[1][2] The eyes of both the Lutino and Albino are red at all ages with white irides when adult, the beak is orange and the feet and legs are pink.
The Ino gene masks the effect of virtually all other mutations, including Opaline, Dark, Dominant Grey, Dilute, and Clearwing.
[3] A Cinnamon Ino, usually called a Lacewing, has pale brown or fawn spots, tail and wing markings.
The Dark-eyed Clear has a similar body colour to the Ino, but has solid reddish-purple eyes without a white iris.
The first known reference to the Ino mutation in the budgerigar was a report by Mr L van der Snickt, a Belgian fancier, in the German avicultural paper Die Gefiederte Welt (The Feathered World) in 1879[full citation?].
In 1930/31, Lutino hens were owned by both Capt H S Stokes of Longdon, near Rugeley in Staffordshire, and Mrs Huntington of Warwick.
In September 1931, Mr E Böhm of Bawerk in Germany bred,[4] as the last of nine young from a pair of Cobalt[7] split Dilutes,[8] a snow-white red-eyed hen[9]—the first recorded Albino.
Both of these strains were established by the original breeders and also by others who acquired early stock from them, in particular by Kurt Kokemüller of Arnum über Hanover, and Mr Schrapel, also of Hanover, who performed together the first genetic investigations[5] into the Ino mutation and published the first correct pairing expectations in the German publication Der Wellensittich (The Budgerigar) in November and December 1933.
[8] A third appearance of the Ino mutation occurred in Germany around 1933, when Mr Kuhlewein bred a Lutino[4] hen in an uncontrolled breeding flight.
Other Ino mutations also appeared in Europe in the early 1930s, and several British fanciers, including Walter Higham,[4] Scott and Camplin, and Tod Boyd, had imported continental Lutinos by the mid-1930s.
Its effect is to inhibit the production of the melanin pigment which is normally present in all feather barbs in either the medullary or cortical cells or both.
This is called epistasis, and Ino is phenotypically epistatic over many other mutations, including Dark, Grey, Opaline, and the Dilute series.
The linkage between the Cinnamon and Ino genes gives rise to two types of split cinnamon-ino cocks, both visually identical.