{"id":1029,"date":"2020-11-09T17:37:34","date_gmt":"2020-11-09T20:37:34","guid":{"rendered":"https:\/\/www.ufrgs.br\/ictio\/?p=1029"},"modified":"2020-11-09T17:37:34","modified_gmt":"2020-11-09T20:37:34","slug":"seasonality-and-interspecific-competition-shape-individual-niche-variation-in-co%e2%80%90occurring-tetra-fish-in-neotropical-streams","status":"publish","type":"post","link":"https:\/\/www.ufrgs.br\/ictio\/2020\/11\/09\/seasonality-and-interspecific-competition-shape-individual-niche-variation-in-co%e2%80%90occurring-tetra-fish-in-neotropical-streams\/","title":{"rendered":"Seasonality and interspecific competition shape individual niche variation in co\u2010occurring tetra fish in Neotropical streams"},"content":{"rendered":"

<\/p>\n

Mayara Pereira Neves<\/strong><\/i>\u00a0, Raul Costa\u2010Pereira, Rosilene Luciana Delariva, Clarice Bernhardt Fialho<\/strong><\/p>\n

Abstract<\/strong><\/div>\n
<\/div>\n

The drivers of intraspecific niche variation and its effects on species interactions are
\nstill unclear, especially in species-rich Neotropical environments. Here, we investigated
\nhow ecological opportunity and interspecific competition affect the degree
\nof individual trophic specialization and the population niche breadth in tetra fish.
\nWe studied the four ecologically similar species (Psalidodon aff. gymnodontus, P. aff.
\nparanae, P. bifasciatus, and Bryconamericus ikaa) in subtropical headwater streams
\n(three sites with two co-occurring species and three sites with only one species). We
\nsampled fish in two contrasting seasons (winter\/dry and summer\/wet) and quantified
\ntheir trophic niches using gut content analysis. Psalidodon bifasciatus was the
\nonly species distributed over all the sampled streams. We observed seasonal differences
\nin population trophic niche breadth of P. bifasciatus just when this species
\nco-occurred with P. aff. gymnodontus. These findings confirm the complex nature of
\nthe effects of interspecific competition, depending, for instance, on the identity of
\nthe competitor. The degree of individual specialization of P. bifasciatus was higher in
\nthe winter, and it was not influenced by the presence of another species. Conversely,
\nthe other two Psalidodon species studied presented greater individual specialization
\nin the summer, when fish consumed a higher proportion of allochthonous items (terrestrial
\ninsects and seeds), and there were no effects only for B. ikaa. Herein, our
\nresults suggest that seasonality in food-resource availability is a major driver of niche
\nvariation and it has the potential to play an important role in how these similar tetra
\nspecies interact and coexist.<\/p>\n

link: https:\/\/onlinelibrary.wiley.com\/doi\/epdf\/10.1111\/btp.12879<\/a><\/p>\n

\"\"<\/a>

F I G U R E 1 Species studied: (a) Psalidodon aff. gymnodontus (UFRGS 25,725, 95.4 mm SL); (b) Psalidodon aff.
paranae (UFRGS 26,232, 48.0 mm LS); (c) Psalidodon bifasciatus (UFRGS 26,235, 85.0 mm SL); and (d) Bryconamericus ikaa (UFRGS 26,246, 49.0 mm SL)<\/p><\/div>\n

\"\"<\/a>

F I G U R E 2 (a) Boxplot of population trophic niche breadth (estimated as distance to centroid, PERMDISP) of P. bifasciatus (Pbi) in streams with co-occurring characid species (S1, S2, and S3) and in allopatry (S4, S5, and S6). B) Population trophic niche breadth of three characid fish species (Pag = P. aff. gymnodontus; Pap = P. aff. paranae) in co-occurrence with P. bifasciatus collected during the winter and summer seasons. Box lower and upper endpoints represent the 25th and 75th quartiles, respectively. The horizontal bar inside each box represents median diet breadth<\/p><\/div><\/p>","protected":false},"excerpt":{"rendered":"

Mayara Pereira Neves\u00a0, Raul Costa\u2010Pereira, Rosilene Luciana Delariva, Clarice Bernhardt Fialho Abstract The drivers of intraspecific niche variation and its effects on species interactions are still unclear, especially in species-rich Neotropical environments. Here, we investigated how ecological opportunity and interspecific competition affect the degree of individual trophic specialization and the population niche breadth in tetra […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1029","post","type-post","status-publish","format-standard","hentry","category-sem-categoria"],"_links":{"self":[{"href":"https:\/\/www.ufrgs.br\/ictio\/wp-json\/wp\/v2\/posts\/1029","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ufrgs.br\/ictio\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ufrgs.br\/ictio\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ufrgs.br\/ictio\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ufrgs.br\/ictio\/wp-json\/wp\/v2\/comments?post=1029"}],"version-history":[{"count":1,"href":"https:\/\/www.ufrgs.br\/ictio\/wp-json\/wp\/v2\/posts\/1029\/revisions"}],"predecessor-version":[{"id":1032,"href":"https:\/\/www.ufrgs.br\/ictio\/wp-json\/wp\/v2\/posts\/1029\/revisions\/1032"}],"wp:attachment":[{"href":"https:\/\/www.ufrgs.br\/ictio\/wp-json\/wp\/v2\/media?parent=1029"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ufrgs.br\/ictio\/wp-json\/wp\/v2\/categories?post=1029"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ufrgs.br\/ictio\/wp-json\/wp\/v2\/tags?post=1029"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}