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

Study of asian chinese of normal range of waveform indices, A Collective St...

A Collective Study performed on Asian Chinese Normotensive Population to Obtain Healthy Normal Range of some Waveform Indices  Background-  Arterial blood pressure waveforms c

How does the excretory system of nematodes work, How does the excretory sys...

How does the excretory system of nematodes work? The metabolic residuals of nematodes are collected by two longitudinal lateral excretory channels that open in one excretory po

Do platyhelminthes have an excretory system, Q. Cnidarians and Poriferans d...

Q. Cnidarians and Poriferans do not have excretory systems. Do platyhelminthes have an excretory system? Platyhelminthes have a primitive excretory system made of flame cells

Light stress in chloroplasts, Light Stress in Chloroplasts As mentione...

Light Stress in Chloroplasts As mentioned earlier, very high light intensity can inhibit photosynthesis due to accumulation of excess of excitation energy. A portion of this r

Bio-security in relation to diseases, B i o-security in relation to disea...

B i o-security in relation to diseases Bio-security is a strategic and integrated approach encompassing policy and regulatory frameworks to analyze and manage risks in the se

Explain the parasite-amoeba, Normal 0 false false false ...

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

Explain iron balance and regulation of iron absorption, Explain Iron Balanc...

Explain Iron Balance and Regulation of Iron Absorption? The body has three unique mechanisms for maintaining iron balance. The first is the continuous reutilization of iron fro

Explain continuous full - thickness incision, Q. Explain Continuous full - ...

Q. Explain Continuous full - thickness incision? Continuous full - thickness incisions are indicated for a variety of situations outlined below. This type of incision may be us

What is manifest squint, What is Manifest Squint (Heterotropia) Manifes...

What is Manifest Squint (Heterotropia) Manifest squint is a deviation of one eye from the normal position when the fusion reflex is present. The subcategories of manifest squin

Explain the selective media - culture media, Explain the Selective Media - ...

Explain the Selective Media - Culture Media? It is used to select specific groups of bacteria by favouring the growth of desired bacteria and inhibiting the growth of undesired

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