Feeding Activity Of Fish Research Articles

Research on quantitative method of fish feeding activity with semi-supervised based on appearance-motion representation

The quantification of fish feeding activity is a prerequisite for precise feeding. Deep learning has achieved notable achievements in the analysis of fish feeding activity. However, existing deep learning methods for analysing fish feeding activity still have some limitations: 1) they are all strongly supervised methods, and require labels to guide learning; 2) they can only qualitatively evaluate the feeding stage, while continuous quantification is not attained. To address these issues, an appearance-motion autoencoder network (AMA-Net) for quantifying fish feeding activity is proposed. Specifically, to avoid the tedious and time-consuming manual labelling, semi-supervised learning is adopted in the network. In the learning phase, only non-feeding samples that do not require labelling are used as training data. During the application phase, the continuous quantification of fish feeding activity is realised through the hypothesis of reconstruction error. Moreover, for higher accuracy and stability in fish feeding activity measurement, the proposed network performs modelling from both appearance and motion with the dual-stream framework to accurately quantify fish feeding activity. The experiments qualitatively and quantitatively analysed the performance of AMA-Net, which confirmed the effectiveness, accuracy and stability of AMA-Net in quantifying fish feeding activity. Further, to realise feed fish on demand, an intelligent feeding decision system is proposed, which can automatically determine whether the fish has completed feeding. The experimental results showed that the feeding decision system accurately and effectively decided the endpoints of the feeding process and provided theoretical support for production practices in aquaculture.

MSIF-MobileNetV3: An improved MobileNetV3 based on multi-scale information fusion for fish feeding behavior analysis

Assessing the intensity of fish feeding activity using fish feeding behavior can help farmers efficiently decide on the amount of feeding bait. However, accurate extraction of fish feeding behavior features is difficult because of the small area of fish in the image and the randomness of fish swimming. To address this problem, an improved MobileNetV3 network, namely multi-scale information fusion (MSIF)-MobileNetV3, was proposed for analyzing the fish feeding behavior. Specifically, MSIF is a novel channel attention module used to replace the Squeeze-and-Excitation (SE) module that improves the attention of the model to fish schools behavior in feeding images using spatial information integration and multi-scale feature fusion. To evaluate the effectiveness of the proposed method, its performance was compared with that of the MobileNetV3 network optimized using multiple training strategies and other classical convolutional neural networks. It was trained and tested using a self-built dataset, and the experimental results showed that the MSIF-MobileNetV3 network using a basic training strategy obtained an optimal classification accuracy of 96.4 % on the test set. Thus, by analyzing the feeding activity of fish, the proposed method can assist in the automatic selection of bait feed under factory farming conditions.

Precision feeding system for largemouth bass (Micropterus salmoides) based on multi-factor comprehensive control

In order to solve a series of problems in the current feeding process, such as inaccuracy, unevenness and high labour costs, a precision feeding system for largemouth bass was developed by integrating feeding management model, water quality monitoring system, fish feeding activity sensor, automatic feeding machine and software platform. Based on the analysis of the growth data of largemouth bass and the bioenergetics principle, the feeding management model for predicting the growth, feed requirements and waste output of largemouth bass was constructed and validated under different culture modes. The real-time DO parameters were used to fine-tune the feed requirements predicted by the model. The feed requirements were then further precisely adjusted by combining the intensity of fish feeding activities. The web platform client used supported the access of any browser and provided a visual interface for software users. The experimental results showed that the feeding management model provides reliable estimates of growth, feed requirements and waste output for largemouth bass. The function of dynamically adjusting the model and feeding parameters through feedback and production data provided by cloud serves or users improved the application effectiveness and scope of the system. The system comprehensively considered multiple factors such as fish biological characteristics, physiological stages, feed nutrients composition, environmental factors and fish appetite, and incorporated relevant technologies or equipment to provide an effective tool for users to shift from experience-driven to knowledge-driven approaches to better optimise production and feeding, thereby improving the economic benefits and environmental sustainability of aquaculture.

