Assorted Endlers Guppy (Poecilia endler)

Recognise the fish and the name

Assorted Endlers Guppy is the trade name for a very small freshwater livebearer in the family Poeciliidae. The scientific label attached to this offer is Poecilia endler. FishBase now lists it as Poecilia wingei, the accepted name also used by Eschmeyer’s Catalog of Fishes. It comes from the Campoma and Buena Vista lagoon systems in Venezuela and reaches 2.0 cm standard length. This active social fish suits a prepared beginner who can provide mature filtration, medium-hard water, swimming room and a deliberate population plan.

FishBase classifies wild Poecilia wingei as a freshwater, tropical, benthopelagic fish and records its global conservation category as Endangered. That status describes wild populations; aquarium fish, fry, plants and water must never be released into a pond, drain or natural waterway.

Use adult measurements for planning

FishBase records a maximum of 2.0 cm standard length. OATA describes Endler guppies as growing to around 2.5 cm, while the original species description includes a female measured at 30.4 mm standard length in a separate stream sample. Standard length ends at the base of the tail. The care profile uses the FishBase figure of 2.0 cm standard length consistently; the separate measurements show that individual specimens can differ.

Small dimensions do not make a bowl or unstable aquarium suitable. These fish swim actively, use social information and can reproduce rapidly when sexes are mixed. Their care therefore depends on mature filtration, usable swimming length, stable medium-hard water and a population plan rather than on fitting the fish into the smallest possible volume.

The assorted name describes a colour assortment rather than a documented locality line. Colour and fin shape can vary, and appearance alone cannot certify ancestry. Keep traceable P. wingei lines separate from common guppies.

Choose the offer and prepare the space

One purchase supplies one Assorted Endlers Guppy. Plan the permanent aquarium around the adult dimensions, group, filter capacity and other inhabitants.

Sex is guaranteed only when the selected option explicitly states male or female. This Assorted Endlers Guppy listing has no sex-guaranteed option. Do not use colour, body depth, body size or a gallery scene to assume which sex will arrive. If a mixed group could create more fish than the aquarium can support, choose an offer that explicitly identifies sex or prepare mature separation capacity before adding any animal.

The gallery images are representative, based on reference photographs of this species, so colours can look slightly different from the live animal. The scenes show representative Endler colouring and body form, not a promise of one exact pattern, sex or individual fish.

Apply the conservative adult-group screen

A species profile from Seriously Fish gives a 45 × 30 cm base and approximately 41 litres for a substantial colony. OATA uses at least 45 litres for a small group of the smaller guppy species. We add a more conservative minimum aquarium length of 60 cm because litres alone cannot describe swimming room, courtship pressure, sight breaks or the needs of tank mates.

Read the complete Endler Guppy care guide when planning the wider setup. You can also browse the Endler guppy collection when a clearly identified sex or named form would suit the population plan better. Before selecting a delivery date, read the current delivery and Live Arrival Guarantee policy and have the mature aquarium tested first.

Match stable medium-hard water

Keep the aquarium at 24–28°C, pH 7.0–8.0 and 15–18 dGH. This is the overlap between the OATA guppy-and-molly guidance and the species profile from Seriously Fish. Use those figures together, with gradual adjustment and stable conditions taking priority over chasing a single ideal number.

Test the aquarium rather than relying on a postcode, the heater dial or a previous reading. Measure temperature with an independent aquarium thermometer and test pH, general hardness, ammonia, nitrite and nitrate with suitable aquarium tests. Our water chemistry guide explains what each value means, while the water matcher helps compare measured aquarium water with the working range.

Change water conditions gradually

If the aquarium sits outside the range, first measure the tap water and review recent water changes, decor and additives. Avoid abrupt pH or hardness adjustment and do not add an unmeasured buffer merely to reach a number. A stable aquarium near the edge of the range is safer than repeated swings caused by rapid intervention.

Use a thermostatically controlled aquarium heater where room conditions cannot hold a suitable year-round temperature. Place and operate it according to its rating, then verify the result in the water. Direct sunlight, cold draughts and large replacement-water temperature differences can all create avoidable swings.

