Spinal curvature is caused by:

Correct option is B

Correct Answer: (b) Myxobolus cerebralis
Explanation:
→ M. cerebralis infects cartilage of juvenile salmonids, causing skeletal deformities including spinal curvature.
→ Disease is known as whirling disease.
Information Booster:
→ Affected fish show erratic swimming and tail-chasing (“whirling”).
→ Parasite transmitted by tubificid worms.
→ Major threat to trout fisheries.
Additional Information: Other parasites listed do not cause spinal deformities.