Sea urchins are members of the phylum Echinodermata, which also includes starfish, sea cucumbers, sand dollars, brittle stars, and crinoids. Like other echinoderms, they have five-fold symmetry (called pentamerism) and move by means of …

Sea urchin, any of about 950 living species of spiny marine invertebrate animals (class Echinoidea, phylum Echinodermata) with a globular body and a radial arrangement of organs, shown by five bands of pores running from mouth to anus over the test (internal skeleton).

What is a sea urchin? Sea urchins belong to a group of marine invertebrates called Echinodermata, which means spiky-skinned. Animals in this group are known as echinoderms and include sea cucumbers, sea lilies, brittle stars and starfish, otherwise known as sea stars. Sea urchins can be found in all of Earth’s oceans.

These spiky little sea creatures are incredibly common throughout the world. They are slow moving creatures, which are commonly found in the intertidal zones of rocky shorelines. Sea urchins have a number of surprising traits to help keep them alive. Read on …

2020年7月29日 · There are more than 900 species of sea urchins around the world from the shallows to the deep sea. Urchins live at depths of more than 24,000 feet. Hidden beneath their spines they have a hard, outer skeleton called a test.

2025年1月11日 · Sea urchins, or simply urchins, are globular echinoderms of the phylum Echinodermata (consisting of starfish, sea cucumbers, sand dollars, brittle stars, and crinoids), forming the class Echinoidea. These animals begin their life as bilaterally symmetrical larvae but develop into adults with pentamerous or five-fold symmetry.

The sea urchin is a small, spiny little sea creature called an echinoderm, part of the class Echinoidea, of which there are more than 940 species worldwide.

2015年8月22日 · 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" and derma meaning "skin"). There are more than 900 species of sea urchins and they come in a range of colors including purple, blue, brown, green, and red.

Sea urchins, particularly the well-studied purple sea urchin (Strongylocentrotus purpuratus), play a pivotal role in marine ecosystems by controlling algal growth and serving as prey for various predators. This article looks at some key features and …

Sea urchins are globular, spiny sea creatures that make up the class Echinoidea. There are around 950 species of sea urchin, and they inhabit the seabed of every ocean and every depth zone, from the tide line to 15,000 feet deep.