Comments
i) Cycloid scales are found in teleast and dipnoi.
ii) These are soft and dermal plates.
iii) Each cycloid scale is roughly circular & flattened.
iv) Each scale is composed of a central nucleus and numerous lines of growth.
v) The free or anterior border is more or less rounded and remains exposed.
vi) The posterior part of the scale is having numerous longitudinal grooves for sucking the nourishment from the skin.
vii) Pulp cavity and dentine are entirely absent.
viii) Cycloid scales are derivatives of the ganoid scales in which ganoin and cosmine layers and bone cells are lost.
