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.
Foraging behaviour at the fourth tropic level: a comparative study of host location in aphid hyperparasitoids
Buitenhuis, R. ; Vet, L.E.M. ; Boivin, G. ; Brodeur, J. - \ 2005
Entomologia Experimentalis et Applicata 114 (2005)2. - ISSN 0013-8703 - p. 107 - 117.
diaeretiella-rapae hymenoptera - nigripes hymenoptera - aphidivorus hymenoptera - selection behavior - alloxysta-victrix - chemical cues - field ecology - parasitoids - ervi - homoptera
In studies of foraging behaviour in a multitrophic context, the fourth trophic level has generally been ignored. We used four aphid hyperparasitoid species: Dendrocerus carpenteri (Curtis) (Hymenoptera: Megaspilidae), Asaphes suspensus Walker (Hymenoptera: Pteromalidae), Alloxysta victrix (Westwood) (Hymenoptera: Alloxystidae) and Syrphophagus aphidivorus (Mayr) (Hymenoptera: Encyrtidae), to correlate their response to different cues with their ecological attributes such as host range and host stage. In addition, we compared our results with studies of primary parasitoids on the same plant–herbivore system. First, the olfactory response of females was tested in a Y-tube olfactometer (single choice: plant, aphid, honeydew, parasitised aphid, aphid mummy, or virgin female parasitoid; dual choice: clean plant, plant with aphids, or plant–host complex). Second, their foraging behaviour was described on plants with different stimuli (honeydew, aphids, parasitised aphids, and aphid mummies). The results indicated that olfactory cues are probably not essential cues for hyperparasitoid females. In foraging behaviour on the plant, all species prolonged their total visit time and search time as compared to the control treatment (clean plant). Only A. victrix did not react to the honeydew. Oviposition in mummies prolonged the total visit time because of the long handling time, but the effect of this behaviour on search time could not be determined. No clear correlation between foraging behaviour and host stage or host range was found. In contrast to specialised primary aphid parasitoids that have strong fixed responses to specific kairomones and herbivore-induced synomones, more generalist aphid hyperparasitoids seem to depend less on volatile olfactory stimuli, but show similarities with primary parasitoids in their use of contact cues while searching on a plant.