Dr. Joanne Norton
Freshwater And Marine Aquarium magazine
Photos and Text by Dr. Joanne Norton
FAMA: May 1982, Vol. 5, #5
Naja gold beginning to lose the black pigment on its mouth.
Naja gold pair in two stages of color change to gold.
The male now has only a small black area remaining.
About eight mutations in angelfish have resulted in the many color variations that exist today. Five of these mutations (dark, stripeless, marble, smokey, and zebra) were discussed in Part 1. This article will deal with the three types of gold angelfish (Naja gold, Hong Kong gold and "New Gold") that have been widely available in the hobby. Commercial production of golds today is limited almost entirely to the new gold, which is gold its entire life (unlike the Naja gold) and has better color than the Hong Kong gold, in which the juvenile resembles a faded silver angelfish.
The Naja gold (sometimes called Wingate gold), which was the first gold angelfish on the market, appeared in 1970 (Axelrod, 1970). It is the only one of the tree golds that looks like wild-type (silver) for the first nine months, more or less, of its life. The first noticeable change is loss of black pigment on the mouth. Then black pigment continues to disappear on the lower part of the fish, while the dorsal areas simultaneously become black. Within a few days or weeks, the time varying among individuals, these black areas disappear as the amount of dark area diminishes, resulting in a gold-colored fish with black pigment remaining in the eyes of most individuals. Naja golds are the only angelfish I have seen that have atypical eyes; my impression is that I can see into the eye's interior.
In the Hong Kong gold (Anon., 1971), the juvenile is similar to wild-type but its dark markings are paler. At maturity, this striped pattern disappears and the fish is gold. Immature Hong Kong golds have an equilibrium problem. When their light is turned on in the morning, or if you shine light at them horizontally instead of from above, they are likely to swim in several head-first somersaults. This behavior has not been observed in the adults that I have had.
The new gold angelfish is gold its entire life. I have examined fry (one day before they became free-swimming) with 10x magnification, and found that they have a reduced number of black pigment cells (appearing as black stipples) compared with wild-type. The new gold never has the dark stripes that are present in the juvenile Hong Kong gold. New golds do not have the eye variation that occurs in Naja golds.
New golds were imported into the U.S. from Singapore in 1973. Earl Wellwood (1974), a Canadian aquarist, stated that he had about 5000 new golds before he sold any. When I talked with Mr. Wellwood in 1976, he told me that he he thought the new golds on the market originated from his stock. Unfortunately, his article did not give the date when he first sold new golds, and therefore he did not make it clear whether or not he released his new golds early enough for these fish to have been raised in Singapore and exported in 1973. I have seen no information on the origin of the Singapore new golds. Ross Socolof (1975) reported new gold angelfish that appeared in stocks at his fish farm, and he also said that new golds turned up in stocks at another Florida fish farm. It is impossible to know, from the information that I have, whether the mutation to new gold occurred only once or more than once within a period of about three years.
Foreground: Naja gold, fully changed to gold.
Foreground: New Gold with one dose of the dominant
gene for veiltail.
I got all wild-type offspring from a cross of Naja gold x new gold. Twelve of these were kept for one year, when they were still wild-type. Thus it appears unlikely that Naja gold is due to a single dominant gene with complete penetrance (always being expressed). The possibility that Naja gold is due to a recessive gene has not been tested, as far as I know.
Crossing Hong Kong gold with black, I obtained only black lace offspring. The F2 included 29 wild-type, 49 black lace, 12 black, 4 Hong Kong gold. It is concluded that Hong Kong gold is due to a recessive gene; also, that the genes for dark and Hong Kong gold are not alleles (occurring at the same location on a chromosome), since mating fish heterozygous for both dark and Hong Kong gold produced some wild-type offspring.
A blushing (two doses of stripeless) female, mated to a Hong Kong gold male, produced 100% stripeless non-gold offspring. The 332 fish in the F2 included 68 wild-type along with some each of blushing, Hong Kong gold blushing, stripeless, stripeless Hong Kong gold, and Hong Kong gold. It is concluded that stripeless and Hong Kong gold are not alleles, since wild-type appeared in the F2 and since Hong Kong gold blushing (two doses each of Hong Kong gold and stripeless) would not occur if these two genes were alleles.
Crosses of new gold x new gold produces 100% new gold offspring. No new golds were produced by matings of new gold x marble, new gold x black, new gold x smokey, or new gold x zebra. Each of the backcrosses of new gold x F1 of these five crosses produced some new gold progeny. Also, a 3:1 ratio (146 wild-type, 50 new gold) was counted for the F2 of new gold x wild-type. Thus, new gold is due to a recessive gene.
I would advise anyone who wants to raise Naja golds to obtain stock from a source that can be trusted to supply offspring from Naja gold parents. From then on, these should be mated only Naja gold to Naja gold if the purpose is to raise this type only. Probably Naja gold stock is no longer easy to locate since new golds have been replacing Naja golds commercially.
Hong Kong golds breed true and also should not be outcrossed with any other color if you want all Hong Kong gold offspring. The same situation exists for the new gold, which breeds true.
Axelrod, Herbert R. Naja's angelfish. Trop. Fish Hobbyist 18:4-13. January 1970
Socolof, Ross, B. Gold, gold now and red, red now. Buntbarsche Bull. No 47:24. March-April, 1975
Wellwood, Earl. A Canadian creation. Canadian Fish Fanciers 1 (4):16-17. 1974