Quiz On Sea Urchins

[MontanaRocknReefer]

How do sea urchins move?

[Homer]

S...........l..............o...............w...... ....l.................y

Homer

[MontanaRocknReefer]

Homer you are to much! Wrong answer though! LOL Johnny

[hesaias]

Tube feet!

[reefguy]

like a starfish, right?

[hayday]

homer-

i don't know about your experiences, but my long, spiny urchin flys around the tank like a pincushion on speed. when he wants to get somewhere, he can really motor.

-hayday

[MontanaRocknReefer]

Reefguy I believe they are related to the starfish family! Johnny

[mojoreef]

This is a tough question Johnny as urchins use several forms of movement. For instance. The carribean three toe uses a complex system of rubber bands and toothpicks, the Burmuda Black has been known to use the meathod of bumper hitching, and the florida flicker useing the trimble meathod of rolling.

Jerel

[asmith]

Our Spiny Urchin has had his fill of algae in the three days that we have had him and is probably going to be stationary through the Super Bowl. We will let you know about his method of movement when he decides to get off the couch.

Andrew

[MontanaRocknReefer]

Check here for answer:
http://www.quia.com/tq/103121.html

[tdwyatt]

johnny (rkymtnreefr) posted:

How do sea urchins move?

and Reefguy posted:

...like a starfish, right?

Both of these creatures are part of the family known as Echinoderms (the phylum Edhinodermata which includes sea urchins, sea stars, sea cucumbers, sand dollars, serpent stars, crinoids, sea biscuits, and basket stars). They all have skeletons made of calcium carbonate, some of them have there skeletons on display as tests in Urchins, and as ossicles in sea stars. In the sea urchins, the ossicles allow for the movement of the spines (CaCO3 ossicles as rotating spines) due to articulation at the junction of the fused ossicles in the test, and in seastars, the ossicles act as fused, jointed beads. All of the Echinoderms display some type of radial or axial symmetry, usually based on five divisions. If you think of sea stars like Linckia as the prototype, then it is easy to see the similarity of each of the creatures. If you bring the tips of the seastars rays (legs) together over it's head, and fuse the spaces between the rays together to form a ball, then you have a sea urchin. They all use ambulacral locomotion via their tube feet. This system is believed to have evolved in this phylum first as a means of collecting and transporting food within the colony, but later developed into the locomotion system we see today in the cucumbers, urchins and sea stars. The move by using hydrostatic pressure to extend their tube feet, then using an adhesive/adhesive dissolver system, "grab" the substrate and use the system to contract the tube food to provide motion. They release the substrate by dissolving the "glue" on the tube foot. They use this same means to extend their stomachs to feed (sea stars) or to extend their feeding tentacles (sea cukes, of both filter-feeding-type and substrate-ingesting-type)

Interestingly enough, they lack a brain, but exhibit brain-like learned responses. Serpent stars seem to "know" when they are about to be fed, and will come out each evening about the same time daily if a regimen is established (anecdotal, not in the literature) and they respond to the scent of food in the water, as well as to light and dark. They do have nervous "complexes that mediate their motions, but little else.

If you want more info, Barnes "Invertebrate Zoology" is a great reference that will go into great detail. Hope this helps

[Spanky]

Originally posted by mojoreef
This is a tough question Johnny as urchins use several forms of movement. For instance. The carribean three toe uses a complex system of rubber bands and toothpicks, the Burmuda Black has been known to use the meathod of bumper hitching, and the florida flicker useing the trimble meathod of rolling.

Jerel

ROTFLMAO

Can we please archive this!