The syllid polychaete Autolytus varius reproduces in the spring
and early summer in Yaquina Bay, Oregon, The fertilized female
epitokes, or Sacconereis, carry the developing eggs and larvae in a
ventral sac until the larvae are ready to be released; incubation
lasts 14 to 18 days in the laboratory, The effects of a small increase
in hydrostatic pressure on the activity of Sacconereis were tested,
When placed in a pressure vessel, these epitokes responded to increases
of 0.39 Bar by orienting dorsally and swimming upward,
and by increasing their swimming rate, Peak activity occurred in
the first minute after a pressure stimulus. Following this, there
was a period of accommodation until the epitokes returned close to
their normal level of activity; the period of accomodation lasted
around 11 minutes, When the pressure was released, the worms
either slowed their swimming rate, or they coiled and sank rapidly
to the bottom of the vessel. Decerebrate Sacconereis of A. varius
did not respond to pressure stimuli. The Sacconereis of A. magnus
and A. prismaticus, and the Polybostrichus of A. prismaticus
demonstrated swimming responses similar to A. varius Sacconereis.
Three other species of polychaetes did not respond to pressure
changes. The hydrostatic pressure response is possibly an adaptation
of a planktonic stage of a normally benthic animal. / Graduation date: 1969
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/37177 |
| Date | 09 May 1969 |
| Creators | Smith, Randall William |
| Contributors | Pratt, Ivan |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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