Question

Which of the following is the most complicated type of canal system which is absent in calcareous sponges?

• A. Euryphylous leuconoid type
• B. Aphodal leuconoid type
• C. Diplodal leuconoid type
• D. None of the above

Answer 1

The correct option is C Diplodal leuconoid type

The calcareous sponges are the smallest and simplest sponges and have radial symmetry. In the diplodal system, a narrow tube called prosodus, connects the incurrent channel and the flagellated chamber and there is also an aphodus connecting the chamber to the excurrent channel. The diplodal system is leuconoid and derived from a rhagon stage.
Thus, the correct answer is option A.