scholarly journals Feeding ecology of Serrasalmus gouldingi (Characiformes: Serrasalmidae) in the lower Anapu River region, Eastern Amazon, Brazil

2016 ◽  
Vol 46 (3) ◽  
pp. 259-270 ◽  
Author(s):  
Bruno da S. PRUDENTE ◽  
Pedro CARNEIRO-MARINHO ◽  
Roberta de M. VALENTE ◽  
Luciano F. de A. MONTAG

Abstract Studies on feeding ecology of fishes are important to understand the relationship between species and environmental seasonal variations. In tropical rivers, these relationships are mainly modeled by hydrological patterns. Thereby, this study aimed to assess the influence of fluviometric variation and life stage (juveniles and adults) in the feeding ecology of Serrasalmus gouldingi in the lower Anapu River region, located in Eastern Amazon, Pará, Brazil. Specimens were collected bimonthly, considering four different hydrological periods. We assessed the diet composition, feeding intensity and niche breadth of the species. Thirty-two dietary items were identified and grouped into ten categories. A total of 279 stomachs were analyzed, showing a predominance of fish fragments, followed by fruits and seeds. The diet composition of S. gouldingi differed only between drought and flood season, although it did not differ between juveniles and adults. An increase in feeding intensity was recorded during the rise in the water level, with a lower feeding intensity observed during transitional season. Serrasalmus gouldingi showed lower niche breadth during flood season, attributed to the high consumption of fruits and seeds, presenting an omnivorous diet with high tendency towards piscivory. Although less evident than in other Amazon watersheds, the flood pulse in the lower Anapu River region is an important factor influencing the feeding ecology of the species.

2013 ◽  
Vol 13 (3) ◽  
pp. 141-147 ◽  
Author(s):  
Andrey Felipe Gomes Gonçalves ◽  
Bruno da Silveira Prudente ◽  
Fernando da Silva Carvalho Filho ◽  
Luciano Fogaça de Assis Montag

The present study describes aspects of feeding ecology of Dash-dot TetraHemigrammus belottii (Characiformes: Characidae) collected in the Urucu River basin in Coari, Amazonas (Brazil), aims to respond the following question: What is the influence of hydrological periods (dry and wet) and spatial distribution in the diet of H. belottii? The specimens were collected between 2006 and 2009 in seven streams in the Urucu basin using standard capture methods. Their stomachs were removed for diet composition analyses. The alimentary items were weighed and identified for subsequent analyzes related to feeding intensity by repletion index (RI%) and importance by alimentary index (AIi%). A total of 227 specimens were analyzed, with a mean standard length of 16.5±5.6 mm. The RI% values indicated that H. belottii fed more intensively during the dry season. The principal items in the diet were Formicidae (IAi% = 69.6), fragments of allochthonous exoskeleton (IAi% = 17.7), and Coleoptera (IAi% = 6.0). The composition of the diet did not vary significantly between seasons or among habitats, which may be related to the abundance of the items exploited by the species throughout the year. Hemigrammus belottii showed a generalist insectivore feeding habits which was mainly composed by allochthonous item.


2016 ◽  
Vol 88 (1) ◽  
pp. 293-308 ◽  
Author(s):  
DANIELE N. CORRÊA ◽  
FERNANDO M. QUINTELA ◽  
DANIEL LOEBMANN

ABSTRACT The snakes Erythrolamprus jaegeri jaegeri and Erythrolamprus poecilogyrus sublineatus are sympatric and syntopic in the coastal region of southern Brazil. Herein, we analyzed the diet composition to evaluate the niche breadth and the prey selection by both species. We examined 192 specimens, and analysis of stomach contents revealed that both species predominantly consume anurans. However, the diet of E. j. jaegeri consists mainly of fish and amphibians, whereas that of E. p. sublineatus is broader, including fish, amphibians, reptiles and mammals. The Standardized Levins Index presented lower values for E. j. jaegeri (BA = 0.17) than for E. p. sublineatus (BA = 0.61), evidencing specialist and generalist strategies for each species, respectively. Regarding prey selection, E. p. sublineatus presented a larger snout-vent length, head, mouth and lower jaw than E. j. jaegeri and fed on larger prey. In addition, positive correlations between the size and weight of predators and prey were confirmed in both species. The results show the development of different mechanisms for co-occurrence of the two species, such as prey selection by size, such that the size of the predator is related to the size of their prey, or by developing different strategies to decrease niche overlap between species.


2011 ◽  
Vol 27 (5) ◽  
pp. 503-513 ◽  
Author(s):  
H. H. de Iongh ◽  
C. B. de Jong ◽  
J. van Goethem ◽  
E. Klop ◽  
A. M. H. Brunsting ◽  
...  

