scholarly journals Resource partitioning and ecomorphological variation in two syntopic species of Lebiasinidae (Characiformes) in an Amazonian stream

2016 ◽  
Vol 46 (1) ◽  
pp. 25-36 ◽  
Author(s):  
Nathália Carina dos Santos SILVA ◽  
Aluízio José Lopes da COSTA ◽  
José LOUVISE ◽  
Bruno Eleres SOARES ◽  
Vanessa Cristine e Souza REIS ◽  
...  
Keyword(s):  
Resource Partitioning ◽  
Trophic Ecology ◽  
Species Coexistence ◽  
Stomach Contents ◽  
Relative Length ◽  
Niche Overlap ◽  
The Body ◽  
Feeding Strategies ◽  
Relative Depth ◽  
Feeding Niche

ABSTRACTResource partitioning is important for species coexistence. Species with similar ecomorphology are potential competitors, especially when phylogenetically close, due to niche conservatism. The aim of this study was to investigate the resource partitioning among populations of two species of lebiasinids (Copella nigrofasciata and Pyrrhulina aff. brevis) that co-occur in a first-order Amazonian stream, analyzing the trophic ecology, feeding strategies and ecomorphological attributes related to the use of food and space by these species. Fish were captured in May and September 2010. The stomach contents of 60 individuals were analyzed and quantified volumetrically to characterize the feeding ecology of both species. Eleven morphological attributes were measured in 20 specimens and combined in nine ecomorphological indices. Both species had an omnivorous-invertivorous diet and consumed predominantly allochthonous items. Both showed a tendency to a generalist diet, but intrapopulational variation in resource use was also detected. Overall feeding niche overlap was high, but differed between seasons: low during the rainy season and high in the dry season. In the latter, the food niche overlap was asymmetric because C. nigrofasciata consumed several prey of P. aff. brevis, which reduced its food spectrum. The ecomorphological analysis suggests that C. nigrofasciatahas greater swimming capacity (greater relative length of caudal peduncle) than P. aff. brevis, which has greater maneuverability and tendency to inhabit lentic environments (greater relative depth of the body). Our results demonstrate that these species have similar trophic ecology and suggest a spatial segregation, given by morphological differences related to locomotion and occupation of habitat, favoring their coexistence.

Dietary overlap and food resource partitioning among fish species of a tropical estuary in Northeastern Brazil

Gaia Scientia ◽  
2016 ◽  
Vol 10 (4) ◽  
pp. 86-95 ◽  
Author(s):  
Adna Ferreira da Silva Garcia ◽  
Ana Lúcia Vendel
Keyword(s):  
Resource Partitioning ◽  
Species Coexistence ◽  
Food Resource ◽  
River Estuary ◽  
Niche Overlap ◽  
Northeastern Brazil ◽  
Dietary Overlap ◽  
Feeding Niche ◽  
Tropical Environments ◽  
Food Resource Partitioning

The current work investigates dietary overlap and food partitioning among nine abundant carnivorous fishes caught in the shallow waters of the Paraíba do Norte river estuary, Paraíba State, Brazil. Fishes were sampled with a beach seine net between January and December 2008 and a total of 958 specimens had their stomach content analyzed. Crustacea was the dominant food resource for Lutjanus alexandrei, L. jocu and Bathygobius soporator, whereas Telostei were consumed mainly by Centropomus undecimalis and C. parallelus. In contrast, Polychaeta were preyed upon mainly by Diapterus rhombeus, Eucinostomus argenteus, Sciades herzbergii and S. parkeri. Although most species consumed similar food items, they did that in varying proportions and amounts. Overall, the niche overlap among species was low (< 0.60), but there were several cases where pair of species had their feeding niche highly overlapped (between 0.72 and 0.97). These findings corroborate the hypothesis that food resource partitioning determines species coexistence in estuarine tropical environments.

