Impulsive sounds change European seabass swimming patterns: influence of pulse repetition interval
Neo, Y.Y. ; Ufkes, E. ; Kastelein, R.A. ; Winter, H.V. ; Cate, C. ten; Slabbekoorn, H. - \ 2015
Marine Pollution Bulletin 97 (2015)1-2. - ISSN 0025-326X - p. 111 - 117.
startle-response - trawling vessel - fish - habituation - behavior - noise - variability - avoidance - zebrafish - recovery
Seismic shootings and offshore pile-driving are regularly performed, emitting significant amounts of noise that may negatively affect fish behaviour. The pulse repetition interval (PRI) of these impulsive sounds may vary considerably and influence the behavioural impact and recovery. Here, we tested the effect of four PRIs (0.5–4.0 s) on European seabass swimming patterns in an outdoor basin. At the onset of the sound exposures, the fish swam faster and dived deeper in tighter shoals. PRI affected the immediate and delayed behavioural changes but not the recovery time. Our study highlights that (1) the behavioural changes of captive European seabass were consistent with previous indoor and outdoor studies; (2) PRI could influence behavioural impact differentially, which may have management implications; (3) some acoustic metrics, e.g. SELcum, may have limited predictive power to assess the strength of behavioural impacts of noise. Noise impact assessments need to consider the contribution of sound temporal structure.
Is the reaction to chemical cues of predators affected by age or experience in fire salamanders (Salamandra salamandra)
Ibanez, A. ; Caspers, B.A. ; Lopez, P. ; Martin, J. ; Krause, E.T. - \ 2014
Amphibia-Reptilia 35 (2014)2. - ISSN 0173-5373 - p. 189 - 196.
diet cues - recognition - avoidance - risk - population - prospectus - preference - responses - tadpoles - behavior
Predation is one of the strongest forces driving natural selection. Predator success reduces future prey fitness to zero. Thus, recognition and avoidance of a potential predator is an essential fitness-relevant skill for prey. Being well equipped in the predator-prey arms race is highly adaptive. In this context we tested whether age and/or potential experience of fire salamanders (Salamandra salamandra) affected their behaviour towards the chemical signature of a potential predator. We evaluated the space use of salamanders in a test arena with a shelter containing chemical cues from a predator (i.e., a rat) and a clean shelter. Our results demonstrate that naïve subadult fire salamanders do show a significant behavioural reaction towards rat odour. However, they do not avoid the chemical cues of the potential predator, but instead have a significant preference for the shelter with rat faeces. In contrast to this, both the naïve adult and wild-caught adult fire salamanders showed neither a preference nor an avoidance of rat scent. These results could suggest a role of age in odour-based predator recognition in salamanders. Similarly, predator recognition through chemical cues could be more important early in life when the young fire salamanders are more vulnerable to predatory attacks and less important in other life stages when salamanders are less subjected to predation. In conclusion, future studies considering wild-caught subadults should disentangle the importance of previous experience for predator chemical recognition.
Effects of Trampling on Morphological and Mechanical Traits of Dryland Shrub Species Do Not Depend on Water Availability
Xu, L. ; Freitas, S.M.A. ; Yu, F.H. ; Dong, M. ; Anten, N.P.R. ; Werger, M.J.A. - \ 2013
PLoS ONE 8 (2013)1. - ISSN 1932-6203
bean-plants - growth - vegetation - stress - resistance - thigmomorphogenesis - heterogeneity - avoidance - tolerance - diversity
In semiarid drylands water shortage and trampling by large herbivores are two factors limiting plant growth and distribution. Trampling can strongly affect plant performance, but little is known about responses of morphological and mechanical traits of woody plants to trampling and their possible interaction with water availability. Seedlings of four shrubs (Caragana intermedia, Cynanchum komarovi, Hedysarum laeve and Hippophae rhamnoides) common in the semiarid Mu Us Sandland were grown at 4% and 10% soil water content and exposed to either simulated trampling or not. Growth, morphological and mechanical traits were measured. Trampling decreased vertical height and increased basal diameter and stem resistance to bending and rupture (as indicated by the increased minimum bend and break force) in all species. Increasing water availability increased biomass, stem length, basal diameter, leaf thickness and rigidity of stems in all species except C. komarovii. However, there were no interactive effects of trampling and water content on any of these traits among species except for minimum bend force and the ratio between stem resistance to rupture and bending. Overall shrub species have a high degree of trampling resistance by morphological and mechanical modifications, and the effects of trampling do not depend on water availability. However, the increasing water availability can also affect trade-off between stem strength and flexibility caused by trampling, which differs among species. Water plays an important role not only in growth but also in trampling adaptation in drylands.
