulis encrasicolus and sardine Sardinops sagax in Algoa Bay, Eastern Cape (South Africa). This study comprised a pre-drought post-drought time period, comparing the responses of the fish larvae to different factors before and after the drought. The current study presents, for the first time, which environmental variables are affecting the anchovy and sardine larvae populations in the region. Easterly wind speed and zooplankton density were the only environmental variables that presented a significant change between the pre- and post-drought periods, increasing after the drought. Generalized additive models (GAMs) were used in order to explore the effects that environmental factors might have in the abundance of anchovy and sardine larvae in Algoa Bay. Specifically, the GAM that best explained the deviance of the anchovy larvae dynamics included the covariates rainfall, easterly wind speed, Chl a concentration, sardine larvae abundance and the interactions SST*Chla and sard*SST. The GAM best explaining sardine larvae abundance included only the easterly wind speed as a covariate. This model showed that there was a positive relationship between the higher values of wind speed and sardine larvae abundance.

  • 9. Cunha, Mario
    et al.
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Monteiro, Nuno
    The intrinsically dynamic nature of mating patterns and sexual selection2015In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 98, no 4, p. 1047-1058Article in journal (Refereed)
    Abstract [en]

    Selection processes are influenced by both biotic and abiotic variables, most of which seasonally fluctuate. Therefore, selection may also vary temporally. Specifically, sexual selection, an integral component of natural selection, will inevitably exhibit temporal variation but the scale at which these changes occur are still not well understood. In this study, performed on a wild population of the sex-role reversed black striped pipefish Syngnathus abaster (Risso, 1827), we contrast variables such as male reproductive success, mating success, female investment, mate choice and operational sex ratio between two periods, either near the onset or end of the breeding season. Sexual selection is stronger early in the breeding season. Male reproductive and mating success are significantly affected by male size during the onset of the breeding season but not during the end. Moreover, we found that larger females reproduce mainly during the onset while smaller females had increased chances of reproducing towards the end. As our sampling was performed in two consecutive years, it could be argued that our results stem primarily from between-year variation. Nevertheless, variation in demographic parameters from the onset to the end of the breeding season is similar to that observed in past sampling events. Hence, we suggest that the change in mating patterns within the breeding season derives from seasonal fluctuations in several abiotic (e.g., temperature) and biotic variables (e.g., operational sex ratio), rendering the expression of selective forces, such as sexual selection, inherently dynamic.

  • 10.
    Enefalk, Åsa
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Huusko, Ari
    National Resources Institute, Finland.
    Louhi, Pauliina
    University of Oulu, Finland.
    Bergman, Eva
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Fine stream wood decreases growth of juvenile brown trout (Salmo trutta)2019In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 102, no 5, p. 759-770Article in journal (Refereed)
    Abstract [en]

    In this study, the growth rate, gut fullness, diet composition and spatial distribution of brown trout was compared between artificial channels with and without fine wood (FW). Access to FW resulted in significantly lower brown trout growth rates over the study period from late summer to early winter as water temperatures declined from 17 °C to 1 °C. Access to FW resulted in minor differences in occurrence of the most common taxa found in brown trout diets, except for chironomid larvae which were found in c. 60% of the brown trout guts from control treatments but in only 30% of the guts from FW treatments in early winter. Diet consisted primarily of case-bearing and free-living Trichoptera larvae, Asellus, chironomid and Ephemeroptera larvae. Brown trout gut fullness was not significantly affected by access to FW bundles. Brown trout aggregated among FW but were more evenly distributed in channels lacking it. Our results suggest that juvenile brown trout use FW as a shelter at a wide range of water temperatures, and that this behaviour may result in reduced growth rates during their first fall and the onset of their first winter. We also show that prey availability and the composition of brown trout diet changes from late summer to early winter and that FW has a small but significant effect on brown trout diet composition.

