scholarly journals Sympatry with the devil? Niche-based approach explains the mechanisms allowing coexistence of native and non-native salmonids

2016 ◽  
Author(s):  
Camille Musseau ◽  
Simone Vincenzi ◽  
Dušan Jesenšek ◽  
Stéphanie Boulêtreau ◽  
Frédéric Santoul ◽  
...  

AbstractNiche-based hypotheses have been proposed to explain processes and mechanisms of success in the establishment of non-native species into native communities. Competition due to niche overlap may lead to native species niche shift and to native species replacement. To understand the ecological consequences of trophic interactions between non-native rainbow trout and native and endangered marble trout, we used as model system the Idrijca river (Western Slovenia) in which marble trout occurs either in allopatry (MTa) or in sympatry (MTs) with rainbow trout (RTs). We focused on different metrics of niche change such as centroid shift, niche overlap and trophic niche breadth using stable isotope analysis (δ15N and δ13C). Our results showed plasticity in niche overlap between MTs and RTs and niche shift of marble trout when occurring in sympatry with RTs, but not due to a niche replacement of MTs by RTs. Niche breadth of marble trout increases in sympatry and the trophic position during the growth period was higher for MTs than MTa.

2021 ◽  
Vol 25 (02) ◽  
pp. 283-300
Author(s):  
Míriam Pilz Albrecht ◽  
◽  
Andressa da Silva Reis ◽  
Vinicius Neres-Lima ◽  
Eugenia Zandonà ◽  
...  

Stable isotope analysis (SIA) has become an essential tool in Ecology, being increasingly used in studies of fish in tropical streams. The SIA allows to reconstruct the animals' diet and its intraspecific variation, to trace the contributions of the main basal resources throughout the food web, to calculate trophic position and trophic niche, including niche overlap and its alterations, and to build food webs. The SIA is also used to understand the impact of environmental changes on fish communities and other aquatic organisms. The number of such studies is increasing in Brazil, but there are still several gaps. In this study, we present the basic concepts on stable isotopes analysis in trophic studies of stream fish - especially those of carbon, nitrogen and hydrogen - their premises, uses and limitations, presenting examples from tropical streams. We also explore new conceptual tools in this area, still not used for stream fish in Brazil, such as fatty acids, stable isotopes in specific compounds, nutritional geometry and ecological stoichiometry concepts such as the Threshold Elemental Ratio.


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.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1578 ◽  
Author(s):  
Nancy Cabanillas-Terán ◽  
Peggy Loor-Andrade ◽  
Ruber Rodríguez-Barreras ◽  
Jorge Cortés

Sea urchins are important grazers and influence reef development in the Eastern Tropical Pacific (ETP).Diadema mexicanumandEucidaris thouarsiiare the most important sea urchins on the Ecuadorian coastal reefs. This study provided a trophic scenario for these two species of echinoids in the coral-rocky reef bottoms of the Ecuadorian coast, using stable isotopes. We evaluated the relative proportion of algal resources assimilated, and trophic niche of the two sea urchins in the most southern coral-rocky reefs of the ETP in two sites with different disturbance level. Bayesian models were used to estimate the contribution of algal sources, niche breadth, and trophic overlap between the two species. The sea urchins behaved as opportunistic feeders, although they showed differential resource assimilation.Eucidaris thouarsiiis the dominant species in disturbed environments; likewise, their niche amplitude was broader than that ofD. mexicanumwhen conditions were not optimal. However, there was no niche overlap between the species. The Stable Isotope Analysis in R (SIAR) indicated that both sea urchins shared limiting resources in the disturbed area, mainlyDictyotaspp. (contributions of up to 85% forD. mexicanumand up to 75% forE. thouarsii). The Stable Isotope Bayesian Ellipses in R (SIBER) analysis results indicated less interspecific competition in the undisturbed site. Our results suggested a trophic niche partitioning between sympatric sea urchin species in coastal areas of the ETP, but the limitation of resources could lead to trophic overlap and stronger habitat degradation.


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.