Trophic niche overlap in two syntopic colubrid snakes (Hierophis viridiflavus and Zamenis longissimus) with contrasted lifestyles

2012 ◽  
Vol 33 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Hervé Lelièvre ◽  
Pierre Legagneux ◽  
Gabriel Blouin-Demers ◽  
Xavier Bonnet ◽  
Olivier Lourdais
Keyword(s):  
Diet Composition ◽  
Feeding Rate ◽  
Species Coexistence ◽  
Niche Partitioning ◽  
Stomach Contents ◽  
Niche Overlap ◽  
Trophic Niche ◽  
Temperate Climate ◽  
Feeding Strategies ◽  
Mean Body Temperature

In many organisms, including snakes, trophic niche partitioning is an important mechanism promoting species coexistence. In ectotherms, feeding strategies are also influenced by lifestyle and thermoregulatory requirements: active foragers tend to maintain high body temperatures, expend more energy, and thus necessitate higher energy income. We studied diet composition and trophic niche overlap in two south European snakes (Hierophis viridiflavus and Zamenis longissimus) in the northern part of their range. The two species exhibit contrasted thermal adaptations, one being highly mobile and thermophilic (H. viridiflavus) and the other being elusive with low thermal needs (Z. longissimus). We analyzed feeding rate (proportion of snakes with indication of a recent meal) and examined more than 300 food items (fecal pellets and stomach contents) in 147 Z. longissimus and 167 H. viridiflavus. There was noticeable overlap in diet (overlap of Z. longissimus on H. viridiflavus = 0.62; overlap of H. viridiflavus on Z. longissimus = 0.80), but the similarity analyses showed some divergence in diet composition. Dietary spectrum was wider in H. viridiflavus, which fed on various mammals, birds, reptiles, and arthropods whereas Z. longissimus was more specialized on mammals and birds. The more generalist nature of H. viridiflavus was consistent with its higher energy requirements. In contrast to our expectation, feeding rate was apparently higher in Z. longissimus than in H. viridiflavus, but this could be an artifact of a longer transit time in Z. longissimus, given its lower mean body temperature. These results allow a better understanding of the ability to coexist in snakes belonging to temperate climate colubrid communities.

scholarly journals Resource use by two electric fishes (Gymnotiformes) of the National Forest Saracá-Taquera, Oriximiná, Pará

2017 ◽  
Vol 15 (2) ◽  
Author(s):  
Bruno E. Soares ◽  
Daniela C. O. Rosa ◽  
Nathália C. S. Silva ◽  
Miriam P. Albrecht ◽  
Érica P. Caramaschi
Keyword(s):  
Resource Use ◽  
Niche Breadth ◽  
Feeding Strategy ◽  
Stomach Contents ◽  
Niche Overlap ◽  
Feeding Strategies ◽  
National Forest ◽  
Microhabitat Use ◽  
Use Patterns ◽  
Head Morphology

ABSTRACT Fishes of the order Gymnotiformes have high diversity of oral and head morphology, which suggests trophic specializations within each clade. The aim of this study was to describe resource use patterns by two fish species (Gymnorhamphichthys rondoni and Gymnotus coropinae) in the National Forest Saracá-Taquera, Oriximiná - Pará, analyzing microhabitat use, diet composition, feeding strategies, niche breadth and niche overlap. Stomach contents of 101 individuals (41 G. rondoni and 60 G. coropinae), sampled in 23 headwater streams were analyzed and volume of food items was quantified to characterize their feeding ecology. Gymnorhamphichthys rondoni was captured mainly on sandy bottoms, whereas G. coropinae in crevices. Both species had a zoobenthivorous diet and consumed predominantly Sediment/Detritus and Diptera larvae, but also included allochthonous prey in their diet. These species had high niche overlap, with small variations related to the higher consumption of Ceratopogonidae larvae by G. rondoni and of Chironomidae larvae by G. coropinae. Both species had a generalist feeding strategy, but G. coropinae had a broader niche breadth. Our results demonstrate that G. rondoni and G. coropinae occupy different microhabitats but rely on similar food resources.

scholarly journals Adaptive foraging behaviour increases vulnerability to climate change

2021 ◽  
Author(s):  
Benoit Gauzens ◽  
Benjamin Rosenbaum ◽  
Gregor Kalinkat ◽  
Thomas Boy ◽  
Malte Jochum ◽  
...  
Keyword(s):  
Climate Change ◽  
Foraging Behavior ◽  
Dynamic Models ◽  
Species Coexistence ◽  
Prey Availability ◽  
Stomach Contents ◽  
Optimal Foraging Theory ◽  
Trophic Niche ◽  
Feeding Strategies ◽  
Adaptive Foraging

