The historical occurrence of sawfishes in the Mediterranean Sea has been the subject of active debate over the last decade (Ferretti et al. 2015). The growing consensus among specialists is that sawfishes may have never occurred in the Mediterranean with stable populations (Harrison & Dulvy, 2014). Conversely, extensive literature search, archival and museum data mining, and extinction probability analyses (Ferretti et al. 2015), provided evidence to support the hypothesis that sawfishes (Pristis pristis and Pristis pectinata) once occurred in the Mediterranean with stable populations. These results challenge several tenets of sawfish temperature tolerance, movement, distribution, and population structure. They would expand sawfishes’ historical distribution range in temperate latitudes and thus raise important questions on how these populations might have survived in the Mediterranean Sea. Molecular techniques on historical DNA promise opportunities for characterizing population structure, biogeography and evolution of elasmobranchs (Leone et al. In prep.). As well, isotopic and microconstituent analyses on rostral teeth can provide further information on date, biogeography, movements and habitat use of the individual specimens (Field et al. 2009). To date we have sampled 58 museum specimens of sawfish. Material labelled as Mediterranean had a great uncertainty on acquisition date and location. Other sawfish remains had no info at all on acquisition date, species identity and capture location. This project intends to use genetic and biogeochemical analyses to address this uncertainty, and eventually using the material identified as coming from the Mediterranean to characterize the population and genetic structure of the sawfishes once occurring in the region.
Restoring the history of sawfish in the Mediterranean from museum exhibits
LEONE, AGOSTINO;CARIANI, ALESSIA;MINELLI, DANIELA;TINTI, FAUSTO;
2015
Abstract
The historical occurrence of sawfishes in the Mediterranean Sea has been the subject of active debate over the last decade (Ferretti et al. 2015). The growing consensus among specialists is that sawfishes may have never occurred in the Mediterranean with stable populations (Harrison & Dulvy, 2014). Conversely, extensive literature search, archival and museum data mining, and extinction probability analyses (Ferretti et al. 2015), provided evidence to support the hypothesis that sawfishes (Pristis pristis and Pristis pectinata) once occurred in the Mediterranean with stable populations. These results challenge several tenets of sawfish temperature tolerance, movement, distribution, and population structure. They would expand sawfishes’ historical distribution range in temperate latitudes and thus raise important questions on how these populations might have survived in the Mediterranean Sea. Molecular techniques on historical DNA promise opportunities for characterizing population structure, biogeography and evolution of elasmobranchs (Leone et al. In prep.). As well, isotopic and microconstituent analyses on rostral teeth can provide further information on date, biogeography, movements and habitat use of the individual specimens (Field et al. 2009). To date we have sampled 58 museum specimens of sawfish. Material labelled as Mediterranean had a great uncertainty on acquisition date and location. Other sawfish remains had no info at all on acquisition date, species identity and capture location. This project intends to use genetic and biogeochemical analyses to address this uncertainty, and eventually using the material identified as coming from the Mediterranean to characterize the population and genetic structure of the sawfishes once occurring in the region.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