How plant architecture affects light absorption and photosynthesis in tomato: towards an ideotype for plant architecture using a functional-structural plant model
Sarlikioti, V. ; Visser, P.H.B. de; Buck-Sorlin, G.H. ; Marcelis, L.F.M. - \ 2011
Annals of Botany 108 (2011)6. - ISSN 0305-7364 - p. 1065 - 1073.
carbon gain - leaf - interception - canopy - morphology - yield - assimilation - efficiency - avoidance - capture
Background and Aims - Manipulation of plant structure can strongly affect light distribution in the canopy and photosynthesis. The aim of this paper is to find a plant ideotype for optimization of light absorption and canopy photosynthesis. Using a static functional structural plant model (FSPM), a range of different plant architectural characteristics was tested for two different seasons in order to find the optimal architecture with respect to light absorption and photosynthesis. Methods - Simulations were performed with an FSPM of a greenhouse-grown tomato crop. Sensitivity analyses were carried out for leaf elevation angle, leaf phyllotaxis, leaflet angle, leaf shape, leaflet arrangement and internode length. From the results of this analysis two possible ideotypes were proposed. Four different vertical light distributions were also tested, while light absorption cumulated over the whole canopy was kept the same. Key Results Photosynthesis was augmented by 6 % in winter and reduced by 7 % in summer, when light absorption in the top part of the canopy was increased by 25 %, while not changing light absorption of the canopy as a whole. The measured plant structure was already optimal with respect to leaf elevation angle, leaflet angle and leaflet arrangement for both light absorption and photosynthesis while phyllotaxis had no effect. Increasing the length : width ratio of leaves by 1·5 or increasing internode length from 7 cm to 12 cm led to an increase of 6–10 % for light absorption and photosynthesis. Conclusions - At high light intensities (summer) deeper penetration of light in the canopy improves crop photosynthesis, but not at low light intensities (winter). In particular, internode length and leaf shape affect the vertical distribution of light in the canopy. A new plant ideotype with more spacious canopy architecture due to long internodes and long and narrow leaves led to an increase in crop photosynthesis of up to 10 %.
Effect of relatedness and inbreeding on reproductive success of Nile tilapia (oreochromis niloticus)
Fessehaye, Y. ; Bovenhuis, H. ; Rezk, M.A. ; Crooijmans, R.P.M.A. ; Arendonk, J.A.M. van; Komen, J. - \ 2009
Aquaculture 294 (2009)3-4. - ISSN 0044-8486 - p. 180 - 186.
fluctuating asymmetry - peromyscus-polionotus - kin recognition - mating systems - rainbow-trout - mate choice - avoidance - depression - traits - populations
It is well established that progeny of inbred matings are less fit than those of outbred matings, and that inbred individuals suffer from reduced viability and fertility. Inbreeding can be avoided by dispersal of progeny or by actively avoiding mating with kin (mate choice). We investigated the effects of sex ratio, relatedness (kinship coefficient) and level of inbreeding on the reproductive success in Nile tilapia under semi-natural mass spawning conditions in two net enclosures (hapas). Fry were collected from the mouth of incubating females on a weekly basis and parentage assignment was done on 1115 offspring from 56 spawnings using seven polymorphic microsatellite markers. Results show that the degree of pairwise relatedness, measured by kinship coefficient, did not have any significant effect on the reproductive success of males. Female total fecundity was significantly affected by the level of inbreeding but not by body weight and gonadosomatic index. Male reproductive success, calculated as the proportion of offspring sired within a single spawning, was significantly affected by the level of inbreeding, body weight, GSI of males and sex ratio. Effects of inbreeding on male reproductive success were higher in the presence of higher number of males suggesting that the effects of inbreeding are magnified under stronger male–male competition. Our results show that there is no inbreeding avoidance via kin recognition and that accumulation of inbreeding in tilapia populations is counterbalanced by reduced reproductive success of inbred males and females
The presence of webbing affects the oviposition rate of two-spotted spider mites, Tetranychus urticae (Acari: Tetranychidae)
Oku, K. ; Magalhães, S. ; Dicke, M. - \ 2009
Experimental and Applied Acarology 49 (2009)3. - ISSN 0168-8162 - p. 167 - 172.
