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Multiple photoreceptor systems control the swim pacemaker activity in box jellyfish
The Journal of Experimental Biology
|December 1, 2009
Summary
Box jellyfish use four eye types in their rhopalia to control swimming. Different eyes have opposite effects on the swim pacemaker, indicating complex visual processing in these cnidarians.
Area of Science:
- Marine Biology
- Neuroscience
- Sensory Biology
Background:
- Box jellyfish (cnidarians) use a swim pacemaker in their rhopalia for propulsion.
- Each of the four rhopalia contains six eyes of four distinct types.
Purpose of the Study:
- To investigate how each of the four eye types influences the box jellyfish swim pacemaker.
- To understand the role of visual input in controlling jellyfish locomotion.
Main Methods:
- Electrophysiological recordings of the swim pacemaker.
- Stimulation of individual eye types and the rhopalia neuropil.
- Comparative analysis of responses to single and multiple eye stimulations.
Main Results:
- Three out of four eye types, along with the rhopalia neuropil, modulate the swim pacemaker.
- Lower lens eyes inhibit the pacemaker when stimulated and increase frequency upon light-off.
- Upper lens eyes and pit eyes show opposing effects compared to lower lens eyes.
Conclusions:
- Box jellyfish exhibit complex visual processing for swim control.
- Differential responses of eye types suggest advanced integration within the rhopalia.
- The interplay between photoreceptors and the swim pacemaker is crucial for jellyfish movement.
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