Scale: a small, flattened, rigid, and definitely circumscribed plate forming part of the external body covering a fish. Scales occur in various shapes and with various compositions. Scale count often used in fish taxonomy. Also part of the common name of the Scale-rayed wrasse, Acantholabrus palloni, family Labridae.
Scaled: with scales.
Scaleless: without scales. Also part of the common name of the Scaleless dragon fishes, family Melanostomiidae.
Alternative forms for scale : scaled, scaleless, scaly.