Meeting Abstract
Chondrichthyes (chimaeras, sharks, skates and rays) are a lineage of vertebrates with skeletons composed entirely of cartilage, that have been around for over 400 million years. This long evolutionary history has led them to exhibit a diverse range in life-history traits, ecology, and biogeography as they are found throughout the world’s marine and freshwater waterways. Chondrichthyans exhibit most forms of sexual reproduction, from egg-laying to live birth: oviparity, multiple types of aplacental viviparity, and placental viviparity. They have also evolved many modes of locomotion, from axial-swimming (tail undulations), undulating or oscillating pectoral fins, to walking (or ‘punting’) along the substrate with pelvic fins. Some species even use a combination of these methods to locomote, depending on their habitat. We described the ecological structuring of chondrichthyan communities over time, with the aim of exploring potential correlates and mechanisms that have shaped modern assemblages. We used reproduction, dietary preference, and locomotor mode to establish the ecospace occupation of extant species from all aquatic ecosystems. By gathering these data from the literature we were able to view the ecosystem and community structures of cartilaginous fishes in 3D morphospace and quantify the functional ecological roles across species. The relevant space these communities fill is limited compared to the theoretical ecospace available throughout the world’s waterways, specifically in the deep-sea. Considering extant taxa in this new framework illuminates which factors have shaped the cartilaginous fish communities of today and how these aquatic ecological assemblages have changed throughout time.
