Biological invasions started when humans moved species beyond their normal geographic limits, facilitating the spread of alien species over the world. In marine environments bivalves are the most notorious invasive species in intertidal rocky habitats. NGSs are useful to understand the molecular mechanisms involved in the invasion process and to manage it. Eco-immunology studies the magnitude and strength of the immune response of alien species and how it could help to predict the invasiveness.
A remarkable case of invasion has been reported in the ecosystem of the Ria of Vigo (Galicia, NW Spain) by the black pygmy mussel Limnoperna securis. This species, endemic of Australia, has spread throughout Asia and the Mediterranean Sea, occupying most of the estuarine ecosystems. The Mediterranean mussel M. galloprovincialis is the autochthonous mussel in Galicia, the second worldwide producer of this species. M. galloprovincialis is also a successful invader that colonized many areas in Africa, America, Australia and Japan. The true potential of the alien L. securis to colonize areas where M. galloprovincialis is established and highly produced is an important issue that must be analyzed in detail.
Can we predict the invasiveness of L. securis by the magnitude of its immune response? Can the invader L. securis represent a serious risk for M. galloprovincialis? To evaluate the suitability of several immune-related hypotheses in our invasion model transcriptomic and functional approaches were used.
Our analyses suggest that the the new environment could impose high energetic costs to L. securis: 1.- mobilization of energy reserves for the activation of osmorregulatory processes and 2.- regulation of the cell cycle to cope with the salinity stress. The relocation of energetic resources to vital physiological processes could be a reasonable explanation for the low immune capabilities observed in L. securis. Although it is difficult to predict the potential replacement of M. galloprovincialis by L. securis, we could suggest that M. galloprovincialis will continue to be the dominant mussel species in the outer part of the Ria of Vigo. The application of this integrated transcriptomic and functional immunological approach to understanding the biology of invasive species is an extremely promising area of research whose knowledge could be used to guide and inform management decisions. Less...