Answer:
demospongi and sclerospongi are two classes of sponge
Explanation:
Sponges have/are:
Body with cells arranged around pores, canals and chambers for the passage of water.
Skeletal structure of spicules and/or spongin.
All aquatic, mainly marine.
Filter feeders.
Sessile adults; sessile, planktonic larvae.
Sexual and asexual reproduction.
Gas exchange is by diffusion.