    Download full text (pdf)
    fulltext
  • 11.
    Engstedt, Olof
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Stenroth, Patrik
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Larsson, Per
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Ljunggren, Lars
    Fiskeriverket.
    Elfman, Mikael
    Lunds universitet, Kärnfysik.
    Assessment of natal origin of pike (Esox lucius) in the Baltic Sea using Sr:Ca in otoliths2010In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 89, p. 547-555Article in journal (Refereed)
    Abstract [en]

    Spawning habitat of pike (Esox lucius) in the Baltic Sea include brackish water bays, brooks and rivers. Elevated salinity concentrations are one of several stressors that might increase the use and importance of freshwater habitats for spawning. In the Baltic Sea, one of the largest brackish seas in the world, freshwater species like pike, perch (Perca fluviatilis), whitefish (Coregonus sp), bream (Abramis brama), ide (Leuciscus idus), roach (Rutilus rutilus) and burbot (Lola iota) all undertake spawning migrations to freshwater. However, over the last decades populations densities of these species have declined, and recruitment failure has been argued to be at least part of the problem. The importance of brooks and rivers as spawning areas for these species have not been quantified and set in relation to spawning success in brackish bays. In this study, we collected 175 adult pike (Esox lucius) on their foraging grounds in the sea. Fish were collected in two regions on the Baltic coast, more than 600 km apart. Subsequently we determined their origin (freshwater or marine) using otolith chemistry. Sagittal otoliths were analysed for strontium using the PIXE-method. The results show that 80 of the 175 pike were recruited in freshwater, and several of the larger specimens showed reoccurring migration behaviour. Data show that freshwater is an important recruitment habitat for Baltic Sea pike, suggesting that habitat improvements in rivers entering the Baltic Sea might significantly contribute to population restoration.

  • 12.
    Gustafsson, Pär
    et al.
    Karlstad University, Faculty of Social and Life Sciences, Department of Biology.
    Greenberg, Larry
    Karlstad University, Faculty of Social and Life Sciences, Department of Biology.
    Bergman, Eva
    Karlstad University, Faculty of Social and Life Sciences, Department of Biology.
    Woody debris and terrestrial invertebrates: effects on prey resourses for brown trout (Salmo trutta) in a boreal stream2014In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 97, no 5, p. 529-542Article in journal (Refereed)
    Abstract [en]

    Intensive forestry and other activities that alter riparian vegetation may disrupt the connectivity and the flux of energy between terrestrial and aquatic habitats and have large effects on biota, especially in small streams. We manipulated the amount of in-stream wood and the flux of terrestrial invertebrate subsidies to determine how these factors affected potential food resources for drift-feeding brown trout (Salmo trutta ) in a boreal Swedish forest stream. Specifically, we followed the effects on the abundance of aquatic and terrestrial invertebrate fauna from June to August 2007. The treatments were 1) addition of wood, unmanipulated terrestrial invertebrate inputs, 2) reduction of terrestrial invertebrate inputs (using canopy covers), no addition of wood, 3) unmanipulated ambient conditions, 4) simultaneous addition of wood and reduction of terrestrial invertebrate inputs. Added wood resulted in greater biomass of aquatic invertebrate biomass, and both input and drift of terrestrial invertebrates were reduced by canopy covers. In terms of total potential prey biomass, the addition of wood with ambient levels of terrestrial invertebrate inputs had the highest standing crop of benthic, wood-living and terrestrial invertebrates combined, whereas the treatment with reduced terrestrial input and no wood added had the lowest standing crop. Our study indicates that forest practices that both reduce the recruitment of wood and the input of terrestrial invertebrates to small streams have negative effects on prey availability for drift-feeding brown trout. The positive effects of wood addition on biomass of aquatic macroinvertebrates may partly compensate for the negative effects of reduced terrestrial invertebrate subsidies.

