There are two common definitions of urchins. An urchin may be a sea urchin, a small prickly animal or to a street urchin or homeless child living on the street.
Sea Urchins have spikes are soft and chalk like , or they can be , hard and covered by a shell-like structure . There are more than 200 types of Sea Urchins , there are many different sizes and shapes of Sea Urchins species.
200 types
Sea star or starfish (Asteroidea)Brittle stars, basket stars, serpent stars (Ophiuroidea)Sea urchins, heart urchins and sanddollars (Echinoidea)Holothurians or sea cucumbers (Holothuroidea)Feather stars and sea lilies (Crinoidea).
You are probably looking for the different TYPES of echinoderms, they are listed below. * Sea Star (starfish they are also called) * Brittle stars * Sea Urchins * Sea Cucumbers * Sand Dollars
Well there are a couple of types like the sea turtle, they eat kelp. So do sea urchins.
Yes, there are also sea cucumbers and crinoids.
sea anemones have stinging tentacles, and sea urchins have spines.
You can't really answer this question because sea urchins have different masses depending on their size. For example, a small sea urchin will have a smaller mass than a big sea urchin.
More sea urchins.
No. Sea urchins live in the sea.
the three germ layers on a squid are the ectoderm, endoderm and mesoderm
Well, honey, cicadas and sea urchins both have support systems, but they're as different as night and day. Cicadas rely on their exoskeleton for structure and protection, while sea urchins have an endoskeleton made of calcium carbonate plates. So, in a nutshell, cicadas wear their support on the outside, while sea urchins keep it all on the inside.