Shark and ray cartilage canals show blood vessels can exist in mature cartilage without endochondral bone formation
Cartilage in adult tetrapod skeletons is known to lack blood vessels. In young birds/mammals, however, a dense network of vasculature-containing tunnels—cartilage canals—perforates the growing skeleton, nourishing cartilage, and developing ossification centers for later bone. As the canals and their vascular network regress as the animals age, healthy cartilage in adults is typically regarded as avascular. We use diverse tissue characterization and visualization (e.g., light/electron microscopy, microCT) to show skeletons of adult rays/sharks (elasmobranchs) possess persistent cartilage canals. Elasmobranch canal morphology and tissue composition support a structural analogy with mammalian cartilage canals, suggesting that early jawed vertebrates had vasculature-invaded cartilage. However, the anatomical location of canals—extending away from, not toward, mineralized tissue—and the lack of endochondral ossification in ray/shark cartilage suggest functions divergent from amniotes. We describe distinctive features and variation in elasmobranch cartilage canals, discuss their potential for tissue mineralization, and implications for their presence in an animal clade with continuously growing cartilaginous skeletons.
Authors
- Sue R. McGlashan (ORCID: https://orcid.org/0000-0002-8666-2456)
- Daniel R. Baum (ORCID: https://orcid.org/0000-0003-1550-7245)
- Mélanie Debiais‐Thibaud (ORCID: https://orcid.org/0000-0002-1377-2515)
- Kady Lyons (ORCID: https://orcid.org/0000-0003-2001-4939)
- Laura J. Ekstrom (ORCID: https://orcid.org/0000-0001-8593-3640)
- Victoria Camilieri‐Asch (ORCID: https://orcid.org/0000-0001-9566-1394)
- Emilio J. Gualda (ORCID: https://orcid.org/0000-0001-5948-5493)
- Theda I. Hinrichs (ORCID: https://orcid.org/0009-0003-3957-4941)
- Ronald Seidel (ORCID: https://orcid.org/0000-0003-4870-6726)
- Michael J.F. Blumer (ORCID: https://orcid.org/0000-0001-9467-6316)
- Lawrence J. Bonassar (ORCID: https://orcid.org/0000-0003-1094-6433)
- Benjamin Flaum (ORCID: https://orcid.org/0000-0003-2114-2668)
- Mason N. Dean (ORCID: https://orcid.org/0000-0002-5026-6216)
- Salman O. Matan (ORCID: https://orcid.org/0009-0002-0291-6867)
- Jana Ciecierska‐Holmes (ORCID: https://orcid.org/0009-0008-8569-0026)
- Maxi Yeatman-Biggs (ORCID: https://orcid.org/0009-0007-7187-7546)
Institutions
- Centre National de la Recherche Scientifique (FR)
- Innsbruck Medical University (AT)
- Max Planck Society (DE)
- University of Auckland (NZ)
- École Pratique des Hautes Études (FR)
- Queensland University of Technology (AU)
- City University of Hong Kong (HK)
- Universität Innsbruck (AT)
- Zuse Institute Berlin (DE)
- Université de Montpellier (FR)
- Cornell University (US)
- Humboldt-Universität zu Berlin (DE)
- Max Planck Institute of Colloids and Interfaces (DE)
- Institut des Sciences de l'Evolution de Montpellier (FR)
- Institut de Recherche pour le Développement (FR)
- Wheaton College - Massachusetts (US)
- California State University, Long Beach (US)
- Universitat Politècnica de Catalunya (ES)
Publication Details
- Journal
- iScience
- Published
- 2026-10-31
- DOI
- https://doi.org/10.1016/j.isci.2026.117871
- Primary Topic
- Ichthyology and Marine Biology
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- Human Frontier Science Program
- University Grants Committee
- Faculty of Medical and Health Sciences, University of Auckland