ABSTRACT "CONGRESS OF THE IBERIAN ASOCIATION OF LIMNOLOGY":
Trichocorixa verticalis, originally distributed in North America and the Caribbean islands, has been registered as an invasive species in South Africa, New Caledonia, Morocco, Portugal and Spain. In natural populations of the United States, it has been described that its predatory activity can control populations of Artemia sp., with important top-down effects on phytoplankton communities. Here we have studied the predator-prey predator relationship between the native brine shrimp Artemia parthenogenetica, and the invasive corixidae T.verticalis, in SW Spain. We investigated the effect of the life stages of Artemia (nauplius, young and adults), its abundance (3, 6 and 12 adult individuals) and its parasitic status (infected with the avian cestode F. liguloides and uninfected) on T.verticalis predation rate, as well as the sex and size of T.verticalis at two different salinities (25 g/l and 55g/l).
The results of this study showed that T.verticalis predated extensively on Artemia, irrespective of its lifes stages. However, T.verticalis selectively predated on Flamingo lepisliguloides- infected Artemia, which is more visible than uninfected individuals due to the effect of the parasite on Artemia colour. We also observed a higher predation rate with increasing the number of prey. The results of this study suggest that T.verticalis may be also important controlling Artemia populations in wetland of the invaded range.
SANTANDER (CANTABRIA)_ SPAIN