  • 13.
    Hart, Paul BJ
    et al.
    Department of Biology, University of Leicester, Leicester LE1 7RH, UK.
    Bergman, Eva
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Calles, Olle
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Eriksson, Stina
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Gustafsson, Stina
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Lans, Linnea
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Norrgård, Johnny R
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Piccolo, John J
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Rees, Nina
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Watz, Johan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Österling, Martin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Greenberg, Larry
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Familiarity with a partner facilitates the movementof drift foraging juvenile grayling (Thymallus thymallus) into a new habitatarea2014In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 97, no 5, p. 515-522Article in journal (Refereed)
    Abstract [en]

    Preferring one social partner over another can enhance fitness. This paper reports that juvenile grayling were significantly more likely to enter and forage in new, upstream habitats when paired with familiar versus unfamiliar social partners. Fish paired with unfamiliar partners or when alone were more reluctant to enter the new area. The entry times for both fish in a familiar pair were significantly correlated, but uncorrelated for unfamiliar fish. These differences between familiars and unfamiliars were consistent over a 2-week period. Fish with familiar partners spent more time within three body lengths of each other than did those with unfamiliars. The results are discussed in relation to optimality models of drift foraging, which do not included sociality. It is suggested that the social dimension creates a more dynamic foraging response to variable environmental conditions and could have consequences for growth.

  • 14.
    Kolm, Niclas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Environmental correlates of diet in the swordtail characin (Corynopoma riisei, gill)2011In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 92, no 2, p. 159-166Article in journal (Refereed)
    Abstract [en]

    In the sexually dimorphic swordtail characin (Corynopoma riisei, Gill), males are equipped with an opercular flag-ornament that has been suggested to function as a food-mimic since females bite at the ornament during courtship. However, virtually nothing is known about the diet in wild populations of this species. In this study, we first investigated composition of and variation in the diet of C. riisei across 18 different populations in Trinidad, using gut content analyses. We then related variation in gut content to habitat features of populations to investigate the potential link between environmental conditions and prey utilization. Our results showed that the dominating food type in the gut was various terrestrial invertebrates, both adults and larvae, but we also document substantial variation in prey types across populations. Furthermore, a canonical correlation analysis revealed a relationship between environmental characteristics and diet: populations from wider and more rapidly flowing streams with more canopy cover tended to have a diet based more on ants and mosquitoes while populations from narrow and slow flowing streams with little canopy cover tended to have a diet based more on springtails, mites and mayfly larvae. Our results add novel information on the ecology of this interesting fish and suggest the possibility of local adaptation reflecting differences in prey availability across natural populations.

  • 15.
    Kolm, Niclas
    et al.
    Uppsala universitet, Zooekologi.
    Arnqvist, Göran
    Uppsala universitet, Zooekologi.
    Environmental correlates of diet in the swordtail characin (Corynopoma riisei, gill)2011In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 92, no 2, p. 159-166Article in journal (Refereed)
    Abstract [en]

    In the sexually dimorphic swordtail characin (Corynopoma riisei, Gill), males are equipped with an opercular flag-ornament that has been suggested to function as a food-mimic since females bite at the ornament during courtship. However, virtually nothing is known about the diet in wild populations of this species. In this study, we first investigated composition of and variation in the diet of C. riisei across 18 different populations in Trinidad, using gut content analyses. We then related variation in gut content to habitat features of populations to investigate the potential link between environmental conditions and prey utilization. Our results showed that the dominating food type in the gut was various terrestrial invertebrates, both adults and larvae, but we also document substantial variation in prey types across populations. Furthermore, a canonical correlation analysis revealed a relationship between environmental characteristics and diet: populations from wider and more rapidly flowing streams with more canopy cover tended to have a diet based more on ants and mosquitoes while populations from narrow and slow flowing streams with little canopy cover tended to have a diet based more on springtails, mites and mayfly larvae. Our results add novel information on the ecology of this interesting fish and suggest the possibility of local adaptation reflecting differences in prey availability across natural populations.

