scholarly journals Diet and ecomorphological relationships of an endemic, species-poor fish assemblage in a stream in the Iguaçu National Park

2015 ◽  
Vol 13 (1) ◽  
pp. 245-254 ◽  
Author(s):  
Mayara Pereira Neves ◽  
Rosilene Luciana Delariva ◽  
Luciano Lazzarini Wolff

This study investigated the morphological and dietary relationships of the fish assemblage in a stream with an endemic fauna and low species richness. The ichthyofauna was sampled quarterly from September 2011 to July 2012, through the electrofishing technique. The stomach contents of 419 individuals belonging to seven species were analyzed by the volumetric method, and the ecomorphological traits of 30 specimens of each species were estimated. The main food items consumed were detritus, aquatic and terrestrial insects, and other aquatic invertebrates. We observed low levels of trophic niche breadth and diet overlap between most species. The PCA scores indicated the occurrence of three ecomorphotypes. PCA axis 1 segregated at one extreme, species with dorsoventrally depressed bodies, longer caudal peduncles, and well-developed swimming fins; and at the other extreme, species with compressed bodies and peduncles, and relatively larger eyes and anal fins. PCA axis 2 segregated species with elongated bodies and ventrally oblique mouths. The partial Mantel test revealed a significant correlation between diet and morphology, indicating independence from the phylogeny. The patterns observed suggest that the low richness did not result in a broadening of the species' trophic niches, or in the absence of some of the main ecomorphotypes expected.

2012 ◽  
Vol 12 (4) ◽  
pp. 258-262 ◽  
Author(s):  
Leandro Talione Sabagh ◽  
Ana Maria Paulino Telles Carvalho-e-Silva ◽  
Carlos Frederico Duarte Rocha

In this study, we present some information of the regarding throphic niche from the anuran toad Rhinella icterica living in high altitudes above 2000 m a.s.l. from a habitat of the Atlantic Forest Biome - the Altitude Fields in the Itatiaia National Park. We found 150 prey items in toad stomachs, belonging to five prey types, as well as skin remains and some remains of plant material. The index of relative importance indicated that most important prey types were beetles and ants, these last composing 70% of the diet numerically and the trophic niche breadth (B) was 1.81. The relatively low diversity of prey types we recorded in the diet of R. icterica of Itatiaia and numerically dominated by ants suggests some preference for this item. We do not found significant relationship between the toad measurements with the preys' measurements. We concluded that R. icterica toads at the highlands of Itatiaia feeds on arthropods, mainly ants and coleopterans and that the high consumption of preys with relatively small and similar size as ants in the diet prevents an expected relationship among frog body or mouth size and prey volume and size.


2019 ◽  
Vol 77 (1) ◽  
pp. 19-32
Author(s):  
Azubuike Victor Chukwuka ◽  
Adedeji Hameed Adebowale ◽  
Oloyede Adeyemi Adekolurejo

Abstract The relationship between morphological traits and feeding ecology of the only two tilapiine cichlids (Sarotherodon galilaeus and Oreochromis niloticus) in Lake Geriyo, northeastern Nigeria, was examined. Stomach contents of 504 individuals were examined and analyzed to relate morphological differences of each species to its dietary preferences. Eleven ecological relevant morphological variables, including total length, standard length, head length, body depth, eye diameter, pectoral spine length, pelvic spine length, dorsal fin ray count, dorsal spine count and anal fin ray count, were also measured and subjected to Principal coordinate analysis (PCoA) to relate morphological differences of each species to its dietary preferences. The PCoA (using Euclidean distance) revealed a large morphological distance between species indicating adaptation for different spatial and vertical distributions within the lake. Furthermore, the correlation of these morphological differences with particular diet categories suggests a potential for specialized trophic tendencies, however, the high occurrence of two major food types (macrophytes and plankton) in stomach contents of both species indicate generalist trophic tendencies. While a high trophic overlap index (0.98) was recorded for both species, the trophic niche breadth was higher for S. galilaeus (4.18±0.32), compared to O. niloticus (3.33±0.24). Despite the large morphological differences of both tilapias, the high trophic overlaps indicate limited food options within Lake Geriyo. In addition, the successful coexistence of the tilapias in the face of limited food resources indicates suitable partitioning of food resources in the lake.


