How many pairs of gill slits do members of the class Cyclostomata have?

Step-by-step solution

The members of subphylum Vertebrata possess notochord during the embryonic period. The notochord is replaced by a cartilaginous or bony vertebral column in the adultVertebrates have a ventral muscular heart with two, three or four chambers, kidneys for excretion and osmoregulation and paired appendages which may be fins or limbs.All living members of the class Cyclostomata are ectoparasites on some fishes.Cyclostomes have a sucking and circular mouth without jaws. Cyclostomes have an elongated body bearing 6-15 pai