INVERTEBRATE ZOOLOGY - H. I. Shcherbak - 2008

KINGDOM MULTICELLULAR ANIMALS (METAZOA)

SUBKINGDOM TRUE MULTICELLULAR ANIMALS (EUMETAZOA)

SECTION TRIPLOBLASTIC (TRIPLOBLASTICA) OR BILATERAL (BILATERIA) ANIMALS

SUBSECTION DEUTEROSTOMIA

PHYLUM ECHINODERMATA

CLASS BRITTLE STARS OR SERPENT STARS (OPHIUROIDEA)

SUBCLASS REGULAR SEA URCHINS (REGULARIA)

This subclass includes sea urchins that exhibit the diagnostic Features of the entire Class. Radial Symmetry predominates in their body plan, which is spherical to slightly flattened. The Mouth is located at the oral pole, and the anus is at the aboral pole. The subclass comprises the majority of modern, highly widespread species. One of the best-known families is Strongylocentrotidae, the roe of many species of which is edible.

Certain littoral species of sea urchins belonging to the family Echinometridae cause considerable damage to port infrastructure. For instance, the purple sea urchin (Strongyla centrotus purpuratus) of the Indian and Pacific Oceans, covered with numerous stout purple spines, bores depressions into steel pilings using them. Among the family Toxopneustidae, there are edible species as well as venomous ones, the toxin of which is dangerous to humans. A puncture from a single spine of Toxopneustes pileolus can induce temporary paralysis throughout almost the entire body.