Suitability of compensatory saltmarsh habitat for feeding and diet of multiple estuarine fish species

AbstractSaltmarsh provides essential fish feeding and nursery habitat but has globally declined by 50%. We used a statistical block design to compare fish feeding activity within human‐engineered or “re‐aligned” saltmarsh to established saltmarsh. Linear and multivariate modelling highlighted that Thinlip Mullet (Chelon ramada) and European Bass (Dicentrarchus labrax) feeding rates were 16% and 31% lower within re‐aligned than established saltmarshes, whereas Gobies (Pomatoschistus spp.) fed at the same rate as in both habitats. Analysis of European bass and Goby gut contents highlighted that important detritivorous prey species were up to 85.6% lower in re‐aligned sites. Lower vegetation density may have negatively affected the feeding ecologies of fishes within re‐aligned sites. However, due to the ecological value and potential for further improvement or habitat development, continued assessment of the beneficial effects of re‐aligned sites for fisheries and net gain perspectives is needed.

Biological Aspects and Feeding Ecology of Sembilang Plotosus canius in Langsa Estuary

The knowledge of the biological aspects and feeding activity of fish is required to manage the lack of data on fisheries. In this study, a total of 200 Plotosus canius were caught and examined to obtain information on their biological aspects, length-weight relationship, and feeding activity. The fish were captured using a gill net and traditional fishing trap called Bubu. Subsequently, all samples were examined for total body weight, total length, condition factor, gonad maturity, and feeding activity. The results showed that the specimens captured were 156 males and 44 females weighing between 95-280 gr and 117-214 gr with the length of 26-39 cm and 28-36.3 cm, respectively. The length-weight relationship showed a negative allometric growth pattern. The mean condition factors of males and females were 1.1048 and 1.0102, respectively. At the same time, the maturity level of gonads was at I and II. Moreover, it was discovered that most organisms in the digestive tract were shrimp, worms, small fish, and crabs, while the highest index of preponderance was in shrimp with 42%. In conclusion, this study showed the new information about length-weight, biological condition, and feeding habits of Plotosus canius, which can be inventoried to strengthen data on sustainable fisheries management.

Dynamic feeding method for aquaculture fish using multi-task neural network

In recirculating aquaculture system (RAS), fish feeding is the most important part in production management, which is not only related to economic benefits, but also the key to ensure fish welfare and increase production. At present, in RAS, fish are basically fed either artificially or automatically (quantitatively supply feed at definite time), which can easily result in under-feeding or over-feeding of fish. Therefore, there is an urgent to develop an intelligent method that realizes appropriate feeding according to the actual demands of fish. This research attempts to explore a fish dynamic feeding method based on the multi-task network to meet the automatic adjustment of both the feeding intervals (the time intervals between feeding points in repeated feeding in a single-round) and feeding rates. The specific objectives of this study include two parts: 1) to construct a multi-task network to analyze the feeding activity of cultured fish and monitor the amount of uneaten feed pellets; 2) to design a feeding strategy based on information obtained from the multi-task network that realizes the dynamic adjustment of feeding intervals and the decision of feeding endpoint. The waste of feed pellets can be reduced by dynamically adjusting the feeding intervals, and the under-feeding and over-feeding of fish can be prevented by determining feeding endpoint. The results indicated that the accuracy of feeding activity classification by multi-task network reached 95.44%, and the mean absolute error (MAE) and mean square error (MSE) in uneaten feed pellet counting were 4.80 and 6.75, which indicate that the multi-task network can accurately monitor the fish feeding activity and the amount of uneaten feed pellets. Based on the two monitored information, combined with the feeding strategy, we dynamically adjusted the feeding intervals and determined the feeding endpoint, and then compared the feeding endpoints with manual judgment to verify the feasibility and accuracy of the dynamic feeding method based on the multi-task network. In summary, this research provides a more accurate and efficient solution for the intelligent and precise feeding of cultured fish, and provides the theoretical foundation for the development of intelligent feeding devices.

Evaluating fish feeding intensity in aquaculture with convolutional neural networks

This paper presents a novel method to evaluate fish feeding intensity for aquaculture fish farming. Determining the level of fish appetite helps optimize fish production and design more efficient aquaculture smart feeding systems. Given an aquaculture surveillance video, our goal is to improve fish feeding intensity evaluation by proposing a two-stage approach: an optical flow neural network is first applied to generate optical flow frames, which are then inputted to a 3D convolution neural network (3D CNN) for fish feeding intensity evaluation. Using an aerial drone, we capture RGB water surface images with significant optical flows from an aquaculture site during the fish feeding activity. The captured images are inputs to our deep optical flow neural network, consisting of the leading neural network layers for video interpolation and the last layer for optical flow regression. Our optical flow detection model calculates the displacement vector of each pixel across two consecutive frames. To construct the training dataset of our CNNs and verify the effectiveness of our proposed approach, we manually annotated the level of fish feeding intensity for each training image frame. In this paper, the fish feeding intensity is categorized into four, i.e., ‘none,’ ‘weak,’ ‘medium’ and ‘strong.’ We compared our method with other state-of-the-art fish feeding intensity evaluations. Our proposed method reached up to 95 % accuracy, which outperforms the existing systems that use CNNs to evaluate the fish feeding intensity.

The neglected role of omnivore fish in the overgrazing of Mediterranean rocky reefs

Sea urchins are considered the most important grazers in Mediterranean shallow sublittoral rocky reef ecosystems, but fish can also have an important role in overgrazing and the reduction of habitat complexity. In this study, the trophic behavior of fish was recorded when provided access to experimental surfaces with increased macroalgal biomass and associated benthic fauna, created by herbivore exclusion cages. After a sufficient period for substantial algal growth, the cages were removed and the activity of fish on these surfaces was recorded for 3 h by an automated photographic camera system. Control surfaces with no restriction on grazers were defined on similar substrates for comparison. To quantify the effects of fish feeding activity on macroalgal coverage, photographic samples were taken immediately after the opening of the cages and after each 3 h recording. The response of fish when the cages were removed was immediate and intense. Feeding activity by 13 different fish species was recorded in total, of which the most frequent were the omnivores Diplodus vulgaris, Coris julis and Thalassoma pavo, and to a lesser extent the herbivore Sarpa salpa. The coverage of erect algae was substantially decreased on the experimental surfaces due to fish feeding activity. The algae were either directly consumed by the fish or cut off when the fish were feeding on macroinvertebrates. We conclude that in addition to grazing by herbivores, fish of higher trophic levels can also significantly affect macroalgal assemblages and restrict the recovery of erect algae in overgrazed reefs where prey is scarce.

Algal turf sediments limit the spatial extent of function delivery on coral reefs

The presence of key organisms is frequently associated with the delivery of specific ecosystem functions. Areas with such organisms are therefore often considered to have greater levels of these functions. While this assumption has been the backbone of coral reef ecosystem-based management approaches for decades, we currently have only a limited understanding of how fish presence equates to function on coral reefs and whether this relationship is susceptible to stressors. To assess the capacity of a stressor to shape function delivery we used a multi-scale approach ranging from tens of kilometres across the continental shelf of Australia's Great Barrier Reef, down to centimetres within a reef habitat. At each scale, we quantified the spatial extent of a model function (detritivory) by a coral reef surgeonfish (Ctenochaetus striatus) and its potential to be shaped by sediments. At broad spatial scales, C. striatus presence was correlated strongly with algal turf sediment loads, while at smaller spatial scales, function delivery appears to be constrained by algal turf sediment distributions. In all cases, sediment loads above ~250–500 g m−2 were associated with a marked decrease in fish abundance or feeding activity, suggesting that a common ecological threshold lies within this range. Our results reveal a complex functional dynamic between proximate agents of function delivery (fish) and the ultimate drivers of function delivery (sediments), which emphasizes: a) weaknesses in the assumed links between fish presence and function, and b) the multi-scale capacity of algal turf sediments to shape reef processes. Unless direct extractive activities (e.g. fishing) are the main driver of function loss on coral reefs, managing to conserve fish abundance is unlikely to yield the desired outcomes. It only addresses one potential driver. Instead, management of both the agents that deliver functions (e.g. fishes), and the drivers that modify functions (e.g. sediments), is needed.

Impact of gonad weight on the length-weight relationships of river catfish (Clupisoma garua) in Bangladesh

This study was intended to assess the effect of gonadal weight on the length-weight relationships for year-round samples of river catfish (Clupisoma garua) collected from Old Brahmaputra River, Bangladesh. The standard length (SL) and body weight (BW) of females varied from 11.8 to 27.8 cm and 23.26 g to 272.23 g. Likewise, the length of male ranged from 8.97 to 18.9 cm and weight varied from 8.44 to 102.0 g, respectively. In monthly length-weight relationship, the slope (b) value including gonad ranged from 2.29 to 3.87 and 2.28 to 3.86 without gonad. The values of coefficient of determination (r2) for extended from 0.774 to 0.994. The generalized relationship of combined data was BW = 0.0107SL3.08. However, the b value at 95% confidence limit suggested that the populations’ growth in all sampling months was isometric except in January. The analysis of covariance indicated no significant difference between length-weight relationships including and excluding gonads. Therefore, this study concluded that the isometric growth reported might be subjected by the comparatively higher temperature of summer months with the enhancement of food availability, intensive feeding and metabolic activity of fishes. Conversely, there was no impact of gonad on the length-weight relationships of Clupisoma garua population.

