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Reprinted with
permission from:
Dr. Joanne Norton
Freshwater And Marine Aquarium magazine
Angelfish Genetics
Photos and Text by Dr. Joanne
Norton
FAMA: August 1982, Vol. 5, #8
Part Four
Parts
One,
Two and
Three of this series covered the inheritance of the
mutant genes affecting color of angelfish. In this article
I shall discuss combinations of zebra and dark with other
genes.
Zebra is the only gene investigated that
looks the same in single and double dose. Hong Kong gold
and new gold are recessive genes, producing gold angelfish
on in double dose. Smokey in double dose results in
chocolate. Dark makes black lace in single dose, black in
double dose. Double-dose marble in most cases has more
black than single-dose marble. Stripeless in single dose
removes the body stripes; in double dose it also decreases
iridescence, resulting in blushing.
A pair of zebra angelfish produced 62
wild-type and 158 zebra offspring. Thus, each of the
parents had one dose of zebra. A number of zebras were
runts while the wild-type offspring appeared more uniform
in size. I measured the total length of each of the
offspring at 51 days of age; the results are given in
Table 1. The percent of small zebras was higher than the
percent of small wild-type. For example, 67.2% of the
zebras were 27mm or less, while only 37.1% of the
wild-type were 27mm or less.
|
- |
- |
number
of wild type |
number
of zebras |
total
length
in
mm |
17
19
20
21
22
23
24
25
26
27
28
29
30
32
34
35 |
1
1
3
2
4
6
6
14
13
9
2
1 |
1
2
4
6
11
12
14
15
17
24
20
17
13
1
1 |
TABLE 1. Sizes of the offspring
of zebra parents
Since vigor is decreased by double doses
or dark, marble and stripeless, I suspected that
double-dose zebra decreases growth rate, resulting in the
higher incidence of runts in the zebra offspring compared
with their wild-type siblings. The obvious size difference
in the zebras can be seen in the photo of three young
zebras, two of which are runts. I selected ten of the
small zebras to raise to adults. When these reached
breeding age, I selected one male and one female to test
to find out whether they had one or two doses of zebra.
Each of these, when mated to wild-type, produced 100%
zebra offspring. The zebra male produced 695 zebra
offspring in two spawns. The zebra female produced a spawn
of 385 zebras. Thus, these zebra parents that were runts
as juveniles were double-dose zebras that were prolific.
They were about average-sized adults, the male being 4"
and the female 3 1/8" total length at one year.
Figure 1: Two double dose zebra (runts) and one
single dose zebra, age 51 days.
Zebra lace, which has one dose of dark
in addition to zebra, is a popular and commercially
important type of angelfish. Zebra lace parents produce a
very unsatisfactory spawn in which 7 out of 16 have
decreased growth rate and/or vigor because they have two
doses of one or both of the genes for dark and zebra. The
expected ratio in the offspring from zebra lace parents is
3 black zebra (1 or 2 doses of zebra plus 2 doses of
dark): 6 zebra lace (1 or 2 doses of zebra plus 1 dose of
dark): 3 zebra: 1 black (2 doses of dark): 2 black lace (1
dose of dark): 1 wild-type. Of the 6 zebra lace, 2 would
be double-dose zebras and, therefore, slow-growing. One
out of 3 of the zebras would be double-dose and,
therefore, slow growing. The 1 black and 3 black zebras
would also be slow-growing. Obviously, zebra lace
angelfish should not be produced commercially by using
zebra lace breeders. A much better cross is a double-dose
zebra female and a true black (two doses of dark) male,
which will produce 100% zebra lace offspring, with no
runts. True blacks can be obtained from black lace
parents, while double-dose zebras are the runts produced
by zebra parents.
An angelfish with one dose of zebra and
one dose of smokey looks like a zebra when very young.
Then the zebra pattern changes into the smokey pattern at
about four to six weeks after hatching. The adult zebra-smokey
looks essentially like a smokey but has spangles in the
dorsal and caudaul fins along with green on the body.
Figure 2: One dose of smokey and one dose of zebra.
Double-dose zebra with one dose of
smokey looks the same as single-dose zebra plus smokey. A
male zebra-smokey was found to be double-dose zebra by
mating him to a wild-type female. All of the offspring
were zebras when young, and about half of these developed
the smokey pattern.
An individual with marble and zebra
looks very much like a marble angelfish but, at maturity,
has spangles in the dorsal and caudal fins as well as
green color on the head.
Figure 3: One dose of marble and one dose of zebra.
Combinations of dark plus zebra, dark
plus marble, and dark plus new gold were discussed in
Part Three. Additional combinations of dark are:
- 2 doses of dark plus zebra: a black
fish with light spangles on the tail. This fish does not
grow well and is small as an adult.
Figure 4: Black zebra (zebra plus two doses of dark).
- 1 dose of dark and 1 dose of
stripeless: "butterfly," in which the dusky-colored body
is without stripes by may have one or more large dark
blotches. Adults have much green color. Addition of new
gold to butterfly darkens the color.
Figure 5: Butterfly Butterfly (one dose of dark and one
dose of stripeless).
- 1 dose of dark and 2 doses of
stripeless: "blue," having a dusky-colored body and,
when young, red gill areas. The adult had iridescent
areas on the fins and body, including the areas over the
gills, so the red gills do not show. Adults also have
green to turquoise on the head, dorsal fin and ventral
fins: thus, the adult is an attractive fish.
Figure 6: Juvenile Blue (one dose of dark and
two doses of stripeless).
Figure 7: Adult male blue (one dose of dark and
two doses of stripeless). Joanne Norton.
- 2 doses of dark and 2 doses of
stripeless: "purple," a dark fish without stripes and
with red gills showing in the juvenile. This fish is not
vigorous and is difficult to raise.
- 1 dose of dark and 1 dose of smokey:
a blotchy dark fish that is light-colored on the
anterior part of the body. The adult has turquoise on
the head and green on the upper part of the body.
Figure 8: One dose of dark and one dose of smokey.
Age 3 mo.
Figure 9: One dose of dark and one dose of smokey.
Mature male.
A fish with 1 dose of dark, 1 dose of
stripeless and 1 dose of zebra looks similar to a
butterfly angelfish but with more dark blotches on the
body. Also, an adult with these three genes has light
spangles in the dorsal, anal and caudal fins.
Figure 10: Juvenile (quarter body size) with one dose
each of dark, stripeless, and zebra.
Figure 11: Adult male with one dose each of dark,
stripeless, and zebra.
By using the proper types of parents you
can obtain 100% of some of the angelfish types. For the
types covered in this article, use the following crosses:
- To get 100% zebra, cross a
double-dose zebra with a wild-type (silver). Do not use
single-dose parents, which produce 25% wild-type and 75%
zebra in which one-third will be runts.
- To get 100% zebra lace, cross a
double-dose zebra female with a true black male. Do not
use zebra lace parents, which produce many types of
offspring, including many runts.
- To get 100% butterfly, cross a
blushing female with a true black male. Do not use
butterfly patents, which produce a ratio of 1 purple: 3
black: 3 butterfly: 3 blue: 2 stripeless: 2 black lace:
1 blushing: 1 wild-type. These would really keep you
busy sorting.
It is not possible to produce 100% blue
(1 dose of dark and 2 doses of stripeless) unless you are
able to raise and get spawns from a purple, which is
difficult. It is better to use blue parents, which produce
25% purple, 50% blue and 25% blushing. It is common for
many of the purples to die during the first week or two,
leaving in the spawn about two-thirds blue and one-third
blushing.
Angelfish Genetics: Part Five
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