Abstract Adaptative foraging behavior should promote species coexistence and biodiversity under climate change as predators are expected to maximize their energy intake, according to principles of optimal foraging theory. We test these assumptions using a dataset comprising 22,185 stomach contents of fish species across functional groups, feeding strategies, and prey availability in the environment over 12 years. Our results show that foraging shifts from trait-dependent prey selectivity to density dependence in warmer and more productive environments. This behavioral change leads to lower consumption efficiency as species shift away from their optimal trophic niche, undermining species persistence and biodiversity. By integrating this adaptive foraging behavior into dynamic models, our study reveals higher risk profiles for ecosystems under global warming.

scholarly journals Ecología trófica y rasgos ecomorfológicos de Triportheus magdalenae (Characiformes: Triportheidae) en el embalse El Guájaro, cuenca baja del río Magdalena, Colombia

2018 ◽  
Vol 66 (3) ◽  
pp. 1208
Author(s):  
Jenny Morales ◽  
Carlos Arturo García-Alzate
Keyword(s):  
Trophic Ecology ◽  
Dietary Habits ◽  
Morphological Characteristics ◽  
Stomach Contents ◽  
Relative Length ◽  
Flood Pulse ◽  
Trophic Niche ◽  
Trophic Specialization ◽  
Magdalena River ◽  
Del Rio

This study integrated morphological characteristics and trophic ecology of Triportheus magdalenae in the El Guájaro reservoir, Atlántico, lower Magdalena River Basin, Colombia, based on the analysis of stomach contents and ecomorphological attributes. Five samplings were made between September 2014 and February 2016 considering each phase of the flood pulse. The fish were sampled using traditional fishing gear such as nets and trawls. The index of food importance (IAi %) was used to establish the dietary habits of the species, and the variation of the diet at interspecific level, and the vacuity coefficient (CV %) was also calculated. The Levins index standardized by Hurlbert (BA) was used to evaluate the amplitude between sizes, sex and hydrological phases. The oropharyngeal structures and the digestive tract were characterized, which together with morphological measurements, allowed and analyze 11 ecomorphological traits related to the use of habitat, such as position in the water column, and the exploitation of a particular trophic resource. The relationship between the ecomorphological traits and the diet of the species was analyzed by canonical correspondence analysis (CCA). We analyzed 89 individuals (34 - 124 mm SL). Triportheus magdalenae was classified as carnivore/zooplanktivore, and has a narrow trophic niche (BA = 0.12). Showed a high exploitation of zooplankton (95.9 % IAi), mostly Cladocera (Ceriodaphnia sp.) and Copepoda (Notodiaptomus sp. and Thermocyclops sp).  The youngest juveniles (34 - 190 mm SL) also consumed allochthonous insects (3.4 % IAi).The ecomorphological traits that contributed the most to this trophic specialization were the relative length of the gillrakers (LRBE) and the number of gillrakers (NBE), which varied significantly from the smaller to the larger ones, with an increase in both number as well as in length as individuals grow, which explains the strongly marked degree of specialization on zooplankton in adults, since they present a greater degree of efficiency in the process of filtering. The vacuity coefficient was high  (54 %), which could be associated with a decrease in the density of zooplankton populations, especially during the time of lower waters strongly influenced by the EL NIÑO event, however the observed diet (22 items food) corresponded to 80 % of the diet estimated (28 estimated food items). 

Resource partitioning among juvenile snappers in a semi-arid estuary in north-eastern Brazil

2020 ◽  
Vol 100 (5) ◽  
pp. 807-816
Author(s):  
Silvia Yasmin Lustosa-Costa ◽  
Maria Rita Nascimento Duarte ◽  
Priscila Rocha Vasconcelos Araújo ◽  
André Luiz Machado Pessanha
Keyword(s):  
Resource Partitioning ◽  
Species Coexistence ◽  
Feeding Strategy ◽  
Mouth Area ◽  
The Body ◽  
Beach Seine ◽  
Eastern Brazil ◽  
North Eastern ◽  
Species Being ◽  
Semi Arid

AbstractResource partitioning is important for species coexistence. Species with similar ecomorphological characters have a high potential for competition, especially when close phylogenetically. The diet and resource partitioning of four snappers (Lutjanus alexandrei, L. analis, L. jocu and L. synagris) was studied in the Tubarão River, north-eastern Brazil, between March and November 2012. Specimens were caught using a beach seine, and a total of 731 stomachs were analysed. The highest abundance of snappers was found near to vegetated habitats in the middle estuary. Crustaceans were dominant in the diet of all four species, being found in over 90% of the stomachs, followed by fish and molluscs. The species did not appear to compete for common resources, probably because there was not always spatial overlap, and differences in the proportions of consumption of items were observed. Ontogenetic comparisons of dietary compositions suggested differences among species, with changes in the diet related to changes in the mouth area as the body size increased. The changes were more evident in L. analis and L. synagris where microcrustaceans (Calanoida, Cyclopoida and Amphipoda) were dominant in the diet of the smaller size classes, and benthic crustaceans (Brachyura) and fish in the diet of larger individuals. The intra- and inter-specific differences in the dietary compositions, differences in the mouth area and feeding strategy contribute to allow the co-existence of these snappers in the study area.

