Halfblack Locus
Non-wild alleles at this locus:
Halfblack (h)
Possible
phenotypes:
Halfblack (h/h)
Halfblack (h/h)
Halfblack is a
recessive gene and does not affect the phenotype when in single dose
(h/+). In double dose however, the rear portion of the fish, from the last
body stripe to the tip of the tail is black, the fins (or the rear portion
of them) are also black. Expression of Halfblack is very sensitive to
environmental conditions. Requirements for the pattern expression have not
been totally worked out and documented, though lighting intensity and
duration, water volume per fish, food and frequency, have all shown to
play a large part in getting fry to eventually "turn".
Some people
have reported better success with expression of Halfblack when using dark
colored gravel or a dark painted tank bottom.
As a result fry
from a Halfblack pair do not always express the phenotype even though they
carry the mutation. Furthermore it is possible to get expressing Halfblack
fry from non-expressing Halfblack parents.
Links to more information about the Halfblack allele
Dr. Joanne Norton, FAMA: August 1985, Vol.8, #8
Dr. Joanne Norton, FAMA: May 1989, Vol.12, #5
Dr. Joanne Norton, FAMA: December 1993, Vol. 16, #12
Approved by The Angelfish Society
Standards Committee on February 11, 2007.
W
