Jawless Fish: Petromyzon and Myxine — NEET Biology
✅ Asked in NEET 2026Researchers found fish-like animals with cartilaginous endoskeleton, ectoparasitic with circular sucking mouth, no paired fins/scales, and 7 pairs of gill slits. Which species fits best?
Researchers found fish-like animals with cartilaginous endoskeleton, ectoparasitic with circular sucking mouth, no paired fins/scales, and 7 pairs of gill slits. Which species fits best?
Answer & NCERT explanation
Correct answer: B — Petromyzon sp.
These features describe Cyclostomata. Petromyzon (lamprey) has a cartilaginous skeleton, circular sucking mouth, ectoparasitic life on fish, no scales/paired fins and 6-15 pairs of gill slits.
Read more NCERT concept on the PYQ
Examples: Petromyzon (Lamprey) and Myxine (Hagfish).
NTA tests your ability to classify jawless fish (agnathans) and identify their key characteristics, particularly Petromyzon (lamprey) and Myxine (hagfish). Students often confuse these primitive vertebrates with other fish groups, mistaking them for cartilaginous or bony fish, or failing to recall their distinctive features like the circular mouth, absence of jaws, and notochord instead of a true vertebral column. Remember: Petromyzon and Myxine are cyclostomes—the most primitive living vertebrates without paired fins or jaws. Focus on their unique adaptations like the sucker-like mouth for parasitic feeding (lamprey) to secure full marks on classification questions.
What does NCERT say about Examples Petromyzon Lamprey and?
Has this concept appeared in NEET?
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Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
88/90MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.