Question

Paragastric cavity of sponges is lined by

• A. Amoebocytes
• B. Chromocytes
• C. Choanocytes
• D. Pinacocytes

Answer 1

Answer: (C)

Choanocytes

A. Amoebocytes are the cells that constitute the mesenchyme. Mesenchyme is the inter connecting proteinaceous gelatinous matrix in sponges. Major types of amoebocytes found moving in between thin layer are, Archaeocytes, Myocytes, Chromocytes, Thesocytes, Collencytes etc.

B. Chromocytes are the pigmented amoebocytes with lobose (thick, bulbous, blunt) pseudopodia.

C. Choanocytes, also called as collar cells, are the specialised flagellated cells that form the gastral epidermis of the inner layer of body wall in sponges. This inner layer is also called as choanoderm.

D. Pinacocytes are the flattened cells that form the dermal epidermis of outer layer of body wall of sponges. This outer layer is also called as pinacoderm.

Hence, paragastric cavity of sponges is lined by choanocytes.

So, the correct answer is 'Choanocytes'.