Growth Of Roach Research Articles

Temperature Effects on Recruitment and Individual Growth of Two Antagonistic Fish Species, Perch Perca fluviatilis and Roach Rutilus rutilus, from a Climate Change Perspective

Perch (Perca fluviatilis) in four boreal lakes and sympatric roach (Rutilis rutilis) in two of these lakes were studied by means of gill net sampling, and age and growth were analyzed to explore whether summer temperature affects recruitment and individual growth of the two species differently. Water temperature logging in the lakes showed a highly significant correlation with air temperature. Year-class strength of the perch was significantly positively affected by the summer air temperature, whereas the temperature effect was non-significant for the roach. There was a significant negative effect of year-class strength of one-year-old perch on roach year-class strength in one lake. ln one of the allopatric perch populations, the year-class strength correlation with temperature failed after biomass removal, probably because fishing affected the age structure. July–August air temperature had a significantly positive effect on individual growth rates of two- to five-year-old perch, whereas the effect on roach growth was less clear. The inclination of perch to predate its competitor, roach, as well as conspecifics, as well as accelerated individual growth, were shown to occur more frequently in years with abundant 1+ perch, i.e., the summer after the rise of a strong year-class. Climate warming may potentially favor perch recruitment and growth.

Линейный рост плотвы при заражении плероцеркоидами Ligula intestinalis в чивыркуйском заливе оз. Байкал

Objective of research: The purpose of the study is to investigate the influence of Ligula intestinalis plerocercoids on linear growth of roach Rutilus rutilus in the Chivyrkuysky bay of the lake Baikal.
 Materials and methods. Roach was caught on a permanent station in the Monakhovo creek of Chivyrkuysky bay of the lake Baikal at the same time interval (June 25-July 5) in 1997-2005. The analysis of roach infection with L. intestinalis plerocercoids was performed based on incomplete parasitological dissections of 807 host specimens at the age of 0+ to 10+. Standard body length (the distance from the tip of the snout to the anterior end of the caudal fin) was used to characterize the linear growth of roach.
 Results and discussion. L. intestinalis plerocercoids wasn’t found out in underyearlings (0+) of roach. The host began to be infected with this tapeworm at the age of 1+. The maximum infection level with L. intestinalis plerocercoids was observed in roach at the age of 3+. That one was significantly reduced in the age of 4+. The infection level of roach with L. intestinalis continued to decrease in the next age groups, going down to a minimum at the age of 7+. The roach wasn’t infected with this tapeworm at the age of 8+–10+. A significant reduction of the infection level in the roach in the age classes 4+ and older after the maximum at the age of 3+ was probably associated with parasite-induced mortality of the host during the growth of the age group 3+ to 4+.
 A standard body length of roach specimens infected with L. intestinalis at the age of 1+ and 2+ was greater than that of uninfected ones. In contrast, the standard body length of the roach specimens infected with this tapeworm was less than that of uninfected ones in subsequent age classes (3 + -6 +). Differences of standard body length between roach specimens infected with L. intestinalis and uninfected ones were statistically significant in the above-mentioned age groups (1 + 6 +). The effect of L. intestinalis plerocercoids on the linear growth of the roach in Chivyrkuysky Bay of the lake Baikal was manifested in an increase of body length of infected host specimens compared to uninfected ones in young age groups (1+ and 2+) and, vice versa, in one’s decrease in age groups 3+–6 +. We proposed to call this effect “reversive”.

Effects of piscivore‐mediated habitat use on growth, diet and zooplankton consumption of roach: an individual‐based modelling approach

SUMMARY 1. We used an individual based modelling approach for roach to (i) simulate observed diel habitat shifts between the pelagic and littoral zone of a mesotrophic lake; (ii) analyse the relevance of these habitat shifts for the diet, activity costs and growth of roach; and (iii) quantify the effects of a hypothetical piscivore‐mediated (presence of pikeperch) confinement of roach to the littoral zone on roach diet, activity costs and growth.2. The model suggests that in the presence of pikeperch, roach shifts from zooplankton as the primary diet to increased consumption of less nutritious food items such as macrophytes, filamentous algae and detritus.3. The growth of roach between May and October was predicted to be significantly higher in the absence of pikeperch, although the net activity costs were about 60% higher compared with the scenario where pikeperch were present.4. These modelling results provide quantitative information for interpreting diel horizontal migrations of roach as a result from a trade‐off between food availability and predation risk in different habitats of a lake.5. Altering the habitat selection mode of planktivorous roach by piscivore stocking has the potential to reduce zooplankton consumption by fish substantially, and could therefore be used as a biomanipulation technique complementing the reduction of zooplanktivorous fish.

