All ETDs from UAB

Advisory Committee Chair

Stephen A Watts

Advisory Committee Members

Addison L Lawrence

James B McClintock

Document Type


Date of Award


Degree Name by School

Master of Science (MS) College of Arts and Sciences


Small Lytechinus variegatus were collected in October 2004 from Port St. Joseph Peninsula State Park, FL (30° N, 85.5° W) and transported to the Texas A&M Shrimp Mariculture Facility in Port Aransas, TX. Subadult sea urchins were held individually in 25 cm x 10 cm diameter cylindrical cages and were fed semi-purified formulated feeds containing 0.55, 1.1, or 2.4 mg Se/kg feed for 12 weeks (n = 16 individuals per feed treatment, 13.67 ± 0.20 SE g initial wet weight, 30.12 ± 0.15 SE mm diameter; 32 ± 2 ppt salinity and 22 ± 1 C). Sea urchins were weighed every 4 weeks and dissected at the end of the 12-week study. High amounts of dietary selenium (2.4 mg Se/kg feed) significantly decreased weight gain, test diameter, test wet and dry weights, gonad production, reproductive potential, and nutritive capacity compared to sea urchins fed 0.55 and 1.1 mg Se/kg feed, suggesting that high amounts of dietary selenium negatively affect normal sea urchin physiology. Observable pathologies in sea urchins fed high amounts of dietary selenium included red coelomic fluid and pigmented organs, suggesting an immunological response. Alhough test weights were reduced, Aristotle’s lantern weights were highest in sea urchins fed high amounts of dietary selenium (2.4 mg Se/kg feed), supporting published theories of lantern plasticity in response to nutrition. A selenium requirement was suggested but not determined in this 12-week study. These data suggest toxicity for high amounts of dietary selenium in L. variegatus, causing a variety of growth inhibitions and pathologies.



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