Evidence for inter- and intraspecific trophic niche separation among deepwater elasmobranchs on the southern Great Barrier Reef, Australia

2020 ◽  
Vol 636 ◽  
pp. 107-121
Author(s):  
SEM Munroe ◽  
CL Rigby ◽  
NE Hussey
Keyword(s):  
Great Barrier Reef ◽  
Trophic Ecology ◽  
Isotope Analysis ◽  
Niche Overlap ◽  
Trophic Niche ◽  
Feeding Strategies ◽  
Niche Separation ◽  
Isotopic Niche ◽  
Barrier Reef ◽  
Trawl Fishery

Quantifying the trophic structure and interactions of deepwater (>200 m depth) elasmobranch assemblages is required to improve our understanding of deepwater ecosystems and the impacts of increased deepwater exploitation. To this end, we investigated the trophic ecology of deepwater elasmobranchs on the Great Barrier Reef (GBR) using a stable isotope (δ13C and δ15N) approach. Our study included 4 species captured in the southern GBR deepwater eastern king prawn trawl fishery: the eastern spotted gummy shark Mustelus walkeri, the piked spurdog Squalus megalops, the pale spotted catshark Asymbolus pallidus, and the Argus skate Dentiraja polyommata. The δ13C and δ15N values of all 4 species ranged from -18.6 to -16.2‰ and 8.3 to 13.8‰, respectively. The small δ13C range was likely due to the limited number of unique carbon baseline sources typically found in deepwater environments. Despite this, 3 of the 4 species exhibited relatively low core (40% SEAb) isotopic niche overlap (<1 to 44%). Isotopic niche separation may be driven by multiple interacting factors including morphology, feeding strategies, or resource partitioning to reduce competition. Isotope analysis also provided evidence for intraspecific variation; S. megalops, D. polyommata and M. walkeri exhibited significant increases in δ15N (~3‰) and δ13C (~2‰) with size. Latitude, longitude, and depth had statistically significant but comparatively minor effects on isotope values (≤1‰) of the 4 species. Cumulatively, our results indicate that isotopic variation among deepwater elasmobranchs on the GBR is principally driven by size and species-level differences in resource use.

scholarly journals Implications of low food availability on resource partitioning among three species of Cichlidae (Pisces: Perciformes) in a Brazilian semi-arid reservoir

2015 ◽  
Vol 27 (1) ◽  
pp. 93-104 ◽  
Author(s):  
Bruno Renaly Souza Figueiredo ◽  
Gabrielle Joanne Medeiros Araujo ◽  
Márcio Joaquim da Silva ◽  
Elvio Sergio Figueredo Medeiros
Keyword(s):  
Food Availability ◽  
Fish Species ◽  
Resource Partitioning ◽  
Food Resource ◽  
Stomach Contents ◽  
Niche Overlap ◽  
Trophic Levels ◽  
Feeding Mode ◽  
Food Items ◽  
Semi Arid

AimResource partitioning has been recognized as a major driver affecting fish communities, with the potential to reduce interespecific competition. This is the result of differences in feeding apparatuses and feeding mode, location of the fish species in the water column and swimming ability, as well as type and size of prey and its availability. The present study surveys a highly limited aquatic system in semi-arid Brazil with regard to habitat and food availability, with very low diversity of fish, and poor in underwater habitat structures and prey, with the objective of understanding resource partitioning among fish species under such conditions.MethodsThree species of Cichlidae (Pisces: Perciformes) were sampled during the dry and wet seasons and had their stomach contents analyzed to evaluate food consumption. The resource partition among fish species was evaluated based on Pianka’s niche overlap index and tested for significance against null models.ResultsIt was observed a low overlap among the study species in food resource use, with individuals tending to specialize to select some food items. This is likely the result of low natural variation in abundance of specific food items associated with fish preferences (both morphological and behavioral).ConclusionsThese results support evidence that, in Brazilian semi-arid aquatic systems, coexistence of fish species seems to be enhanced by the partition of food items at specific trophic levels. Within this context, flow variability would have a key hole in fish coexistence by promoting a high diversity of aquatic habitat elements available for colonization of fish and their prey. Furthermore, food resources available to fish play an important role in this dynamics since prey foods are expected to vary in abundance as the habitat changes.

