Endlers – Detailed Guide: Care, Diet, and Breeding

Endlers or Endler’s livebearers are a diminutive and colorful fish species that are popular in the hobby and ideal for tropical tanks. Interestingly, Endlers bear a striking resemblance with the Common guppy and some enthusiasts argue that both are the same species, however, this is not true.

Endlers are hardy, peaceful, and can survive in a wide range of pH, hardness, and water temperature conditions. Also, this is a good candidate for small aquariums due to its little size, so if you have been thinking of species to add to your 10-gallon tank, this fish fits.

In this article, I will explain everything there is to know about the Endlers and how to care for them successfully in an aquarium.

Quick Notes about Endlers

Name	Endlers
Other Names	Endler’s livebearers, Endler’s Guppy, Cumana Guppy or Campoma Guppy
Scientific Name	Poecilia wingei
Tank size (minimum)	10 gallons (~40 liters)
Keeping	Easy
Breeding	Easy
Size	up to 3 – 4 cm (~ 1.5 – 2 inches)
Optimal Temperature	22 – 28 °C (72 – 82 °F)
Optimal PH	7.0 – 8.0
Optimal GH	12 – 20
Dwellers	Middle to top
Nitrate	Less than 40
Diet	Omnivore
Temperament	Peaceful
Life span	up to 3 years
Color Form	Males are fluorescent, females are a silver color.

Origin and Taxonomy of Endlers

The Endler’s livebearer is known by the binomial name Poecilia wingei. This colored small fish species was first collected from Laguna de Patos, Cumana in north-eastern Venezuela by Franklyn F. Bond in 1937.

It became known in the aquarium trade after its rediscovery in 1975 by Dr. John Endler, whom the species was named after.

The first samples of the fish to be introduced to the aquarium trade were those collected by Dr. Endler and since then, more quantity of the fish have been collected and utilized to broaden the captive breeding stock.

Unfortunately, the original population of fish at the discovery site Laguna de Patos are threatened and they are in danger of extinction as a result of pollution and human activities.

Notably, the first population of Poecilia to be given the name Poecilia wingei was discovered by Fred Poeser and Michael Kempkes in the Campoma region of Venezuela in 2005.

Interesting Fact: The scientific name of Endler’s livebearers (Poecilia wingei) was derived from the Greek word poikilos which means ‘variegated or variable’, and wingei; in honor of the Danish biologist Øjvind Winge (1886 – 1964) who worked extensively on Guppy genetics.

Habitat of Endlers

Endlers are native to Paria Peninsula, Venezuela. They inhabit freshwater lagoons and connected streams within the country, huge populations occur in the Campoma and Buena Vista lagoons, Carúpano in north-eastern Venezuela.

They are also present in Laguna de Patos, Cumana, and in the lagoon’s connected streams and canals.

Their habitat is quite shallow and surrounded by trees which keeps them shaded; they contain very warm, hard water with substantial levels of salinity, and these factors should be replicated in the aquarium.

Description of Endlers. Gender difference

Endlers are characterized by their small sizes.

• The male Endlers are smaller than females, about an inch in size and their colors are very intense; ranging from the black, orange, blue, yellow, red, and metallic green.
• Female Endlers are usually 1.8 inches in length and may grow up to 2 inches. Furthermore, females are stouter and dull-colored (pale silver or gold), unlike the males that possess vibrant colored shades and markings.

Under proper captive care, the species can live for 2 – 3 years.

Endlers and Hybridized Strains.

Endlers are classified to distinguish between pure and hybridized strains.

• N Class: Endlers that have not been subject to hybridization. N class Endlers are considered to be pure strains, having originated from the wild population in Venezuela.
• P Class: They have the traits of N Class Endlers but lack the documentation that proves their lineage.
• K Class: Referred to as hybrids. These are offspring produced from hybridization with guppies or other livebearers.

Important: Mixing different strains in the same tank will result in offspring with characteristics of both strains. On the contrary, if you want to keep the offspring’s traits pure, you need to use separate tanks for each strain.

Difference Between Endlers and Guppies

The Endler’s guppy (Poecilia wingei) is closely related to the Common guppy (Poecilia reticulata). Although it can be very hard to see the difference between Endlers and Fancy guppy, they are still not exactly the same.

