2015年8月22日 · Sea Urchin Anatomy. One look at a sea urchin and you can see why they would be called sea hedgehogs. 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").

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 …

2025年1月9日 · 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).

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.

Sea urchins control their tube feet via their water vascular systems. Tube feet exist on the outside of the sea urchin, and are how sea urchins grab and bring food towards their mouth, and move along the sea floor. The ring canal is central to this system, with five radial canals branching out from this central piece along inside of the test ...

2023年5月11日 · Each part of the sea urchin’s anatomy plays a crucial role in its survival, locomotion, feeding, and reproduction. The combination of these specialized structures allows sea urchins to adapt and thrive in various marine environments.

In this article we will discuss about the structure of Sea Urchin (Echinus) with the help of a diagram. 1. It is commonly known as “sea urchin” and is formed in shallow water in both rocky and sandy place in sea. 2. Body is Sub-globular and convex or dome-shaped above and flattened below. The aboral and oral surfaces are distinct.

Click on the urchin to see inside. Click again for outside. Problems with this site? Click here.

2008年7月23日 · Sea urchins are spherical, oval or flattened free-moving echinoderms covered with spines. Their soft tissue anatomy is characterized by a dominant digestive tract, a varying number of gonads, and the highly specialized water vascular system with its external appendages, the tube or ambulacral feet.

Black sea urchins (Echinometra lucunter). Below: spinesin the feet of bathers. Right: hyperkeratotic noduleson the hands of a diver who suffered several injuries caused by black sea urchins (foreign body granuloma). Attempts to remove spines are often futile due to their fragile and friable nature. ↑ Auerbach P. Chapter 73.