What is meant by ambulacral groove?

ambulacral groove: (Echinodermata: Asteroidea) A groove or furrow bordered by large spines extending along the oral surface of each arm of sea stars, that contain two to four rows of small tubular projections called feet or podia.

What does the word echinoidea mean?

sea urchins
Medical Definition of Echinoidea : a class of motile bottom-dwelling echinoderms comprising the sea urchins and related forms.

What is the ambulacral system in echinoderms?

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 ambulacral system with diagram?

Explanation: Ambulacral is a term typically used in the context of anatomical parts of the phylum Echinodermata or class Asteroidea and Edrioasteroidea. This ambulacral groove extends from the mouth to the end of each ray or arm.

What is the function of Ambulacral groove?

The grooves are called ambulacral grooves and are filled with many soft projections, the suckers of the tube feet. Large spines line the ambulacral groove, and they are used for locomotion. On the aboral surface, a small and hard-to-see anus is located in the middle of the central disc.

What is the difference between open and closed Ambulacral groove?

If the radial canals run down the ambulacral grooves and are not covered by plates then the system is considered “open”, if the radial canals are primarily internal and externalized through pores, the system is “closed”.

What does Cnidaria mean in Latin?

New Latin Cnidaria, phylum name (from Greek knī́dē “nettle, sea nettle”—of uncertain origin— + Latin -āria, neuter plural of -ārius -ary entry 2) + -an entry 1.

Do echinoderms have blood?

Without blood or a heart, an echinoderm instead utilizes a water vascular system to carry oxygen to its vital organs.

What does Madreporite mean?

The madreporite /ˌmædrɪˈpɔːraɪt/ is a light colored calcareous opening used to filter water into the water vascular system of echinoderms. The water vascular system of the sea star consists of a series of seawater-filled ducts that function in locomotion and feeding and respiration.

What is Pedicellariae function?

The presumed functions of E. 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).

Where does the word Echinoidea come from?

Echinoidea comes from the Greek word ‘echinos’ meaning “spiny” and includes the sea urchins, sand dollars, and heart urchins. Echinoids are the sister taxa to holothuroidians within the Echinozoa clade.

What kind of body plan does an echinoderm have?

Echinoids lack arms, but their tests reflect the typical pentamerous plan of echinoderms in their five ambulacral areas. The most notable modification of the ancestral body plan is that the oral surface has expanded around to the aboral side, so that the ambulacral areas extend up to the area around the anus ( periproct ).

Which is the best definition of the ambulacral system?

Definition of ambulacral system : the water-vascular system of echinoderms

What are the two types of echinoid test?

Since the end of the Paleozoic, most echinoid tests have been composed by two sets of plates—ambulacral (through which tube feet protrude) and interambulacral. Typically, two rows of each type adjoin each other and alternate between ambulacral and interambulacral areas.