The effect of fasting and refeeding on temperature preference, activity and growth of roach, Rutilus rutilus

Most fish species are regularly subjected to periods of starvation during which a reduction of energy turnover might be favourable for the animal. This reduction of energy flux may be achieved by changes in thermal behaviour and/or swimming activity. We investigated such behavioural changes during starvation and subsequent refeeding in roach, Rutilus rutilus, with respect to energetic benefits and growth maximisation. Roach, acclimated to a wide range of temperatures (4, 12, 20, 24, 27 and 30°C), were fed to excess, subjected to 3weeks of starvation and subsequently refed in order to determine the temperature dependence of feeding rates, growth rates and conversion efficiency (K1) under control conditions and during compensatory growth. When exposed to a thermal gradient, control animals preferentially selected a temperature of 26.8±0.9°C, which is in the range of the optimal temperatures for feeding, growth and conversion efficiency. Starving fish showed a distinct circadian pattern of the mean selected temperature (MST). They migrated to cooler water in the dark (MSTdark=22.8±1.1°C) but returned to warmer water during daytime. This behaviour may be regarded as a trade-off between the potentially higher food density in warmer water areas and the energetic benefit of selecting cooler water patches. The circadian pattern of MST was gradually abandoned upon refeeding and control values were reached again after 3weeks. Energetically more effective than behavioural hypothermia was the reduction of swimming activity. During starvation, activity peaks were slightly lower than under control conditions and mean daily activity decreased by about 50%. Swimming velocity, however, was not affected by feeding regime. After a period of starvation fish showed compensatory growth at all temperatures, even below 12°C, where these animals normally do not grow. This suggests that after a period of starvation the critical temperature for growth shifts to lower values.

FACILITATION AMONG PISCIVOROUS PREDATORS: EFFECTS OF PREY HABITAT USE

The combined effects of predators on prey may substantially differ from thatof each predator species alone because of alterations in prey behavior. Using enclosures within a pond, we examined experimentally the effects of two piscivorous predators on prey mortality and prey resource levels in two habitats. The two predators use two different foraging modes, which also allowed us to examine the behaviorally induced indirect effects of prey on predator growth and prey food resources. Both perch (Perca fluviatilis) and pike (Esox lucius) caused significant mortality of roach (Rutilus rutilus), and the combined predator mortality was higher than predicted from a multiplicative prey consumption model. Growth rates of perch were similar when enclosures contained only perch and when they contained perch combined with pike. The growth rate of pike was higher when they were together with perch compared to when alone. Growth of roach was similar among treatments. The invertebrate food resources of roach increased by a factor 10 in the open water but remained at similar levels throughout the experiment in the vegetation. Biomass of Daphnia longispina, the dominant zooplankton species in the open water, was strongly correlated with mortality of roach, indicating a density-mediated indirect effect of predators on prey resources. There was no indirect effect on D. longispina in the vegetation caused by habitat restriction of roach and only a weak relationship in the open water. There was a strong indirect effect of pike predation on macroinvertebrates induced by a habitat shift of roach. Our results suggest that there was facilitation between predators caused by conflicting antipredator behavior of roach, which resulted in density-mediated indirect effects on prey resources. The behavioral response of roach to the two predators also induced indirect effects on invertebrate prey.

Changes in roach ( Rutilus rutilus L.) population structure induced on draining a large reservoir

The influence of draining a large reservoir (Pareloup, South of France) on the population structure and the growth of roach is studied in this work. This reservoir, with an area of 13 km 2, drained in June 1993, was refilled 2 months later. Fish were sampled monthly before draining (1981) and after refilling (1997) by nylon monofilament gill nets used at the same catching effort for both periods. This permitted a comparison to be made between the density of roach and length distribution before and after refilling. Changes in growth were determined by scalimetry. The observed difference in population structure and growth underlined that the differences are mainly due to a greater growth rate after refilling during the first 2 years of roach life. These growth changes are explained by the decrease in roach density and the increase in 1993 of the biomass of Zooplankton, which constitute the main feeding resource for 0 + and 1 + roach. The study led us to propose hypotheses on the ecological significance of growth changes induced by refilling, which can be considered as a rejuvenation of the aquatic ecosystem.

A bioenergetic approach on food consumption of roach (Rutilus rutilus (L.)) in a eutrophic lake

A bioenergetics model was fitted for roach to estimate their food consumption in L. Vesijarvi, southern Finland. When tested with independent data the consumption estimates by the bioenergetics model differed less than 10 % from those obtained with other methods. Sensitivity analysis showed that the model estimates are most sensitive to changes in the respiration parameters, the relative change in the consumption estimate being of the same magnitude as that in the value of the parameter. In L. Vesijarvi the bioenergetics model underestimated the seasonal growth of roach age groups 3 and 5 in July and overestimated the growth of older roach, which was due to differences in food availability. The decline in the proportion of maximum ration consumed (the P-values of the model) in late summer was steepest in the age groups 3 and 5 due to the the collapse of the cladoceran density, while older roach were able to complement their diets with plants and detritus. The daily consumption rates were highest in July-August reaching 1.2-2.5g ww in the different age groups. It is suggested that the growth rate of roach is at present limited by the long capture and handling times of the small-sized cladocerans dominant in the lake. Older age groups can complement their diets with other food items but they are also forced to carry out energy-consuming migrations and their growth rate remains low.

