Digestive system of class asteroidea, Biology

Assignment Help:

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.


Related Discussions:- Digestive system of class asteroidea

Aril - seed appendages, Aril - Seed Appendages It is an outgrowth that...

Aril - Seed Appendages It is an outgrowth that arises from the funicle or the testa near the raphe and covers the seed partially or completely. It is often referred to as the

Effects of solid waste pollution, The improper handling and transfer of the...

The improper handling and transfer of the solid wastes results in various health and environmental hazards, such as: 1.      Spoilage of landscape: Municipal wastes heap up o

Breast cancer, Breast Cancer Normal 0 false false ...

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

Iceberg phenomenon in relation to diabetes, Q. Iceberg phenomenon in relati...

Q. Iceberg phenomenon in relation to diabetes? Diabetes Mellitus cases are diagnosed by a doctor or a health worker by taking history, blood test for sugar level. But the undia

Primate heritage, Table provides you the classification of the living prima...

Table provides you the classification of the living primates. The primate fossil history dates back to 60 million years i.e. to Paleocene times, more specifically to the cretaceous

Simple indigestion, S i m p l e indigestion The disease is common ...

S i m p l e indigestion The disease is common in stall-fed individuals. Consumption of indigestible food material, moldy and nutritionally unbalanced feed results in simpl

The control group should be identical, If you have a control group for your...

If you have a control group for your experience, which of the following statements is true? A. The control group should be identical to each test group with the exception of one va

Competition - processes in succession , Competition - Processes in Successi...

Competition - Processes in Succession The aggregation of individuals in an area leads to inter specific and intra specific competition. The competition is usually for

Haccp is a food-related operation, HACCP  is a food-related operation to: ...

HACCP  is a food-related operation to: A) Identify and assess hazard at every stage of operation, right from start to finish B) Determine the critical control points C) E

Define keratomalacia - micronutrient deficiencies, Define Keratomalacia - M...

Define Keratomalacia - Micronutrient Deficiencies? This is a condition of rapid destruction and liquefaction of full thickness of cornea, leading lo prolapse of iris, resulting

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd