First, watch this mesmerizing time-lapse video from the BBC...
Now, let me tell you some of the remarkable things I have learned about the sea star, a.k.a. the starfish:
- Sea stars live in all oceans - including the Antarctic, where the video was filmed and where the 24-inchers in the 2nd photo were caught - and at all depths.
- Most of the 1,800 species have 5 rays (or arms), but some have as many as 50.
- The small circle near the center of a sea star is porous and functions as a water valve.
- "Tube feet" emerge from the grooves on the underside of the rays to assist in eating and locomotion.
- Most sea stars move slowly, but some are capable of rapidly "gliding" across the sea floor.
- A microscopic eye on the end of each ray allows the sea star to distinguish between light and dark.
- Sea stars have 2 stomachs, one of which can protrude out of the mouth to engulf food.
- They have complex nervous systems, but no brain.
- Sea stars reproduce sexually or asexually, releasing gametes either by pairing one-to-one or "free-spawning" in groups.
- Some species can reproduce by fragmentation, with an entire sea star growing from a detached arm. Others can regenerate their own lost arms.