Forschungs- & Entwicklungsinformationsdienst der Gemeinschaft - CORDIS


MED-CORE Berichtzusammenfassung

Project ID: ICA3-CT-2002-10003
Gefördert unter: FP5-INCO 2
Land: Italy

Data base on genetic diversity of key species

The amphipod Talitrus saltator was selected within the MEDCORE project as one the key species, suitable for monitoring ecological changes in the supralittoral environment

Both temporal and spatial genetic variation within Talitrus saltator was analyzed by our team in Rome. On the average the degree of allozyme heterozygosity detected was not very high, in agreement with the results already obtained for this species. Nevertheless the values of the observed heterozygosity (Ho) vary broadly not only among populations collected from different sites but also among samples collected along the Uccellina beach. U01 was characterized by the lowest value among the Uccellina samples, similar to the values found in KAM, KAV and ROG.

It is important to highlight that during recent field surveys at U01 (May 2003) we could not find any talitrid, probably because of the strong local erosion of the coast, which in turn might have had a dramatic effect on the persistence of the local subpopulation. As a matter of fact genetic variability can be reduced as a result of bottleneck. A reduction in the effective size of a natural population is often associated with higher risk of local extinction.

Different factors, i.e anthropic pressure, could have similar effects on the genetic variability of populations. In this respect, it is important to note that KAM, KAV and ROG were collected from beaches highly impacted by tourism. U92 and U04 show comparable mean level of Ho; these two values are the highest observed among T.saltator populations.

Overall, the allozyme data collected for this part of the MEDCORE project are in good agreement with previous results obtained on T.saltator in our lab (De Matthaeis et al., 2000a, 2000b; Ketmaier et al., 2003, 2005a). In particular, new and previous data all suggest the presence of a stable dune belt and/or the lack of human activities on the beaches being major factors affecting the pattern of genetic variability of talitrid populations.

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Reported by

Dipartimento di Biologia Animale e dell'Uomo
viale dell'Università
00185 Roma
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