The starfish (commonly as a sea star) is generally found with 5 arms that are attached to a central disc. This central disc is the activity center of the starfish and also contains the mouth of the starfish.
The starfish feeds on oysters and clams, the 2 stomachs of the starfish helping with the digestion of complex organisms. The starfish uses one stomach to begin the digestion of the food, and the other stomach to expand outwards and engulf their prey. Starfish can be found in the oceans all around the world.
Due to the slow moving nature of the starfish, the starfish is preyed upon by many animal predators including fish, crabs, rays, sharks, humans and birds when the starfish are washed onto the shore.
The starfish has the incredible ability to regenerate itself into a new starfish, with a single lost arm attached to a portion of the central starfish body disc!
Starfish do not rely on a jointed, movable skeleton for support and movement (although starfish are still protected by their skeleton), but instead possess a hydraulic water vascular system that aids the starfish in movement.
The water vascular system of the starfish has many projections called tube feet on the ventral face of the starfish's arms which function in movement and aid with feeding.
Starfish can change their gender when it is convenient to them. The female starfish is capable is releasing over 2 million eggs at any one time, although the average amount of eggs that the female starfish releases is closer to 1 million. The eggs released by the female starfish are then fertilized by the male starfish and the fertilized eggs develop into larvae which are able to swim about. Starfish larvae swim for about three weeks before settling and beginning metamorphosis into the more common appearance of the starfish.
The starfish is today considered to be a threatened species of animal mainly due to habitat loss and pollution which are drastically reducing the starfish populations.