	Endler’s guppy (Poecilia wingei)	Common guppy (Poecilia reticulata)
Size	Smaller up to 1.5 – 2 inches	A little bigger up to 1.5 – 2.5 inches
Tail	Composed of two little smaller fins	Wider and richer in color
Color intensity	much more intense, enhanced metallic body pigmentation	less intense
Main coloration	golden gray	silvery gray
Body marks	black comma on the bodies
Body Shape	less stocky	more stocky
Gonopodium	has one hook	Has several hooks

Endlers Behaviour

Endler’s livebearers are extremely active, they love swimming and exploring various areas of an aquarium.

Also, these little creatures will engage themselves in different activities such as grazing on algae, staring at the tank glass, or interactive displays.

They are very inquisitive; there are scenarios where they often come to investigate an activity, nibble at your fingers or even approach cleaning tools without fear of being harmed.

Adult males are usually peaceful whereas the females may act territorially, and that is why you need to have many of them. Most times, they will actively interact and shoal in the water without being aggressive towards one another.

Notably, once the light goes off, they will retreat to the bottom and rest until the light return. The likelihood of seeing them at the upper levels during dark is not ruled out, and this happens more often in community tanks housing larger fish species that dwell at the bottom.

Features:

• Social: No
• Active: Yes
• Peaceful: Generally yes

Feeding Endlers

Endlers are omnivorous, and they often consume algae, biofilm, small insects, and plant matter in their natural habitat. Hence, they will benefit hugely from a varied diet of plant and animal matter while in captivity.

Endlers are not picky eaters, they can be fed:

• frozen or live food,
• high-quality fish pellets,
• flake food,
• portions of vegetable matter.

Live foods include:

• brine shrimp,
• blood worms,
• grindal worms,
• tubifex worms,
• daphnia.

As regards to the plant diet, you can feed them blanched vegetables:

• spinach,
• kale,
• lettuce.

Additionally, there are a variety of commercially available fish foods to chose from, they are all rich in nutrients and specially formulated for aquarium fish.

Since this is a small species with tiny mouths, you may be required to grind the large flake foods into smaller pieces before feeding your Endlers, that way, they won’t have a hard time ingesting it.

Endlers should be fed once or twice a day, and be sure to feed them little portions that they can finish within a small interval.

Features:

• Diet Type: Omnivore
• Food Preference: 
• Feeding Frequency: Daily

You can also read:

• How to Blanch Сucumbers and Zucchini for Shrimp, Snails and Fish the Right Way
• Indian Almond Leaves and Alder Cones in a Shrimp Tank.

Tank Requirements and Water Parameters

Tank size:

This is a very small fish species, hence, it can be housed even in the small tanks. However, if you plan on keeping a group of about 5 Endlers, a 10 gallon (40 L) tank is recommended.

Larger tanks would be required for housing more numbers of this fish, taking into consideration that they are prolific breeders.

Note: Due to their increased activity levels and considering how quickly they reproduce, Endlers should not be kept in very small tanks. It will become too small very soon and you will have to upgrade it.

You can also read my article “Stocking a 5 Gallon Tank. Fish and Inverts.”.

Water Parameters:

Temperature: Endlers dwell in warmer waters in the wild, so this should be replicated in the tank. Maintain a water temperature range of 72 – 82 °F (22 – 28 °C) in a tank containing this fish species.

pH: Endlers are very hardy fish and can tolerate a wide range of water parameters. However, for optimal conditions, they will appreciate a neutral – slightly alkaline pH, value preferably between 7.0 – 8.0. Always monitor the water pH regularly with a testing kit and add a buffer to remedy low pH conditions.

Hardness: They prefer a tank that contains fairly hard – very hard water (12 – 30° GH). Endlers will survive in soft water, although that might be detrimental eventually.

Lighting:

They require bright diffused aquarium lighting and a LED light fixture is ideal for this purpose. Use the timer to regulate light/dark periods daily.

Substrate:

Endlers tend to roam around the lower levels to observe things and also to search for tiny food particles or plant matter to consume.

It is best to use aquarium sand or smooth medium-sized gravel at the bottom of the tank. Avoid the usage of large coarse gravel that can scratch or cause injuries to their small bodies.

Filtration:

Personally, I would always recommend using sponge filters or matten filters for any small tank setup. These filters are cheap, easy to maintain and clean, provide a lot of surface to graze on, and absolutely safe for the Endlers’ fry.

