Question

In canal system of porifera, the pathway of water flow is

• A. Ostia $\to$ Spongocoel $\to$ Osculum $\to$ Exterior
• B. Spongocoel $\to$ Ostia $\to$ Osculum $\to$ Exterior
• C. Osculum $\to$ Spongocoel $\to$ Ostia $\to$ Exterior
• D. Osculum $\to$ Ostia $\to$ Spongocoel $\to$ Exterior

Answer 1

The correct option is A Ostia $\to$ Spongocoel $\to$ Osculum $\to$ Exterior

• Ostia are the inhalant pores in sponges through which water enters the body.
• Osculum are the exhalent pores in sponges through which water flows out of the body.
• Spongocoel is the central cavity in the body of sponges which opens to outside through osculum.

Water enters the body of sponges through ostia and reaches spongocoel. From spongocoel, water flows out of body to the exterior through osculum.

Hence, in canal system of porifera, the pathway of water flow is :

Ostia, Spongocoel, Osculum, Exterior

So, the correct answer is 'Ostia →→ Spongocoel →→ Osculum →→ Exterior'.