Abstract:The relationship between herbivore diet quality, and diet composition (the range of food plants consumed) and body mass on resource partitioning of herbivores remains the subject of an ongoing scientific debate. In this study we investigated the importance of diet composition and diet quality on resource partitioning among eight species of savanna herbivore in north Cameroon, with different body mass. Dung samples of four to seven wild herbivore and one domesticated species were collected in the field during the dry and wet period. Diet composition was based on microhistological examination of herbivore droppings, epidermis fragments were identified to genus or family level. In addition, the quality of the faecal droppings was determined in terms of phosphorus, nitrogen and fibre concentrations. The results showed that there was no significant correlation between body mass and (differences in) diet composition for wet and dry season. When all species are considered, only significant relationships are found by the Spearman rank correlation analyses during the wet season between body mass and phosphorus and nitrogen, but this relationship did not exist during the dry season. When the analyses focuses on ruminants only (thus leaving out hippo), none of the relationships between body mass and diet quality was significant in either season. During the dry season the proportion of graminoids ranged between 10% (small unidentified herbivore species) to 90% (hippopotamus), during the wet season this proportion ranged from 60% (zebu) to 90% (hippopotamus). All species but zebu had more graminoids in their dung during wet season compared with dry season. However all species but hartebeest had more graminoids old stems in their dung during the dry season, compared with the wet season. The niche breadth for food categories consumed by kob (0.300), hippo (0.090), hartebeest (0.350), roan (0.510) and zebu (0.300) was much greater in the dry season than in the wet season for kob (0.120), hippo (0.020), hartebeest (0.190), roan (0.090) and zebu (0.200). When looking at grass taxa consumed, the niche breadth of kob (0.220), hartebeest (0.140), and roan (0.250) was also greater in the dry season when compared with the wet season for kob (0.050), hartebeest (0.120) and roan (0.120). The opposite was found for zebu and hippo. Comparison of the species’ diet compositions with randomized data showed that dietary overlap between different herbivore species was much higher than what would be expected on the basis of chance, demonstrating surprisingly limited niche separation between species. This offers potential for competition, but it is more likely that the high niche overlap indicates absence of competition, due to low herbivore densities and abundant food resources, permitting species to share non-limiting resources. With increasing herbivore densities and subsequent increasing scarcity of resources, the relationship between diet quality and body mass in combination with increased niche separation is expected to become more visible.


Author(s):  
Izaskun Preciado ◽  
Francisco Velasco ◽  
Ignacio Olaso ◽  
Jorge Landa

The diet of black anglerfish Lophius budegassa is described for the Cantabrian Sea (North Atlantic coast of Spain) from seasonal samples obtained onboard commercial vessels from January 1993 to December 1994. The stomach contents of fish caught on the continental shelf were examined, and differences in the diet in relation to age-class, season and depth were studied. The age-classes were grouped according to a cluster analysis of diet composition. As a result, three groups were obtained: the first two corresponded to juveniles between 2 and 7 years old, and the third one corresponded to adults between 8 and 15 years old. Although Micromesistius poutassou was an important prey for all ages, the youngest black anglerfish fed mainly on small benthic fish. In contrast, large prey species such as Phycis blennoides and Merluccius merluccius were eaten almost exclusively by adults. The diet composition changed during the year. The changes in the diet of black anglerfish older than 3 years were more related to seasonal differences than to between-size differences. These seasonal shifts were mainly marked by the varying importance of Trachurus trachurus and M. merluccius in their diet. Feeding intensity also showed seasonal variations, with a significant decrease in autumn. An indirect effect of depth on the feeding ecology of black anglerfish was also found, since both age and diet composition changed with depth.


2017 ◽  
Vol 8 (1) ◽  
pp. 240-248
Author(s):  
James H. Johnson ◽  
Marc A. Chalupnicki ◽  
Ross Abbett ◽  
Avriel R. Diaz ◽  
Christopher C. Nack

Abstract Fish feeding ecology has been shown to vary over a 24-h period in terms of the prey consumed and feeding intensity. Consequently, in order to best determine the interspecific feeding associations within a fish community, examination of the diet at multiple times over a 24-h period is often necessary. We examined the diel feeding ecology of three fish species that were numerically dominant in a Lake Ontario embayment during summer. The diet of each of the three species, young-of-year Pumpkinseed Lepomis gibbosus, Golden Shiner Notemigonus crysoleucas, and Brook Silverside Labidesthes sicculus, was distinct with no significant overlap in diet composition occurring within any of the 4-h time intervals. The diet composition of each species suggested that Brook Silverside were feeding at the surface (terrestrial invertebrates and aquatic surface dwelling hemipterans), whereas young-of-year Pumpkinseed (amphipods) and Golden Shiner (tipulids) were feeding on different benthic prey. Differences in feeding periodicity were most pronounced for young-of-year Pumpkinseed. Our findings provide valuable insights on interspecific feeding associations among these three fish species during summer in a Lake Ontario embayment.


