Effects of structural heterogeneity provided by the floating macrophyte Eichhornia azurea on the predation efficiency and habitat use of the small Neotropical fish Moenkhausia sanctaefilomenae

• Published in: Hydrobiologia Vol. 624; no. 1; pp. 161 - 170
• Main Authors: Padial, André Andrian, Thomaz, Sidinei Magela, Agostinho, Angelo Antonio
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01-05-2009; Springer Netherlands; Springer; Springer Nature B.V
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal, plant and microbial ecology; Aquariums; Aquatic environment; Aquatic plants; Biological and medical sciences; Biomedical and Life Sciences; Chironomus; Cypricercus; Ecology; Eichhornia azurea; Fish; Floating plants; Flowers & plants; Freshwater & Marine Ecology; Fundamental and applied biological sciences. Psychology; General aspects; Habitat utilization; Habitats; Heterogeneity; Life Sciences; Macroinvertebrates; Marine biology; Moenkhausia sanctaefilomenae; Predation; Prey; Primary Research Paper; Protected species; Roots; Studies; Synecology; Trophic relationships; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Zoology; Structural heterogeneity; Macroinvertebrates; Trophic interactions; Monocotyledones; Tropical zone; Eichhornia; Trophic relation; Moenkhausia sanctaefilomenae; Habitat selection; Predator efficiency; Heterogeneity; Aquatic environment; Vertebrata; Hydrobiology; Pontederiaceae; Pisces; Angiospermae; Eichhornia azurea; Spermatophyta; Aquatic plant; Invertebrata; Neotropical Region
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1007/s10750-008-9690-8

Macrophytes have a fundamental structuring role in aquatic environments. Several authors have suggested that trophic interactions are particularly mediated by aquatic plants. In the current article, we evaluated the effects of the structural heterogeneity provided by Eichhornia azurea (Kunth) roots on predation and habitat use by the small fish Moenkhausia sanctaefilomenae (Steindachner). We tested the hypotheses that (i) high structural heterogeneity protects macroinvertebrates against predation by M. sanctaefilomenae; (ii) distinct prey types are differently protected by the refuge provided by roots; and (iii) the behavior of M. sanctaefilomenae is affected by the structural heterogeneity provided by macrophyte roots. To test these hypotheses, we performed an experiment in 20 l aquaria in which macroinvertebrates (Cypricercus sp. and Chironomus sp.) were exposed to M. sanctaefilomenae predation for 4 h under three structural heterogeneities, represented by different root densities. High structural heterogeneity protected macroinvertebrates against predation. Additionally, E. azurea roots similarly protected different prey species. The macrophyte spatial structure substantially changed the habitat use of M. sanctaefilomenae. In general, our results corroborated the hypothesis that the structural heterogeneity provided by E. azurea roots significantly affects predation and habitat use by M. sanctaefilomenae.