womersleyi schicha acari - predatory mite - spinning behavior - phytophagous mite - plant - phytoseiidae - aggregation - kanzawai - eggs - avoidance
Several species of tetranychid mites including Tetranychus urticae Koch (Acari: Tetranychidae) construct complicated three-dimensional webs on plant leaves. These webs provide protection against biotic and abiotic stress. As producing web is likely to entail a cost, mites that arrive on a leaf with web are expected to refrain from producing it, because they will gain the benefit of protection from the existing web. Mites that produce less web may then allocate resources that are not spent on web construction to other fitness-enhancing activities, such as laying eggs. To test this, the oviposition rate of T. urticae adult females was examined on leaves with web. As a control, we used leaves where the web had been removed, hence both types of leaves had been exposed to conspecifics previously and were thus damaged. On leaves with web, the oviposition rate of T. urticae females was higher than on leaves where the web had been removed. Therefore, the presence of web constructed by conspecifics enhanced the oviposition rate of T. urticae females. This provides indirect evidence that mites use the web constructed by conspecifics and thereby save resources that can be allocated to other traits that enhance reproductive success
A rule-based model of barley morphogenesis, with special respect to shading and gibberellic acid signal transduction
Buck-Sorlin, G.H. ; Hemmerling, R. ; Kniemeyer, O. ; Burema, B.S. ; Kurth, W. - \ 2008
Annals of Botany 101 (2008). - ISSN 0305-7364 - p. 1109 - 1123.
natural-environment - light environment - leaf emergence - main shoot - growth - phytochrome - biosynthesis - population - elongation - avoidance
Background and Aims: Functional¿structural plant models (FSPM) constitute a paradigm in plant modelling that combines 3D structural and graphical modelling with the simulation of plant processes. While structural aspects of plant development could so far be represented using rule-based formalisms such as Lindenmayer systems, process models were traditionally written using a procedural code. The faithful representation of structures interacting with functions across scales, however, requires a new modelling formalism. Therefore relational growth grammars (RGG) were developed on the basis of Lindenmayer systems. Methods: In order to implement and test RGG, a new modelling language, the eXtended L-system language (XL) was created. Models using XL are interpreted by the interactive, Java-based modelling platform GroIMP. Three models, a semi-quantitative gibberellic acid (GA) signal transduction model, and a phytochrome-based shade detection and object avoidance model, both coupled to an existing morphogenetic structural model of barley (Hordeum vulgare L.), serve as examples to demonstrate the versatility and suitability of RGG and XL to represent the interaction of diverse biological processes across hierarchical scales. Key Results: The dynamics of the concentrations in the signal transduction network could be modelled qualitatively and the phenotypes of GA-response mutants faithfully reproduced. The light model used here was simple to use yet effective enough to carry out local measurement of red:far-red ratios. Suppression of tillering at low red:far-red ratios could be simulated. Conclusions: The RGG formalism is suitable for implementation of multi-scaled FSPM of plants interacting with their environment via hormonal control. However, their ensuing complexity requires careful design. On the positive side, such an FSPM displays knowledge gaps better thereby guiding future experimental design.
Prediction of cannibalism in juvenile Oreochromis niloticus based on predator to prey weight ratio, and effects of age and stocking density
Fessehaye, Y. ; Kabirb, A. ; Bovenhuis, H. ; Komen, J. - \ 2006
Aquaculture 255 (2006)1-4. - ISSN 0044-8486 - p. 314 - 322.
clarias-gariepinus - size - fish - larvae - availability - recognition - populations - aggression - avoidance - walleyes
Factors influencing size-dependent cannibalism in Nile tilapia, Oreochromis niloticus, were investigated in controlled conditions. First, individual-based trials were conducted to develop a linear regression model to predict the occurrence of cannibalism based on body measurements. Oral gape (G, mm), body depth (D, mm) and weight (W, g) of 140 fish were measured and we estimated maximum prey weight (Wprey) for a given predator weight (Wpredator): Log10Wprey = 1.03Log10Wpredator - 1.13. This model was verified by conducting 76 single pair trials. The revised model based on observed cannibalism is: Log10Wprey = Log10Wpredator - 1.17. Several experiments involving a group of prey and predators were conducted to elucidate the relative importance of factors that influence cannibalism. Cannibalism was significantly affected by stocking density, age of fish and predator/prey weight ratio. Logit models of mortality data of both the individual-based and observations based on a group of predators and prey estimated R50 (the predator/prey weight ratio at which an encounter of a predator and prey resulted in a predation success of 50%) to be 14.6 and 14.8, respectively. The results of these experiments can be used to reduce fry losses due to cannibalism
Habitat selection by chironomid larvae: fast growth requires fast food
Haas, E.M. de; Wagner, C. ; Koelmans, A.A. ; Kraak, M.H.S. ; Admiraal, W. - \ 2006
Journal of Animal Ecology 75 (2006)1. - ISSN 0021-8790 - p. 148 - 155.
