Question

Bath sponge Euspongia, has an endoskeleton of

• A. Calcareous spicules
• B. Siliceous spicules
• C. Spongin fibres
• D. Both A and B

Answer 1

Answer: (C)

Spongin fibres

A. Calcareous spicules are made up of calcium carbonate and are present in endoskeleton of sponges belonging to class Calcarea.

B. Siliceous spicules are made up of silica and are present in endoskeleton of sponges belonging to class Hexactinllida and some sponges of class Demospongiae.

C. Spongin fibres are present in the skeleton of sponges belonging to class Demospongiae

Euspongia belong to the class Demospongiae and hence, it has an endoskeleton of spongin fibres.

So, the correct answer is 'Spongin fibres'.