2017 ◽  
Vol 27 (3) ◽  
pp. 720-731 ◽  
Author(s):  
Camille Musseau ◽  
Simone Vincenzi ◽  
Dušan Jesenšek ◽  
Stéphanie Boulêtreau ◽  
Frédéric Santoul ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256339
Author(s):  
Samanta Dodino ◽  
Nicolás A. Lois ◽  
Luciana Riccialdelli ◽  
Michael J. Polito ◽  
Klemens Pütz ◽  
...  

Magellanic penguins (Spheniscus magellanicus) disperse widely during winter and are a major consumer of marine resources over the Patagonian Shelf. Magellanic penguins were equipped with geolocators at Martillo Island in late February- early March 2017 and recaptured at the beginning of the next breeding season to recover the devices and to collect blood samples for stable carbon (δ13C) and nitrogen (δ15N) isotope analysis. We evaluated their whole winter dispersal and their trophic niche by sex during the last month of the winter dispersal. Also, we evaluated their spatial overlap with bottom trawl and shrimp fisheries using data from satellite fisheries monitoring. Penguins dispersed northwards up to 42°S and showed latitudinal spatial segregation between sexes during May to August (females were located further north than males). In contrast, during the last month of the winter dispersal females were located more southerly and showed lower trophic position than males. Also, females did not dive as deep as males during winter. We found high overlap between both fisheries and penguin’s spatial use in regions with documented interaction. However, no sex-specific statistical differences with fisheries overlap were found. Our results highlight the importance of understanding the spatial domains of each sex and assessment of their potential conflicts with bottom trawl fishery and shrimp fishery during the winter period.


2018 ◽  
Vol 19 (1) ◽  
Author(s):  
Camila F. Moser ◽  
Mateus de Oliveira ◽  
Fernanda R. de Avila ◽  
Diogo Dutra-Araújo ◽  
Renata K. Farina ◽  
...  

Abstract: The species Boana bischoffi and Boana marginata are endemic to the Atlantic Forest, where they often occur in sympatry. There is a large gap in the knowledge of natural history of both species. In this study, we aimed to describe and compare the diet composition of B. bischoffi and B. marginata in the southern domain of the Brazilian Atlantic Forest. We analyzed the gastrointestinal contents of 43 individuals of B. bischoffi and 30 individuals of B. marginata. Both showed a high trophic niche overlap (0.90 Ojk). The most important prey categories for both species belonged to the orders Araneae and Coleoptera. The species niche breadth (Bsta) varied from 0.35 to 0.42, suggesting a generalist feeding behavior for both species. Our data provide unprecedented information on these species' food composition, contributing to a better knowledge of the natural history of neotropical anurans.


Apidologie ◽  
2012 ◽  
Vol 44 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Cândida M. L. Aguiar ◽  
Gilberto M. de M. Santos ◽  
Celso F. Martins ◽  
Steven J. Presley

2017 ◽  
Author(s):  
Simone Vincenzi ◽  
Alain J Crivelli ◽  
Dusan Jesensek ◽  
Ellen Campbell ◽  
John C Garza

AbstractInvasions occurring in natural environments provide the opportunity to study how vital rates change and life histories evolve in the presence of a competing species. In this work, we estimate differences in reproductive traits, individual growth trajectories, survival, life histories, and population dynamics between a native species living in allopatry and in sympatry with an invasive species of the same taxonomic Family. We used as a model system marble trout Salmo marmoratus (native species) and rainbow trout Oncorhynchus mykiss (non-native) living in the Idrijca River (Slovenia). An impassable waterfall separates the stream in two sectors only a few hundred meters apart: a downstream sector in which marble trout live in sympatry with rainbow trout and a upstream sector in which marble trout live in allopatry. We used an overarching modeling approach that uses tag-recapture and genetic data (> 2,500 unique marble and rainbow trout were sampled and SNP-genotyped) to reconstruct pedigrees, test for synchrony of population dynamics, and model survival and growth while accounting for individual heterogeneity in performance. The population dynamics of the two marble trout populations and of rainbow trout were overall synchronous. We found higher prevalence of younger parents, higher mortality, and lower population density in marble trout living in sympatry with rainbow trout than in marble trout living in allopatry. There were no differences in the average individual growth trajectories between the two marble trout populations. Faster life histories of marble trout living in sympatry with rainbow trout are consistent with predictions of life-history theory.


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