  • 16.
    Kolm, Niclas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology, Animal Ecology.
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Sex-specific territorial behaviour in the Banggai cardinalfish, Pterapogon kauderni2004In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 70, no 4, p. 375-379Article in journal (Refereed)
    Abstract [en]

    In a field experiment, we studied how levels of aggression in males and females in established pairs of the Banggai cardinalfish were influenced by the sex of an experimentally introduced individual larger and more attractive than its resident counterpart. Contrary to previous studies on other cardinalfish species, and contrary to expectations in a sex role reversed species, the male was the main aggressor towards an intruder. Moreover, residents were more aggressive towards an intruder of the same sex as themselves. Furthermore, even though females often courted introduced, larger males, no intruder managed to take over the partnership of any resident. We suggest that our findings imply relatively equal sex roles in the Banggai cardinalfish and we discuss the evolution of sex specific territory defence and its significance in the Banggai cardinalfish as well as the implications of such behaviour in the interpretations of sex roles in general.

  • 17.
    Kolm, Niclas
    et al.
    Uppsala universitet, Zooekologi.
    Berglund, Anders
    Uppsala universitet, Zooekologi.
    Sex-specific territorial behaviour in the Banggai cardinalfish, Pterapogon kauderni2004In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 70, no 4, p. 375-379Article in journal (Refereed)
    Abstract [en]

    In a field experiment, we studied how levels of aggression in males and females in established pairs of the Banggai cardinalfish were influenced by the sex of an experimentally introduced individual larger and more attractive than its resident counterpart. Contrary to previous studies on other cardinalfish species, and contrary to expectations in a sex role reversed species, the male was the main aggressor towards an intruder. Moreover, residents were more aggressive towards an intruder of the same sex as themselves. Furthermore, even though females often courted introduced, larger males, no intruder managed to take over the partnership of any resident. We suggest that our findings imply relatively equal sex roles in the Banggai cardinalfish and we discuss the evolution of sex specific territory defence and its significance in the Banggai cardinalfish as well as the implications of such behaviour in the interpretations of sex roles in general.

  • 18.
    Larsson, Stefan
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Linnansaari, Tommi
    Vatanen, Sauli
    Serrano, Ignacio
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Haikonen, Ari
    Feeding of wild and hatchery reared Atlantic salmon (Salmo salar L.) smolts during downstream migration2011In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 92, no 3, p. 361-369Article in journal (Refereed)
    Abstract [en]

    In general, hatchery salmonid smolts experience higher mortality during migration than wild smolts, which is suggested to be due to domestication effects and that hatchery fish lack experience of the natural environment. However, possible differences in feeding during smolt migration between hatchery and wild smolts have rarely been addressed. We compared the number of feeding smolts and stomach fullness among wild Atlantic salmon smolts, hatchery-reared smolts released as 1-year-old parr, and hatchery-reared smolts released as 2-year-old smolts during their descent to sea in River Tornionjoki. In addition, estimations of prey selection among the smolt groups were conducted. A high proportion of wild smolts and smolts stocked as parr actively fed during the smolt migration. A lower proportion of smolts stocked as smolts was feeding and their stomach fullness were much reduced in comparison with the two other groups. The study also indicated that the feeding of migrating smolts is selective rather than opportunistic. In conclusion, this study suggests that stocked 2-year-old smolts may enter sea with an inferior foraging behaviour and it is a possibility that this may contribute to the observed low post-smolt survival in the Baltic Sea.

  • 19.
    Linløkken, Arne
    et al.
    Karlstad University, Faculty of Social and Life Sciences, Department of Biology.
    Bergman, Eva
    Karlstad University, Faculty of Social and Life Sciences, Department of Biology.
    Greenberg, Larry
    Karlstad University, Faculty of Social and Life Sciences, Department of Biology.
    Holt Seeland, Per Arne
    Environmental correlates of population variables of perch (Perca fluviatilis) in boreal lakes2008In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 82, no 4, p. 401-408Article in journal (Refereed)
    Abstract [en]

