| 1. |
- Sigvald, Roland, et al.
(författare)
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Molecular identification of bloodmeals and species composition in Culicoides biting midges
- 2013
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Ingår i: Medical and Veterinary Entomology. - : Wiley. - 0269-283X .- 1365-2915. ; 27, s. 104-112
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Tidskriftsartikel (refereegranskat)abstract
- Investigations of host preferences in haematophagous insects, including Culicoides biting midges (Diptera: Ceratopogonidae), are critical in order to assess transmission routes of vector-borne diseases. In this study, we collected and morphologically identified 164 blood-engorged Culicoides females caught in both light traps and permanent 12-m high suction traps during 20082010 in Sweden. Molecular analysis of the mitochondrial cytochrome c oxidase subunit I (COI) gene in the biting midges was performed to verify species classification, discern phylogenetic relationships and uncover possible cryptic species. Bloodmeal analysis using universal vertebrate cytochrome b primers revealed a clear distinction in host selection between mammalophilic and ornithophilic Culicoides species. Host sequences found matches in horse (n = 59), sheep (n = 39), cattle (n = 26), Eurasian elk (n = 1) and 10 different bird species (n = 18). We identified 15 Culicoides species previously recorded in Scandinavia and four additional species haplotypes that were distinctly different from the described species. All ornithophilic individuals (n = 23) were caught exclusively in the suction traps, as were, interestingly, almost all mammalophilic species (n = 41), indicating that many biting midge species may be able to cover long distances after completing a bloodmeal. These results add new information on the composition of Culicoides species and their host preferences and their potential long-distance dispersal while blood-engorged.
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| 2. |
- Witzgall, Peter, et al.
(författare)
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"This is not an Apple"-Yeast Mutualism in Codling Moth
- 2012
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Ingår i: Journal of Chemical Ecology. - : Springer Science and Business Media LLC. - 1573-1561 .- 0098-0331. ; 38:8, s. 949-957
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Tidskriftsartikel (refereegranskat)abstract
- The larva of codling moth Cydia pomonella (Tortricidae, Lepidoptera) is known as the worm in the apple, mining the fruit for food. We here show that codling moth larvae are closely associated with yeasts of the genus Metschnikowia. Yeast is an essential part of the larval diet and further promotes larval survival by reducing the incidence of fungal infestations in the apple. Larval feeding, on the other hand, enables yeast proliferation on unripe fruit. Chemical, physiological and behavioral analyses demonstrate that codling moth senses and responds to yeast aroma. Female moths are attracted to fermenting yeast and lay more eggs on yeast-inoculated than on yeast-free apples. An olfactory response to yeast volatiles strongly suggests a contributing role of yeast in host finding, in addition to plant volatiles. Codling moth is a widely studied insect of worldwide economic importance, and it is noteworthy that its association with yeasts has gone unnoticed. Tripartite relationships between moths, plants, and microorganisms may, accordingly, be more widespread than previously thought. It, therefore, is important to study the impact of microorganisms on host plant ecology and their contribution to the signals that mediate host plant finding and recognition. A better comprehension of host volatile signatures also will facilitate further development of semiochemicals for sustainable insect control.
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| 3. |
- Eggers, Sönke, et al.
(författare)
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Differential demographic responses of sympatric Parids to vegetation management in boreal forest
- 2014
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 319, s. 169-175
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Tidskriftsartikel (refereegranskat)abstract
- Large-scale removal of small-diameter trees (i.e. thinning from below) in boreal forest can diminish niche diversity for birds that rely on a well-developed understory for nesting and foraging. Yet, few studies have examined how reduced niche diversity in managed forests affects fitness measures in closely-related species and the ability of competing species to co-exist. We related forest thinning to population trends of the willow tit Poecile montana (declining) and its dominant competitor the crested tit Lophophanes cristatus (stable), and conducted a 3-year comparative study to determine how variation in understory spruce density differentially influences survival and reproduction in these species. In line with our prediction that crested tits would gain resource priority under conditions of reduced forest understory complexity, willow tits and their nestlings suffered a disproportionate decline in both nest and adult survival prospects relative to crested tits as understoiy spruce density declined. Willow tits also had increased numbers of tail feather fault bars with decreasing understory complexity, further supporting the idea that willow tits suffer from food shortage and increased predation risk in areas of reduced understory. The long-term population declines of willow tits in boreal forest appears linked to large scale harvest of small-diameter spruce trees that provide important understory vegetation. A patchy arrangement of different thinning treatments through 'Understory Retention Thinning' (URT) may provide a cost-effective way to restore long-term structural complexity and biodiversity in densely stocked conifer stands. (C) 2014 Elsevier B.V. All rights reserved.
