Question

what is the class that comprises 76% of the species in phylum porifera? gastropoda demosponge hexactinellid

Explanation:

Gastropoda is a class in the phylum Mollusca, not Porifera. Hexactinellid (glass sponges) is a class in Porifera but only makes up a small percentage. Demosponge is the largest class in Porifera, comprising about 76% of sponge species.

Answer:

Demosponge