However, for bigger tanks, sponge filters may not be good enough. In this case, you will need either hang on the back or canister filters.

Heater:

If there are temperature fluctuations in the place you live, it can be a good idea to have a thermostat heater. Thermostat heaters work by maintaining a set temperature. Once the temperature goes below a certain degree, it turns on.

Note: Keep in mind that warm water will be ideal for breeding.

Decorations:

A densely planted tank is best suited for keeping Endler’s livebearers. Be sure to cultivate lots of plants in the tank because this offers the fish ample places to hide especially in situations where they are kept with larger tank inhabitants.

Plants like Java fern, Java moss, Dwarf Hairgrass should be planted in the foreground and background, in addition to floating plants (like Guppy grass, Water sprite, Water Wisteria, Salvinia auricalata, Frogbit, etc.) to provide shade and shelter for fry.

Also, decors such as driftwood, caveworks, and hollow logs are essential because they complement the aesthetics of the aquarium, and also provide breeding ground and hiding spots thereby making the fish more comfortable.

Basic Tank Equipment (links to check the price on Amazon) Filter: Sponge filter, Matten Filter. Fluval 407 Performance Canister Filter, etc. Heater: Eheim Jager Aquarium Thermostat. Aquarium pump: Tetra whisper Air pump  Substrate: Carib sea sand, etc. Decor: Malaysian Driftwood, PVC pipes, Coconuts, Decorations, etc.

Care and Maintenance

Endlers are nearly unproblematic and since they do not excrete much waste in the tank water, caring for them is a whole lot easier. Regardless of the little bioload, you still need to install a quality filter to provide enough filtration, thus keeping the water clean and maintaining good water quality.

Moreover, due to the tiny sizes of the fry, they are at risk of being sucked into the aquarium filter. This can be averted by taking the necessary action, you just have to cover the filter intake with a fine mesh.

Always be mindful of the plants’ growth, you are required to trim the overgrown shoots from time to time to halt excess growth in the tank. If there are floating plants present, then you should prune them as well.

Endlers are able to tolerate and thrive in a saltwater environment, in captivity they can be breed in freshwater or brackish conditions. Hence, if you decide to breed them in a brackish tank, add 1 tablespoon of salt per 5 gallons and make sure that other inhabitants can handle the conditions.

Additionally, replace about 25% bi-weekly or 10% weekly to keep the water clean, though the need for this would be minimized if it is a species-only aquarium and the filter is running efficiently.

Mating Behavior

According to the study, Endler’s females do not show a preference for males of their

own species, for higher levels of coloration, or for larger size in males.

Scientists believe that it is because in natural waters in the habitat of the Endler’s are turbid and murky, thus challenging the proposal of mate choice by sight.

In addition, compared to Fancy guppies, Endler’s males rarely display jumps and chasing behavior (a mating behavior) because females leave promptly if uninterested in the male’s advances.  

1. Endler’s male will attempt to become visible to the female in the face-to-face position.
2. Next, he turns both sides to the female, like the common guppy.
3. Finally, the male circles around the female and attempts to copulate with his forwardly turned gonopodium.
4. If the female accepts him, he positions himself under the female, while his color pattern darkens.

Breeding Endlers

Endlers are known to breed with no hassles. They belong to the group ‘Livebearers’, and as the name suggests, the fish gives birth to live young offspring/fry once every 23-24 days rather than laying eggs.

Females are able to store milt from previous mating sessions and this enables them to bear fry for months in the absence of males, this process is called superfetation.

Fry brood ranges from just 1 to about 20 fry, although this is dependent on several variables which include the age, health, and size of the female.

Note that a tank with warmer water temperature will result in more male fry while cooler temperatures favor the birth of more females.

The birth process can be too stressful for female Endlers, and some may die shortly after giving birth to offspring.

Endlers rarely eat their own fry, unlike guppies. However, other tankmates wouldn’t mind going after them to satisfy their cravings. Breeding in a heavily planted tank will aid the fry escape predators by giving them access to ample hiding spots.

Alternatively, they can be raised in a separate small tank until they attain mature sizes.

Endler fry exhibit rapid growth when fed a few times a day. Finely crushed flake foods, algae wafers, specially-prepared powder fry food, and baby brine shrimp are good food options for them.

