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(Cretella et al. 1990; Sella et al. 1993; Mauro et al. 2003; Casu et al. 2010). Sirnilar
problerns rnay also arise in the distinction between P. ulyssiponensis s.I. and Patella
vulgata Linnaeus, 1758, distributed on the rocky shore frorn Portugal to Norway, and P.
ulssiponensis s.i. and Patella candei (d'Orbigny, 1839), endemie to the Macaronesian
islands (i.a., Cabral2003; Pagarete 2005).
Since the specimens of P. ulyssiponensis s.l. often share the sarne habitat (lower part of the
intertidal rocky shores) with the above-rnentioned three species (Fretter & Graharn 1976;
Cretella et al. 1990; Sella et al. 1993; Weber et al. 1998; Pagarete 2005; Petraccioli et al.
2010), the ecologists are often compelled to classify them as "Patella spp." (i.a. , Maggi et
al. 2009).
Specific constant genetic pattems (''DNA barcoding") have been helpful in species
attribution of individuals whose morphological features cannot be used confidently at this
scope (see Hebert et al. 2003; but also Ebach & Holdrege 2005). In particular, different
studies (Mauro et al. 2003; Sa-Pinto et al. 2005, 2008; Casu et al. 2010) have proved that
the "traditional" rnolecular taxonomy, based on the sequences ofthe rnitochondrial gene
Cytochrorne c Oxidase subunit I (COI), the so-called "Folrner region" (Folrner et al. 1994),
unequivocally discrirninates P. ulyssiponensis s.I. frorn P. caerulea, P. vulgata and P.
candei.
Arnong the analytical rnethods based on the identification of specific rnutations in a
nucleotide sequence, the Restriction Fragment Length Polymorphisrns PCR-based (PCR-
RFLP) (Wolf et al. 1999) technique represents an alternative, useful tool for the
identification of species, sueh as those belonging to Mollusca (e.g., Boudry et al. 1998;
Fermindez et al. 2000; Chapela et al. 2003; Zhang et al. 2005). Since PCR-RFLP does not
require nucleotide sequencing procedures, it rnay be routinely applicable in surveys
devoted to rapid taxonornic identifications of nurnerous sarnples.

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Gìan Luca Dedola: ANALISI DELLA VARIABILITÀ GENETICA DI PATELLA FéRRUGINEA, PATEL-LA ULl'SSIPONENSIS (MOLLUSCA: GASTROPODA) E PINNA
NOBILIS (MOLLUSCA: BIVALVIA): lLCONTRJBUTO DEl DATI MOLECOLARI ALLA CONSERVAZIONE DI SPECIE MINACCIATE- Tesi di douorato in Scienze
della natura e delle sue risorse • indiri7.zo BK>logi.a Ambientale, Università degli Studi di Sassarl