Seasonal Variations and Interspecific Differences in Metabolomes of Freshwater Fish Tissues: Quantitative Metabolomic Profiles of Lenses and Gills.

This work represents the first comprehensive report on quantitative metabolomic composition of tissues of pike-perch (Sander lucioperca) and Siberian roach (Rutilus rutilus lacustris). The total of 68 most abundant metabolites are identified and quantified in the fish lenses and gills by the combination of LC-MS and NMR. It is shown that the concentrations of some compounds in the lens are much higher than that in the gills; that indicates the importance of these metabolites for the adaptation to the specific living conditions and maintaining the homeostasis of the fish lens. The lens metabolome undergoes significant seasonal changes due to the variations of dissolved oxygen level and fish feeding activity. The most season-affected metabolites are osmolytes and antioxidants, and the most affected metabolic pathway is the histidine pathway. In late autumn, the major lens osmolytes are N-acetyl-histidine and threonine phosphoethanolamine (Thr-PETA), while in winter the highest concentrations were observed for serine phosphoethanolamine (Ser-PETA) and myo-inositol. The presence of Thr-PETA and Ser-PETA in fish tissues and their role in cell osmotic protection are reported for the first time. The obtained concentrations can be used as baseline levels for studying the influence of environmental factors on fish health.

Do advantages in resource exploration lead to better body condition?

The colonization of novel reservoirs tends to support opportunistic species that undergo mass proliferation after the reservoir is formed. It is common that in this process, a species will change its diet based on resource availability. This is the case in the Salto Caxias reservoir, Iguacu River, where five Astyanax species presented changes in their diets after damming. The present study aimed to evaluate possible changes in the feeding activity and condition factor of five sympatric species of Astyanax in the Salto Caxias reservoir in different areas impacted by damming. Sampling was carried out before and after damming the Salto Caxias reservoir. The fish feeding activity and nutritional status were inferred by the mean stomach repletion index and the mean condition factor, respectively. Most of the studied species showed a general decrease in feeding activity and condition factor. Both studied regions, the upstream region and the dam region, presented changes in the analyzed factors. These observations suggest that regardless of diet changes, nutritional status is negatively impacted in altered environments. The nutritional deficit occurs (i) if the diet is altered due to adaptive limitations on the use of the available resources and (ii) if the diet remains unaltered due to the scarcity of the preferred feeding resource. Such decreases might lead to reductions in the population size due to limitations on growth and reproduction until the environment feeding resources can sustain those populations.

DIY Automated Feeding and Motion Recording System for the Analysis of Fish Behavior.

Fish species such as medaka or zebrafish are widely used as animal models to study physiology, disease development, and treatment efficacy. They are also used to study the rapidly growing field of behavior research, such as social interactions, anxiety, and the influence of environmental factors. Here we describe an automated experimental setup allowing the recording of general locomotor activity in combination with a food-on-demand system. It can simply be built with some basic electronic knowledge. Our setup enables the recording of locomotor and feeding activity of several fish for long-term studies, excluding disturbing external influences. A description of the automated recording system is given, as well as examples of recordings to illustrate its applicability for the study of fish behavior. The construction manual and operation instructions can be downloaded for free.

Design and Construction of Automatic Fish Feeder using Atmel 8052 Microcontroller

This paper was proposed to design an automatic fish feeder system using Atmel microcontroller application. In a way, it is to control the fish feeding activity by using a fish feeder that combined the mechanical and electrical system to form a device which control the fish feeding activity. This device consists of feed storage, feed stand, display unit, microcontroller and DC motor. The feeds controlled by DC motor which is located under feed storage. A control system was then attached to this device allowing the fish to be fed at preset time as required by user. Hence, promising efficiency and productivity in fish pond in long run. Display unit his is basically the user interface where working of the system is displayed on a screen so that the user have an idea what is going on the system. The message will be displayed on a 16 by 2 liquid crystal display. The controller came with a keypad giving users more option in determining the suitable speed for the motor. In addition, the feed in the automatic fish feeder system will be controlled by the rotation speed of DC motor. Test results at the discharge interval of 4hours and dispensing time of 90minutes within 24hours showed that 15kg of feeds were evenly broadcast across the pond of 12cm less amount of feed lost was recorded compare to manual feeding. The machine adequately manages and preserves feed under harsh conditions.