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| 4. |
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| 5. |
- Kvarnemo, Charlotta, 1963, et al.
(författare)
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Gravida hanar och konkurrerande honor
- 2014
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Ingår i: Havsutsikt. - 1104-0513. ; 2014:1, s. 6-7
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Hos fisken tångsnälla blir pappan gravid. Hanen förser ungarna med syre och näring under utvecklingen, men han kan också själv ta upp näring som kommer från äggen. Honor konkurrerar om att få para sig med hanar som har plats för hennes ägg, och de gillar särskilt att para sig med stora hanar. Trots det ger de ägg med mer näring till små hanar.
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| 6. |
- Sköld, Helen Nilsson, et al.
(författare)
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Hormonal regulation of female nuptial coloration in a fish.
- 2008
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Ingår i: Hormones and behavior. - : Elsevier BV. - 1095-6867 .- 0018-506X. ; 54:4, s. 549-56
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Tidskriftsartikel (refereegranskat)abstract
- Physiological color change in camouflage and mating is widespread among fishes, but little is known about the regulation of such temporal changes in nuptial coloration and particularly concerning female coloration. To better understand regulation of nuptial coloration we investigated physiological color change in female two-spotted gobies (Gobiusculus flavescens). Females of this species develop an orange belly that acts as an ornament. The orange color is caused by the color of the gonads combined with the chromathophore based pigmentation and transparency of the skin. Often during courtship and female-female competition, a rapid increase in orange coloration, in combination with lighter sides and back that increases skin and body transparency, gives the belly an intense 'glowing' appearance. To understand how this increased orange coloration can be regulated we analysed chromatic and transparency effects of neurohumoral agents on abdominal skin biopsies in vitro. We found prolactin and alpha-melanocyte stimulating hormone (MSH) to increase orange coloration of the skin. By contrast, melatonin and noradrenaline increased skin transparency, but had a negative effect on orange coloration. However, mixtures of melatonin and MSH, or melatonin and prolactin, increased both orange coloration and transparency. This effect mimics the chromatic 'glow' effect that commonly takes place during courtship and intra sexual aggression. Notably, not only epidermal chromatophores but also internal chromatophores lining the peritoneum responded to hormone treatments. There were no chromatic effects of the sex steroids 17beta-estradiol, testosterone or 11-ketotestosterone. We hypothesize that similar modulation of nuptial coloration by multiple hormones may be widespread in nature.
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| 7. |
- Trona, Federica, et al.
(författare)
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Neural coding merges sex and habitat chemosensory signals in an insect herbivore
- 2013
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 280:1760, s. 20130267-
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the processing of odour mixtures is a focus in olfaction research. Through a neuroethological approach, we demonstrate that different odour types, sex and habitat cues are coded together in an insect herbivore. Stronger flight attraction of codling moth males, Cydia pomonella, to blends of female sex pheromone and plant odour, compared with single compounds, was corroborated by functional imaging of the olfactory centres in the insect brain, the antennal lobes (ALs). The macroglomerular complex (MGC) in the AL, which is dedicated to pheromone perception, showed an enhanced response to blends of pheromone and plant signals, whereas the response in glomeruli surrounding the MGC was suppressed. Intracellular recordings from AL projection neurons that transmit odour information to higher brain centres, confirmed this synergistic interaction in the MGC. These findings underscore that, in nature, sex pheromone and plant odours are perceived as an ensemble. That mating and habitat cues are coded as blends in the MGC of the AL highlights the dual role of plant signals in habitat selection and in premating sexual communication. It suggests that the MGC is a common target for sexual and natural selection in moths, facilitating ecological speciation.
