In 1975, the first pink guppies appeared in David Liebman's breeding room in the United States of America. He developed this strain over an almost ten year period and called this new strain “PINGUS” which stands for PINk GUppieS. In the year 1979 he presented them for the first time in the June issue of the “Freshwater And Marine Aquarium” (FAMA) magazine. He created not only a new strain but also found a new body base colour by accident. So pingu and pink is not the same. Pingu means nowadays a certain strain of guppies on the pink body base colour.

For this pingu strain, which is actually a pink “half black” AOC strain, you do not need ten years but a single mutation. So you need only 2 generations, a half black strain and lots of luck to develop them. Mr. Liebman had this luck and bred this strain further to show fishes. They also got the name “pink” because of the pink peduncle area, which is typical for pink in combination with the sex-linked Nigrocaudatus 2(NiII), the allele for a half black phenotype in grey strains. If he would have got the same mutation, but in another strain, he would probably not have given them the name “pink” name because this body base colour itself has only very little to do with a really pink guppy. You need lots of fantasy to see a pink coloration on a adult pink guppy without Ni II. It is more like a slightly lighter grey which is similar to bronze (alias tiger in Asia, alias gold in Europe).

This pingu strain of Mr Liebman, which was quit expensive in the beginning, found at first its way across the United States of America and Japan before it also came to Europe in the early 1980’s. In Europe they became a sensation at first but it didn’t last long. Nowadays they are a pretty rare strain in Europe as well as in the United States of America and only a few breeders breed or show them. A reason could be the difficulties of this strain. Although many strains were involved in development and decades of selective breeding happened to them, they seldom become good show fishes. They also do not match the differences standards because they are pink, which is not colourful, nor a recognised pattern, but (genetically) a kind of half black which is far a away from a really solid black.

The body base colour pink is like most body base colours, except for grey (or "wild type"), a single recessive body base colour. It is an autosomal recessive allele like e.g. albino, so both genders pass it on their descendants. But at first nobody noticed this because the intensity of melanin-production of the scale-edges is similar to grey. A exception is the lower body and peduncle area were there is a less dense coloration of the scales. At the beginning of the caudal it is almost invisible.

The area between the scale-edges, the flesh so to say, is only slightly effected by this reduced melanin-production and so it appears only slightly brighter than grey. Females without the NiII allele look similar to bright grey or more often very similar to bronze females. Only pink fries look much brighter than grey fries and the difference is clearly visible. But as they get older, they loose this bright coloration and look more like grey.

In combination with albino it looks bright flesh-coloured and the albino allele has no influence on the appearance of extra sex-linked NiII allele, so albino-pink pingus still look pink.

The intensity of the coloration of the scale-edges varies depending on their mood as well as in grey strains. They can adapt to their environment and show in a bright tank much less melanin, so they look brightly grey.

Which colours and patterns pink guppies are able to show and how they do it, is not yet adequately explored and documented. All colours and patterns seem to appear different than on other body base colours, so they are modified in their expression by the pink allele.

Red for example can not be shown in a way like other body base colours like grey or gold do it. It does not become that intensive and also not really red. On the dorsal and caudal it appears more orange or brownish, if it appears at all. If they can show it on the body, is still a unsolved mystery because there are no pink red strains yet. All known pink strains so far show no red at all on the body. Magentas for example show no red on the body of pink guppies.

In contrast to red yellow can be shown on pink. But it appears more white on the body than intensive yellow. The lace snake skin pattern varies from shiny yellow till slightly bluish silver. The pink body base colour allele also modifies this pattern in a way that it becomes more coarse. Pink mikarifs (sex-linked snake skin + autosomal homozygous Stoerzbach metal) look more white and less yellowish on pink.

This picture shows a pink moscow mikarif round tail, a new strain developed by the author:

In this strain, the Stoerzbach metal allele also has a strong influence on the coloration of the dorsal and caudal fin. Both show no longer a dark blue colour like in normal pink moscow strains but a bright blue coloration.

Platinum appears greenish or light blue but not yellow at all. Together with the Stoerzbach metal allele, it looks almost like a pingu.

This picture shows a pink platinum Stoerzbach metal bottom sword, bred by Ramona Osche / Germany.

The picture was used with permission.

The similarity of the pink coloration of the peduncle of this guppy and normal pingus is remarkable. Platinum and homozygous Stoerzbach become a solid gold pattern on most other body base colours, which is knows as “full gold”. But on pink the same allele combination results in a green till pink coloration, very similar to pingu strains, although the male above does not have the NiII allele. This shows how special pink guppies are.

Without a restriction blue and black can be shown on pink. But blue appears more shiny than on other body base colours. The most popular blue pink strain are pink moscows (also known as panda) which are a combination of the pink body base colour, the metal head of the moscows, the moscow blue which is located on both sex chromosomes and often a y-linked snake skin.

Green should be visible on pink. All necessary colour cells (xanthophores, melanophores and irdidophores) exist but there is no such strain yet. There is also no solid white pink strain yet.