Author(s):  
Pablo Pita ◽  
Juan Freire

Although necessary for sustainable management of coastal ecosystems the understanding of trophic ecology of kelp fishes remains largely limited in the NE Atlantic. In this paper, stable isotope ratios of carbon (C) and nitrogen (N), complementarily with analyses of stomach contents, were used to investigate the trophic ecology of an Atlantic kelp forest fish assemblage targeted by spear fishers in Galicia (NW Spain). Trophic habits of the fishes were consistent across the species ranges and six trophic niches were identified. Chelon labrosus was the only pelagic omnivore, while Conger conger and Dicentrarchus labrax were the principal predators, preying on benthic osteichthyes. The intermediate carnivorous Diplodus sargus mainly preyed on benthic molluscs, while Labrus bergylta exploited a wider range of prey. Although associated with different trophic niches, the two morphotypes of L. bergylta showed some degree of diet overlap, providing little support to the hypothesis of their separate management. Moreover, L. bergylta can be a keystone species whose adequate management has relevant implications for the sustainable use of the European kelp forest ecosystems.


2020 ◽  
Vol 50 (1) ◽  
pp. 54-60
Author(s):  
Bruno Eleres SOARES ◽  
Naraiana Loureiro BENONE ◽  
Daniela Cristina Oliveira ROSA ◽  
Luciano Fogaça de Assis MONTAG

ABSTRACT Environmental variation affects the availability of spatial and trophic resources in Amazonian streams and may be important factors structuring the diet of fishes. We analyzed the diet composition and trophic niche breadth of the lebiasinid splash tetra, Copella arnoldi, aiming to evaluate how environmental variation in Amazonian streams affects the species’ trophic niche. Fish were captured and environmental factors were recorded in 20 streams in the Caxiuanã National Forest, in the eastern Amazon, in November 2010. We made a semi-quantitative analysis of stomach contents of 200 individuals. Copella arnoldi exhibited an omnivorous diet composed mainly of detritus and allochthonous invertebrates. Environmental variation (stream width, stream depth, canopy cover and flow) did not affect the diet composition or trophic niche breadth of the species, possibly due to the regional integrity of the forest within the boundaries of the protected area. Riparian cover probably minimizes the effect of the small-scale variations in food resources, thus leading to a locally homogeneous diet composition in the splash tetra C. arnoldi.


Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 285
Author(s):  
Enrico Lunghi ◽  
Fabio Cianferoni ◽  
Stefano Merilli ◽  
Yahui Zhao ◽  
Raoul Manenti ◽  
...  

Speleomantes are the only plethodontid salamanders present in Europe. Multiple studies have been performed to investigate the trophic niche of the eight Speleomantes species, but none of these studies included hybrid populations. For the first time, we studied the trophic niche of five Speleomantes hybrid populations. Each population was surveyed twice in 2020, and stomach flushing was performed on each captured salamander; stomach flushing is a harmless technique that allows stomach contents to be inspected. We also assessed the potential divergence in size and body condition between natural and introduced hybrids, and their parental species. Previously collected data on Speleomantes were included to increase the robustness of these analyses. In only 33 out of 134 sampled hybrid Speleomantes we recognized 81 items belonging to 11 prey categories. The frequency of empty stomachs was higher in females and individuals from natural hybrid populations, whereas the largest number of prey was consumed by males. We compared the total length and body condition of 685 adult salamanders belonging to three types of hybrids and three parental (sub)species. Three group of salamanders (one hybrid and two parental species) showed significantly larger size, whereas no difference in body condition was observed. This study provided novel ecological information on Speleomantes hybrid populations. We also provided insights into the potential divergence between hybrids and parental species in terms of size and body condition. We discuss our findings, and formulate several hypotheses that should be tested in the future.


2010 ◽  
Vol 100 (5) ◽  
pp. 521-527 ◽  
Author(s):  
K.M. Mikac ◽  
N.N. FitzSimmons

AbstractMicrosatellite markers were used to investigate the genetic structure among invasive L. decolor populations from Australia and a single international population from Kansas, USA to determine patterns of dispersal. Six variable microsatellites displayed an average of 2.5–4.2 alleles per locus per population. Observed (HO) heterozygosity ranged from 0.12–0.65 per locus within populations; but, in 13 of 36 tests, HO was less than expected. Despite low levels of allelic diversity, genetic structure estimated as θ was significant for all pairwise comparisons between populations (θ=0.05–0.23). Due to suspected null alleles at four loci, ENA (excluding null alleles) corrected FST estimates were calculated overall and for pairwise population comparisons. The ENA-corrected FST values (0.02–0.10) revealed significant overall genetic structure, but none of the pairwise values were significantly different from zero. A Mantel test of isolation by distance indicated no relationship between genetic structure and geographic distance among all populations (r2=0.12, P=0.18) and for Australian populations only (r2=0.19, P=0.44), suggesting that IBD does not describe the pattern of gene flow among populations. This study supports a hypothesis of long distance dispersal by L. decolor at moderate to potentially high levels.


