Non-indigenous animal species naturalized in Iberian inland waters

Invasions by human-introduced non-indigenous species (NIS) are one of the main threats to biodiversity and a driving force of global change (Vitousek et al. 1997, Mack et al. 2000, Clavero and García-Berthou 2005). The Iberian Peninsula (IP) is a hotspot of biodiversity (Médail and Quézel 1999) and a knowledge of the invasive species inhabiting it is essential for conservation and environmental management. Naturalized vertebrates and plants in the IP have received considerable attention (see e.g. Vilà et al. 2001, Pleguezuelos 2002, Sobrino et al. 2002, Lloret et al. 2004, Alcaraz et al. 2005), but its invasive invertebrates are very poorly known. Although there are many records of some invertebrate invasive species, particularly crustaceans, there are very few available reviews of selected taxa of invertebrate invaders in the IP (e.g. Espadaler and Collingwood 2001). The aim of this chapter is to review the animal species naturalized in Iberian inland waters, including vertebrates and free-living and parasitic invertebrates. As usual, the taxonomy and biogeography of vertebrate species are much better known than for invertebrates, so our data for invertebrates should be regarded as a preliminary check-list. Similarly, the parasites of non-commercial aquatic species are poorly studied and the data in the IP mostly come from studies of the eel, Anguilla anguilla (Linnaeus), thus certainly underestimating the range of introduced parasites (Blanc 1997, 2001). We feel, however, that it is important to provide such a first check-list because many of the invertebrates involved are nowadays common in the IP and for many of them it is largely unknown even by biologists that they are not indigenous to the IP. Increasing the awareness on the introduced status and current distribution of these species is essential to reduce their spread and impact.