Cubozoans, are marvelous animals. They look like basic jellyfish, but they can swim really fast,glide around barriers, and see fairly well considering they do not have a brain. Cubozoans have a square shape when viewed from above, which is how they got their name. They have four evenly spaced out tentacles or bunches of tentacles and well -developed eyes. They have a large range of eyesight. Not suprisingly, giving their squishy figure, there are not many fossil cubozoans known. Today there are about 20 known species found in tropical and semitropical waters. They are umbrella shaped rather than domed or crowned-shaped. The underside of the umbrella includes a flap, concentrating and increasing the flow of water expelled from the umbrella. As a result, cubozoans move more rapidly than other jellyfish.
Cubozoans tentacles are huge, in fact some range to 8-10 ft. Their tentacles are very important to them, as they protect them from danger and help them catch prey.
Hydrozoans have two body forms. One is the medusa , a
jelly-like, umbrella-shaped, freely swimming form with a mouth and tentacles
that face down. The other is a colony of polyps or tube-shaped
sacs that have a mouth and tentacles that face up. The polyp form is fixed to
the material on which it lives. Most hydroids have both a medusa and a polyp
Medusae have a typical and
easily recognizable body shape. The shape of polyps ranges from giant
coral-like colonies through feathers and flowers to microscopic balls of
tissue. The medusae and polyps of
most hydroids are clear. Among colored species, the color often comes
from the food the hydroids eat. The most common color is red from crustaceans, which are water-dwelling animals, such as shrimp, that have
jointed legs and a hard shell but no backbone.