Elasmobranch
Definition
The subclass containing sharks, skates, and rays, all characterized by a cartilaginous rather than bony skeleton. Forensic identification methods specific to this group exploit characters such as ceratotrichia and dermal denticle morphology.
- Taxonomic rank
- Subclass
- Includes
- Sharks, skates, and rays
- Skeleton
- Cartilaginous, not bony
- ID characters
- Ceratotrichia, dermal denticle morphology
Common questions
Why does a cartilaginous skeleton complicate species identification in seized product?+
Cartilage decomposes and processes differently from bone and rarely survives in fins, meat, or powdered products, so identification relies on cartilage-specific structures like ceratotrichia (fin rays) or on DNA barcoding rather than the skeletal morphology used for bony fish.
What is a dermal denticle and why is it useful in casework?+
It is a small tooth-like scale embedded in elasmobranch skin, and its shape and arrangement vary by species; because denticles survive in skin and leather products, they can support species identification even after a shark has been processed into goods.
Related terms
- Ceratotrichia
- Flexible, unsegmented cartilaginous rods that form the internal skeleton of elasmobranch fins. Their number, branching pattern, and cross-sectional morphology are species-informative and...
- CITES Appendix II
- A listing that allows commercial international trade in a species but requires export permits certifying legal and sustainable acquisition. Non-detriment findings (NDFs)...
- Fin Spine
- A stiff calcified spine present anterior to the dorsal fins in many shark species (notably spiny dogfish, Squalus acanthias). Spine presence, shape,...
- Mini-Barcode
- A short DNA barcode amplicon (typically 100-250 bp) designed for use when template DNA is fragmented by drying, heat, or age. Standard...
- Vertebral Age Rings
- Paired light and dark bands deposited in shark vertebrae in a manner analogous to tree rings. Counting band pairs under transmitted or...