Question

Select the set of fishes which belong to the class Osteichthyes :

• A. Saw fish, Fighting fish and Dog fish
• B. Devil fish, Cuttlefish and Hagfish
• C. Flying fish, Angel fish and Fighting fish
• D. Starfish, Hagfish and Cuttlefish

Hint:

Logic Tip: Beware of "fake" fishes! Starfish (Echinoderm), Jellyfish (Cnidarian), Cuttlefish (Mollusc), and Devil fish (Mollusc) are all invertebrates. Seeing any of these immediately disqualifies the option!

Answer 1

The Correct Option is C

Step 1 : Understanding the Question:
This question requires us to identify a group where all members belong to the class Osteichthyes, which are the bony fishes. This involves distinguishing them from cartilaginous fishes (Chondrichthyes) and other marine organisms that are not true fishes.
Step 2 : Key Formulas and Approach:
1. Osteichthyes: Vertebrates with bony skeletons, terminal mouths, and opercula (e.g., Exocoetus, Betta).
2. Chondrichthyes: Vertebrates with cartilaginous skeletons and ventral mouths (e.g., sharks, saw fish).
3. Non-fishes: Invertebrates like Starfish (Echinoderms) or Devil fish (Molluscs) that have "fish" in their common name.
Step 3 : Detailed Explanation:

Evaluating Option (A): Saw fish ({Pristis}) and Dog fish ({Scoliodon}) are cartilaginous fishes (Chondrichthyes). Only Fighting fish is bony. This set is incorrect.

Evaluating Option (B): Devil fish ({Octopus}) and Cuttlefish ({Sepia}) are molluscs. Hagfish ({Myxine}) is a cyclostome. None are bony fish. This set is incorrect.

Evaluating Option (D): Starfish is an echinoderm. Hagfish is a cyclostome. Cuttlefish is a mollusc. This set is incorrect.

Evaluating Option (C):
Flying fish ({Exocoetus}): Marine bony fish.

Angel fish ({Pterophyllum}): Bony fish commonly found in aquariums.

Fighting fish ({Betta}): Freshwater bony fish.

All three are true bony fishes.

Step 4 : Final Answer:
The set containing only bony fishes (Osteichthyes) is Flying fish, Angel fish, and Fighting fish. This matches option (C).