The Fault in Our Sea Stars: Analyzing Sea Star Wasting Disease in A.forbesi

Friday, February 12, 2016
Jacqueline Forson, Massachusetts Academy of Sciences, Worcester, MA
Asteroid echinoderms (sea stars) along the East and West Coast have been and are being monitored for indications of necrosis, white lesions, and unresponsive behavior. Sea Star Wasting Disease (SSWD) is a term used in relation of a widespread outbreak targeting asteroids. Recently, some evidence points towards Densovirinae (SSaDV) as a potential cause of echinoderm outbreak. Investigations of the histology of A. forbesi show cuticle loss, edema, and vacuolation of cells in the epidermis. Following the protocols of identifying a virus, the DNA structures of A. forbesi tissue, hemolymph and skin samples were isolated in order to detect the presence or absence of Densovirus. Controlled and treated northeast echinoderms kept at the University of Rhode Island show statistically significant variance. Of the 189-echinoderm samples, 97 showed an absence of lesions and 42 showed a presence of lesions. Through further analysis, organisms with an absence of lesions had a standard deviation of 13.82 indicating a large variance between the days of exposure versus the number of organisms without lesions. However, comparison of organisms with lesions to the days of exposure showed a standard deviation of 1.48. Bacterial colonies, grown using gel bands showing indications of VP1 or VP4, sent for sequencing further diverges from the hypothesis. Averages of percent identity to the published VP1 sequence shows 50.50% identity of all the submitted bacterial colonies, significant for an alignment of a viral protein. The bacterial colonies, initially indicating VP4, were anomalies because they had an average of 15.94% identity. Results from this experiment highlight an importance to continue research on this keystone species.