reproduction

Morgan Hunt
December 27, 08
H Biology A
Asteroidea Reproduction

Star fish are both sexual and asexual, depending on how you think of it.
Most reproduce sexually. Each arm holds a pair of gonads that become almost filled with eggs or sperm during the time of breeding. Most species are broadcast spawners, which means eggs and sperm are released into the water column to be fertilized. To increase the chances of fertilization, sea stars come together when they are ready to spawn. The crown-of-thorns sea star, releases a potent chemical into the water column to attract the opposite sex. As for the Asterias Rubens, the female produces small eggs that are released into the sea and fertilized externally to develop as planktotrophic larvae. Eventually, they go through metamorphosis and settle on the seabed to grow into adults. This type of reproductive strategy is known as indirect-development.
Some sea stars brood their young. Females hold their fertilized eggs in a brood space either under the arm, in the stomach, or keep them warm in the gonads. If they are kept in the stomach or gonads, they develop within and escape through small openings the female's body wall called gonopores.
However, seven species (that tend to be very small) are known to willingly pinch off one or more arms that then redevelop a complete new disc and arms.
Freeman, S. (n.d). Asteroidea (Sea Stars). In Answers. Retrieved December 27, 2008, from http://www.answers.com/topic/asteroidea-sea-stars-biological-family.