Behavior and Functional Morphology of Respiration in the Basket Star, Gorgonocephalus eucnemis and Two Brittle Stars in the Genus Ophiothrix

• Main Author: Hainey, MacKenna
• Other Authors: Emlet, Richard
• Language: en_US
• Published: University of Oregon 2019
• Subjects: Bursal ventilation; Functional morphology; Ophiuroidea; Organismal biology; Ossicles; Respiration
• Online Access: http://hdl.handle.net/1794/24233

Gorgonocephalus eucnemis, Ophiothrix suensonii and Ophiothrix spiculata are aerobic Echinoderms. Previous observations on the anatomy of these two genera state five pairs of radial shields and genital plates are responsible for regulating the position of the roof of the body disc and the flushing of water in and out of the bursae. Rates of bursal ventilation increase by an average 60-64% when the ophiuroid is exposed to an increase in food or a decrease in dissolved oxygen in Gorgonocephalus. When exposed to hypoxic oxygen concentrations O. suensonii and O. spiculata increased bursal-ventilation rates by (means of) 35% and 28%. Measurements of DO from inside and outside the bursae show that DO is being absorbed during bursal-ventilations. These findings suggest bursal ventilation is a means of respiration and increased rates of bursal-ventilation may help meet increased oxygen demands during feeding and some periods of hypoxia. This dissertation includes unpublished, co-authored material.