As of May 2014, starfish are considered to be threatened. Also known as sea stars, these marine animals are easily preyed upon because they are unable to move quickly. Their underwater predators include fish, rays, crabs and sharks.Know More
The shoreline is equally problematic for starfish, where their predators are marine birds as well as humans who may seek to take home an oceanic souvenir. Pollution in recent years has also played a role in the decline in the number of starfish.
Starfish live in oceans worldwide and are generally comprised of a center disk with five arms. They move about with the use of a hydraulic water vascular system rather than a jointed skeleton.Learn more about Starfish
Starfish breathe through their feet. Their feet are made of thin tissue that gases can easily move through. Starfish’s tubed feet and tiny bumps all over their bodies transport the oxygen from the seawater to their tissues. They move carbon dioxide from their tissues to the seawater.Full Answer >
Starfish do not have bones, but instead have a series of hard plates that provide structure and support to their bodies. Starfish and other critters like them are called echinoderms, or marine invertebrates, which are tailed, finned animals that have backbones — they are not actually fish at all.Full Answer >
The key to determining if a starfish is alive or dead is to look for movement. However, because starfish are not the most mobile organisms on the planet, it can be difficult to tell if they are alive or dead. If you cannot observe any movement at all, the starfish is probably dead.Full Answer >
Starfish move using tube feet on their undersides. Their feet use seawater to form a hydraulic system. The starfish's vascular system is open and relies on the water around it rather than internal pressure. Starfish can only move outside of water for a short time. A starfish left out of water for too long loses its ability to move, and it dies if not quickly returned to the ocean.Full Answer >