It then releases enzymes to digest the coral polyps, which can take several hours. This is the simplest invertebrate animal. The process involves the releasing of sperm and eggs -- or gametes -- near each other so fertilization can occur.
Most reproduce sexually through external fertilization. It's behaviorally simple but in a variable environment, the success rate of … External fertilization occurs outside the body of an organism. The crown of thorns starfish is a well-known coral predator that can devour 10 square meters of coral annually. Fertilization in Starfish and Sea Urchin: Roles of Actin. External fertilization may seem a mite impersonal, but it carries with it several advantages as well as risks. Echinoderm - Echinoderm - Asexual reproduction: Asexual reproduction in echinoderms usually involves the division of the body into two or more parts (fragmentation) and the regeneration of missing body parts. Types of Fertilization: Once you have established that an animal can reproduce sexually, there are two types of fertilization that can occur. A large and synchronized population of oocytes in the gonad can be induced to undergo maturation by addition of the hormone 1-methyladenine (1-MA). Starfish commonly reproduce by free-spawning: releasing their gametes into the water where they hopefully are fertilized by gametes from the opposite sex. One of several animal reproductive methods, external fertilization generally only occurs in aquatic creatures as water acts as a vehicle through which sperm can travel. Most are asymmetrical and reproduce either through asexual means or through internal, self-fertilization because most are hermaphrodites.

A COTS feeds itself by thrusting its stomach out of its body and onto the coral reef. Fertilization takes place outside the starfish in their environment through the gonopore. Starfishes are echinoderms. Does a jellyfish have internal or external fertilization? The less chance of fertilization is compensated by the enormous amounts of eggs and sperm cells.In birds, once the egg is laid, it is surrounded by a calcareous shell through which only gaseous exchange can take place. Starfish Reproduction. Most species of starfish releases their eggs and sperm directly into the water, so fertilization is external. Chun JT(1), Vasilev F(2), Limatola N(2), Santella L(3).
This is a vertebrate animal with bilateral symmetry which has an endoskeleton.

To reproduce, fish have to produce the eggs and sperm required for sexual reproduction. Most reproduce sexually with external fertilization. External fertilization is a mode of reproduction in which a male organism's sperm fertilizes a female organism's egg outside of the female's body.