When moving an Endler between waters, compare temperature and chemistry before transfer and acclimatise slowly. The aim is to prevent a sudden change while keeping the fish’s time in transport water proportionate to the journey and condition.

Mature the filter before stocking

Use a fully matured biological filter before any Endler enters the aquarium. The RSPCA explains that fish release toxic ammonia; beneficial bacteria in a working filter convert it to nitrite and then to the safer nitrate. An aquarium that merely looks clear can still contain harmful ammonia or nitrite.

Confirm zero detectable ammonia and nitrite with repeated tests before stocking. A calendar alone cannot show that the biological filter can process waste. If this is your first setup, follow our guide to preparing and maturing a tropical aquarium before choosing livestock.

Size filtration for the whole population

• Count every fish and other waste-producing animal, not only the new Endler.
• Allow for additional feeding and possible fry in a mixed-sex group.
• Maintain surface movement so oxygen reaches both fish and filter bacteria.
• Protect an intake when a small fish or fry could be trapped against it.
• Choose flow that allows every fish to hold position and feed without constant effort.

Seriously Fish gives a turnover of four to five times the aquarium volume per hour for its approximately 41-litre example, equivalent to a filter rating of about 165–205 litres per hour. Treat that as a worked example rather than a universal filter prescription: media capacity, real flow after installation, aquarium layout and the complete animal population also matter.

Check the filter for blockages during routine maintenance. If media needs cleaning, rinse it lightly in aquarium water removed during a water change. Do not run it under the tap. Do not replace all media simply because a packaging calendar says to do so.

Add livestock gradually. A mature filter’s bacterial population responds to the existing waste load; a sudden increase in animals and feeding can exceed that capacity. If ammonia or nitrite appears, pause further additions, reduce avoidable waste, check the filter and perform suitable conditioned water changes while monitoring closely.

Plants support a healthy layout but do not replace filtration or cycling. A planted aquarium can still be immature, overstocked or oxygen-poor, so use test results and fish behaviour rather than plant growth as the safety check.

Build swimming room and cover

Give the group open horizontal swimming room together with structured cover. Endlers are active despite their small size, and a 60 cm aquarium provides more usable travel distance than a short container with a similar volume. Keep the central or front area open enough to watch every fish swim, feed and move away from pursuit.

A planted setup is strongly recommended by Seriously Fish, including floating plants. Live plants can create sight breaks, shelter and calmer margins without filling every centimetre. Artificial plants and aquarium-safe ornaments can also provide cover when their surfaces cannot snag fins. Arrange them in separate clusters so a fish can leave another’s line of sight rather than becoming trapped in one dense corner.

Balance cover with observation

Cover has two effects in a livebearer aquarium. It can help a pursued fish avoid constant attention, but it can also increase survival of young fish. Decide whether that result fits the population plan before adding dense floating roots or fine-leaved planting throughout the aquarium.

Leave enough access for gravel cleaning, filter checks and close observation. Persistent hiding must not disappear behind the decor unnoticed. View the aquarium from more than one angle and check that each individual can reach food without entering another fish’s defended position.

Use aquarium gravel or sand as appropriate for the complete community. Keep ornaments stable and avoid sharp edges around fins. Maintain useful surface movement while preserving at least some calmer water where small fish can rest without being pushed continuously.

A secure lid is a sensible part of the complete aquarium. Route cables and filter returns without leaving avoidable gaps, while maintaining the ventilation required by the equipment. Keep the aquarium away from direct sunlight and draughts so the layout does not sit inside a cycle of daily heating and cooling.

Plan a social group, not a number per litre

OATA advises keeping at least three guppies and suggests two females to each male in mixed groups to reduce stress on females and other inhabitants. Our more conservative house recommendation is five or more Endlers where aquarium capacity, the sex plan and other livestock allow. Five is a planning screen rather than permission to keep adding fish until a litres-per-fish calculation is full.