floodplain lake-sediments - riparius meigen - community composition - tentans diptera - toxicity tests - organic-matter - particle-size - bioassays - invertebrates - avoidance
1. Sediments have been considered as a habitat, a cover from predators and a source of food, but also as a source of potential toxic compounds. Therefore, the choice of a suitable substrate is essential for the development of chironomids. 2. For the midge Chironomus riparius (Meigen 1804) the growth rate of larvae has often been related to the food quality in sediments rather than to the amount of toxicants in the sediment. Both food quality and sediment-bound toxicants have been reported to determine the field distribution of chironomid larvae. 3. We therefore studied the habitat selection by C. riparius larvae of floodplain lake sediments, differing in both food quality and concentrations of sediment-bound toxicants. We offered the different sediments pairwise to the chironomid larvae in a choice experiment and their settlement in the paired sediments was determined after 10 days. 4. It was observed that larvae showed a clear preference for sediments with higher food quality, which also provided better growth conditions, and that the food quality overruled avoidance of the sediments with higher toxicant concentrations. 5. Our observations correspond with the persistence of this fast growing opportunistic chironomid species in organically enriched aquatic ecosystems independent of the contamination level.
Real-time automated measurement of Xenopus leavis tadpole behavior and behavioral response following triphenyltin exposure using the multispecies freshwater biomonitor (MFB)
Schriks, M. ; Hoorn, M.K. van; Faassen, E.J. ; Dam, J.W. van; Murk, A.J. - \ 2006
Aquatic Toxicology 77 (2006)3. - ISSN 0166-445X - p. 298 - 305.
chemical cues - differential predation - feeding-behavior - waste-water - avoidance - larval - fish - biomarkers - crustacea - patterns
The present study examines whether behavior of Xenopus laevis tadpoles, when measured with the multispecies freshwater biomonitor (MFB), can be a sensitive and practical parameter for quantification of behavioral effects induced by toxic compounds. The MFB system is capable of automated simultaneous recording and integration of different types of movement over time. Basic tadpole behavior was studied under standard ambient temperature and colder conditions. At lower temperatures the time spent on low frequency behavior such as swimming and ventilation decreased, while at higher frequency movements associated with subtle tail tip oscillations it increased. Changes in behavior were also studied during the process of metamorphosis when both the morphology and physiology of tadpoles change. In the course of metamorphosis the tadpoles decreased the time spent on swimming and increased tail tip oscillations, especially in the period shortly before and during metamorphic climax. Additional experiments were performed to investigate whether the MFB could be used to quantify behavioral effects of exposure to a toxic compound. A 48h exposure to a sublethal concentration of 1.25mugL(-1) triphenyltin (TPT) significantly increased low frequency behavior, whereas 5mugL(-1) TPT significantly reduced this type of behavior while the number of periods of total inactivity increased. One week after transferring the animals to clean water, registered behavior of tadpoles in the highest TPT group (5mugL(-1)) was normal again for this developmental stage. The results show that the MFB can be used as a new tool for automated registration of sublethal toxic effects on tadpole behavior including recovery.
Electronic diary assessment of pain-related fear, attention to pain, and pain intensity in chronic low back pain patients.
Roelofs, J. ; Peters, M.L. ; Patijn, J. ; Schouten, E.G. ; Vlaeyen, J.W. - \ 2004
Pain 112 (2004)3. - ISSN 0304-3959 - p. 335 - 342.
cold pressor pain - fibromyalgia patients - anxiety - memory - hypervigilance - distraction - disability - experience - avoidance - model
The present study investigated the relationships between pain-related fear, attention to pain, and pain intensity in daily life in patients with chronic low back pain. An experience sampling methodology was used in which electronic diary data were collected by means of palmtop computers from 40 chronic low back pain patients who were followed for one week. Attention to pain was hypothesized to mediate the relation between pain-related fear and pain intensity. Further, pain-related fear as a trait characteristic was expected to moderate the relation between attention to pain and pain intensity. Multi-level analysis was used for all analyses. Although the tested mediation models yielded statistically significant mediation effects, the sizes of these effects were relatively small and clinically irrelevant. Instead, results suggested that pain-related fear and attention to pain independently predicted pain intensity. No evidence for moderation of the relation between attention to pain and pain intensity by pain-related fear as a trait characteristic was found. Implications of the results from this study are discussed and suggestions for future research are provided.