The diet and growth of roach (Rutilus rutilus (L.)) in Lake Vesij�rvi and possible changes in the course of biomanipulation

Previous studies have suggested that the roach Rutilus rutilus (L.) stock of Lake Vesijarvi is one of the main factors delaying the recovery of the lake after sewage diversion. This study is concerned with the documentation of the diet of roach in the lake. In total, 531 roach were examined. Both in the pelagial and in the littoral the roach had mixed diets in May and in September—October. The importance of zooplankton decreased and the importance of benthos and plants increased with increasing size of roach. In July, in the pelagic zone all sizes of roach fed exclusively on zooplankton (Bosmina spp.), while in the littoral zooplankton had the highest volume proportions only in the smallest (<130 mm) roach. The frequent use of plant food and slow growth rate of large roach indicate a low availability of animal prey. As the fish densities decrease due to the mass removal taking place in the lake, the percentage of plant food in the diets of roach will probably decrease and the growth of roach will increase. Additionally, the tendency of the roach to migrate into the pelagic zone in early summer may be reduced, which would decrease their predation on the zooplankton.

Competition between a Planktivore, a Benthivore, and a Species with Ontogenetic Diet Shifts

Along a gradient of increasing productivity in lakes, the abundance of perch (Perca fluviatilis) first increases and then decreases, whereas the abundance of ruffe (Gymnocephalus cernuus) and that of roach (Rutilus rutilus) continue to increase. Perch, unlike roach and ruffe, undergoes dramatic ontogenetic diet shifts. The decrease in the abundance of perch along the productivity gradient may be due to competition from roach at its plankton—feeding stage and from ruffe at its benthic—macroinvertebrate—feeding stage. Previous studies of these three species have focused on the effects of roach on the other species. To further examine the competitive relationship among these species, we studied the effect of increasing the density of ruffe, while maintaining a relatively high, constant density of roach, on the diet and growth of perch. Food resources were also monitored during this 2—mo experiment, which was conducted in 10 enclosures in a pond in southern Sweden. Based on prior experiments we expected roach, an efficient planktivore, to reduce the biomass of zooplankton in all enclosures. Moreover, we expected that the increased density of benthic—feeding ruffe would force perch to increase its consumption of zooplankton, resulting in reduced growth. We found, as predicted, that the biomass of cladocerans of copepods decreased over time but was not affected by ruffe density. The biomass of the commonly consumed macroinvertebrates Sialis (a megalopteran), trichopterans, and ephemeropterans was lower in enclosures with ruffe than in enclosures without ruffe. Moreover, the biomass of Sialis decreased and that of chironomids and the clam Pisidium increased over time. High ruffe densities were related to an increased proportion of zooplankton in the diet of perch in August, but not in September. The diet of ruffe changed little along the ruffe gradient. Only the proportion of trichopterans (in August) and Pisidium (in September) in the diet of ruffe increased along the ruffe gradient. The growth of both perch and ruffe decreased with increasing ruffe density, whereas the growth of roach was constant. These data suggest that one reason perch decrease in abundance along a productivity gradient may be because they are competitively sandwiched between plantivore and benthivore specialists.

Lethal and sublethal threshold values of aluminium and acidity to pike ( Esox lucius), whitefish ( Coregonus lavaretus pallasi), pike perch ( Stizostedion lucioperca) and roach ( Rutilus rutilus) yolk-sac fry

The newly-hatched fry of four fish species were exposed for 10 days in semistatic tests at pH values of 4.00–6.00 to AI at nominal concentrations of 0–800 μg 1 −1. Test waters were made in lake water (Ca 0.11 mmol 1 −1 by adding H 2SO 4 and Al 2(SO 4) 3. Based on the observations on mortality (LC 50) and swimming activity (EC 50), the four species had the following ranking for their sensitivity to acidity and Al: roach > pike perch > whitefish > pike. At the end of the 10-day test the LC 50 and EC 50 values of Al were identical for the most sensitive species, roach, whereas those for pike and whitefish were significantly different at that time. Al and low pH clearly retarded pike and roach yolk-sac fry growth, which was coincident with a slower absorption of the yolk. Al decreased pike growth at pH values ≤ 5.25 and roach growth even at pH 5.75. In whitefish, which have a small yolk sac; the effects of pH and Al on growth were not so clear. In general, the more Al the water contained, the more toxic was the acidic water. The threshold pH values (lowest pH for survival and safe pH) for the four species were, depending on the Al concentration: pike 4.0–5.3 whitefish 4.5–5.5 pike perch 4.8–5.8 and roach 5.0–6.0.

