Search results for "Stickleback"
showing 10 items of 11 documents
Consistent isotopic differences between Schistocephalus spp. parasites and their stickleback hosts
2015
Published version available at http://dx.doi.org/10.3354/dao02893 Parasite−host systems show markedly variable patterns in isotopic fractionation: parasites can be either depleted or enriched in 15N and 13C as compared to their hosts. However, it remains unknown whether isotopic fractionation patterns are similar in comparable parasite−host systems from markedly different ecosystems. Results of this study show that large-sized Schistocephalus spp. endoparasites are consistently depleted in 15N (by on average −2.13 to −2.20‰) as compared to their nine-spined stickleback Pungitius pungitius and three-spined stickleback Gasterosteus aculeatus hosts. The differences between parasites and host f…
Assaying waterborne psychoactive drugs by the response to naturalistic predator cues in the stickleback (Gasterosteus aculeatus)
2020
Abstract Ecotoxicological effects of psychiatric drugs and drug metabolites released by the human population are of increasing environmental concern. In this study we evaluate behavioral responses to visual predator cues in wild caught three-spined stickleback (Gasterosteus aculeatus) after exposure to water-born citalopram, a widely prescribed selective serotonin reuptake inhibitor with antidepressant and anxiolytic effects. Fish were exposed to ecological relevant concentrations of citalopram (0.15 or 1.5 μg L−1) for 10 or 20 days. After drug exposure, individual fish were moved to a test arena where they were exposed to two naturalistic visual predator cues; a shadow from beneath, which …
Large differences in catch per unit of effort between two minnow trap models
2013
Background: Little is known about variation in catch per unit of effort (CPUE) in stickleback fisheries, or the factors explaining this variation. We investigated how nine-spined stickleback (Pungitius pungitius) CPUE was influenced by trap model by comparing the CPUEs of two very similar minnow trap models fished side-by-side in a paired experimental design. Results: The galvanized trap type (mean CPUE = 1.31 fish h–1) out-fished the black trap type (mean CPUE = 0.20 fish h–1) consistently, and yielded on average 81% more fish. Conclusions: The results demonstrate that small differences in trap appearance can have large impacts on CPUE. This has implications for studies designed to investi…
Spatiotemporal and gender-specific parasitism in two species of gobiid fish
2018
Parasitism is considered a major selective force in natural host populations. Infections can decrease host condition and vigour, and potentially influence, for example, host population dynamics and behavior such as mate choice. We studied parasite infections of two common marine fish species, the sand goby (Pomatoschistus minutus) and the common goby (Pomatoschistus microps), in the brackish water Northern Baltic Sea. We were particularly interested in the occurrence of parasite taxa located in central sensory organs, such as eyes, potentially affecting fish behavior and mate choice. We found that both fish species harbored parasite communities dominated by taxa transmitted to fish through …
Community structure affects trophic ontogeny in a predatory fish.
2016
While most studies have focused on the timing and nature of ontogenetic niche shifts, information is scarce about the effects of community structure on trophic ontogeny of top predators. We investigated how community structure affects ontogenetic niche shifts (i.e., relationships between body length, trophic position, and individual dietary specialization) of a predatory fish, brown trout (Salmo trutta). We used stable isotope and stomach content analyses to test how functional characteristics of lake fish community compositions (competition and prey availability) modulate niche shifts in terms of (i) piscivorous behavior, (ii) trophic position, and (iii) individual dietary specialization. …
Segregation and co-occurrence of larval cestodes in freshwater fishes in the Bothnian Bay, Finland
1992
SUMMARYTwo autogenic (Triaenophorus crassus and T. nodulosus) and four allogenic (Diphyllobothrium latum, D. dendriticum, D. ditremum and Schistocephalus solidus) larval cestode species were found in 13 out of 31 fish species studied from the Bothnian Bay, NE Baltic. Gasterosteus aculeatus was the most heavily infected fish with 4 larval cestode species; for two of them (D. ditremum and S. solidus) the three-spined stickleback was found to be the required fish intermediate host. Among allogenic cestode species, those restricted to different definitive host species segregated their larval population in relation to the fish host, while, for example, D. ditremum and S. solidus, both maturing i…
Characterisation of the external features ofSchistocephalus solidus (M�ller, 1776) (Cestoda) from different geographical regions and an assessment of…
1995
A comparative study of some morphological (segment number, scolex morphology and biometry, length and weight) and biological (maturation in different hosts) features ofSchistocephalus solidus plerocercoids and adults from different geographical regions (Baltic Sea and the British Isles) was carried out. The length of the plerocercoids fromGasterosteus aculeatus was shown to be the variable that best correlated with segment number. A very clear bimodal distribution of segment numbers separated the majority of British and Baltic plerocercoids (British n=21, mean length 25.48, SD 5.63, range 14–34 mm; mean segment number 66.33, SD 8.68, range 51–86. Baltic n=30, mean length 33.23, SD 4.64, ran…
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…
Divergent Macroparasite Infections in Parapatric Swiss Lake-Stream Pairs of Threespine Stickleback (Gasterosteus aculeatus)
2015
Spatial heterogeneity in diversity and intensity of parasitism is a typical feature of most hostparasite 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 populationpairs 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…
Cannibalism facilitates gigantism in a nine-spined stickleback (Pungitius pungitius) population
2016
Cannibalism is a taxonomically widespread phenomenon that can fundamentally affect the structure and stability of aquatic communities, including the emergence of a bimodal size distribution (“dwarfs” and “giants”) in fish populations. Emergence of giants could also be driven or facilitated by parasites that divert host resources from reproduction to growth. We studied the trophic ecology of giant nine-spined sticklebacks (Pungitius pungitius) in a Finnish pond to evaluate the hypotheses that gigantism in this population would be facilitated by cannibalism and/or parasitic infections by Schistocephalus pungitii cestode. Stomach content analyses revealed an initial ontogenetic dietary shift f…