nope.
Some bivalves have bilateral symmetry but
no radial symmetry.
No, They are bilaterally symmetrical. Radially symmetrical animals include echinoderms (starfish, sea stars, sea urchins) and many plants.
Cnidaria (Hydra, jellyfish, sea anemones, corals, etc.), generally have radial symmetry, although not all sea anemones or corals do. Echinodermata (sea stars, sea urchins, crinoids, sea cucumbers, etc.) are radially symmetrical as adults, but not as larvae.
Mollusk have bilateral symmetry
Polyps are radially symmetrical.
Brain corals are hemispherical or spherical in shape resembling a brain. They must me radially symmetrical organism.
Hydra are symmetrical radially from the top
bilateral symmetry
Most annelids are essentially tubes so they are radially symmetric.
All mollusks exhibit bilateral symmetry, meaning their body can be divided into two mirror-image halves along one plane. While some mollusks, such as bivalves, have hinged shells, this trait is not universal among all mollusks. Radial symmetry and the ability to swim are also not characteristics found in all mollusks. Thus, bilateral symmetry is the defining feature present in all members of this diverse phylum.
Some well known gastropods, which are mollusks, are snails and slugs, and they exhibit what is known as BILATERAL SYMMETRY. The only other kind of symmetry that exists in the animal kingdom, with the exception of colonial species such as the sponge, is RADIAL SYMMETRY. This second type is exhibited by starfish, for example. Cephalopods, another type of mollusk, may appear to be radially symmetric, but are actually bilaterally symmetric due to the composition of their cephalic (head) region.
They both have a true coelom and bilateral symmetry.
Yes. Crabs and other crustaceans have bilateral symmetry. Bilateral symmetry means something has symmetry across one plane (known as the sagittal plane, and directly down the centre of their body), which means one side of their body approximately mirrors the other side.