anatomy of a starfish

ring canal

Circular canal in which filtered water enters through the madreporite and branches out into the radiated canals.

rectal cecum

Lateral duct of the terminal part of the digestive tract, where waste is stored before being expelled through the anus.

anus

Terminal orifice of the digestive tract allowing waste to be ejected; most of the undigested food is regurgitated rather than expelled through the anus.

stomach

Dilated section of the digestive tract preceding the intestine; it receives food to be digested.

gonad

Each of the two glands located in each arm, producing gametes (spermatozoids or ovules) depending on the sex of the starfish.

pyloric cecum

Radiated duct of the digestive tract producing digestive enzymes and also allowing digested food to be stored.

gonopore

Dorsal opening through which gametes (spermatozoids and ovules) are expelled into the water to be fertilized.

intestine

Section of the digestive tract between the stomach and the anus where absorption of nutrients is carried out and waste is transformed into fecal matter.

radial canal

Canal running the length of the arm; it receives water from the annular canal, which then passed into the tube feet.

ampulla

Bulb that contracts to let water enter the tube foot, allowing it to extend; when it dilates, the foot retracts.

esophagus

Muscular membranous channel of the anterior section of the digestive tract; it allows food to reach the stomach.

mouth

Anterior cavity of the digestive tract located on the ventral surface that allows food to be ingested.