Begin with the aquarium’s usable length, mature filter capacity and existing population. Then decide whether each fish can swim, feed and leave another’s path. A 45-litre minimum for a small group and a 60 cm minimum length are starting filters; neither predicts a safe maximum once tank mates or fry are included.

Choose the group structure deliberately

Mature males have a narrow modified anal fin called a gonopodium, while mature females have a broader triangular anal fin. Males are often smaller and more colourful, but colour, body size, body depth or a rounded abdomen alone must not be treated as proof. Observe anal-fin shape only when the fish is mature enough for the feature to be clear.

No sex ratio prevents all conflict. Seriously Fish notes that males can be peaceful towards one another while females may act territorially, and it recommends several females where females are kept. Individual behaviour, usable space and access to food still decide whether the arrangement works.

At feeding time, watch the whole group rather than the first fish that reaches the food. Persistent exclusion, cornering, clamped or damaged fins, loss of body condition or hiding through several observation periods calls for intervention. Reposition sight breaks, reassess stocking and use a mature separation aquarium when one fish remains at risk.

Never add another fish simply to dilute aggression without checking capacity. A larger social group can spread attention in a suitable aquarium, but it also increases waste, feeding competition and potential reproduction.

Feed small portions the whole group can eat

Endlers are omnivorous. In nature, the species feeds on zoobenthos and detritus, while aquarium guidance recommends an appropriately small complete food with plant or algal content. Choose fine flake or small granules that the smallest fish can take without repeated spitting.

OATA recommends one daily portion that the fish finish within a few minutes. It also suggests suitably small live or frozen variety, including daphnia, small bloodworm or tubifex, and notes that Endlers may need smaller items such as cyclops. A safe compatible variety can supplement the complete staple, but one frozen food should not replace a balanced base diet.

Use the fish to judge particle size and portion

1. Crush or select the food so every fish can swallow it cleanly.
2. Distribute it across more than one point when dominant fish intercept the first particles.
3. Watch each individual take food rather than assuming the group has eaten.
4. Stop when the portion is consumed within a few minutes.
5. Reduce the next portion when food repeatedly reaches the substrate uneaten.

Overfeeding creates two problems at once: uneaten food decays into toxic waste, and excess intake can distort body-condition checks. Increase a portion only after observing that all food is taken promptly and slower fish still receive enough. Reassess after adding fish, discovering fry or changing food type.

Visible algae is not a complete diet. Likewise, treats rich in animal matter do not remove the need for vegetation or algal content. Store dry food in a cool, dry place, handle frozen food safely and avoid repeated thawing and refreezing.

If one Endler stops feeding, observe whether it is being excluded or whether its swimming, breathing, colour or body condition has changed. Test water promptly rather than solving a reduced appetite by scattering more food. Remove persistent leftovers and check that the filter continues to move water normally.

Fry require particles they can physically take and a population plan that accounts for their extra feeding and waste. Do not move adults or young fish into an immature container merely to simplify feeding.

Use a repeatable weekly routine

Carry out a 25% partial water change at least once each week, following OATA’s maintenance guidance. Use a siphon where needed to remove solid waste from accessible substrate, and treat replacement tap water with a conditioner that neutralises chlorine or chloramine before it enters the aquarium.

Match replacement water closely enough to prevent an abrupt temperature or chemistry change. A weekly change is a baseline, not a reason to ignore test results: extra waste from fry, heavier feeding or a larger community may require an earlier response.

Weekly checkpoint

• Test ammonia and nitrite and confirm both remain at zero.
• Record nitrate against the normal tap-water reading.
• Check temperature with the independent thermometer.
• Inspect the filter flow, intake and surface movement.
• Observe every fish feeding, swimming and moving away from others.
• Look for spots, wounds, swelling, damaged fins or body-condition changes.

Keep a simple written log. Trends are easier to recognise when temperature, pH, hardness, nitrogen readings, maintenance and population changes have dates beside them. A single acceptable reading cannot show whether conditions have been drifting over several weeks.

First-week checkpoints

During the first day, focus on steady swimming, balance, breathing and the ability to leave another fish’s path. Test water if behaviour changes. Over the first week, confirm that the new fish takes suitably small food and that established animals do not exclude it. Delay further stocking while the filter and social group adjust.

