What is the meaning of calcareous ossicles?
Ossicles are small calcareous elements embedded in the dermis of the body wall of echinoderms. They form part of the endoskeleton and provide rigidity and protection. They are found in different forms and arrangements in sea urchins, starfish, brittle stars, sea cucumbers, and crinoids.
What does the Ambulacral system do?
Echinoderms possess a unique ambulacral or water vascular system, consisting of a central ring canal and radial canals that extend along each arm. Water circulates through these structures and facilitates gaseous exchange as well as nutrition, predation, and locomotion.
What is meant by Ambulacral?
: of, relating to, or being any of the radial areas of echinoderms along which run the principal nerves, blood vessels, and elements of the water-vascular system ambulacral grooves.
What are the functions of tube feet Madreporite and Ambulacral groove?
The madreporite is an opening to the water vascular system on the aboral surface. A mouth occurs on the oral surface. The ambulacral groove is on the oral surface from which tube feet project through the body wall. There is one eyespot on the tip of each arm.
Where are Pedicellariae located?
sea stars
How many types of Pedicellariae are there?
There are three types of pedicellariae (ophicephalous, tridentate and globiferous, figure 2) and any given species might have two or more types.
What are Pedicellariae made of?
Pedicellaria are small, snapper-like skeletal elements that are used by the echinoderm to keep small organisms from settling on its body. Echinoderms also have a spacious coelom (an open, fluid-filled body cavity lined with tissue), large gonads, and (usually) a complete gut.
What is the role of Pedicellariae?
cordatum pedicellariae are (1) cleaning of the body surface and ciliary structures (trifoliates), (2) protection against sedimenting particles (tridactyles), and (3) defense of the peribuccal area against potential small predators (globiferous pedicellariae).
What is another name for the Madreporite?
The madreporite is an essential part of the circulation system in echinoderms. Through this plate, which is also called a sieve plate, the echinoderm draws in seawater and expels water to fuel its vascular system.
In which group of animals Madreporite is found?
echinoderms