    We examined relationships among perch population variable parameters in two types of lakes, lakes with perch (P-lakes, n = 15) and lakes with perch and roach (PR-lakes, n  = 10) using redundancy analysis (RDA) to relate population variables to environmental factors. Effects from environmental factors were tested for significance by means of permutation tests (Monte Carlo). Three factors, pH, altitude and fraction of roach (by number) in the gill net catches, explaining 47.9% of the variation, had significant effects on perch population variables. The significance of pH was improved by partialing out the effect of conductivity and roach. Similarly, the significance of altitude was improved by partialing out the effect of pH and roach, and the significance of roach was improved by partialing out the effect of pH and altitude. When the fraction of pike in the catch was included in the analysis, the effect of roach was not significant and vice-versa, as roach and pike fractions were correlated with each other. The effect of pike was significant when roach was not included, but the effect was not as strong as the effect of roach. A biplot was constructed by plotting population variables on the first and second RDA axis, with arrows showing five selected environmental factors. Growth of 3+ to 5+ perch was positively related to pH and altitude, perch catch per unit effort was negatively related to pH and altitude, and age specific perch weight was negatively related to fraction of roach. The relationship between growth of 2+ perch and pH was not as strong as the relationship between pH and the growth of older perch. Moreover, the growth of 2+ perch was negatively related to the fraction of roach, probably due to competition between young zooplankton feeding perch and roach.

  • 20.
    Lisney, Thomas J.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Hawryshyn, Craig W.
    Ocular dimensions and cone photoreceptor topography in adult Nile Tilapia Oreochromis niloticus2010In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 88, no 4, p. 369-376Article in journal (Refereed)
    Abstract [en]

    Information on the anatomy of the eye and the topography of cone photoreceptor cells in the retina is presented for the Nile Tilapia (Oreochromis niloticus). In adults, the shape and proportions of the ocular components of the prominent eye conform to the general form of fish eyes, as determined using cryo-sectioned eyes. The lens is approximately spherical and there is little variation in the distance from the centre of the lens to the border between the choroid and retina at a range of angles about the optical axis. The average ratio of the distance from the centre of the lens to the retina: lens radius (Matthiessen's ratio) is 2.44:1. In retinal wholemounts, single and double (twin) cone photoreceptors, forming a square mosaic, are present. Peak photoreceptor densities for both morphological cone types are found in the temporal retina. Using peak cone densities and estimates of focal length from cryo-sectioned eyes, visual acuity is calculated to be 5.44 cycles per deg. The lack of apparent specific ocular or retinal specializations and the relatively low visual acuity reflect the lifestyle of the Nile Tilapia and may allow it to adapt to changes in visual environment in its highly variable natural habitat as well as contributing to the 'ecological flexibility' of this species.

  • 21.
    Lissåker, Maria
    Stockholm University, Faculty of Science, Department of Zoology.
    Does time of the season influence filial cannibalism in the sand goby, Pomatoschistus minutus?2007In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 80, no 1, p. 69-75Article in journal (Refereed)
    Abstract [en]

    According to life-history theory, filial cannibalism by fish that breed over one season only should be more beneficial early than late in the season if they eat eggs to invest energy into later clutches. Also, filial cannibalism may be more costly late in the season if finding ripe females for replacing eaten eggs is harder then. On the other hand, offspring hatching early may have a competitive advantage over fry hatching late and hence provide higher fitness to the parent. Using data collected over three successive years, I tested if sand goby males are more prone to eat of their eggs early than late in the reproductive season. I found no difference in the amount of eggs eaten or in the frequency of males eating the whole clutch between early and late in the season. Furthermore, there was no difference in the frequency of males who ate parts of their clutches, early compared to late. This might reflect a tradeoff between quality (early hatching offspring) and quantity (producing as many offspring as possible over a long reproductive season). If so, the lack of seasonal pattern of filial cannibalism found in sand gobies might be the result of opposing selection pressures.

