Q.110) All living members of the class Cyclostomata are:
A) Ectoparasite
B) Free living
C) Endoparasite
D) Symbiotic
Q.110) Cyclostomes, such as lampreys and hagfishes, are jawless vertebrates. All living members of this class are ectoparasites on some fish. They attach to the host's body and suck blood and body fluids using their circular, sucker-like mouth.
Hence, the correct answer is Option (1).