Ambulacral is a term typically used in the context of anatomical parts of the phylum

Echinoderm An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea ...

ata or class Asteroidea and

Edrioasteroidea Edrioasteroidea is an extinct class of echinoderms. The living animal would have resembled a pentamerously symmetrical disc or cushion. They were obligate encrusters and attached themselves to inorganic or biologic hard substrates (frequently har ...

. Echinoderms can have ambulacral parts that include

ossicles The ossicles (also called auditory ossicles) are three bones in either middle ear that are among the smallest bones in the human body. They serve to transmit sounds from the air to the fluid-filled labyrinth (cochlea). The absence of the auditory ...

, plates, spines, and suckers. For example, sea stars or "star fish" have an ambulacral groove on their oral side (underside). This ambulacral groove extends from the mouth to the end of each ray or arm. Each groove of each arm in turn has four rows of hollow tube feet that can be extended or withdrawn. Opposite the ambulacral groove is an ambulacral ridge on the aboral side of each ray, known as an

ambulacrum Ambulacrum is an architectural word that denotes an atrium, courtyard, or parvise in front of a basilica or church that is surrounded by arcades or colonnades, or trees, and which often contains a fountain A fountain, from the Latin "fon ...

. These have interambulacra between them.

Etymology

From the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

'ambulācrum', meaning 'walk planted with trees', 'avenue', ' alley' and '

walking Walking (also known as ambulation) is one of the main gaits of terrestrial locomotion among legged animals. Walking is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults o ...

place' Derives from' 'ambulāre', meaning 'to walk' or 'Amble' meaning 'To walk slowly or leisurely'. Has Indo-European roots - deriving from 'Ambhi'The Free Dictionary (n.d.) ambulacra, nlineAvailable at: http://www.thefreedictionary.com/ambulacra ccessed 14th Nov 2014

References

Echinoderm anatomy {{echinoderm-anatomy-stub