Abstract

MOTTA DIAZ, Angela J; LONGO, Magnolia  and  ARANGUREN-RIANO, Nelson. Temporal variation of taxonomic diversity and functional traits of aquatic macroinvertebrates in temporary rivers on Old Providence Island, Colombia. Actu Biol [online]. 2017, vol.39, n.107, pp.82-100. ISSN 0304-3584.  https://doi.org/10.17533/udea.acbi.v39n107a10.

Intermittent streams in Colombia are located principally in dry forest zones and are important in maintaining the hydrological cycle and sustaining biodiversity and the water supply for local human populations. Some aspects of the functioning of these systems are not known in detail, especially in insular areas. This study describes the changes in the species composition, diversity, and some functional traits of macroinvertebrates related to discharge fluctuations in three intermittent streams on Old Providence Island. Sampling was performed during dry and rainy seasons. Ten (10) and 50 functional traits categories were selected, including trophic, physiological, morphological, behavioral and life cycle characteristics. A principal component analysis confirmed a strong seasonality associated with changes in electric conductivity, alkalinity, and dissolved oxygen. Sixty genus-level morphotypes were identified, with highest diversity in the Chironomidae (Diptera). According to a Canonical Correspondence Analysis, Chironomus, Pyrgophorus, Haitia and Dero were associated with high values in electrical conductivity, dissolved oxygen, and total hardness. With respect to functional traits, during dry season mechanisms for resisting specialized to resist the desiccation (cocoon or diapause), asexual reproduction, seasonal short life cycles, preferences for litter microhabitat, and trophic habit scrapers redominated, such as Ancylidae, Dero, Anopheles, Microvelia and Neritina. During rainy season bodies protected with shells or cases, seasonal long life cycles, and trophic collectors were found, such as Macrobrachium, Polypedilum, Helicopsyche, Beardius and Chironomus. In conclusion, hydrological conditions affect the taxonomic and functional structure of the macroinvertebrates, and some physiological traits and life histories are essential for persistence in temporal environments.

Keywords : benthic fauna; temporary waters; functional ecology; stomach contents; insular rivers and streams.

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