The males reach breeding age and mature in about 3-5 weeks, it takes them a little longer to develop full-color depth and intensity. On the other hand, females are able to fully mature and produce fry broods after two months.

In addition, having more males than females in your tank will help to keep the population lower and vice versa.

Important: Bear in mind that Endlers will easily hybridize/crossbreed with the common guppy and dilute the gene pool. Therefore, they should not be kept in the same tank with guppies if the aim is to preserve the species and maintain pure strains.

Crossbreeding

The Endler’s guppy (Poecilia wingei) and the Fancy guppy (Poecilia reticulata) are able to mate and produce offspring.

Even though the fry of this hybridization may look really interesting, I would strongly advise not to do that.

The point is that their gene pool will be altered. As a result, they can have health issues and genetic mutations in the long run.

Endlers and Suitable Tankmates

It makes a lot of sense if Endlers are kept together with tank mates that are relatively small, quiet, peaceful, and can share the same water parameters with them.

Ideally, Endlers are best maintained in a species-only aquarium due to their relatively small sizes. They are unsuitable for community tanks containing large species of fish and other animals.

Endlers are compatible with:

–         Fish

Chili Rasboras, Harlequin Rasboras, Neon tetras, Least Killifish, Clown Killifish, White Cloud Mountain Minnow, Celestial Pearl Danio, Zebra Danio, Sparkling Gourami, Platys, Corydoras catfish, Cherry barbs, Swordtails, Southern platyfish, Pygmy Cories, Otocinclus Catfish, Panda Garra, etc.

–      Dwarf shrimp:

If you are planning to keep Endlers with dwarf shrimp, you should understand the risks. In most cases, adult dwarf shrimp are safe. However, it cannot be said about shrimplets. They will definitely feed on them!

Even heavily planted tanks may not be enough for the baby shrimp to hide. Endlers are very inquisitive. They will look and dig into every corner of your tank, scaring the small shrimp out and then they feed on them.

Overall, it can be very hard to breed shrimp with Endlers. So, if you are serious about breeding shrimp, I would not recommend taking any risk. You simply cannot allow any fish in the shrimp tank!

Note: Be careful with Ghost shrimp, this species is a little bit more on the aggressive side. These shrimp will eat anything they can catch, including fish fry. The good news is that they are not great hunters and will not decimate the fry population.

• Freshwater Snails

Endlers can share the same tank with any type of freshwater snails (for example, Japanese trapdoor snails, Ramshorn snails, Nerite snails, Malaysian Trumpet snails, Black Devil Snails, Asolene spixi, Rabbit Snails, etc.).

Avoid

Keep Endlers away from most types of crayfish and freshwater crabs. Even small African Dwarf Frogs can and will try to catch them whenever it is possible.

In Conclusion

The Endler’s livebearers are one of the best species of freshwater fish you can possibly have in your home aquarium. They are peaceful, undemanding, not prone to illness, easy to care for, and will breed all year round. Fantastic fish for beginners and for advanced hobbyists.

The major downside is the availability of pure strains. They are rare but you may be fortunate to find some at a local fish store. Otherwise, you will need to source them online through reputable fish breeders.

References:

1. Ramsay, Chloe, “Mate Choice and Hybridization: Comparing the Endler’s Guppy (Poecilia wingei) and the Common Guppy (Poecilia reticulata)” (2014). Undergraduate Honors Theses. Paper 183.
2. Description of Poecilia (Acanthophacelus) wingei n. sp. from the Paría Peninsula, Venezuela, including notes on Acanthophacelus Eigenmann, 1907 and other subgenera of Poecilia Bloch and Schneider, 1801 (Teleostei, Cyprinodontiformes, Poeciliidae). Contributions to Zoology, 74 (1/2) 97-115 (2005) Odour preference in guppy (Poecilia wingei) males is influenced by the social environment. Behaviour (2016) DOI:10.1163/1568539X-00003387
3. Strategic exploitation of fluctuating asymmetry in male Endler’s guppy courtship displays is modulated by social environment. Evolutionary biology. doi: 10.1111/jeb.12567
4. The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.anbehav.2013.12.010
5. The Association Between Personality Traits, Morphological Traits and Alternative Mating Behaviour in Male Endler’s Guppies, Poecilia wingei. Ethology 122 (2016) 1–12
6. Allevamento sperimentale in laghetto artificiale di una linea selvatica di Poecilia wingei in via d’estinzione. 2007