PERSONAL DE APOYO
BENITEZ Hernan Hugo
Effect of tannins on survival and development of Daphnia menucoensis and the abundances of bacteria
ÁLVAREZ, M. F.; BENÍTEZ, H. H.; VILLEGAS CORTEZ, J. C.; GABELLONE, N. A.; CLAPS, M. C.
CHEMISTRY AND ECOLOGY
TAYLOR & FRANCIS LTD
Lugar: Londres; Año: 2016 vol. 32 p. 742 - 755
Polyphenols ? products of organic-matter decomposition enteringwater bodies from autochthonous and especially allochthonoussources ? affect primary producers, bacterioplankton, andzooplankton to consequently modify food webs. Cladocerans arewidely used in research experiments because they constitute themost frequent prey of high-trophic-level organisms in the majorityof lakes, and certain species symbolise the ecologic prototype ofthe generalist filter feeder. In our study area?s shallow lakes,cladocerans, though generally of low abundance, do attainsignificantly high biomasses. We accordingly evaluated themortality of the cladoceran Daphnia menucoensis Paggi, 1996exposed to different tannin concentrations along with thebacterial abundance. In two experiments D. menucoensis femalesexposed to high tannin concentrations reproduced inefficiently,exhibited high mortality, and manifested altered behaviour, suchas reduced reflexes and diminished mobility. Though tanninsapparently affected algal abundances, the cladoceran herbivorystrongly reduced those numbers. Positive effects on bacteria,however, were not recorded. High-allochthonous-organic-matter-containing water bodies support trophic webs becausebacterioplankton provide an alternative energetic base for thezooplankton, as possibly occurs in shallow lakes of the Salado-River basin, characterised by cyclic hydrologic periods alternatingbetween draught and flooding and intensive land use. Inconclusion, tannins diminish D. menucoensis?s survival, locomotion,and the capacity to respond to stimuli.