Investigating dermal behavioral responses in California red urchins
Graduation Date
2016
Document Type
Thesis
Program
Other
Program
Thesis (M.S.)--Humboldt State University, Biology, 2016
Committee Chair Name
Edward Metz
Committee Chair Affiliation
HSU Faculty or Staff
Keywords
Opsin, Rayleigh test, Circular statistics, Dermal vision, Red urchin, Photoreceptors, Urchin behavior, Humboldt State University -- Theses -- Biology, Blue light
Abstract
Recent research on sea urchins has shown that they possess unexpected visual capabilities. Behavioral tests have revealed that they are able to detect the spatial distribution and wavelength of light using the surface of their body. The well-studied purple urchin (Strongylocentrotus purpuratus) has a larger relative, the red urchin (Mesocentrotus franciscanus), which provides a number of advantages for studies in phototaxis. Light treatments used red, blue, and ultraviolet LEDs to illuminate one half of an urchin body. My results from red urchin trials agreed with published results from the purple urchin, indicating that both red and purple sea urchins show pronounced, significant negative phototaxis in the presence of blue light. My second study used targeted blue light beams as a probe to attempt to map red urchin responses on the geography of its body. To improve on previous published efforts, novel methods were designed to track an urchin during experimental trials, to analyze behavioral data, and reduce handling effects. Results indicate that a touch or chemical stimulus may confound the stimulus of blue light wavelengths, and that handling bias should be an important consideration in behavioral methods. Based on the results, a new detailed plan is presented for method modification to further research in this system.
Recommended Citation
Zourdos Williams, Cari Anne, "Investigating dermal behavioral responses in California red urchins" (2016). Cal Poly Humboldt theses and projects. 1805.
https://digitalcommons.humboldt.edu/etd/1805
https://scholarworks.calstate.edu/concern/theses/bk128d19g