Integrated Taxonomy and Species Diversity of the Historical Chondrichthyan Collection of the Zoology Museum "Pietro Doderlein" at the University of Palermo (Italy).

In the context of the progressive tendency to perceive a degraded environmental state as normal, due to the loss of memory of past ecological conditions (i.e., the Shifting Baseline Syndrome), natural history museum collections represent invaluable resources for studying long-term biodiversity shifts. This study deals with the taxonomic validation of the chondrichthyan species from the historical ichthyological collection assembled by Pietro Doderlein from 1863 to 1922 at the Museum of Zoology of the University of Palermo. The chondrichthyan specimens were digitally catalogued to meet current standards of museum documental identification. Biometric measurements were taken for each specimen, and an integrated analytical approach-combining morphology and ancient DNA analysis-was applied to assign species identities. The collection comprises 342 specimens associated with 76 valid codes. Of these, 288 specimens were identified to species level by morphology, revealing 58 discrepancies with the historical identifications. Sixteen specimens that could not be morphologically assigned were analyzed by DNA barcoding, resulting in eight additional species-level identifications. In total, 62 valid species belonging to 27 families were digitally catalogued according to ministerial guidelines. This taxonomic validation and cataloguing of the "P. Doderlein" chondrichthyan collection represent the first successful effort to bridge the gap in available data and tissue resources from Italian historical natural museums.