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| 8. |
- Iwarsson, Mattias
(författare)
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Epifytiska växter i Sverige
- 2015
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Ingår i: Fauna och flora. - 0014-8903. ; 110, s. 26-40
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- A total of 122 vascular plant species arereported growing as epiphytes in Sweden. Wittrock(1894) recorded 105 species, 34 of which were foundalso in the present study. In all, 51 species wew foundin this study, 17 of which were new compared toWittrock (1894).All observations were photo-documented, andthis material can be found in the form of pdf-fileson the Fauna & Flora website http://www.artdata.slu.se/FaunaochFlora/default.asp. Table 3 presents alist of all (122) scientific names in alphabetical order.In accordance with Wittrock (1894), the treesharbouring epiphytes were divided into the followingthree sections: stem-base b 0.1-0.6m above theground, mid-section m 0.6-2m above the ground, oron the unbranched trunk, and crown section k ≥2mabove the ground, or in the tree-crown.When more observations are added, it will probablybecome evident that most epiphytic species cangrow in all three sections.The majority of the epiphytic species (66) are perennials,and six of them are sporophytes. Three speciesare biennial, and 29 are annuals; mainly summer annuals,but also a few winter annuals. 13 shrub speciesand 11 tree species were found as epiphytes. Themost common epiphytic species was, in fact, rowanSorbus aucuparia. The tree species harbouring the largestnumber of epiphytes (31 species) was maple Acerplatanoides.The question of how these species came to growepiphytically is also discussed. None of them is a trueepiphyte, adapted to grow in trees. Evidently some ofthe species are wind-dispersed, whereas many othersare transported by animals (notably ants, squirrels andbirds). Mattias Iwarsson Centrum för biologisk mångfald.E-post: mattias.iwarsson@slu.se and Mattias.Biologi@telia.com
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| 9. |
- Blake, Chelsea A., et al.
(författare)
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Conspecific boldness and predator species determine predation-risk consequences of prey personality
- 2018
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Ingår i: Behavioral Ecology and Sociobiology. - : Springer-Verlag New York. - 0340-5443 .- 1432-0762. ; 72:8, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: Individual variation in the behavior of prey can influence predation risk in complex ways. We ran individual roach (Rutilus rutilus), a common freshwater fish, through a standard refuge emergence protocol to characterize their boldness, a key animal personality trait. We then paired a bold and a shy roach and exposed the pair to one of two predator species that have contrasting hunting modes to ascertain how personality traits shaped their survival during predator encounters. When a paired bold and shy prey fish interacted with a perch predator (active foraging mode), bold and shy prey were consumed in almost equal numbers. However, pike predators (ambush foraging mode) selectively consumed more shy prey, and prey body size and boldness score both contributed significantly to which prey fish was eaten. Our findings support the idea that multiple predators with different foraging modes, and hence differential selection on prey personality, could contribute to maintaining variation in personality in prey populations. Furthermore, for social species, including shoaling fish, the ultimate consequences of an individual’s personality may depend upon the personality of its nearby conspecifics. Significance statement: Animals of the same species often look similar, but individuals show differences in their behavior that can have important consequences, for instance when these individuals interact with predators. The common roach is a freshwater fish that shows inter-individual variation in its propensity to take risks, a key personality trait often termed boldness. Variation in boldness may affect the outcome when roach interact with predators, i.e., if they get eaten or survive. However, we found the impact of roachs’ personality type depends on what species of predatory fish they face. When we put a shy and a bold roach together with predatory perch, the roachs’ personality did not significantly affect which individual was eaten. But when the predator was a pike, the predators selectively ate more shy roach, and the likelihood an individual would be eaten depended on their body size.
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| 10. |
- Braga Gonçalves, Inês, et al.
(författare)
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Effects of female mating order and male size on embryo survival in a pipefish.
- 2015
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Ingår i: Biological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4066 .- 1095-8312. ; 114:3, s. 639-645
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Tidskriftsartikel (refereegranskat)abstract
- In species that provide parental care, individuals should invest adaptively in their offspring in relation to the preand post-zygotic care provided by their partners. In the broad-nosed pipefish, Syngnathus typhle L., females transfer large, nutrient-rich eggs into the male brood pouch during mating. The male broods and nourishes the embryos for several weeks before independent juveniles emerge at parturition. Given a choice, females clearly prefer large partners. Yet, females provide protein-richer eggs when the same individual mates with a smaller than a larger male. In the present study, we allowed each female to mate with one small and one large male, in alternated order. We found a strong effect of female mating order, with larger clutches and higher embryo mortality in first- than second-laid broods, which may suggest that eggs over-ripen in the ovaries or reflect the negative effects of high embryo density in the brood pouch. In either case, this effect should put constraints on the possibility of a female being selective in mate choice. We also found that small and large males produced embryos of similar size and survival, consistent with the reproductive compensation hypothesis, suggesting that, in this species, larger males provide better nourishment to the embryos than smaller males.
