1Laboratory of Aquatic Zoology, Division of Research and Postgraduate Studies, National Autonomous University of Mexico, Campus Iztacala Av. de Los Barrios No.1, C.P. 54090, Los Reyes, Tlalnepantla, State of Mexico, Mexico.
Biology Department, National Autonomous University of Mexico, Campus Iztacala, Av. de Los Barrios No.1, C.P. 54090, Los Reyes, Tlalnepantla, State of Mexico, Mexico.
* Correspondence author; E. Mail: joluga@servidor.unam.mx.
Asplanchna is a predatory rotifer that induces changes in the morphology of its prey, the brachionid rotifer Brachionus calyciflorus through the release of an allelochemical (kairomone asplanchnin) into the medium. We quantified the morphological changes (lorica size and posterolateral spine length) of B. calyciflorus in response to presence of 3-con-phyletic predators (Asplanchna girodi, Asplanchna brightwellii and Asplanchna sieboldii). All 3-predators induced significantly large lorica size and longer posterolateral spines in B. calyciflorus. However, magnitude of spine induction and body size changes in rotifer depended on the predator species and the duration of culture. The magnitude of induced morphological changes was in the decreasing order: A. sieboldii > A. brightwellii > A. girodi. Depending on the predator species, the body size and posterolateral spines of B. calyciflorus increased from 4 to 24% and 50 to 115% than control, respectively. The predator type and density also affected the ratio of posterolateral spine length to body length. This ratio ranged from 0.15 to 0.23 in control, but was higher (0.24 to 0.48) in the presence of any test species of Asplanchna.
Allelochemical, Asplanchna brightwellii, Asplanchna girodi, Asplanchna sieboldii, Brachionus calyciflorus, kairomone, morphometry, phenotype, predator-prey
