Cycloid and Ctenoid Scales | 水產百科網

Cycloidscaleshaveasmoothposteriormarginlackingctenii.Theword'cycloid'comesfromtheGreekcyclo,meaningcircle.Cycloidandctenoidscalesconsistof ...

Ctenoid scales have a variously developed spiny posterior margin (the word ctenoid comes from the Greek cteno, meaning comb, and refers to the comb-like ctenii on the margin of the scale).

Many authors feel that lumping all scales with a spiny posterior margin under the term ctenoid is an oversimplification. Three types of ctenoid scales are recognised; crenate, with simple indentations in the margin, spinoid, with developed spines that are continuous with the main body of the scale, and ctenoid, in which the ctenii are formed as separate bony growths which are distinct from the main body of the scale.

Cycloid scales have a smooth posterior margin lacking ctenii. The word cycloid comes from the Greek cyclo, meaning circle.

Cycloid and ctenoid scales consist of two main regions, a surface bony layer, composed of an organic framework impregnated largely with calcium based...