Digestive system of class asteroidea, Biology

Digestive System of Class Asteroidea

Most asteroids are scavengers or carnivores and feed on snails, bivalves, polychaets, other echinoderms, fish, sponges, sea anemones and polyps of hydroids and corals. Some feed on plankton and detritus. The digestive system of sea stars extends between the oral end and aboral disc of the animal. The mouth lies at the centre of a muscular peristomial membrane. The mouth is followed by a short oesophagus that in turn opens into a large stomach. The stomach occupies most of the interior of the disc and is divided by a horizontal constriction into a large oval cardiac stomach and a smaller, flattened pyloric stomach. The walls of gastric stomach are pouched. In each arm a pair of digestive glands or pyloric caeca are present and their ducts open into pyloric stomach. The pyloric stomach leads into a short tubular intestine on the aboral side. The intestine opens to the outside through a minute anus at the centre of the aboral surface of the disc. A number of small outpocketings called rectal caeca arise from the intestine.

Posted Date: 2/4/2013 1:13:38 AM | Location : United States







Related Discussions:- Digestive system of class asteroidea, Assignment Help, Ask Question on Digestive system of class asteroidea, Get Answer, Expert's Help, Digestive system of class asteroidea Discussions

Write discussion on Digestive system of class asteroidea
Your posts are moderated
Related Questions


Which type of genetic disease can be identified from the visual analysis of the number of chromosomes present in a karyotype? The counting and the identification of chromosomes

Q. Describe the Morphological Characteristics? One of the first steps in the identification of bacteria in food is microscopic examination to ascertain the shape, size, aggreg

When a fatty acid reacts with glycerol, the result is- Select one: a. Formation of an amide b. Formation of an ester c. Formation of hydrocarbon d. Formation of a th

a report on similarities and diffrences between protozoans and mesazoans

Define the Uremia and Nitrogen Disposal? In animals, faecal and renal nitrogen were enhanced and decreased uremia was seen in normal and nephrectomised animals. The mechanisms

What are the plant root hairs? Where can they be found and what is their function? The root hairs are external elongated projections of the root epidermis. Their role is to

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Why Water and Electrolytes are important for exercise? Water and electrolytes are important for exercise performance as they maintain blood volume and osmolality, thermoregulat