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The first black angelfish were obtained from black lace
parents in the 1950s. These blacks, which I call "true black,"
have two doses of the genetic factor for dark, whereas black
lace have only one dose of dark. True blacks have faint vertical
body stripes, which can be seen by shining a flashlight at the
fish.
Fig. 1: Juvenile black having one dose of dark and one dose of marble.
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| Fig. 1: Juvenile black having one dose of dark and one dose of marble. |
It was not until the late 1960s, after the marble angelfish
became available, that another type of black angelfish was
possible. This black has one dose of dark and one dose of marble
(Norton, 1971). The black marbled pattern on a dark gray
background is evident in juveniles and can be detected in
strongly illuminated adults. The genetic factors for dark and
marble are alleles (Norton, 1982a).
The third type of black angelfish to appear is one that has
one dose of dark and one dose of "new gold," which is an allele
of dark and marble (Norton, 1982a). The genetic factor for "new
gold" which I shall refer to as "gold" in the rest of this
article, increases the expression of both dark and marble
(Norton, 1982a). A black angelfish having the dark-gold genetic
makeup has a somewhat brassy body color and fairly obvious
vertical stripes on the body.
Fig. 2: Juvenile black velvet (two doses of stripeless, one dose of dark, one dose of gold).
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| Fig. 2: Juvenile black velvet (two doses of stripeless, one dose of dark, one dose of gold). |
Fig. 3: Adult male blue angelfish (two doses of stripeless, one dose of dark). Black velvet is the same, with the addition of one dose of gold.
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| Fig. 3: Adult male blue angelfish (two doses of stripeless, one dose of dark). Black velvet is the same, with the addition of one dose of gold. |
The newest and best black angelfish, which I call "black
velvet," is the same, genetically, as the dark-gold type, but in
addition it is blushing. That is, it has two doses of stripeless
(making blushing) along with one dose of dark and one dose of
gold. Black velvet is the same genetically as "blue" with the
addition of one dose of gold. The black velvet angelfish is a
smooth, velvety black with no stripes.
There are two other types of black angelfish without body
stripes. One is a true black (two doses of dark) that has been
raised in continuous light instead of with the lights turned off
at night (Norton, 1982b). The other is a true black with one
dose of stripeless. True blacks are low in vigor, slow-growing,
and have a high mortality rate of the fry. Therefore, true
blacks should be replaced by more vigorous black, which have
only a single dose of the genetic factor for dark.
Parents having the dark-marble genetic makeup will produce
offspring in the ratio of 1 true black: 2 black (dark-marble
genetic makeup): 1 double-dose marble. Thus, only 50% of the
offspring will be good blacks. The true blacks and double-dose
marbles are slow-growing and have a high mortality rate. There
are three kinds of fish to sort. Sorting and slow-growing runts
can be avoided by crossing a double-dose marble with a true
black. This cross will produce 100% of the desired dark-marble
genetic makeup (Norton, 1982a). The disadvantage of this cross
is that it requires the maintenance of two low-vigor lines, the
true black and the double-dose marble.
Fig. 4: Adult male black velvet angelfish. He is a blushing (two doses of stripeless) with one dose of dark and one dose of gold.
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| Fig. 4: Adult male black velvet angelfish. He is a blushing (two doses of stripeless) with one dose of dark and one dose of gold. |
Using parents that have the dark-gold genetic makeup will
produce offspring in the ratio of 1 true black: 2 black
(dark-gold genetic makeup): 1 gold. There will be three types of
fish to sort, including the true black runts. Better results are
obtained from a cross of gold and true black, which will produce
100% of the vigorous type of black (one dose each of dark and
gold). A ratio of 1 gold: 1 black (dark-gold genetic makeup) can
be obtained by crossing a gold with a dark-gold type of black.
The disadvantages of the dark-gold type of black are its brassy
color instead of deep black and its body stripes.
Adding one dose of stripeless to the dark-gold type of black
will eliminate the body stripes. However, in doing this you
would have to maintain two separate lines (one blushing, one not
blushing) for the breeders.
Fig. 5: Adult male blue angelfish (two doses of stripeless, one dose of dark). Black velvet is the same, with the addition of one dose of gold.
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| Fig. 5: Adult male blue angelfish (two doses of stripeless, one dose of dark). Black velvet is the same, with the addition of one dose of gold. |
The body stripes of the dark-gold type of black can be
eliminated by two doses of stripeless (blushing). The advantage
of this method is that only one line of breeders is necessary.
Crossing a gold blushing (two doses each of gold and stripeless)
with a black velvet (two doses stripeless, one dose of dark, one
dose of gold) will produce 50% black velvet and 50% gold
blushing. This production of only two types of offspring can
continue generation after generation by always crossing a gold
blushing with a black velvet.
My original black velvets were obtained from a clown female
(clown: see Norton, 1983) that had one blushing parent;
therefore, this female had one dose each of dark, zebra and
stripeless. This female, crossed with a gold blushing male,
produced a spawn containing some black velvets.
To decrease inbreeding in the black velvet line, you could
introduce a gold blushing from another source. But, this may not
be necessary if you always select the most vigorous and
fast-growing young to save for your next breeders. Some
commercial producers make the mistake of sorting a spawn, taking
the largest individuals to sell, and leaving the smaller ones to
grow more for later use. Then slow-growing fish end up as
breeders because they are the only ones available.
Comparing the advantages and disadvantages of the various
types of black angelfish, I feel that the black velvet is the
best for commercial production, the home aquarium, and showing.
The true black may have somewhat deeper color than the black
velvet, but it is undesirable because of its low vigor and poor
reproductive ability. The black-marble type has the disadvantage
that it is produced best from two strains that are not robust
fish. The dark-gold type of black is produced, if desired, from
one strain, but its colot is not very good. Black velvet,
produced the same as the dark-gold type of black, has better
color.
Although the black velvet angelfish is obtained from mixed
spawns of 50% black velvet and 50% gold blushing, at least these
two types are easily distinguished at any age and are relatively
easy to sort. Also, their sorting is not interrupted by fading
of color, making it necessary to stop sorting until the colors
come back (as happens with black lace, for example). A distinct
advantage of the black velvet is that only one strain is
required to produce it. Black velvet crossed with gold blushing
will produce black velvet and gold blushing offspring in about
equal numbers. The strain "breeds true" in a sense, producing
only two types of offspring.
Literature Cited
Norton, Joanne. Angelfish-breeding and
genetics.
The Aquarium 6(10):34-41 1971
-------.Angelfish genetics. Part three.
Freshwater and Marine Aquarium 5 (7):8-10 et seq. 1982a.
-------.Angelfish genetics. Part six.
Freshwater and Marine Aquarium 5(10):38-40. 1982b.
-------.Clown angelfish.
Freshwater and Marine Aquarium 6(5):15-17 et seq. 1983.
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