AMBULACRARIA Meaning and
Definition
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Ambulacraria is a taxonomic group within the animal kingdom, encompassing two major phyla: Echinodermata and Hemichordata. These organisms share common characteristics such as a radial symmetry, a coelom (fluid-filled body cavity), and a unique system of fluid-filled tubes called ambulacral systems.
Echinodermata, commonly known as echinoderms, includes starfish, sea urchins, sand dollars, and sea cucumbers. These organisms possess a hard calcareous endoskeleton, which often takes the form of spines or plates. They also exhibit a system of water vascular canals that helps with locomotion, feeding, and respiration.
Hemichordata, on the other hand, consists of a small group of worm-like marine animals called acorn worms or graptolites. They possess a distinct structure called a proboscis, which can be used for feeding and respiration. Hemichordates also have a segmented body, a nerve cord, and a pharynx with gill slits.
Both Echinodermata and Hemichordata are deuterostomes, meaning that during embryonic development, the first opening that forms becomes the anus, while the second opening becomes the mouth.
The term "ambulacraria" derives from the Latin words "ambulacrum" (meaning "walkway" or "way of walking") and "aria" (meaning "related to" or "pertaining to"). It refers to the presence of ambulacral systems in these organisms, which are responsible for important biological functions such as movement and feeding.
Etymology of AMBULACRARIA
The etymology of the word "ambulacraria" can be traced back to two Latin words: "ambulacrum" and "aria".
The word "ambulacrum" originally referred to a walkway or a path for walking in Latin. In biology, it was later used to describe the grooved or tube-like structure found in certain animals, such as echinoderms, which functions in locomotion and feeding.
The suffix "aria" is derived from the Latin suffix "-arius", meaning "pertaining to" or "related to".
Therefore, when combined, "ambulacraria" refers to a taxonomic group that includes echinoderms and hemichordates, two types of marine invertebrate animals. The word highlights their shared ambulacral systems, which are important for movement and other functions in these organisms.
