Fish recruitment in a large, temperate floodplain: the importance of annual flooding, temperature and habitat complexity
Gorski, K. ; Leeuw, J.J. de; Winter, H.V. ; Vekhov, D.A. ; Minin, A.E. ; Buijse, A.D. ; Nagelkerke, L.A.J. - \ 2011
Freshwater Biology 56 (2011)11. - ISSN 0046-5070 - p. 2210 - 2225.
upper parana river - of-the-year - life-history - carassius-auratus - american fishes - lowland rivers - abundance - patterns - connectivity - larval
1. Large river floodplains are considered key nursery habitats for many species of riverine fish. The lower Volga River floodplains (Russian Federation) are still relatively undisturbed, serving as a suitable model for studying the influence of flooding and temperature on fish recruitment in floodplain rivers. 2. We examined the interannual variability in recruitment success of young-of-the-year (YOY) fish in the lower Volga floodplain in relation to flood pulse characteristics and rising water temperatures in the spring. We sampled four areas with different flooding regimes, in three consecutive years (2006–2008). 3. Extensive areas with a long duration of flooding accommodated high densities of young fish. This suggests that extended inundation improves the recruitment success of river fish. In areas with extensive flooding, the biomass of YOY of most fish species was about three times higher in 2006 and 2007 than in 2008. We hypothesise that low spring temperatures in 2008 may have caused this reduced recruitment and that a flood synchronised with rising temperature enhances recruitment success. 4. Extensive flooding was particularly favourable for species characterised by large body size, delayed maturation, high fecundity and low parental investment, such as pike Esox lucius, roach Rutilus rutilus and ide Leuciscus idus. Gibel carp Carassius gibelio, a species tolerant of high temperature and hypoxia, did particularly well in small waterbodies in the driest parts of the floodplain. 5. Structural characteristics of floodplain waterbodies explained much of YOY fish density. These species–environment associations varied from year to year, but some species such as common bream Abramis brama, roach and gibel carp showed consistent relationships with structural habitat characteristics in all years, despite large interannual fluctuations in flood pulse and spring temperature
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.