Purple Sea Urchin

Purple Sea Urchin

Arbacia punctulata

Size: to 3"

Sea Urchins may be found on any solid structure, from tidal rocks to deep wrecks, although in our region they are more common in shallow estuarine waters than offshore.

This animal is related to the starfish, and shares many of its traits, with one exception. Starfish are predators, feeding upon clams and mussels, while these sea urchins are strict vegetarians. I once ordered Sea Urchin at a sushi bar, but I never even tasted it, it smelled so bad. Nonetheless, it is a delicacy in much of the far east. Unlike tropical black urchins, our northern ones are not poisonous, and the spines are not even particularly sharp.

Sea urchin anatomy
Sea urchin anatomy
Purple Sea Urchin
Purple Sea Urchin obverse
The underside, showing mouth, tube feet among the spines, and 5-way symmetry
Herb Segars Photography

Mermaid's Purse

The Mermaid's Purse is not an invertebrate at all - it is a fish egg capsule. The egg capsule of a skate or ray, to be precise. The "horns" are to secure the capsule in seaweed. You may find one with a baby skate growing inside, but most are empty. They are included here with bivalves because they are often found scattered around the bottom like shells, up to 3" long. They certainly don't look like fish!

Printed from njscuba.net