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| 11. |
- Hambäck, Peter, et al.
(författare)
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Mating affects resource selection and modulates associational effects between neighbouring resources
- 2017
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Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 126, s. 1708-1716
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Tidskriftsartikel (refereegranskat)abstract
- Associational effects occur when the attack rate on a resource depends on neighbouring resources in the environment. These effects are predicted to result from mismatches experienced by the consumer organism in resource selection along hierarchical search levels. As resource selection depends on sensory information used during search behaviour, we expected that different physiological states of an insect might modulate the outcome of associational effects due to differences in resource selection. We used Drosophila melanogaster, as a model organism for olfactory-guided behaviour in insects, to study the effects of mating induced behavioural changes on associational effects between two alternative resources. We found that mating has no effect on the ability of D. melanogaster to locate resource patches, but rather affects the perception of the resources within the patch. Consequently, we only found associational effects in the experiments with unmated females and not in the experiments with mated females. Our results suggest that the lack of associational effects for mated females resulted from changes in the use of short-range olfactory cues, leading to random selection among the resources. In conclusion, our results suggest that the physiological state of an insect modulates associational effects by affecting resource selection rates within the patch.
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| 12. |
- Kuijper, D. P. J., et al.
(författare)
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Paws without claws? Ecological effects of large carnivores in anthropogenic landscapes
- 2016
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 283:1841
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Tidskriftsartikel (refereegranskat)abstract
- Large carnivores are frequently presented as saviours of biodiversity and ecosystem functioning through their creation of trophic cascades, an idea largely based on studies coming primarily out of relatively natural landscapes. However, in large parts of the world, particularly in Europe, large carnivores live in and are returning to strongly human-modified ecosystems. At present, we lack a coherent framework to predict the effects of large carnivores in these anthropogenic landscapes. We review how human actions influence the ecological roles of large carnivores by affecting their density or behaviour or those of mesopredators or prey species. We argue that the potential for density-mediated trophic cascades in anthropogenic landscapes is limited to unproductive areas where even low carnivore numbers may impact prey densities or to the limited parts of the landscape where carnivores are allowed to reach ecologically functional densities. The potential for behaviourally mediated trophic cascades may be larger and more widespread, because even low carnivore densities affect prey behaviour. We conclude that predator-prey interactions in anthropogenic landscapes will be highly context-dependent and human actions will often attenuate the ecological effects of large carnivores. We highlight the knowledge gaps and outline a new research avenue to study the role of carnivores in anthropogenic landscapes.
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| 13. |
- Lebreton, Sebastien, et al.
(författare)
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Feeding regulates sex pheromone attraction and courtship in Drosophila females
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- In Drosophila melanogaster, gender-specific behavioural responses to the male-produced sex pheromone cis-vaccenyl acetate (cVA) rely on sexually dimorphic, third-order neural circuits. We show that nutritional state in female flies modulates cVA perception in first-order olfactory neurons. Starvation increases, and feeding reduces attraction to food odour, in both sexes. Adding cVA to food odour, however, maintains attraction in fed females, while it has no effect in males. Upregulation of sensitivity and behavioural responsiveness to cVA in fed females is paralleled by a strong increase in receptivity to male courtship. Functional imaging of the antennal lobe (AL), the olfactory centre in the insect brain, shows that olfactory input to DA1 and VM2 glomeruli is also modulated by starvation. Knocking down insulin receptors in neurons converging onto the DA1 glomerulus suggests that insulin-signalling partly controls pheromone perception in the AL, and adjusts cVA attraction according to nutritional state and sexual receptivity in Drosophila females.
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| 14. |
- Näslund, Joacim, 1985, et al.
