Question

The characteristic features of family Notocotylidae are
(A) Flukes have no ventral sucker
(B) Flukes have ventral sucker
(C) Eggs of flukes have filaments at both ends
(D) Ovary is always pre-testicular
Choose the correct answer from the options given below:

• A. (A), (C) and (D) only.
• B. (B) and (D) only.
• C. (A) and (C) only.
• D. (B), (C) and (D) only.

Hint:

"Monostome" means "single mouth/sucker". Because Notocotylids are monostomes, they lack a ventral sucker (A is correct, B is incorrect). Eliminating B immediately narrows down the options.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The family Notocotylidae includes monostome trematodes (flukes) that primarily parasitize the cecum and large intestine of waterfowl, other birds, and some mammals.
Detailed Explanation:
Let us evaluate the morphological features of Notocotylid flukes:
- (A) Flukes have no ventral sucker: Correct. Notocotylids are "monostome" flukes, meaning they possess an oral sucker but lack a ventral sucker (acetabulum). Thus, statement (A) is correct, and statement (B) is incorrect.
- (C) Eggs of flukes have filaments at both ends: Correct. The eggs of Notocotylid flukes possess long polar filaments at both ends, which is a characteristic diagnostic feature. Thus, statement (C) is correct.
- (D) Ovary is always pre-testicular: Incorrect. In Notocotylids, the testes are situated at the extreme posterior end of the body, and the ovary is located symmetrically between the two testes (intertesticular position), not anterior to them (pre-testicular). Thus, statement (D) is incorrect.
Therefore, the correct features are (A) and (C).

Step 2: Final Answer:
The correct combination is (A) and (C) only, which corresponds to Option (C).