Puzzling over spurdogs: molecular taxonomy assessment of the<i>Squalus</i>species in the Strait of Sicily
Alice Ferrari, Simone Di Crescenzo, Alessia Cariani, Valentina Crobe, Anna Benvenuto, Federica Piattoni, Cecilia Mancusi, L. Bonnici, Juan José Bonello, Patrick J. Schembri, Fabrizio Serena, Daniela Massi, Antonino Titone, Fausto Tinti
Abstract
The actual occurrence of Squalus megalops in the Mediterranean Sea has recently been questioned. Several research works \nwhich sought to assess available morphological and meristic features that differentiate S. megalops from other Squalus species in \nthe Mediterranean Sea, revealed poor discriminatory power and high variability of the assessed characters, especially when \ncomparing S. megalops and S. blainville. The application of molecular tools does not support the presence of S. megalops. \nIn the present study, we screened spurdog species from the Strait of Sicily using a molecular taxonomy approach based \non two mitochondrial DNA markers and we report the occurrence of two Squalus lineages characterizing specimens \ncollected from the stretch of sea between Tunisia, southern Sicily, Malta and Libya. The results support the hypothesis \nthat a common species, S. blainville, currently inhabits the Mediterranean Sea, while a second and rare species is probably \nan occasional visitor with high morphological similarity to the S. megalops and S. blainville but is genetically distinct from \nboth. Within this perspective, the occurrence of S. megalops in the Mediterranean Sea is not confirmed and our study \nhighlights the taxonomic uncertainties in relation to the occurrence and distribution of Squalus species in this region. We \nencourage the establishment of a coordinated international effort to implement a comprehensive and integrated taxonomic \nassessment on this genus which represents an irreplaceable component of the biodiversity of the area.