{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T17:40:17Z","timestamp":1790271617935,"version":"4.1.0"},"reference-count":43,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2025,10,19]],"date-time":"2025-10-19T00:00:00Z","timestamp":1760832000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>In the Chondrichthyes Raja asterias and Myliobatis aquila and in the Teleost Sparus aurata, the appendicular skeleton of the pectoral fins (including the calcified structures of the mouth in M. aquila) was investigated to find out how the specific skeletal segments were formed and stiffened over the course of evolution, not only with regard to the adaptation of the ontogenesis of the cartilage \u201canlagen\u201d to the mechanical requirements of locomotion in the water column, but also to the specific feeding habits (durophagy) of M. aquila. The morphology of the pectoral fins of the three species showed a different layout, characterized by the geometry of the basic units (aligned tesserae and calcified radial columns), which provide varied flexibility of the pectoral fins, suggesting an adaptation to the \u201cpelagic\u201d and \u201cbenthic\u201d locomotion patterns in the environment where the species live. The morphology of the calcified structures in the mouth of M. aquila showed the presence of two different masticatory systems: the first (external) with the rows of teeth resting on the maxillary and mandibular arches, and the second (internal, in the oral cavity) with the symphyseal plates specialized for durophagy. Chemical\u2013physical analyses revealed that the calcified cartilage matrix of the Chondrichthyes fin rays, teeth and durophagy plates is stiffened by the same Ca3(PO4)2 mineral phase deposed in the organic matrix of the Teleost S. aurata fins (with the characteristic SEM morphological texture of calcified bone matrix). The hitherto unknown presence of two different chewing systems in M. aquila documents an evolutionary adaptation to nutritional requirements that can be explained by two hypotheses: the coexistence of two functioning systems in current specimens, allowing for the ingestion of harder and softer prey (or plant food), or the persistence of a rudimentary dentition that is no longer used (vestigial dentition). Furthermore, the texture of the calcified matrix in teleost fishes, as observed by scanning electron microscopy, may indicate a bone-like organic matrix substrate, similar to that found in endochondral ossification.<\/jats:p>","DOI":"10.3390\/ani15203034","type":"journal-article","created":{"date-parts":[[2025,10,20]],"date-time":"2025-10-20T09:23:34Z","timestamp":1760952214000},"page":"3034","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Skeletal Adaptations to Locomotion and Feeding in Mediterranean Batoids (Raja asterias, Myliobatis aquila) and the Teleost Sparus aurata: A Comparative Study"],"prefix":"10.3390","volume":"15","author":[{"given":"Ugo E.","family":"Pazzaglia","sequence":"first","affiliation":[{"name":"Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, 25121 Brescia, Italy"},{"name":"Department of Medicine and Technological Innovation, University of Insubria, 21100 Varese, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7532-7951","authenticated-orcid":false,"given":"Genciana","family":"Terova","sequence":"additional","affiliation":[{"name":"Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-1779-1836","authenticated-orcid":false,"given":"Marzia","family":"Guerrini","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Physical Chemistry Section, C.S.G.I. (Consorzio Inter Universitario per lo Sviluppo dei Sistemi a Grande Interfase), University of Pavia, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9646-4958","authenticated-orcid":false,"given":"Piero A.","family":"Zecca","sequence":"additional","affiliation":[{"name":"Department of Medicine and Technological Innovation, University of Insubria, 21100 Varese, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0161-2434","authenticated-orcid":false,"given":"Guido","family":"Zarattini","sequence":"additional","affiliation":[{"name":"Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, 25121 Brescia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1428-8124","authenticated-orcid":false,"given":"Fabrizio","family":"Serena","sequence":"additional","affiliation":[{"name":"Institute of Marine Biological Resources and Biotechnology, National Research Council (CNR-IRBIN), 91026 Mazara del Vallo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cecilia","family":"Mancusi","sequence":"additional","affiliation":[{"name":"Environmental Protection Agency of Tuscany Region (ARPAT), 57126 Livorno, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3738-6632","authenticated-orcid":false,"given":"Marcella","family":"Reguzzoni","sequence":"additional","affiliation":[{"name":"Department of Medicine and Technological Innovation, University of Insubria, 21100 Varese, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,19]]},"reference":[{"key":"ref_1","unstructured":"Hall, B.K. 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