Poecilia reticulata endlers is one of over 150 ovoviparous (prior to birth the fry receive nourishment through egg yolk and not through the trophotaenia system used by true viviparous fishes) livebearing fishes grouped into the Poecilia family. It looks, acts and behaves like a Guppy, Poecilia reticulata, to such an extent that it appears to be a sub-species of this very popular fish and at the present time is thus classed as Poecilia reticulata endlers but, as you will see, there are slight differences so it may be that in the future this fish will be given a different classification within the Poecilia family?
NOTE: These fish have been seen benched in 2007 under the name P.wingei
The wild location of Poecilia reticulata endlers is not clear. This fish first arrived in the U.K. in the early 1980's and at this time was a fish which was available mainly to the members of specialist livebearer groups and was known under the name of Endler's Livebearer.
As aquarium bred stocks of this fish have increased so has the availability and it is starting to become a more regular sight in the tanks of aquatic retail outlets where it is sold under the trade name of Dwarf Guppy and this is the name which will be used in the text of this article.
Any tank which contains a group of Dwarf Guppies is a tank to behold as these are lovely little fish which are always active and need no special requirements in order to reproduce.
Thankfully commercial fish breeders have yet to turn their attentions to changing the body colours and fin 'shapes of the Dwarf Guppy so the fish seen for sale in aquatic retail establishments greatly resemble those first seen in the U.K.
The background body colour and fins of both the male and the female Dwarf Guppy is olive. The female has no foreground body colour. The background body colour of the male is a myriad patchwork of dark green, black, purple, red, orange and blue and it is amazing how such a small body can hold so many colours.
The fins of the male are short-based. The dorsal fin is pointed and can reach back as far as the caudal peduncle (the last area of body prior to the caudal fin) and the colouration here is often a mixture of sky blue and orange. The caudal fin is forked in appearance but in reality these forks rarely extend out of the olive background. The forks are orange in colour and a good show fish has forks which are of an even size. The anal fin of the male is modified to form a gonopodium.
The F.B.A.S. Fish Size Guides give the size for male Dwarf Guppies as reaching 25mm (approx. 1inch) in total body length and the female 35mm (approx. 1 1/2 inches) in total body length. Males or females seen for sale above the quoted sizes should be avoided as there is always the chance that these may be the result of crosses with the normal Poecilia reticulata.
Due to their small size, there is no special requirement when it comes to choosing a tank in which to house these fish. A 24" x 12" x 12" (60x30x30cm) tank will easily house a small breeding group of between twelve and fifteen Dwarf Guppies(two females for every male).
As long as regular water changes are made, filtration in such a small tank can be minimal, eg, a sponge filter. Like all Poecilia species these fish prefer hard water with a pH between 7 and 8 with the temperature around 76°F (24°C).
House in a well planted tank as this gives the adults a sense of security, provides shelter for any females hounded by the constant attention of the males and provides shelter for any unexpected fry. Dwarf Guppies are an ideal fish to add to a well planted tank as they will do no damage to even the most delicate leaved plants. To highlight the colours of the male Dwarf Guppy use a dark tank substrate, dark rocks, eg, coal and small pieces of simulated bogwood.
Dwarf Guppies are usually kept in a single species tank but will mix happily with small Rasbora, Pencilfish and small Loach or Catfish species.
To avoid the chance of cross-breeding do not mix any other Poecilia species with Dwarf Guppies.
All the standard commercial foods are readily taken by this fish, but remember they have very small mouths. Live foods are beneficial but not essential to their wellbeing . Although many fish will refuse Microworms after they leave the fry stage of their lives these fish never lose their love of this easily cultured food.
As with all Poecilia species no special care or conditions are needed in order to get the Dwarf Guppy to breed. These fish are sexually mature at around three months of age. The males are constantly chasing the females in the hope of mating and in a tank with a dominant male the sub-dominant males will 'sneak breed' at any given chance.
As with all ovoviparous livebearers the male transfers milt through his gonopodium into the body of the female. The female stores this milt in her body and at intervals of four weeks (the female does have the ability to destroy this milt should she breed with another male) uses this milt to fertilise eggs within her body. She retains these eggs until they begin to hatch and then releases what are in reality miniature versions of the adults (if very stressed she will release eggs and/or dead fry). A few days prior to the release of her fry the female takes on a very rounded appearance and the area around her anal fin turns a deep black (gravid spot).
When a normal female Poecilia reticulata releases her fry she will release them all within a couple of hours but this is not usually the case with the female Dwarf Guppy and it often takes several hours for a female to release all her fry. Remember that brood numbers increase as the maturity of their mother increases. Dwarf Guppies are not as quick to eat their own fry as many other Poecilia species and the stronger ones from each brood usually survive long enough to be caught by the fishkeeper and moved into a separate tank or breeding trap until they are large enough to be retuned safely to their parents tank. To save a whole brood either move the female to a separate tank (which contains either real or plastic plants in which the fry can hide to escape the attentions of their mother) or into a breeding trap when she looks close to releasing her fry.
The fry of the Dwarf Guppy are very strong and hardy. Given good feedings of Microworm, Brine Shrimps and a good quality fry food they grow very quickly and within a few weeks can be returned to their parents tank. Remember that if the fry are given a small tank of their own they will grow faster and stronger than if confined to a breeding trap.
Dwarf Guppies breed true, so the young males and females are miniature versions of their parents and in this respect can differ greatly from the mixed fry often seen in broods of the normal Poecilia reticulata.
For a few generations it is possible to inter-breed within what is basically a family group and still produce good quality fry but females from outside this is group should be introduced at regular intervals as otherwise the quality of the fry produced will start to fall.
If you are looking for an interesting livebearing fish give the Dwarf Guppy a try.
Last updated July 2007