About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal zone to deep seas of 5,000 m (16,000 ft). [1] . They typically have a globular body covered by a spiny …

Sep 4, 2025 · A sea urchin’s body is covered by a rigid shell or test comprising fused plates of calcium carbonate. It is formed internally beneath a thin epidermis, followed by a dermis and a thin layer of …

Sea urchin shells serve several crucial purposes in their survival and adaptation to their marine environments. The primary function of sea urchin shells is protection. The hard, calcareous structure …

Aug 22, 2015 · They have hard rounded shells covered with sharp movable spines. Urchins are part of the phylum Echinoderm and their name comes from Ancient Greek (echinos meaning "hedgehog" …

Apr 1, 2025 · 25 Types of sea urchins. Did you know that there are more than 950 species of sea urchin? Sea urchins can be regular or irregular. We look at some of the most common sea urchin …

Dec 3, 2025 · Lytechinus variegatus, a pale-greenish urchin of the southeastern coast of the United States and the Caribbean, and the large, short-spined Psammechinus (sometimes Echinus) miliaris …

Sea urchins tend to be small, globular, and have their soft internal organs protected by a hard, internal, calcite shell, or test, made of plates (calcitic ossicles) fitting closely together and located under the …

Aug 12, 2024 · Learn about the unique features and functions of sea urchin shells, including their porous calcium carbonate secretion, spiral pattern formation, and flexible yet robust composition.

Jun 22, 2020 · The sea urchin is able to protect itself in the harsh underwater environment due to the shape of its shell and its interlocking plates. The shell is stronger than expected due to its ability to …

Shop real Sea Urchin shells, sustainably collected from Maine. Each unique shell is perfect for beach crafts, weddings, coastal décor, and DIY art projects.