A Revision of the North Pacific swell sharks (Scyliorhinidae: Cephaloscyllium) with comments on zoogeography

M.S. Thesis Project:   

I came to Moss Landing Marine Labs in the spring of 2004. Initially I was studying the effects of erosion in Elkhorn Slough, however, the Ichthyology Lab soon “lured” me in. After taking an Advanced Topics course on Systematics, I discovered I have a knack for finding the minute and often hidden key characters that distinguish a new species.

One of my side-projects at MLML involved the description of a new species of lantern-shark (Family: Etmopteridae, Genus: Etmopterus). Etmopterids are small, enigmatic sharks widely distributed in temperate and tropical waters around seamounts and along continental margins. Lanternsharks are deepwater sharks that possess unique rows of photophores over much of their ventral surface. The new species, Etmopterus burgessi (Schaaf-DaSilva and Ebert, in press), is named after George H. Burgess from the Florida Museum of Natural History. Etmopterus burgessi is unique from its congeners based on characters such as snout width, flank and caudal markings, and placement of dermal denticles. I presented this research at the Western Society of Naturalists in 2005.

My Master’s thesis consists of a revision of the systematics of the catshark genus, Cephaloscyllium. Cephaloscyllids are also known as swell sharks because they can quickly gulp air or water when perturbed, swelling up to deter predation. My thesis work involves the re-description of the Japanese swell shark, C. umbratile, as well as descriptions of two new western North Pacific species. The local swell shark species, C. ventriosum, is quite common in southern California including Catalina Island. I am interested in comparing the eastern North Pacific group with the eastern South Pacific group, which ranges into Chile, to see if they are in fact the same species. The biogeography and evolutionary history of this group is rather fascinating to me as well. My methods are based on morphometric and meristic data, but may expand to include genetic data in the future, if I pursue a PhD.

Currently, I plan to graduate from MLML in the Spring of 2007, and apply to the scientific illustration credential program at UCSC.