calcareous ring

zoology

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June 22, 2026

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The calcareous ring is a skeletal structure found in holothurians, which are a type of echinoderm. This ring is composed of plates and surrounds the esophagus, the tube connecting the mouth to the stomach. Unlike the Aristotle's lantern in echinoids, the calcareous ring in holothurians does not function as a feeding apparatus. Instead, it serves as an attachment point for muscles. Echinoderms, in general, possess a skeleton made of calcium carbonate ossicles, which can form various structures like tests, spines, and vertebrae, providing armor and support.123

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echinoderm
Skeleton
…ring of plates, called the calcareous ring, surrounds the tube leading from the mouth to the stomach (i.e., the esophagus) of holothurians. Although located in a similar position to that of the echinoid Aristotle’s lantern, the calcareous ring functions as a point of insertion for muscles, not as a feeding…
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…ring of plates, called the calcareous ring, surrounds the tube leading from the mouth to the stomach (i.e., the esophagus) of holothurians. Although located in a similar position to that of the echinoid Aristotle’s lantern, the calcareous ring functions as a point of insertion for muscles, not as a feeding…
Read More