The spelling of the word "Ambulacra" can be quite tricky, but understanding its phonetic transcription can make it easier. The IPA (International Phonetic Alphabet) transcription for this word is /æmˈbjuləkrə/. The "a" in "ambula" is pronounced as a short "a" sound, while the primary stress is on the second syllable "bu". The "cra" at the end of the word is pronounced with a schwa sound. Overall, the IPA transcription breaks down the word into its individual sounds, helping to make correct spelling a little easier.
Ambulacra is a term that originates from the field of biology, specifically marine biology, and refers to a set of tube feet or pore-like structures that are present on the underside of echinoderms, such as sea stars, sea urchins, and sand dollars. These tube feet are arranged in distinct patterns and occur in multiples of five, which is a characteristic feature of these organisms.
The ambulacra are located on the oral or ventral aspect of the echinoderm's body, forming a series of radial rows that extend outward from the central disk. These rows create ambulacral grooves between them, in which the tube feet are housed. Each tube foot consists of a muscular sac-like structure, known as an ampulla, which is connected to a suction cup-like structure, known as a podium or sucker. These tube feet play a vital role in locomotion, feeding, respiration, and sensory perception for the echinoderm.
In addition to their locomotory function, the ambulacra are also involved in capturing and manipulating prey, as well as in the respiration and excretion processes. The presence and arrangement of ambulacra are important taxonomical features used to classify and differentiate different species of echinoderms.
In summary, ambulacra are the specialized rows of tube feet found on the ventral side of echinoderms, enabling them to perform many functions necessary for their survival in the marine environment.
The perforated series of plates in the crusts of the sea-urchins through which the walking feet are protruded.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.
The word "ambulacra" has its roots in Latin. It is derived from the Latin word "ambulare", which means "to walk" or "to move about". This term is closely related to the word "ambulatory", which signifies movement or walking. In the context of biology and zoology, "ambulacra" refers to the radial canals or channels found in the water vascular system of echinoderms such as starfish and sea urchins. These ambulacra are responsible for locomotion and respiration in these organisms, hence the derivation from the Latin term for movement.