2005 ◽  
Vol 95 (3) ◽  
pp. 233-240 ◽  
Author(s):  
Norma Machado da Silva ◽  
Carina da Conceição Fantinel ◽  
Vera Lucia da Silva Valente ◽  
Vitor Hugo Valiati

Ecological parameters such as trophic niche overlap and niche breadth were computed from the frequency of all drosophilid species collected in 2001 and 2002, in the urban area of Porto Alegre city, Brazil. Independently of place, drosophilids community composition and components breeding or feeding sites, the highest frequencies of Zaprionus indianus (Gupta, 1970) were obtained during seasons with higher average temperatures, especially during summer. From a total of the 19,146 individuals of Z. indianus sampled, 80% were found in this season. The data of trophic niche breadth suggest a higher opportunism of adult flies in feeding substrate use, but the females are still selective in oviposition substrate choice. For the values of niche overlap, only for some species, did we find any correlation between these and species richness and/or number of resources, and the most of the correlation values considering breeding and feeding sites were positive. The colonization of Z. indianus in Porto Alegre could be leading to adjustments in the survival strategies of the resident species, but it is possible that many species have conditions for coexisting with the invader.


Author(s):  
Maria Florencia Viozzi ◽  
Juan Manuel Cabrera ◽  
Federico Giri ◽  
Debora de Azevedo Carvalho ◽  
Verónica Williner

We analyze whether ontogenetic diet change in Aegla uruguayana (Schmitt, 1942) is related to the morphological changes in chelae and mandibles. We use a combination of scanning electron microscope observation (SEM), dietary composition analysis (stomach observation, trophic niche amplitude, trophic overlap, and feeding strategy), and geometric morphometric tools (discriminant analysis and two-block partial least squares analysis). The two structures analyzed by SEM show differences between juvenile and adult specimens, both in their cuticle and morphology specializations. In juveniles, the absence of the lobular tooth is the notable feature. However, in adult sizes it is marked development. Both groups have simple setae with infracuticular articulation and denticles with different arrangements between groups. In the incisive mandible process, the teeth and spines present sharper points in juveniles and considerable wear in adults. Aegla uruguayana presented two trophic strategies: a profile of more predatory traits when younger and mostly detritivorous when adults. The analysis of geometric morphometry substantiates the patterns observed in SEM and stomach contents analysis. The morphology of smaller specimens is associated with the consumption of animal items (ephemeropterans larvae and cladocerans), while in those of larger sizes; it is related to the consumption of plant remains.


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.


2019 ◽  
Vol 70 (8) ◽  
pp. 1116 ◽  
Author(s):  
B. C. K. Kliemann ◽  
M. C. Baldasso ◽  
S. F. R. Pini ◽  
M. C. Makrakis ◽  
S. Makrakis ◽  
...  

The diet of Glanidium ribeiroi was investigated in lotic stretches downstream from a cascade of reservoirs to determine how it responds to intraspecific and environmental variations. Monthly sampling was performed from 2013 to 2016 at sites including the main channel of the Iguaçu River and tributaries in preserved basins and agricultural land. The diet of individuals in the preserved tributaries was primarily associated with allochthonous resources, whereas in the non-preserved tributaries and main channel the diets were primarily associated with autochthonous resources. Trophic niche breadth and intraspecific variability differed significantly among sampling areas and size classes. Trophic niche overlap among size classes and sampling areas was low. Positive and negative relationships between the trophic niche breadth and the standard length of individuals were also found in different sampling areas. Intraspecific and ontogenic variations were strongly and consistently associated with forest cover. Individuals responded differently to local environmental variations due to differences in landscape gradients and life cycle changes. Therefore, the effects of spatial heterogeneity on diet composition and intraspecific variations therein appear to be crucial to the success of the populations evaluated. These results may help with the implementation of conservation measures for this and other endemic species.


Sign in / Sign up

Export Citation Format

Share Document