Question

An example of the class Hexactinellida is
A) Spongilla
B) Euplectella
C) Grantia
D) Leucosolenia

Answer 1

Hint:The class Hexactinellida belongs to Phylum Porifera. The most famous glass sponge belongs to the class Hexactinellida.

Complete answer:
The four organisms mentioned above belong to kingdom Animalia. For this question, the first thing we will do is we will find the phylum and class to which these organisms belong to.
Option A: Spongilla is a freshwater sponge belonging to the class Demospongiae of Phylum Porifera. Therefore, this is an incorrect option.
Option B: Euplectella is classified under class Hexactinellida of Phylum Porifera, as Euplectella possess six-rayed triaxon spicules which is a characteristic of sponges belonging to the class Hexactinellida. Therefore, this is the correct option.
The biological classification of Euplectella is Kingdom: Animalia, Phylum: Porifera, Class: Hexactinellida, Order: Lyssacinosida, Family: Euplectillidae, Genus: Euplectella.
Euplectella is a glass sponge, found in the deep ocean and provides home for certain crustaceans. The skeleton of Euplectella is composed of triaxon spicules, which give rise to glassy appearance to the sponge.
Option C According to the biological classification, Grantia belongs to the class Calcarea of Phylum Porifera. Hence, this is an incorrect option.
Option D: Leucosolenia is a colonial marine sponge, belonging to the class Calcarea of Phylum Porifera. Hence, this is an incorrect option.

Therefore, the correct option is (D) Euplectella.

Note: The characteristics of hexactinellida are,
- They are deep sea sponges and lack epidermal covering.
- Their skin is made up of spicules of silica.
- Instead of epidermal covering they are covered with amoebocytes.