Marty Schmidt is a CSUMB undergraduate and UROC intern studying marine science with Pacific Shark Research Center at Moss Landing Marine Laboratories.
In addition to sorting elasmobranch specimens and gathering morphometric data on new sharks, this weekend (and almost every weekend) my fellow Shark Army interns and I are transforming shark skeletons into learning models for future outreach programs. It’s called skeletonization.
We do this for a lot of shark, skate, ray, and chimaera specimens that are discarded from other studies. Since these organisms have cartilaginous skeletons rather than bone, we use different skeletonizing techniques than are used on birds or primates. For example, instead of using flesh-eating beetles and Potassium Hydroxide to remove material from skeletons, we carve away the tissue with dissecting tools like scalpels. Soaking the specimens in hot water also helps loosen tissue. When the skeletal pieces are completely clean, we fixate and place them in formalin or bleach, then dry them in a dehydrating oven or under sunlight, a process called desiccation. The results are great representations of the internal skeletons of elasmobranches.
We have done this for many of our studied species at Pacific Shark Research Center, such as Leopard Sharks, Elephant Sharks and Thornback Rays. We also use desiccation to preserve tissue samples and whole specimens, such as denticle samples or crania. For example, this proved a solid method to create models of leopard Shark skins and parts of a White-spotted Chimaera. It might seem morbid, but these practices make it possible to display the intricacy of fishes containing cartilaginous skeletons for future and current outreach opportunities, such as helping children and others learn more about sharks.