(författare)
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State-dependent behavior and alternative behavioral strategies in brown trout (Salmo trutta L.) fry
- 2016
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Ingår i: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 0340-5443 .- 1432-0762. ; 70:12, s. 2111-2125
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Tidskriftsartikel (refereegranskat)abstract
- © 2016, The Author(s).Abstract: Animals generally adjust their behavior in response to bodily state (e.g., size and energy reserves) to optimize energy intake in relation to mortality risk, weighing predation probability against the risk of starvation. Here, we investigated whether brown trout Salmo trutta adjust their behavior in relation to energetic status and body size during a major early-life selection bottleneck, when fast growth is important. Over two consecutive time periods (P1 and P2; 12 and 23days, respectively), food availability was manipulated, using four different combinations of high (H) and low (L) rations (i.e., HH, HL, LH, and LL; first and second letter denoting ration during P1 and P2, respectively). Social effects were excluded through individual isolation. Following the treatment periods, fish in the HL treatment were on average 15–21% more active than the other groups in a forced open-field test, but large within-treatment variation provided only weak statistical support for this effect. Furthermore, fish on L-ration during P2 tended to be more actively aggressive towards their mirror image than fish on H-ration. Body size was related to behavioral expression, with larger fish being more active and aggressive. Swimming activity and active aggression were positively correlated, forming a behavioral syndrome in the studied population. Based on these behavioral traits, we could also distinguish two behavioral clusters: one consisting of more active and aggressive individuals and the other consisting of less active and aggressive individuals. This indicates that brown trout fry adopt distinct behavioral strategies early in life. Significance statement: This paper provides information on the state-dependence of behavior in animals, in particular young brown trout. On the one hand, our data suggest a weak energetic state feedback where activity and aggression is increased as a response to short term food restriction. This suggests a limited scope for behavioral alterations in the face of starvation. On the other hand, body size is linked to higher activity and aggression, likely as a positive feedback between size and dominance. The experiment was carried out during the main population survival bottleneck, and the results indicate that growth is important during this stage, as 1) behavioral compensation to increase growth is limited, and 2) growth likely increases the competitive ability. However, our data also suggests that the population separates into two clusters, based on combined scores of activity and aggression (which are positively linked within individuals). Thus, apart from an active and aggressive strategy, there seems to be another more passive behavioral strategy.
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| 15. |
- Uller, Tobias, 1977, et al.
(författare)
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Direct exposure to corticosterone during embryonic development influences behaviour in an ovoviviparous lizard
- 2006
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Ingår i: ETHOLOGY. - : Wiley. - 0179-1613 .- 1439-0310. ; 112:4, s. 390-397
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Tidskriftsartikel (refereegranskat)abstract
- It is becoming increasingly clear that conditions experienced during embryonic development can be of major importance for traits subsequent to parturition or hatching. For example, in mammals, offspring from stressed mothers show a variety of changes in behavioural, morphological, and life-history traits. The effects of maternal stress on trait development are believed to be mediated via transfer of glucocorticoids, the main hormones released during the stress response, from mother to offspring. However, also other physiological maternal responses during stress could be responsible for changes in offspring phenotype. We investigated the direct effects of corticosterone on offspring development, without other confounding factors related to increased maternal stress, by injection of corticosterone in eggs of the ovoviviparous lizard Lacerta vivipara. Corticosterone-manipulated offspring did not show impaired development, reduced body size or body condition at parturition. However, corticosterone-treated offspring showed altered anti-predator behaviour, as measured by the time required to emerge from shelter after a simulated predator attack. Differential steroid exposure during development, possibly mediated by maternal stress response, may explain some of the variation in behaviour among individuals in natural populations.
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| 16. |
- Alström, Per
(författare)
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Recent northward range expansion promotes song evolution in a passerine bird, the Light-vented Bulbul
- 2013
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Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 26, s. 867-877
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Tidskriftsartikel (refereegranskat)abstract
- In common with human speech, song is culturally inherited in oscine passerine birds (songbirds'). Intraspecific divergence in birdsong, such as development of local dialects, might be an important early step in the speciation process. It is therefore vital to understand how songs diverge, especially in founding populations. The northward expansion of the Light-vented Bulbul Pycnonotus sinensis (J. F. Gmelin, 1789) into north China in the last 30years provides an excellent opportunity to study birdsong evolution. We compared similar to 4400 songs from newly established northern populations with similar to 2900 songs from southern populations to evaluate song divergence after recent expansion. The total pool of syllables and especially song types was considerably smaller in the north than in the south, indicating founder effects' in the new population. The ancestral pattern of mosaic song dialects changed into a pattern of wide geographical sharing of a few song types and syllables, likely the result of fewer geographical barriers to meme flow', and the recent spread across a large area in the north. Our results suggest that song evolution and vocal trait shifts can arise rapidly after range expansion, and that in the Light-vented Bulbul founder effects', geographical isolation, and recent rapid expansions played important roles in the evolution of song dialects.