  • 22. Milbrink, Göran
    et al.
    Petersson, Erik
    Holmgren, Staffan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Long-term effects of nutrient enrichment on the condition and size-structure of an alpine brown trout population2008In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 81, no 2, p. 157-170Article in journal (Refereed)
  • 23.
    Milbrink, Göran
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Petersson, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Holmgren, Staffan
    Long-term effects of nutrient enrichment on the condition and size-structure of an alpine brown trout population2008In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 81, no 2, p. 157-170Article in journal (Refereed)
    Abstract [en]

    Long-term effects of nutrient enrichment on a population of brown trout inhabiting a small, alpine lake in north-central Sweden have been studied for nearly 20 years. The study took place between 1981 and 1999 starting up between 1982 and 1987 with full nutrient enrichment of phosphorus and nitrogen in a ratio by weight of 1:8, followed by a period of reduction by half between 1988 and 1994, and thereafter no enrichment at all. Growth of the brown trout population was low before the application of nutrients. Fertilization promoted the development of zooplankton in great abundance, which gave rise to abundant food for the trout. Already during the first year of nutrient addition the average 4+ and 5+ fish had increased in weight by nearly 50% and in length by about 30%. Maximum growth was reached 5-6 years later-weight by about 175% and length by about 50% higher than before application. The slope of the growth curves for fish of ages 2+ to 5+ increased significantly from 1981 to 1987, and so did the size-variation with a high proportion of the fish reaching larger size. After each change in nutrient treatment the mean weights of 5-6-year-old trout were maintained for about 3 years. Five years after termination of fertilization growth was nearly back to the original state. Although badly needed, long-term studies of fish populations like this are few in the literature.

  • 24.
    Näslund, Joacim
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. University of Gothenburg, Sweden.
    Rosengren, Malin
    Johnsson, Jörgen I.
    Fish density, but not environmental enrichment, affects the size of cerebellum in the brain of juvenile hatchery-reared Atlantic salmon2019In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 102, no 5, p. 705-712Article in journal (Refereed)
    Abstract [en]

    This paper describes a study on the environmentally dependent brain size plasticity in hatchery-reared Atlantic salmon Salmo salar L. Using a factorial experimental design, we tested whether tank fish density, local hatchery standard (150 fish . m(-2)) vs. reduced (50 fish . m(-2)) and structural enrichment, a bundle of submerged plastic stripes, had effects on the size of the cerebellar region of the brain. Fish reared at reduced density had smaller cerebella, while structural enrichment had no detectable effects. The density effect on cerebellum, which is involved in locomotion and cognition, confirms previous results from hatchery-reared Atlantic salmon. The lack of detectable positive effects of enrichment, which contrasts some previous studies, provide further evidence for a complex relationship between environmental complexity and brain growth.

  • 25.
    Piccolo, John J
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Frank, Beatrice M
    Hayes, John W
    Food and space revisited: The role of drift-feeding theory in predicting the distribution, growth, and abundance of stream salmonids2014In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 97, p. 475-488Article in journal (Refereed)
  • 26.
    Piccolo, John J.
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Noakes, David L. G.
    Oregon State University, USA.
    Hayes, John W.
    Cawthron Institute, New Zealand.
    Preface to the special drift foraging issue of Environmental Biology of Fishes2014In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 97, no 5, p. 449-451Article in journal (Refereed)
  • 27.
    Robinson-Wolrath, Sarah
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution.
    Video Playback Versus Live Stimuli for Assessing Mate Choice in a Pipefish2006In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 75, no 4, p. 409-414Article in journal (Refereed)
    Abstract [en]

    In this study, I investigated the application of the video playback technique to studies on mate choice in the pipefish, Syngnathus typhle. In this sex-role reversed species, the males are predominately the choosing sex, and given a choice, prefer to mate with larger females. As such, I tested if this known mate preference remained when using this novel experimental technique. Specifically, I compared the response of males to video images of females to that of live females. Results revealed that male pipefish showed a stronger preference for the larger female in the video playback treatment than in the clear glass (two-way interaction) live female treatment. This experiment has, therefore, demonstrated that the pipefish respond in the predicted direction in response to video playback, and as such proves to be a reliable method to study mate preferences in this species.

