A starfish.
or sex fish
starfish
The scientific name of a cushion starfish is Culcita novaeguineae.
alge.
Yhe common name for sea anemone is actiniaria
Thromidia catalai is the heavyest known sea star (although other sea stars can grown larger in terms of diameter/arm span.It weighs over 6kg, and can have a span of up to 63cm.It has no common name, but due to its appearance, it is often nicknamed "fat star".
The name of the sea star that has many legs is the sun star. The sun star can have up to 40 arms.
a starfish
Star of the sea
sea star
That is its common name. ( =P )The scientific name for leafy sea dragons is "Phycodurus Eques"
it really depends on the type of sea star you are wanting to know about. Common ones are about the size of your hand and are fairly light.
Um...brittle star?