Question

Presence of pedicellariae is the characteristic of
A. Hydrozoa
B. Asteroidea
C. Crustacea
D. Cephalopoda

Answer 1

Sea star belongs to this class whose phylum is Echinodermata. Seastar, sea urchin, etc. are examples of this class.

Complete answer:
A pedicellaria is a small clamp or claw-shaped accessory, typically used on echinoderms in marine stars and marine urchins. Each pedicelli is an efficient organ, which is capable of reflecting on the environment and which has its own set of muscles, neuropils and sensory receptors. In sea stars, there are two main types of pedicellaria. They are straight and crossed. Straight pedicellariae are generally larger and are on the face of the body, while crossed pedicellariae are smaller and more often found on branches raised above the surface of the body or in clumps around the spines. The crossed type with an elastic ligament connects to the test.
Sea Star pedicellariae may either be located on the surface of the test or attached to flexible stalks. Depending on the species, the spine, in pits on abactinal, marginal or actinal surfaces on the surface of the animal's body or inside of the ambulacral tubular foot furrow may be surrounded by pedicellariae. The sea star belongs to the phylum Echinodermata and the class Asteroidea. Therefore, the presence of pedicellariae is the characteristic feature of Asteroidea.

Thus, the correct answer is option B. i.e., Asteroidea.

Note: Pedicellariae are modified spines which have a pincer-like structure at one end. Pedicellariae are one of several specific minute organs, which resemble forceps which are carried in large numbers on the external integument of the sea urchins and starfish and also often on the dorsal spines of the marine urchins.