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A pdf with figures for this research is available for download below.


Pterobranchs are a group of marine invertebrates within the Hemichordata, which share characteristics with both chordates and echinoderms. Pterobranchs live in colonies of secreted tubes, coenicia, which are composed of a gelatinous material of unknown composition. Visually, the tubes appear similar to the tunic of tunicates, a group of invertebrates within the Chordata. The nonproteinaceous tunic of tunicates is composed of cellulose, which is unusual. The goal of this study was to determine the composition of the pterobranch coenicium. Some aspects of pterobranch phylogeny are still unclear even after multiple molecular and morphological studies. Identification of any new shared characteristics with either echinoderms or chordates would be valuable in determining clearer relationships among these taxa. Purification methods, histology, and microscopy techniques were used to study the structure and properties of the tube material. To date, the results indicate that that the tube material may be protein but the composition is unknown.


Biochemistry | Biology | Evolution | Zoology

Lukasz J Sewera Biology Research Honors Thesis Figures April 15 2011.pdf (3142 kB)
Supplement to Honors Thesis: Figures