What are the cyclostomes?
Q: What are the cyclostomes?
A: The cyclostomes are the lamprey and hagfish, which are the only two living jawless fish known as Agnatha.
Q: What recent data shows about living agnathans?
A: Recent molecular data from rRNA and mtDNA reveal that these living agnathans are monophyletic.
Q: How many species of cyclostomes are there?
A: There are about 100 species of cyclostomes.
Q: Are hagfish vertebrates?
A: Yes, hagfish are vertebrates.
Q: Do hagfish possess vertebrae?
A: No, hagfish do not have vertebrae.
Q: How did hagfish lose their vertebrae?
A: It is believed that hagfish lost their vertebrae as a result of their lifestyle adaptations.
Q: Why are cyclostomes called "round mouths"?
A: Cyclostomata means "round mouths" because their mouths cannot close due to the lack of a jaw, so they have to constantly cycle water through the mouth.