The most well known pink strains are pingu strains. Pingus are basically a combination of the pink body base colour and the Nigrocaudatus II allele plus and colour allele for the fins. So they are nothing else than half blacks which are no longer black but pink. Why the black coloration becomes pink, although there are enough melanophores, is still a mystery. It seems as if instead of a reinforced melanophore development it comes to a reinforced iridophore development in the same area. The NiII allele also influences the fins, so they often appear at least near the base of the caudal pink. The fins are often orange, if half black red were used, yellow, white or pink. Blue fins are also possible but they become bright blue. Selective breeding for a intensive pink colour is necessary to maintain it. So there is a no difference to half black strains on other body base colours where you try to breed a solid black. But in contrast to albinos, which cannot show half black because of the lack of melanin in the melanophores (black colour cells), double recessive pink-albino still show the pink.

Pingu females do not look like other pink females. They show a pink peduncle without a noticeable scale coloration in this part of their bodies. So it is quit easy to differentiate a pingu female from a female of any other strain. A typical pingu female looks like this:

Pingus are the only delta tail guppies on this body base colour. The angle is not that bad often but they have big problems in developing the right length. Most pingu strains show a too short delta caudal. The pink allele suppresses the development, although it does not suppress the sword alleles itself which shows for example the earlier mentioned pink platinum bottom sword. You can compensate this undesirable trait with lots of selective breeding and out-crosses to other delta strains. The dorsal fin is not affected.

Often you see dark, bluish or almost black heads in pingu strains. In most cases this is the result of an out-cross with a blue moscow strain. It helps a bit to get a bigger delta tail but the positive effect is rather small and there is also a disadvantage, the blue coloration. The pingus can get a bluish sheen on the pink coloration. This male shows clearly the influence of the moscow ancestors:

Besides the pink pingu strains there is another rather popular pink strain: pink moscows, also known as panda guppies. This strain does not have the NiII allele, and so they are short tail guppies. This strain was not developed by a single breeder and then spread all over the world, like it was done with the pingus. No, this strain was several times developed around the world. Crosses with blue moscows were done several times and in the F2 these blue short tails appeared. This happened for example in Japan, where they got the name panda. In Europe the first pink moscows appeared in Sweden in the mid of the 1990ies. They are the origin of almost all European pink moscow lines nowadays. In the United States of America Luke Roebuck developed them himself, too.

All pink moscows (or pandas) are very similar and their genetic is almost the same. It consists of the pink allele, the moscow metal head, the y-linked moscow blue peduncle and fins as well as x-linked moscow blue. Most pink moscows also have y-linked snake skin above the moscow blue. How this combination was developed is not known but it is very hard to get rid of the snake skin. They show more or less the snake skin pattern on the peduncle. In combination with the autosomal Zebrinus / cobra bar allele, the snake skin pattern of appears as single line or bars. Without the Zebrinus allele, the snake skin becomes much better and looks almost like a lace snake skin. It requires an outcross to get rid of the homozygous Zebrinues. The snake skin pattern can also be shown on the caudal but most breeders seem to select them for a solid dark blue caudal, which is quit easy to achieve in this strain (because the pink allele modifies the expression of the snake skin allele). The dorsal is always dark blue or dark grey, although the snake skin pattern has also an influence on the coloration of this fin, which can easily be seen if a test cross with a grey strain was done. On grey the still show the moscow blue with the snake skin pattern above it but they show also a patterned dorsal. So the pink allele suppresses the expression of the snake skin pattern on the dorsal.

This young male is a good example of pink moscow with very little snake skin, although it is still there:

This solid blue caudal of this male is the result of lots of selective breeding because pink moscows can loose this trait. Then the caudal shows snake skin or is colourless on some parts but the dark blue is only left on the body. This happens especially after an out-cross, in true breeding pink moscow lines you seldom see a caudal which is not solid blue.

In comparison to pingu females, pink moscow females show only a slightly brighter peduncle. They do not show the blue coloration. So they show us how this body base colour really looks like without the influence of other colour alleles.

These are two pink moscow females of the author which were kept in a well planted tank:

In a bare breeding tank, were there are less chances to hide for the females, they become brighter coloured in a way that they reduce the amount of melanin they show in their scales. Females of the same strain look then like this:

Pink moscows as well as all other colours and patterns on pink so far, except for NiII, are short tails caused by the pink allele. So the length-growth is suppressed but they are not automatically round tails.

This picture shows a male of a F1 after an outcross of a pink moscow male with a grey female:

The caudal of pink moscows is short but can also have a delta shape because they are actually real delta tails from their genetics. The male above clearly shows this. To get a good round tail shape you need lots of selective breeding to get at first this shape and then also maintain it or spade tail-like males will appear. In the past, crosses with real round tail strains didn’t helped much to solve this problem.

Another big problem for pink moscows is the coloration of the caudal. Often there is a colourless outer rim, especially if the caudal has a good round shape. So it requires a selection for a good shape and a good coloration of the caudal. Another problem is the dark coloured dorsal. This coloration depends on the mood of the males, so it can happen that it becomes almost colourless from time to time. There is no way yet to fix this coloration. Normally the shape is no big problem (it should be round for a round tail, not pointed) but the length varies a lot. So selection for the right coloration and length is necessary. These characteristics make pink moscows not any easy round tail strain to work with.

The most special trait of all pink guppies is their ability to show patterns and colours in a unique way which differs from all other body base colours. The reason for this trait could be an increased number of guanophores/iridophores. The inability of the pink moscows to show a really dark coloured head as well the extraordinary shine of all colours and patterns indicate this.

There are still a lot of test crosses to be done to discover all mysteries of this rare body base colour. We know for example that bottom swords are possible but what about pink double swords or top swords? Nobody can predict the outcome of a new cross with pink guppies, so let’s find out!