Locomotion in echinodermata, Biology

Assignment Help:

Locomotion in Echinodermata

Locomotion in echinoderms is accomplished through a unique canalicular system which is termed as the water-vascular system. This system is characteristic of echinoderms, in most of that it is quite well developed. It consists of a series of canals derived from the coelom. The canals consist of a fluid. Sea water has free access to the system via a perforated sieve plate called the madreporite on the aboral side of the animal. The fluid is much more like seawater but has a high content of potassium ions. Some proteins and several types of amoebocytes float in it. The structural organisation of the water-vascular system is chiefly the same in all echinoderms, though deviations from the basic plan occur. To study the components of the system, we might take the water-vascular system of the star-fish, as typical example. Its main component applicable from the point of view of locomotion consists of a pentagonal circumoral vessel that is termed as the ambulacral ring canal. From the ring canal are given off five radial vessels. Every radial canal extends up to the tip of the arm. It gives off a large number of side vessels along its course. Each side vessel leads into a tube-foot or podium, which is a hollow conical or cylindrical process with an ampulla and a terminal sucker. A Valve is present at the junction of lateral vessel with the tube-foot.


Related Discussions:- Locomotion in echinodermata

Define nutrient and drug interaction, Define Nutrient and Drug Interaction?...

Define Nutrient and Drug Interaction? Modern medicine has given us many useful drugs that not only prolong and save lives but in fact improve the quality of our lives. Have you

What food items include in clear liquid diet, What Food items include in cl...

What Food items include in clear liquid diet -  Clear, fat free soups/broths -  Light coffee, tea (without milk or cream) -  Strained fruit juices -  Tender coconut wa

Determine the ideal clinical conditions of teeth, The ideal clinical condit...

The ideal clinical conditions of teeth which we know already include: - the absence of pain. - less than 0.1 mm initial hori-ontal mobility under lateral forces of less than

What is symbiotic nitrogen fixation, a) What is symbiotic nitrogen fixatio...

a) What is symbiotic nitrogen fixation? b) Name the two protein components required for this process. Define their role.

Embryological evidences of evolution, EMBRYOLOGICAL EVIDENCES - A co...

EMBRYOLOGICAL EVIDENCES - A comparative study of embryology of different groups of animals reveals certain features that provide evidences for organic evolution. There ar

Water absorption and transpiration, Water Absorption and Transpiration ...

Water Absorption and Transpiration The rate of water absorption is controlled by the rate of transpiration. A high water potential in the atmosphere would reduce water loss fr

Define reduction of blood lipids, Define Reduction of blood lipids? Thi...

Define Reduction of blood lipids? This effect have been especially observed with saponins. Diets containing saponin-rich foods (300-500 mg saponins/day) e.g. soya, alfalfa, chi

Lactose intolerance - modification of carbohydrate intake, Define Lactose i...

Define Lactose intolerance - Modification of carbohydrate intake? This has been covered under the section on digestion and absorption earlier. We learnt that in case of lactose

Differences between vertebrates and the other chordates, What are the diffe...

What are the differences between vertebrates and the other chordates? Vertebrates are dissimilar because they have a spinal column (vertebral column). In these animals the noto

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