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| 17. |
- Barber, I., et al.
(författare)
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Behavioural responses to simulated avian predation in female three spined sticklebacks the effect of experimental Schistocephalus solidus infections
- 2004
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Ingår i: Behaviour. - 0005-7959 .- 1568-539X. ; 141, s. 1425-1440
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Tidskriftsartikel (refereegranskat)abstract
- Plerocercoid larvae of Schistocephalus solidus are common parasites of three-spined sticklebacks that require the ingestion of stickleback hosts by birds to complete their life cycle. Amongst wild-caught sticklebacks, infection is associated with a reduction in antipredator behaviour; however, to date no study has examined the escape responses of experimentally infected sticklebacks, and thus assigning causality remains difficult. Here, we compare aspects of the antipredator behaviour of five experimentally infected female sticklebacks with shamexposed controls over a 16 post-exposure week period. During weeks 1-7 post-exposure, the escape responses of infected fish did not differ significantly from those of sham-exposed fish. However, over weeks 9-15, when infected fish had developed plerocercoids of >50 mg—the size at which they become infective to birds —a lower proportion of infected fish performed directional responses and reached cover within 2 s of the strike. Infected fish also performed a lower frequency of ‘staggered dashes’, and a higher frequency of ‘slow swims’, than shamexposed fish over weeks 9-15. Amongst sham-exposed fish, re-emergence from cover was uncommon throughout the study, but infected fish regularly left cover during weeks 9-15. Our results support those of previous studies examining behavioural change in naturally infected fish and, although other explanations remain possible, our finding that behaviour change in experimentally-infected fish is limited to hosts harbouring single infective parasites provides further evidence that the behaviour changes may be parasite adaptations.
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| 18. |
- Barber, I., et al.
(författare)
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Effects of experimental Schistocephalus solidus infections on growth, morphology and sexual development of female three-spined sticklebacks, Gasterosteus aculeatus
- 2003
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Ingår i: Parasitology. - 0031-1820 .- 1469-8161. ; 126, s. 359-367
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Tidskriftsartikel (refereegranskat)abstract
- The use of naturally infected hosts in studies attempting to identify parasite-induced changes in host biology is problematical because it does not eliminate the possibility that infection may be a consequence, rather than a cause, of host trait variation. In addition, uncontrolled concomitant infections may confound results. In this study we experimentally infected individual laboratory-bred female three-spined sticklebacks Gasterosteus aculeatus L. with the pseudophyllidean cestode Schistocephalus solidus [Muller], and compared the morphology and growth patterns of infected females with sham-exposed controls over a 16-week period. Fish were fed a ration of 8% body weight per day. Non-invasive image analysis techniques allowed the growth of individual plerocercoids to be tracked in vivo throughout the course of infection, and patterns of host and parasite growth were determined. Females that developed infections diverged morphometrically from unexposed control females and exposed-uninfected females at 6 weeks post-infection, with the width of the body at the pectoral fins giving the earliest indication of infection success. When including the plerocercoid, infected females gained weight more quickly than controls, but when plerocercoid weight was removed this trend was reversed. There was no effect of infection on the increase in fish length. Plerocercoids grew at different rates in individual hosts, and exhibited measurable sustained weight increases of up to 10% per day. Final estimates of plerocercoid weight from morphometric analysis prior to autopsy were accurate to within +/-17% of actual plerocercoid weight. At autopsy, infected female sticklebacks had significantly lower perivisceral fat reserves but had developed significantly larger ovaries than controls. The results are discussed in relation to previous studies examining natural infections, and the value of utilizing experimental infections to examine ecological aspects of host-parasite interactions is discussed.
