Identify the incorrect statement regarding bony fishes:
I: They have four pairs of gills which are covered by an operculum on each side.
II: Due to the absence of air bladder, they have to swim constantly to avoid sinking.
III: Skin is covered with placoid scales.
IV: Mouth is mostly terminal.
 
1. Only II 2. Only II and III
3. Only I and IV 4. Only IV
Subtopic:  Comparative study of Cartilagenous & Bony Fishes | Class Osteichthyes |
 62%
Level 2: 60%+
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