|
Two types of seastars in reference to this topic and they use two different types of locomotion. The "slower" seastars are members of Asteroides and depend on a high pressure hydrovascular system of chambers and vascular lumens called the ambulacral system as their mechanism of locomotion. It primarily drives locomotion via the tube feet, which adhere to the substrate, contract as fluids are pumped out, then relax and "unglue" from the substrate to move. It requires the orchestration of all the tube feet to accomplish directional movement. The other group is the Ophuroids, which rely on intervetebral musculature rather than the ambulacral system for locomotion, and are both quite quick to move and very agile. In this group, tube feet provide mostly traction, while the musculature provides the mechanical advantade of speed and flexibility. Due to intraossical articulation, many of these seastars are restricted to movement within a single plane, others are quite flexible and capable of wide-angle moves in relation to the plane of travel.
...and the Ophuroids are quite capable of caturing fish searching the rock for a place to sleep.
__________________
Tom <"))))>(
(TDWyatt)
Wise men speak because they have something to say; fools, because they have to say something. -Plato
Last edited by tdwyatt; 01-21-2004 at 11:28 AM.
|