  • 28.
    Scharnweber, Kristin
    et al.
    Department of Biology and Ecology of Fishes, Leibniz Institute of Freshwater Ecology & Inland Fisheries, Berlin.
    Plath, Martin
    Tobler, Michael
    Feeding efficiency and food competition in coexisting sexual and asexual livebearing fishes of the genus Poecilia2011In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 90, no 2, p. 197-205Article in journal (Refereed)
    Abstract [en]

    Considering its immediate costs of producing dispensable males, the maintenance of sexual reproduction is a major paradox in evolutionary biology. Asexual lineages that do not face such costs theoretically should replace sexuals over time. Nonetheless, several systems are known in which closely related sexual and asexual lineages stably coexist. In the present study, we studied a sexual/asexual mating complex of a sperm-dependent parthenogenetic fish (amazon molly, Poecilia formosa) and its sexual congeners, the sailfin molly P. latipinna and the Atlantic molly P. mexicana. We asked whether differences in feeding behavior could contribute to their stable coexistence. We conducted a laboratory experiment to compare feeding efficiencies and also measured the competitive abilities between the two reproductive forms. Additionally, we measured gut fullness of fishes caught in natural habitats. Contrary to our predictions, we could not find P. formosa to be less efficient in feeding. We argue that food competition in mollies plays a minor role in mediating coexistence between closely related asexual and sexual mollies.

  • 29. Vincent, Amanda C.J.
    et al.
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Ahnesjö, Ingrid
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Reproductive ecology of five pipefish species in one eelgrass meadow1995In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 44, no 4, p. 347-361Article in journal (Other academic)
    Abstract [en]

    Synopsis Pipefishes have rarely been watched in the wild and have never before been followed in their common seagrass habitats. This study explores the reproductive ecology of five species of pipefishes living in a Swedish eelgrass meadow during parts of four breeding seasons, tagging four of the species. Pipefish are remarkable for their specialised paternal care: only males aerate, osmoregulate and nourish the developing embryos. Two of the species (Entelurus aequoreus andNerophis ophidion) have simple ventral gluing of eggs on the trunk while three species (Syngnathus acus, S. rostellatus andS. typhle) have fully enclosed brood pouches on their tails. Males of the former species receive eggs from one female while males of the genusSyngnathus receive partial clutches from several females. Sex ratios of adults on the site differed from equal to male-biased to female-biased, according to species.S. typhle were most numerous and were resighted most often. They were present throughout the breeding season whereas there were temporal shifts in the presence of the other species on the meadow and in some sex ratios. Most species occurred in the deeper, denser part of the meadow but there was some habitat separation by species and sex. All species tended to stay low in the eelgrass, primarily coming up above the eelgrass to display and mate. No species showed site fidelity either to a home range or to the meadow, withE. aequoreus adults spending least time on the meadow. Sexual size dimorphism differed: males were larger inS. rostellatus, the same size inS acus and smaller in the other species. Although the species overlap in habitat requirements and breeding season, the only observed interspecific interactions were abortive courtships betweenSyngnathus species.

  • 30.
    Watz, Johan
    et al.
    Karlstad University, Faculty of Social and Life Sciences, Department of Biology.
    Piccolo, John
    Karlstad University, Faculty of Social and Life Sciences, Department of Biology.
    Bergman, Eva
    Karlstad University, Faculty of Social and Life Sciences, Department of Biology.
    Greenberg, Larry
    Karlstad University, Faculty of Social and Life Sciences, Department of Biology.
    Day and night drift-feeding by juvenile salmonids at low water temperatures2014In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 97, no 5, p. 505-513Article in journal (Refereed)
    Abstract [en]

