In which of the following fishes is diphycercal form of caudal fin present?

Correct option is A

Correct Answer: (a) Lung fish
Explanation:
→ Lungfishes possess a diphycercal caudal fin where the vertebral column extends straight into the middle of the fin, forming a single continuous lobe.
→ This fin type is primitive and typical of ancient fish groups.
→ It aids in slow, controlled swimming in heavily vegetated or stagnant waters.
Information Booster:
→ Diphycercal tails are also seen in some eel-like fishes and early fossil fishes.
→ Reflects evolutionary retention of ancestral fin morphology.
→ Lungfishes use this tail structure along with paired fins for maneuvering in low-oxygen habitats.
Additional Information (Other Options):
(b) Sturgeon – heterocercal caudal fin.
(c) Shark – heterocercal caudal fin.
(d) Flying fish – forked/lunate caudal fin for gliding.