Why are cirrus cumulus cloud sometimes called mackerel clouds?

Cirrus cumulus clouds are sometimes called "mackerel clouds" due to their resemblance to the scales of a mackerel fish. This name is derived from the cloud's appearance, which features a pattern of rippling, wavy formations that mimic the texture and coloration of mackerel. The term reflects both the visual characteristics of the clouds and their often-significant presence in the sky, signalling changes in weather.