Growth of 0+ Roach (Rutilus rutilus) in Relation to Temperature and Size in a Shallow Eutrophic Lake: Comparison of Field and Laboratory Observations

The growth rates of larval and juvenile roach (Rutilus rutilus) were measured in the laboratory at different temperatures under conditions of excessive food supply. Using these data, the maximum growth rate of 0+ roach in relation to size and water temperature could be adequately described with an equation of the type: dW/dt = amax∙Wb∙(T−c) (W = weight, T = temperature, t = time). Using this equation the growth of larval and juvenile roach in Tjeukemeer was predicted for 12 successive years. The predicted growth rates were about 20% lower than the observed growth rates. Reasons for this bias are discussed. The results indicate that food is not limiting growth of roach in Tjeukemeer.

Distribution and variation in the growth of roach, Rutilus rutilus (L.), and dace, Leuciscus leuciscus (L.), in a river catchment in south‐west England

The distribution and growth of roach and dace in the R. Exe catchment was studied. Distribution conformed to the classic theories of zonation, although human interference extended or reduced the range of species. Distinct differences were found in the growth rates of roach and dace between different regions of the catchment. Both species achieved their fastest growth in zones where the river topography portrayed their ‘preferred’ habitat characteristics, i.e. the fast‐flowing middle and slow‐flowing lower reaches for dace and roach, respectively. Female roach were found to grow considerably faster than male fish, whilst no sexual differentiation in growth rates was found in dace. Considerable fluctuations in year class strength were observed in both species.

Acclimatization of roach, Rutilus rutilus (L.), to toxic components of kraft pulp mill effluents

Roach ( Rutilus rutilus) were exposed, along with their appropriate controls, to a simulated bleached kraft mill effluent (KME-Sa+CP) first for 38 days at a concentration of 0.035 × LC 50 and then for 14 days at 0.07 × LC 50. During the experiment, their tolerances to KME-Sa+CP were tested five times by measuring the 48-hr LC 50 values. In addition, the growth of roach was monitored. At the end of the exposure, accumulation of [ 14C]pentachlorophenol in various parts of the fish (total PCP in water 15.6 μg/liter) was measured. When the fish were preexposed to KME-Sa+CP, the acute tolerance of this mixture in roach increased by 30–39%, but the response was abolished in 31 days. Fish growth remained unchanged during the experiment. Measurement of PCP accumulation revealed no difference in the absorption rate, but under steady-state conditions the degree of bioconcentration was 16% lower ( P < 0.02) in preexposed roach than in their unexposed controls. This difference was entirely accounted for in the head and visceral parts of the fish. Even when no final changes were noted in tolerance and growth rate of the fish, the authors suggest that the significantly lowered body burden implied acclimatizatory compensation under subchronic exposure of this xenobiotic.

Changes in the rate of growth in a stunted roach Rutilu rutilus population

Data is presented concerning the growth of roach in a South Lancashire lake. Results from a sample of roach in May 1969 indicate the slowest growth rate for which published records are available. A comparison of the length/age and weight/age relationships between data for May 1969 and May/June 1971 yields significant between‐year differences indicating an increase in the growth rate during that period. A study of the growth history of individual year classes using back‐calculated values from operculum measurements suggests that for both sexes the observed increase in the rate of growth commenced after the 1965–67 period during which very weak year classes were produced. The mean length of females appears to have been larger than that of males from the age of four onwards but the 95% confidence intervals are almost totally overlapping for each pair of values and a statistical comparison of growth rates between the sexes indicates no significant differences. Data for the sexes combined is compared with published results from other British and Continental waters.

Comparative observations on the growth rate and year class strength of roach Rutilus rutilus L. in two Cheshire lakes, England

In this study some comparative data on the growth rate and year class composition of roach in two Cheshire meres (Rostherne and Tatton) are given. The populations are characterised by year class instability and high growth rates, both of which are most extreme in Tatton Mere. The growth of roach in Tatton Mere is the highest yet recorded from Britain.The concurrence of two (1969, 1973) strong year classes in both lakes, suggests that climate is an important factor which conditions year class strength. However, although there is some correlation between year class strength and the water temperature index (&gt;14° C) the ultimate cause of year class variability remains obscure. There is no evidence to suggest that year class failure is due to parasitic infestation by Ligula intestinalis or to predation by perch upon roach fry. Year class failure may be due to the mortality of eggs related to the time of spawning. The observed difference in growth rate between the two populations may be attributed to a difference in density caused by the disparity of year class representation in Rostherne Mere and Tatton Mere. However, despite these differences, the net biomass achieved (36–39 kg ha−1) may be similar in both lakes. Superimposed on the effects of density an influence of temperature is noted.