Identi®cationofFourScallopSpeciesUsingPCRand RestrictionAnalysisoftheRibosomalDNAInternal TranscribedSpacerRegion M.J. Lo Âpez-Pin Äo Ân, A. Insua, and J. Me Ândez* Departamento de Biologõ Âa Celular y Molecular, Universidade da Corun Äa, A Zapateira s/n, 15071 A Corun Äa, Spain Abstract: Polymerase chain reaction PCR) and restriction fragment length polymorphism RFLP) analysis of the ribosomal DNA region spanning the 5.8S RNA gene and the 2 ¯anking internal transcribed spacers ITSs) was performed to establish DNA-based molecular markers for the identi®cation of the scallops Aequipecten opercularis, Chlamys distorta, Mimachlamys varia, and Pecten maximus. Chlamys distorta was distinguished simply by ITS size. Species-speci®c restriction patterns were found with the restriction enzyme AluI, and also with SmaI for A. opercularis and M. varia. When ITS sizes and the RFLPs obtained with SmaI were combined, the 4 scallops were also differentiated. Additional species-speci®c RFLPs were revealed after ITS-2 PCR am- pli®cation and subsequent digestion with Hsp92II. Using this marker, canned scallops were identi®ed. Thus this work provides a simple, reliable, and rapid method for the identi®cation of scallops that can be used when species-speci®c morphologic characteristics are removed or when specimens are small in size. Key words: molecular genetic markers, scallop identi®cation, ribosomal DNA, internal transcribed spacer, PCR, RFLP. INTRODUCTION The scallop species Aequipecten opercularis, Chlamys dis- torta, Mimachlamys varia, and Pecten maximus are widely distributed along the European coasts Brand, 1991; Wag- ner, 1991), occurring from Norway to northwest Africa and also in the Mediterranean with southern Spain as eastern limit for C. distorta and P. maximus). All are important members of the plankton, during their larval development, and the benthic communities once settlement takes place. Except for C. distorta, the other 3 species are of economic interest: A. opercularis is commercially ®shed both in the Atlantic and in the Mediterranean, M. varia in French Atlantic waters, and P. maximus along the Atlantic coast Ansell et al., 1991; Renzoni, 1991; Roman, 1991). Identi®cation of these scallops is mostly achieved by employing morphologic criteria Wagner, 1991). This re- quires the presence of the shell and a detailed analysis when specimens are small in size Pen Äa et al., 1998). When spe- cies-speci®c morphologic characteristics are removed leaving only adductor muscles or as a result of processing for canned products), as is the case once specimens arrive to the market, the identi®cation becomes problematic. For this reason, molecular and biochemical techniques to Received January 2, 2002; accepted January 28, 2002. *Corresponding author: telephone 34-98116700, ext. 2055; fax 34-981167065; e-mail ®na@udc.es Mar. Biotechnol. 4, 495±502, 2002 DOI: 10.1007/s10126-002-0030-0