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| 19. |
- Brand, Jack A., et al.
(författare)
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Temperature change exerts sex-specific effects on behavioural variation
- 2023
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - 0962-8452 .- 1471-2954. ; 290:2002
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Tidskriftsartikel (refereegranskat)abstract
- Temperature is a key factor mediating organismal fitness and has important consequences for species' ecology. While the mean effects of temperature on behaviour have been well-documented in ectotherms, how temperature alters behavioural variation among and within individuals, and whether this differs between the sexes, remains unclear. Such effects likely have ecological and evolutionary consequences, given that selection acts at the individual level. We investigated the effect of temperature on individual-level behavioural variation and metabolism in adult male and female Drosophila melanogaster (n = 129), by taking repeated measures of locomotor activity and metabolic rate at both a standard temperature (25°C) and a high temperature (28°C). Males were moderately more responsive in their mean activity levels to temperature change when compared to females. However, this was not true for either standard or active metabolic rate, where no sex differences in thermal metabolic plasticity were found. Furthermore, higher temperatures increased both among- and within-individual variation in male, but not female, locomotor activity. Given that behavioural variation can be critical to population persistence, we suggest that future studies test whether sex differences in the amount of behavioural variation expressed in response to temperature change may result in sex-specific vulnerabilities to a warming climate.
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| 20. |
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| 21. |
- Cattaneo, Alberto Maria, et al.
(författare)
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TRPA5, an Ankyrin Subfamily Insect TRP Channel, is Expressed in Antennae of Cydia pomonella (Lepidoptera : Tortricidae) in Multiple Splice Variants
- 2016
-
Ingår i: Journal of Insect Science. - : Oxford University Press (OUP). - 1536-2442. ; 16
-
Tidskriftsartikel (refereegranskat)abstract
- Transient receptor potential (TRP) channels are an ancient family of cation channels, working as metabotropic triggers, which respond to physical and chemical environmental cues. Perception of chemical signals mediate reproductive behaviors and is therefore an important target for sustainable management tactics against the codling moth Cydia pomonella L. (Lepidoptera: Tortricidae). However, olfactory behavior strongly depends on diel periodicity and correlation of chemical with physical cues, like temperature, and physical cues thus essentially contribute to the generation of behavioral response. From an antennal transcriptome generated by next generation sequencing, we characterized five candidate TRPs in the codling moth. The coding DNA sequence of one of these was extended to full length, and phylogenetic investigation revealed it to be orthologous of the TRPA5 genes, reported in several insect genomes as members of the insect TRPA group with unknown function but closely related to the thermal sensor pyrexia. Reverse transcription PCR revealed the existence of five alternate splice forms of CpTRPA5. Identification of a novel TRPA and its splice forms in codling moth antennae open for investigation of their possible sensory roles and implications in behavioral responses related to olfaction.
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| 22. |
- Corral-López, Alberto, 1984-, et al.
(författare)
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Functional convergence of genomic and transcriptomic architecture underlies schooling behaviour in a live-bearing fish
- 2024
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Ingår i: Nature Ecology and Evolution. - : Springer Nature. - 2397-334X. ; 8:1, s. 98-110
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Tidskriftsartikel (refereegranskat)abstract
- The organization and coordination of fish schools provide a valuable model to investigate the genetic architecture of affiliative behaviours and dissect the mechanisms underlying social behaviours and personalities. Here we used replicate guppy selection lines that vary in schooling propensity and combine quantitative genetics with genomic and transcriptomic analyses to investigate the genetic basis of sociability phenotypes. We show that consistent with findings in collective motion patterns, experimental evolution of schooling propensity increased the sociability of female, but not male, guppies when swimming with unfamiliar conspecifics. This finding highlights a relevant link between coordinated motion and sociability for species forming fission–fusion societies in which both group size and the type of social interactions are dynamic across space and time. We further show that alignment and attraction, the two major traits forming the sociability personality axis in this species, showed heritability estimates at the upper end of the range previously described for social behaviours, with important variation across sexes. The results from both Pool-seq and RNA-seq data indicated that genes involved in neuron migration and synaptic function were instrumental in the evolution of sociability, highlighting a crucial role of glutamatergic synaptic function and calcium-dependent signalling processes in the evolution of schooling.
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