Trophic ecology of sea urchins in coral-rocky reef systems, Ecuador
Sea urchins are important grazers and influence reef development in the Eastern Tropical Pacific (ETP). Diadema mexicanum and Eucidaris thouarsii are 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...
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PeerJ Inc.
2016-01-01
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| Online Access: | https://peerj.com/articles/1578.pdf |
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| author | Nancy Cabanillas-Terán Peggy Loor-Andrade Ruber Rodríguez-Barreras Jorge Cortés |
| author_facet | Nancy Cabanillas-Terán Peggy Loor-Andrade Ruber Rodríguez-Barreras Jorge Cortés |
| author_sort | Nancy Cabanillas-Terán |
| collection | DOAJ |
| description | Sea urchins are important grazers and influence reef development in the Eastern Tropical Pacific (ETP). Diadema mexicanum and Eucidaris thouarsii are 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 thouarsii is the dominant species in disturbed environments; likewise, their niche amplitude was broader than that of D. mexicanum when 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, mainly Dictyota spp. (contributions of up to 85% for D. mexicanum and up to 75% for E. 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. |
| first_indexed | 2024-03-09T07:24:36Z |
| format | Article |
| id | doaj.art-fbb5fc3f048d4ff695659ec6e763766c |
| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T07:24:36Z |
| publishDate | 2016-01-01 |
| publisher | PeerJ Inc. |
| record_format | Article |
| series | PeerJ |
| spelling | doaj.art-fbb5fc3f048d4ff695659ec6e763766c2023-12-03T07:08:58ZengPeerJ Inc.PeerJ2167-83592016-01-014e157810.7717/peerj.1578Trophic ecology of sea urchins in coral-rocky reef systems, EcuadorNancy Cabanillas-Terán0Peggy Loor-Andrade1Ruber Rodríguez-Barreras2Jorge Cortés3Departamento Central de Investigación, Universidad Laica Eloy Alfaro de Manabí, Ciudadela Universitaria. Vía San Mateo, Manta, Manabí, EcuadorDepartamento Central de Investigación, Universidad Laica Eloy Alfaro de Manabí, Ciudadela Universitaria. Vía San Mateo, Manta, Manabí, EcuadorDepartment of Biology, University of Puerto Rico at Bayamón, Puerto RicoCentro de Investigación en Ciencias del Mar y Limnología (CIMAR), and Escuela de Biología, Universidad de Costa Rica, San Pedro, San José, Costa RicaSea urchins are important grazers and influence reef development in the Eastern Tropical Pacific (ETP). Diadema mexicanum and Eucidaris thouarsii are 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 thouarsii is the dominant species in disturbed environments; likewise, their niche amplitude was broader than that of D. mexicanum when 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, mainly Dictyota spp. (contributions of up to 85% for D. mexicanum and up to 75% for E. 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.https://peerj.com/articles/1578.pdfDiadema mexicanumEucidaris thouarsiiStable isotopesRocky reefsNiche breadthEastern Tropical Pacific |
| spellingShingle | Nancy Cabanillas-Terán Peggy Loor-Andrade Ruber Rodríguez-Barreras Jorge Cortés Trophic ecology of sea urchins in coral-rocky reef systems, Ecuador PeerJ Diadema mexicanum Eucidaris thouarsii Stable isotopes Rocky reefs Niche breadth Eastern Tropical Pacific |
| title | Trophic ecology of sea urchins in coral-rocky reef systems, Ecuador |
| title_full | Trophic ecology of sea urchins in coral-rocky reef systems, Ecuador |
| title_fullStr | Trophic ecology of sea urchins in coral-rocky reef systems, Ecuador |
| title_full_unstemmed | Trophic ecology of sea urchins in coral-rocky reef systems, Ecuador |
| title_short | Trophic ecology of sea urchins in coral-rocky reef systems, Ecuador |
| title_sort | trophic ecology of sea urchins in coral rocky reef systems ecuador |
| topic | Diadema mexicanum Eucidaris thouarsii Stable isotopes Rocky reefs Niche breadth Eastern Tropical Pacific |
| url | https://peerj.com/articles/1578.pdf |
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