0000000000223829

AUTHOR

Bjarni K. Kristjánsson

0000-0001-6984-5771

showing 3 related works from this author

Variation in egg size and offspring phenotype among and within seven Arctic charr morphs.

2022

Maternal effects have the potential to alter early developmental processes of offspring and contribute to adaptive diversification. Egg size is a major contributor to offspring phenotype, which can influence developmental trajectories and potential resource use. However, to what extent intraspecific variation in egg size facilitates evolution of resource polymorphism is poorly understood. We studied multiple resource morphs of Icelandic Arctic charr, ranging from an anadromous morph—with a phenotype similar to the proposed ancestral phenotype—to sympatric morphs that vary in their degree of phenotypic divergence from the ancestral anadromous morph. We characterized variation in egg size and…

egg sizediversificationEcologyevoluutiobiologianieriädevelopmental plasticitymunatresource polymorphismemotmaternal effectsjälkeläisetfenotyyppifreshwatermuuntelu (biologia)Ecology Evolution Behavior and SystematicsNature and Landscape ConservationEcology and evolution
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Variation in parasite resistance of Arctic charr, Salvelinus alpinus, between and within sympatric morphs

2021

Abstract Genetic variation in resistance against parasite infections is a predominant feature in host–parasite systems. However, mechanisms maintaining genetic polymorphism in resistance in natural host populations are generally poorly known. We explored whether differences in natural infection pressure between resource‐based morphs of Arctic charr (Salvelinus alpinus) have resulted in differentiation in resistance profiles. We experimentally exposed offspring of two morphs from Lake Þingvallavatn (Iceland), the pelagic planktivorous charr (“murta”) and the large benthivorous charr (“kuðungableikja”), to their common parasite, eye fluke Diplostomum baeri, infecting the eye humor. We found t…

0106 biological sciencesgenetic structuresZoologyparasitismiBiology010603 evolutionary biology01 natural sciencesParasite loadnieriätrematode03 medical and health sciencesloisetAdaptive radiationGenetic variationParasite hostingmuuntelu (biologia)breeding colorationEcology Evolution Behavior and SystematicsResearch ArticlesQH540-549.5030304 developmental biologyNature and Landscape ConservationSalvelinusOriginal Research0303 health sciencesResistance (ecology)freshwater fish ecotypeEcologyhost–parasite interactionimumadothost– parasite interactionbiology.organism_classificationgeneettinen muunteluresistenssiimmunogenesspeciationSympatric speciationSexual selectionadaptive radiationEcology and Evolution
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Water temperature, not fish morph, determines parasite infections of sympatric Icelandic threespine sticklebacks (Gasterosteus aculeatus)

2013

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 hos…

0106 biological sciencesstickleback morphotypeseducationZoologyhabitat specializationGasterosteus010603 evolutionary biology01 natural sciencesADAPTIVE RADIATIONSCENTRAL FINLANDEcological speciation03 medical and health sciencesCATARACT FORMATIONecological speciation14. Life underwaterPERCH PERCA-FLUVIATILISSPATIAL VARIATION3-SPINED STICKLEBACKSEcology Evolution Behavior and SystematicsOriginal Research030304 developmental biologyNature and Landscape ConservationTREMATODE PARASITESAbiotic componentAdaptive radiationHELMINTH COMMUNITIES0303 health sciencesARCTIC CHARRBiotic componentEcologybiologyEcologyCOMPONENT COMMUNITYSticklebackbiology.organism_classification6. Clean waterDiplostomumhost-parasite interactionsHabitatSympatric speciation1181 Ecology evolutionary biologyFreshwater fishta1181lajiutuminenAdaptive radiation; Diplostomum; Ecological speciation; Habitat specialization; Stickleback morphotypes; Host-parasite interactionsEcology and Evolution
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