Attracting Common Carp to a bait site with food reveals strong positive relationships between fish density, feeding activity, environmental DNA, and sex pheromone release that could be used in invasive fish management.

Measurement of environmental DNA (eDNA) is becoming a common technique to survey for rare and invasive fish due to its sensitivity and specificity. However, its utility is limited by an incomplete understanding of factors governing its sources and fates. Failure to detect eDNA is especially difficult to interpret so surveillance techniques often collect large numbers of samples across broad regions. If, however, fish could be reliably attracted to a single location where their eDNA could be easily measured that would be useful. We conducted a proof‐of‐concept study of this idea using invasive Common Carp. We monitored the distribution of radio‐tagged Carp and their eDNA across a 67 ha lake focusing at the bait site while a pheromone (Prostaglandin F2α; PGF 2α) was also measured to determine their reproductive condition. Prior to baiting, Carp were patchily distributed and while eDNA was occasionally detectable, it was patchy and only loosely associated with moderately dense groups of fish. Further, neither Carp, nor their eDNA were consistently measurable at the bait site and surrounding region, and the pheromone was not measurable at all. However, once baiting commenced, Carp started visiting the bait site and feeding, especially at night, where eDNA levels increased 500‐fold as fish densities doubled and PGF 2α became detectable. Fish presence, eDNA and pheromone concentrations peaked at night after 6 days, strongly suggesting feeding activity was the main driver. While the presence of eDNA precisely coincided with this aggregation, levels had dropped dramatically within 5 m. PGF 2α levels dropped less rapidly and demonstrated the presence of live mature fish. We suggest that food could be used to train fish to come to locations where they otherwise are too scarce to be reliably measured, increasing their eDNA release, making them measurable, and their reproductive condition also discernable by measuring pheromones.

Use of acoustic refuges by freshwater fish: Theoretical framework and empirical data in a three‐species trophic system

Abstract Sounds are more easily transmitted underwater than through air and many freshwater fish species can hear them, particularly over the low frequencies. Recent studies on freshwater fish evidenced that hearing sensitivities can be limited by the level of ambient noise, a phenomenon also known as acoustic masking. However, it is still unclear whether variations in ambient noises, such as those produced by human activities, may alter fish trophic interactions. The general objective of this study was to propose and evaluate a theoretical framework explicitly linking fish attack rates to species hearing sensitivities and ambient noise levels in freshwater ecosystems. The proposed model shows that the feeding activity of fish at an intermediate position in the food web is conditional on the probability of being acoustically detected by their predators, or of encountering an acoustically distressed resource. Model simulations and preliminary field results suggest that yellow perch (Perca flavescens) could feed more actively in the presence of augmented ambient noise levels. Yellow perch captures per unit effort were higher by a factor of 2.7 in noisy versus quiet days. We argue that fish exposed to intermediate levels of noise could maximise the probability of detecting food patches while minimising their predation risk. Acoustic monitoring programmes for freshwater ecosystems require a fundamental knowledge of underwater noise levels, species hearing sensitivities and features affecting sound propagation. The approach proposed in this paper is seminal in linking the above descriptors in a coherent mathematical framework to understand the effect of underwater sounds on trophic interactions. Such framework is needed to make testable predictions and generalise to other taxa and ecological contexts.

Near-infrared imaging to quantify the feeding behavior of fish in aquaculture

In aquaculture, fish feeding behavior under culture conditions holds important information for the aquaculturist. In this study, near-infrared imaging was used to observe feeding processes of fish as a novel method for quantifying variations in fish feeding behavior. First, images of the fish feeding activity were collected using a near-infrared industrial camera installed at the top of the tank. A binary image of the fish was obtained following a series of steps such as image enhancement, background subtraction, and target extraction. Moreover, to eliminate the effects of splash and reflection on the result, a reflective frame classification and removal method based on the Support Vector Machine and Gray-Level Gradient Co-occurrence Matrix was proposed. Second, the centroid of the fish was calculated by the order moment, and then, the centroids were used as a vertex in Delaunay Triangulation. Finally, the flocking index of fish feeding behavior (FIFFB) was calculated to quantify the feeding behavior of a fish shoal according to the results of the Delaunay Triangulation, and the FIFFB values of the removed reflective frames were fitted by the Least Squares Polynomial Fitting method. The results show that variations in fish feeding behaviors can be accurately quantified and analyzed using the FIFFB values, for which the linear correlation coefficient versus expert manual scoring reached 0.945. This method provides an effective method to quantify fish behavior, which can be used to guide practice.

