Notes from NEET topper
Class – Cyclostomata
The members of the Cyclostomata class are notable for their unique characteristics and parasitic lifestyle. These organisms are ectoparasites that attach themselves to specific fish species. They exhibit the following distinctive traits:
Body Shape: Cyclostomata organisms have elongated bodies.
Respiration: They possess 6-15 pairs of gill slits, which they use for breathing.
Mouth Structure: Unlike most other creatures, Cyclostomata have a specialized circular mouth without jaws.
Body Features: These organisms lack scales and paired fins.
Skeletal Structure: Their cranium (skull) and vertebral column (backbone) are made of cartilage rather than bone.
Circulatory System: Cyclostomata have a closed circulatory system.
Habitat and Reproduction: While they primarily inhabit marine environments, Cyclostomata migrate to freshwater for spawning. Following reproduction, they typically have a short lifespan, with their larvae undergoing metamorphosis and returning to the ocean.
