Labial Cartilages in Sharks –more to it than meets the eye

Autor(en)

Claudia Klimpfinger, Jürgen Kriwet

Abstrakt

Labial cartilages are paired structures located outside the jaws whose purpose in sharks is not completely clear yet. Labial cartilages vary a lot in current shark species, ranging from three pairs to a complete reduction, from massive to slender and from long to short. In our currentwork we used CT-images as a non-invasive method to check for labial cartilages in different shark species occupying different ecological niches and using different feeding strategies. The goal is to find out if the labial cartilages are a phylogenetic or an ecological trait. Therefore,we used nine species, which then were grouped according to their ecological niche into deep living, oceanic and benthic. We were able to detect that the labial cartilages in the oceanic species –especially in those known for ram-feeding behavior –were massively reduced while the ones in the benthic species were well conserved and strongly developed. Among the species classified by us as deep living we saw rather unique adaptations in the labial cartilages in comparison to the benthic group. For example,the cookie-cutter shark Isistius brasiliensis has very strong, fused labial cartilages and the ones of the frilled shark Chlamydoselachus anguineus are very slender. Therefore,we assume that the labial cartilages are an ecological trait and can give additional information on the feeding behavior in sharks and are also capable of giving information about the feeding behavior in extinct species, since labial cartilages were also detected in fossils. In future works we are goingto check on as many species as possible to either confirm or refuse this theory. A phylogenetic signal was not discovered so far and the developmental basis of these structures still is ambiguous.

Organisation(en)

Institut für Paläontologie

Seiten

40-40

Anzahl der Seiten

1

Publikationsdatum

2019

Peer-reviewed

Ja

ÖFOS 2012

106010 Entwicklungsbiologie, 105118 Paläontologie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/da692c4f-28d5-484d-8a1a-a89222c6868a