Habitat and social context affect memory phenotype, exploration and co-variance among these traits

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Anti-predator behaviour in the freshwater gastropod Lymnaea stagnalis

The freshwater gastropod Lymnaea stagnalis was used as a model organism to investigate the mechanisms employed by prey species to fine-tune anti-predator behaviour to match their environment. Lymnaea stagnalis was found to exhibit both genetic adaptation of innate responses and also induced responses to predator cues. Snails were also capable of responding to predation cues via associative learning dependent on recent experience. Constitutive responses were found to differ between populations depending on the predator regime that the population experienced in the wild. Artificial selection produced in only two generations a difference in the magnitude of response between high and low response selected lines equal to those seen between field populations in two generations. At the same time these selected lines maintained phenotypic plasticity and responded to exposure to predator cues during development. This developmental plasticity led to an increased response to predation cues in the low selected line equivilent to that in the high response selection line; a lack of induced change in behaviour in the high response selection line suggested a physiological limitation on the maximum anti-predator response. The response in the low selection lines indicates that plasticity in anti-predator behaviour could allow individuals with low innate responses to compensate with high levels of induced response. Finally, L. stagnalis was able to utilise alarm cues from prey guild members (i.e. other freshwater gastropods) to assess predation risk, a response that was dependent on the phylogenetic relationship between L. stagnalis and the species producing the alarm cue. However, this response was dependent on whether the species was found sympatrically ( cohabiting the same water body) with L. stagnalis. Together, the rapid microevolution of constitutive responses in L. stagnalis, its ability to show induced responses and associative learning indicates that this species may be able to respond rapidly to a novel predation environment, and therefore allow colonistion of new habitats or identification of novel predators

Repeatability and degree of territorial aggression differs among urban and rural great tits (<i>Parus major</i>)

Animals in urban habitats face many novel selection pressures such as increased human population densities and human disturbance. This is predicted to favour bolder and more aggressive individuals together with greater flexibility in behaviour. Previous work has focussed primarily on studying these traits in captive birds and has shown increased aggression and reduced consistency between traits (behavioural syndromes) in birds from urban populations. However, personality (consistency within a behavioural trait) has not been well studied in the wild. Here we tested whether urban free-living male great tits show greater territorial aggression than rural counterparts. We also tested predictions that both behavioural syndromes and personality would show lower consistency in urban populations. We found that urban populations were more aggressive than rural populations and urban birds appeared to show lower levels of individual behavioural repeatability (personality) as predicted. However, we found no effect of urbanisation on behavioural syndromes (correlations between multiple behavioural traits). Our results indicate that urban environments may favour individuals which exhibit increased territorial aggression and greater within-trait flexibility which may be essential to success in holding urban territories. Determining how urban environments impact key fitness traits will be important in predicting how animals cope with ongoing urbanisationpublishersversionPeer reviewe

How stress alters memory in 'smart' snails

Cognitive ability varies within species, but whether this variation alters the manner in which memory formation is affected by environmental stress is unclear. The great pond snail, Lymnaea stagnalis, is commonly used as model species in studies of learning and memory. The majority of those studies used a single laboratory strain (i.e. the Dutch strain) originating from a wild population in the Netherlands. However, our recent work has identified natural populations that demonstrate significantly enhanced long-term memory (LTM) formation relative to the Dutch strain following operant conditioning of aerial respiratory behaviour. Here we assess how two populations with enhanced memory formation (i.e. ‘smart’ snails), one from Canada (Trans Canada 1: TC1) and one from the U.K. (Chilton Moor: CM) respond to ecologically relevant stressors. In control conditions the Dutch strain forms memory lasting 1–3 h following a single 0.5 h training session in our standard calcium pond water (80 mg/l [Ca(2+)]), whereas the TC1 and CM populations formed LTM lasting 5+ days following this training regime. Exposure to low environmental calcium pond water (20 mg/l [Ca(2+)]), which blocks LTM in the Dutch strain, reduced LTM retention to 24 h in the TC1 and CM populations. Crowding (20 snails in 100 ml) immediately prior to training blocks LTM in the Dutch strain, and also did so in TC1 and CM populations. Therefore, snails with enhanced cognitive ability respond to these ecologically relevant stressors in a similar manner to the Dutch strain, but are more robust at forming LTM in a low calcium environment. Despite the two populations (CM and TC1) originating from different continents, LTM formation was indistinguishable in both control and stressed conditions. This indicates that the underlying mechanisms controlling cognitive differences among populations may be highly conserved in L. stagnalis

Confirmation of Galba truncatula as an intermediate host snail for Calicophoron daubneyi in Great Britain, with evidence of alternative snail species hosting Fasciola hepatica

BACKGROUND: Fasciola hepatica is a highly prevalent parasite infecting livestock in Great Britain, while Calicophoron daubneyi is an emerging parasite within the GB livestock industry. Both F. hepatica and C. daubneyi require an intermediate host snail to complete their life-cycles and infect ruminants; however, there has been no confirmation of the intermediate host of C. daubneyi in GB, while there are questions regarding alternative host snails to Galba truncatula for F. hepatica. In this study, PCR was used to identify C. daubneyi hosting snail species on Welsh pastures and to identify any alternative snail species hosting F. hepatica. FINDINGS: Two hundred and sixty four snails were collected between May-September 2015 from six farms in mid-Wales known to have livestock infected with C. daubneyi and F. hepatica. Fifteen out of 134 G. truncatula were found positive for C. daubneyi, one of which was also positive for F. hepatica. Three snail species were found positive for F. hepatica [18/134 G. truncatula, 13/52 Radix balthica, and 3/78 Potamopyrgus antipodarum (New Zealand mud snail)], but no evidence of C. daubneyi infection in the latter two species was found. CONCLUSION: This study indicates that G. truncatula is a host for C. daubneyi in GB. Galba truncatula is also an established host of F. hepatica, and interactions between both species at intermediate host level could potentially occur. Radix balthica and P. antipodarum were found positive for F. hepatica but not C. daubneyi. This could indicate a role for alternative snail species other than G. truncatula in infecting pastures with F. hepatica in GB. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-015-1271-x) contains supplementary material, which is available to authorized users