    Drift-feeding salmonids in boreal streams face temperatures below physical optima for extensive periods of the year. Because juvenile salmonids react to low water temperatures by becoming nocturnal, knowledge about their foraging ability at low light intensities in cold water is needed to accurately estimate energy intake during non-summer conditions. In a laboratory stream channel, we studied temperature effects on the drift-feeding behaviour of juvenile Atlantic salmon, brown trout, and European grayling in simulated daylight and moonlight at temperatures ranging from 2 °C to 11 °C. Prey capture probability was positively related to temperature, but the temperature dependence did not agree with predictions of the Metabolic Theory of Ecology. Furthermore, reaction distance was positively related to temperature for the three species, which may be one of the underlying mechanisms responsible for the temperature effects on prey capture probability. Overall, the three species had similar capture rates at the different temperature and light levels, although there were species differences. European grayling had a slightly higher prey capture probability than brown trout, and brown trout had a shorter reaction distance than Atlantic salmon and European grayling. These results have implications for both energetics-based drift-foraging theory and for studies of winter ecology.

  • 31.
    Öhman, Marcus C.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Rajasuriya, Arjan
    National Aquatic Resources Agency, Sri Lanka.
    Relationships between habitat structure and fish communities on coral and sandstone reefs1998In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 53, p. 19-31Article in journal (Refereed)
    Abstract [en]

    The influence of habitat structure on reef-fish communities at Bar Reef Marine Sanctuary, Sri Lanka, was investigated. The relationship between habitat characteristics and the distribution and abundance och 135 species of fishes was examined on two reef types: coral and sandstone reefs. Results suggested that the reef fish communities were strongly influenced by various aspects of reef structure. However, relationships between habitat variables and fish communities structure, varied between the two reef types. Fish species diversity was correlated with a number of habitat variables on the sandstone reefs, although structural complexity seemed to play the dominant role. There were no correlations between habitat structure and fish diversity on the coral reefs. Total abundance was not related to any one habitat parameter on either reef type. However, abundances of some species, families and trophic groups were correlated with habitat features. These specific correlations were commonly related to food and shelter availability. For example, coral feeders were correlated with live coral cover, and pomacentrid species, which used branching corals for protection, showed a significant relationship with the density of Acropora colonies. This shows that a summary statistic such as total abundance may hide important information. Effects of habitat structure on the distribution patterns of the fish communities was further investigated using multidimensional scaling ordination and the RELATE-procedure. With the MDS-ordinations for both habitat and fish community composition it was possible to show that the multivariate pattern between the two ecological components was clearly correlated.

  • 32.
    Österling, Martin
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Ferm, Julia
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Piccolo, John J.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Parasitic freshwater pearl mussel larvae (Margaritifera margaritifera L.) reduce the drift-feeding rate of juvenile brown trout (Salmo trutta L.)2014In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 97, p. 543-549Article in journal (Refereed)
    Abstract [en]

    In this paper we describe, for the first time, the effects of freshwater pearl mussel (Margaritifera margaritifera L.) encystment on the drift-feeding behavior of juvenile brown trout (Salmo trutta L.). Because both mussel and salmonid populations are often threatened, this study not only adds knowledge to the understanding of host-parasite systems, but it is also of conservation value. Individual trout, mussel-encysted (25.1 ± 5.7 larvae · g-1 body weight, n = 5) or non-encysted (n = 5), were fed with chironomid larvae in a flow-through stream aquarium. Feeding trials were filmed and analyzed by counting the numbers of chironomid larvae each individual ate, and by estimating the prey-capture distance. Non-encysted trout had a significantly higher drift-foraging rate than did encysted trout, and they captured significantly more prey further away from their focal point. Thereduced foraging success of encysted trout was mainly due to their failure to catch prey relatively further from their focal point. This suggests that reduced foraging success of encysted trout may be due to poorer energetic status, butthe physical effects of mussel larvae on prey handling time cannot be ruled out. Encysted trout caught approximately 20% fewer prey, which would result in a reduction in growth potential during the period of mussel encystment. Reduced energetic status might also result in reduced competitive ability or in increased exposure to predation risk.

    Download full text (pdf)
    Authors_proof
1 - 32 of 32
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf