The role of ecophysiological and behavioral traits in structuring the zooplankton assemblage in a deep, oligotrophic, tropical lake
Por:
CirosPerez, J, OrtegaMayagoitia, E, Alcocer, J
Publicada:
1 nov 2015
Resumen:
Zooplankton inhabiting deep, oligotrophic, tropical lakes must cope with scenarios where the combination of resource limitation, high visual-predation risk, UV-induced damage and seasonal development of anoxic waters, entail particular challenges for organisms, uncommon in temperate environments. We assessed the diel vertical migration—DVM—(UV/predation-avoidance strategy), numerical response, and starvation resistance (physiological strategies to cope with food scarcity) of the copepod Leptodiaptomus garciai and the rotifers Hexarthra jenkinae and Brachionus sp. “Mexico,” which constitute the zooplankton assemblage of Alchichica, a high-altitude, deep, oligotrophic, hyposaline, warm-monomictic lake located in Mexico. L. garciai followed the normal pattern of DVM in all seasons; with organisms concentrated ˜ 20 m deeper than the depth of 1% photosynthetically active radiation at mid-day, with evasion from the planktivore Poblana alchichica as the most probable driver. However, copepods could not evade the euphotic zone owing to the anoxic conditions of the hypolimnion during the well-established stratification period. Rotifers did not migrate vertically. The dominance of copepods throughout the year can be explained by their low food threshold, high proportion of usable reserves and the lowest rate of mass loss at food deprivation. Contrastingly, rotifers are scarce and intermittent due to frequent resource limitation and because they lose mass at higher rates. However, they are able to suddenly increase due to their high growth rates. We demonstrated that the interaction between environmental constraints and the specific combinations of traits can explain zooplankton structure in the lake. This study enlightens the necessity to improve current limnological models with data from tropical lakes. © 2015 Association for the Sciences of Limnology and Oceanography.
Filiaciones:
CirosPerez, J:
Univ Nacl Autonoma Mexico, Proyecto Invest Limnol Trop, FES Iztacala, Tlalnepantla De Baz, Edo De Mexico, Mexico
OrtegaMayagoitia, E:
Univ Nacl Autonoma Mexico, Proyecto Invest Limnol Trop, FES Iztacala, Tlalnepantla De Baz, Edo De Mexico, Mexico
Alcocer, J:
Univ Nacl Autonoma Mexico, Proyecto Invest Limnol Trop, FES Iztacala, Tlalnepantla De Baz, Edo De Mexico, Mexico
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