2013 ◽  
Vol 20 (6) ◽  
pp. 1284-1292
Author(s):  
Nan LIN ◽  
Yazhou JIANG ◽  
Xingwei YUAN ◽  
Jing GUO ◽  
Jianzhong LING ◽  
...  

2018 ◽  
Vol 13 (4) ◽  
pp. 691-701 ◽  
Author(s):  
Katsumi Matsushima ◽  
Makoto Hyodo ◽  
Noriyuki Shibata ◽  
Yoshihiro Shimizu ◽  
◽  
...  

A field demonstration project on flexible dam operation at the Managawa dam in the Kuzuryu River Basin has been implemented since 2000. The goal is to restore flow and sediment regimes in the Managawa River, which flows along the Ono-city and is located below the dam. Flexible dam operation stores inflow discharge into a reservoir, which generally uses part of the flood control capacity and appropriately discharges the stored water to the river, also known as the “flood pulse,” for restoring dynamic fluvial systems and the resulting ecological processes. In addition, other options have been carried out in combination with flexible dam operation, for example, sediment replenishment since 2003 and channel rehabilitation since 2007. This article reveals the positive impacts and effectiveness of flexible dam operation, sediment replenishment, and channel rehabilitation, and discusses challenges and future prospects toward translating the field demonstration project into dam management on the ground level. First, we classified reach types to identify the impact of various management options, e.g., flexible dam operation, sediment replenishment, and channel rehabilitation. These management options can influence respected reaches. We conducted a macro-scale analysis to understand the relationship between the aforementioned management options and dynamic fluvial systems, addressing changes in gravel riverbed, vegetation, and habitat types (riffles and pools). Second, a micro-scale analysis was conducted to understand the relationship between the management option and changes in attached algae to sediment and macro-invertebrates, etc. The results show the effectiveness of the middle-scale flood pulse to restore dynamic fluvial systems, increase habitat diversity, and sustain ecological processes. Furthermore, we discussed the impacts of such options on the flow and sediment regimes in Managawa River and revealed that flexible dam operation reduces the occurrence of low flow and midscale floods. It was also revealed methods such as sediment replenishment and channel rehabilitation play an important role in increasing the effectiveness of the middle-scale flood pulse and restoring dynamic fluvial systems, even though sediment replenishment is not sufficient to restore sediment regimes (i.e., bring then back to pre-dam conditions).


2017 ◽  
Vol 170 ◽  
pp. 152-163 ◽  
Author(s):  
Mário André Trindade Dantas ◽  
Alexander Cherkinsky ◽  
Hervé Bocherens ◽  
Morgana Drefahl ◽  
Camila Bernardes ◽  
...  

2019 ◽  
Vol 6 (1) ◽  
pp. 180917 ◽  
Author(s):  
Hideyuki Doi ◽  
Kwang-Hyeon Chang ◽  
Shin-ichi Nakano

Zooplankton species have different feeding habits, but the diversity of their food resources and the factors governing them are still largely unknown. We here estimated the differences in the trophic niche breadths of dominant zooplankton species in ponds, using stable isotopes. To understand the differences in trophic niches of different zooplankton species, we measured the carbon and nitrogen stable isotope ratios and calculated the nearest-neighbour distance (NND), and standard deviation of NND (SDNND) of the bi-plot space of stable carbon and nitrogen isotopes in pond zooplankton. We tested the relationship between the NND/SDNND and environmental factors, as well as the zooplankton biomass, using generalized linear models (GLMs). For cladocerans, including Bosmina, Ceriodaphnia and Daphnia, the NNDs were significantly correlated with the biomass, pond morphology (volume and depth), total phosphorous (TP) and fish presence. For copepod species, including Eodiaptomus and cyclopoids, NNDs were significantly correlated with pond morphology, TP and fish presence, but not with biomass. In GLMs of SDNND, significant correlated factors were less than those for NND, and for some species, pond morphology and TP were significantly correlated with SDNND. Here, we found that the NND and SDNND of zooplankton species were related to various factors, including their biomass, predator presence, pond size and water quality. For cladocerans, biomass may be supported by trophic niche breadth, probably because of the consequences of resource competition. Also, predation and ecosystem size may influence trophic niche breadth due to changes in zooplankton behaviours.


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