Effects of fish on field resource utilization and rice growth in rice-fish coculture

Rice field can provide habitat for fish and other aquatic animals. Rice-fish coculture can increase rice yield and simultaneously reduce the use of chemicals through reducing rice pest occurrence and nutrient complementary use. However, how fish uses food sources (e.g. phytoplankton, weeds, duckweed, macro-algal and snail) from rice field, and whether the nutrients releasing from those food sources due to fish transforming can improve rice growth are still unknown. Here, we conducted two field experiments to address these questions. One was to investigate the pattern of fish activity in the field using the method of video recording. The other was to examine the utilization of field resources by fish using stable isotope technology. Rice growth and rice yield were also exa-mined. Results showed that fish tended to be more active and significantly expanded the activity range in the rice-fish coculture compared to fish monoculture (fish not living together with rice plants). The contributions of 3 potential aquatic organisms (duckweed, phytoplankton and snail) to fish dietary were 22.7%, 34.8% and 30.0% respectively under rice-fish coculture without feed. Under the treatment with feed, however, the contributions of these 3 aquatic organisms to the fish die-tary were 8.9%, 5.9% and 1.6% respectively. The feed contribution was 71.0%. Rice-fish coculture significantly increased the nitrogen concentration in rice leaves, prolonged tillering stage by 10-12 days and increased rice spike rate and yield. The results suggested that raising fish in paddy field may transform the nutrients contained in field resources to bioavailable for rice plants through fish feeding activity, which can improve rice growth and rice yield.

Preliminary study of acceleration based sensor to record nile tilapia (Oreochromis niloticus) feeding behavior at water surface

In this preliminary study, the acceleration based sensor was developed to monitor the activity of Nile tilapia (Oreochromis niloticus) feeding behavior at the water surface. This study was conducted for three weeks in a fish pond with 40 m2 in size, stocked with 850 fingerlings of Nile tilapia strain Nirwana-2 (average biomass of 13 g, fed four times a day at 8 am, 12 pm, 4 pm, and 8 pm). The acceleration sensor system was installed floating in the pond and was designed in a way so that the xz plane of the sensor will be parallel with water surface, while the y-axis will be pointing downward. By sensing the acceleration caused by the surface wave, the activities of fish near surface water could be monitored. The result showed that there were three distinctive patterns could be observed which was related to the feeding activity of fish. Generally, it can be concluded that this acceleration based sensor system can be integrated with automatic feeder machine, in particular by analyzing the recorded patter, it is possible to monitor when the fish stop eating, and so the right amount of feed could be given to the fish.

Food resources and cyprinid diet in permanent and temporary Mediterranean rivers with natural and regulated flow

AbstractThis study addresses the differences in food availability, diet and feeding activity of the Iberian barbel, between permanent and temporary nonregulated rivers, and the effect of flow regulation on feeding parameters. A total of 267 adult barbels were seasonally collected in four nonregulated and regulated rivers from permanent and temporary basins, and their gut content was analysed. Locally available food sources were evaluated across sites and seasons. Barbels from the permanent nonregulated river exhibit a more variable and diversified diet in which invertebrates assumed a large importance, especially during high flows. Barbels from the temporary nonregulated river presented a more uniform diet composed of plant material and detritus, particularly in drought seasons. Flow regulation affected different flow components in both systems, but the effects on food resources and barbels' diet were similar, resulting in an intra‐annual stabilisation of resource availability and fish diet, with a higher consumption of plants and detritus. Changes in fish diet and feeding activity in both nonregulated and regulated rivers were strongly associated with the seasonal variability of streamflow components, particularly between low‐ and high‐flow periods, and with the reduction in flow variability in the case of dam regulation. Results from this study can be used to improve guidelines for flow requirement implementation.