Learning performances in young horses using two different learning tests.
Visser, E.K. ; Reenen, C.G. van; Schilder, M.B.H. ; Barneveld, A. ; Blokhuis, H.J. - \ 2003
Applied Animal Behaviour Science 80 (2003)4. - ISSN 0168-1591 - p. 311 - 326.
yearling horses - conditioning trials - 2-year-old horses - social-dominance - ability - maze - avoidance - behavior - tasks - age
To achieve optimal performance in equine sports as well as in leisure not only the physical abilities of the horse should be considered, but also the horse's personality. Besides temperamental aspects, like emotionality, or the horse's reactivity towards humans in handling situations, the learning ability of the horse is another relevant personality trait. To study whether differences in learning performance are consistent over time and whether individual learning performance differs between learning tests or is affected by emotionality, 39 young horses (Dutch Warmblood) were tested repeatedly in two learning tests. An aversive stimulus (AS) was used in one learning test (the avoidance learning test) and a reward was used in the other learning test (the reward learning test). During both learning tests behaviour as well as heart rate were measured. Each test was executed four times, twice when horses were 1 year of age, and twice when they were 2 years of age. Half of the horses received additional physical training from 6 months onwards. In both tests horses could be classified as either performers, i.e. completing the daily session, or as non-performers, i.e. returning to the home environment without having completed the daily session. There were some indications that emotionality might have caused non-performing behaviour, but these indications are not convincing enough to exclude other causes. Furthermore, there seem to be no simple relationships between measures of heart rate, behavioural responses putatively related to emotionality and learning performance. Horses revealed consistent individual learning performances within years in both tests, and in the avoidance learning test also between years. There was no significant correlation between learning performances in the avoidance learning test and the learning performances in the reward learning test. It is concluded that individual learning abilities are consistent over a short time interval for an avoidance learning test and a reward learning test and over a longer time for the avoidance learning test. Furthermore, results indicate that some horses perform better when they have to learn to avoid an aversive stimulus while others perform better when they are rewarded after a correct response. It is suggested that these differences may be relevant to design optimal individual training programmes and methods.
Infochemical-mediated intraguild interactions among three predatory mites on cassava plants
Gnanvossou, D. ; Hanna, R. ; Dicke, M. - \ 2003
Oecologia 135 (2003)1. - ISSN 0029-8549 - p. 84 - 90.
biological-control - drosophila parasitoids - tetranychus-urticae - phytoseiid mites - manihoti acari - competition - prey - avoidance - behavior - africa
Carnivorous arthropods exhibit complex intraspecific and interspecific behaviour among themselves when they share the same niche or habitat and food resources. They should simultaneously search for adequate food for themselves and their offspring and in the meantime avoid becoming food for other organisms. This behaviour is of great ecological interest in conditions of low prey availability. We examined by means of an olfactometer, how volatile chemicals from prey patches with conspecific or heterospecific predators might contribute to shaping the structure of predator guilds. To test this, we used the exotic predatory mites Typhlodromalus manihoti and T. aripo, and the native predatory mite Euseius fustis, with Mononychellus tanajoa as the common prey species for the three predatory mite species. We used as odour sources M. tanajoa-infested cassava leaves or apices with or without predators. T. manihoti avoided patches inhabited by the heterospecifics T. aripo and E. fustis or by conspecifics when tested against a patch without predators. Similarly, both T. aripo and E. fustis females avoided patches with con- or heterospecifics when tested against a patch without predators. When one patch contained T. aripo and the other T. manihoti, females of the latter preferred the patch with T. aripo. Thus, T. manihoti is able to discriminate between odours from patches with con- and heterospecifics. Our results show that the three predatory mite species are able to assess prey patch profitability using volatiles. Under natural conditions, particularly when their food sources are scarce, the three predatory mite species might be involved in interspecific and/or intraspecific interactions that can substantially affect population dynamics of the predators and their prey.