Recent molecular evidence suggests staurozoans are medusozoans that diverged
from Medusozoa before the medusa stage emerged. Morphological studies are needed to determine whether this framework can provide insight into medusa evolution. I studied
the neuromuscular morphology of two staurozoans, Haliclystus ‘sanjuanensis’ and
Manania handi using FMRFamide and α-tubulin antibodies to label neurons, and
phalloidin to label muscles. Results indicate that similar to polyps, staurozoans possess
one regionally differentiated FMRFamide and α-tubulin immunoreactive (IR) nerve net,
and smooth muscles only. Comparisons with other cnidarians indicate that ancestral
medusozoans had a marginal circular muscle and muscular manubrium, but lacked the
parallel conducting nerve nets, striated muscle, and pacemaker required to coordinate
medusa swimming. A possibly light-sensitive concentration of neurons at the base of the
primary tentacles suggests that staurozoan primary tentacles are homologous to
medusozoan rhopalia. The unique neuromusculature of nematocyst clusters suggests a
defensive or predatory function for these staurozoan synapomorphies. / Graduate / 0287 / 0317
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/6981 |
| Date | 22 December 2015 |
| Creators | Westlake, Hannah |
| Contributors | Page, Louise Roberta |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | Available to the World Wide Web, http://creativecommons.org/licenses/by-nc-nd/2.5/ca/ |
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