scholarly journals Not all nudibranchs are carnivorous: trophic ecology of Polycerella emertoni in the Ebro Delta

2020 ◽  
Vol 645 ◽  
pp. 67-82
Author(s):  
J Camps-Castellà ◽  
M Ballesteros ◽  
R Trobajo ◽  
M Pontes ◽  
P Prado
Keyword(s):  
Trophic Ecology ◽  
Video Recording ◽  
Stomach Contents ◽  
Ebro Delta ◽  
Seasonal Abundance ◽  
Feeding Strategies ◽  
Mixing Models ◽  
Habitat Features ◽  
Feeding Activities ◽  
Multiple Feeding

Nudibranchs have always been regarded as a group of specialized predators. In Alfacs Bay (Ebro Delta, Spain), the cryptic nudibranch Polycerella emertoni is found associated with the pseudo-indigenous bryozoan Amathia verticillata, which has been thought to be its target prey. Here, we assessed the trophic ecology of P. emertoni using a combination of methods, including stable isotope analyses coupled with Bayesian mixing models, examination of stomach contents, and video recording of feeding activities. A morphological analysis of the radula was also conducted to explore a possible relationship with feeding behavior. Finally, we investigated the seasonal abundance of both species throughout an entire year in order to assess the nature and strength of their association. Contrary to current belief, our results show that P. emertoni is a micro-herbivore that feeds on the periphyton covering A. verticillata (up to 99% of the diet, according to mixing models). In particular, a diverse diatom community was observed on A. verticillata, and several of these taxa were found within the stomach contents of P. emertoni. Our results evidence a distinctive radular formula and morphology compared to other species and suggest the presence of multiple feeding strategies in nudibranchs. The high seasonal association observed between P. emertoni and A. verticillata may be attributed to mimicking habitat features as a mechanism to avoid predation. The possible effects of periphyton removal in the survival of detached fragments of A. verticillata may have implications for the dispersal of fouling species and functioning of ecosystems.

scholarly journals Habitat heterogeneity on feeding habit of two sympatric and congeneric characidae fishes in two tropical reservoirs

2016 ◽  
Vol 106 (0) ◽  
Author(s):  
Vanessa G. Lopes ◽  
Jorge L. Nessimian ◽  
Elidiomar R. Da-Silva ◽  
José Henrique C. Gomes ◽  
Ana Carolina I. M. Dias ◽  
...  
Keyword(s):  
Habitat Heterogeneity ◽  
Stomach Contents ◽  
Niche Overlap ◽  
Feeding Habit ◽  
Feeding Strategies ◽  
Fish Diet ◽  
Environmental Features ◽  
Tropical Reservoirs ◽  
Stomach Contents Analysis ◽  
Nmds Analysis

Abstract Food flexibility and omnivory are important features pronounced in Neotropical freshwater fish species, particularly for Astyanax species. Traditionally most fish diet resources are known to be originated in the aquatic environment, however recent studies have pointed to the importance of allochthonous sources. Besides, the colonization of macrophytes, common at several tropical reservoirs, may enhance insectivory in fish diet expanding or concentrating the area of available resources for feeding. Here we employed stomach contents analysis of two sympatric Astyanax species to access the importance of habitat differentiations as spatial complexity in two tropical reservoirs with different environmental features. The NMDS analysis indicated separation in the diet of these species between reservoirs (Stress= 8.28%). Additionally, analysis of variance revealed a significative difference in the volume of food itens ingested between the reservoirs (Anova one-way F(1, 132)=4.4446; p= 0.037). This points out the importance of environmental conditions on the composition of the diet of fishes. This study highlighted the insectivorous feeding habit of Astyanax species and revealed different feeding strategies between sympatric fishes despite high niche overlap in both environments. Habitat heterogeneity increasing food resources availability plays an important role in the diet strategy of these Astyanax species and on their constant maintenance in the two different reservoirs.

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