First-month checkpoints

Review whether the original capacity plan still matches reality. Count every fish, including fry; compare current feeding with the starting portion; inspect plant growth around swimming routes; and verify that nitrate remains manageable through the normal routine. Move decor only for a defined reason such as persistent pursuit, trapped debris or blocked flow.

Do not clean every part of the aquarium on the same day. Preserve biological stability by protecting mature filter media, avoiding complete substrate disturbance and retaining enough established surfaces. The aim is to remove waste without resetting the bacterial community that processes it.

If ammonia or nitrite rises above zero, respond immediately with testing, conditioned water changes and filter checks. Pause livestock additions and reduce avoidable excess food until readings return to zero and remain stable.

Respond early to health and population changes

A settled Endler should swim steadily, breathe regularly, hold its fins normally and show a consistent feeding response. The RSPCA’s fish-health guidance identifies changes in swimming, breathing, colour, temperament, appearance, body condition and feeding as reasons to investigate.

Do not choose salt, heat or medication from one symptom. Similar signs can arise from water quality, equipment failure, injury, social pressure or disease. Test ammonia, nitrite, nitrate, pH and temperature; inspect the filter and heater; and review recent livestock, food and maintenance changes. Seek a fish vet when signs are severe or persist.

A study of one captive P. wingei line recorded spinal deformities in 22 of 600 fish and discussed several possible contributors. That figure is not a species-wide rate, and a curved body does not identify one cause. Do not breed an affected fish or diagnose it from appearance alone.

Prepare for livebearer reproduction

Mixed-sex Endlers can reproduce readily. Plan mature spare capacity, filtration, appropriately small complete food and responsible rehoming before young fish appear. A life-history study of ten litters and 122 fry examined reproduction under one laboratory regime; use it as confirmation that population growth needs planning, not as a timetable or brood promise.

If fry appear, count them when practical, retest water and reassess filter capacity immediately. Do not transfer them into an uncycled container. Separate sexes only where identification is confident and both groups have mature suitable housing. Predation by adults or tank mates is not a responsible population-control plan.

Screen every companion before mixing

No fixed tank-mate list can guarantee a successful community. Screen each proposed companion for adult size, water range, predation risk, fin-nipping, territorial behaviour, feeding speed and the combined space required by every social group. The aquarium must meet the needs of all its inhabitants at the same time.

Apply the compatibility screen in order

1. Water: confirm the companion can remain long term at 24–28°C, pH 7–8 and 15–18 dGH.
2. Adult size: reject any species large enough to swallow an Endler.
3. Fins and behaviour: avoid known fin-nippers and persistent aggressive fish.
4. Space: add the companion’s footprint and social-group needs to the Endler plan.
5. Feeding: check that small Endlers can receive food before faster or larger animals intercept it.
6. Separation: keep a mature alternative ready if individual behaviour defeats the plan.

OATA specifically says Endler guppies should not be kept with species large enough to eat them or with fish that may nip their fins, such as barbs. These are direct avoid rules. A fish described only as peaceful still needs the full screen because peaceful species can differ sharply in size, water chemistry, activity and feeding speed.

Seriously Fish names dwarf corydoras, small peaceful rainbowfish and peaceful tetras as examples that may work. Treat each as a candidate, not an automatic match. Identify the exact species, check its adult group and water needs, and ensure the aquarium has enough room beyond the Endlers’ own minimum plan.

Add animals slowly and observe the complete aquarium during feeding and quieter periods. Repeated chasing, cornering, missed meals, damaged fins or abnormal hiding means the combination needs intervention rather than more livestock.

Protect lineage and plan for small invertebrates

Avoid common guppies, Poecilia reticulata. Seriously Fish reports that the two species will crossbreed, and morphological and molecular work supports P. wingei as a distinct species while showing that appearance can overlap. Colour, tail shape or an informal trade label cannot establish pedigree.

Keep documented lines in separate aquariums and retain their ancestry details. If offspring have uncertain or mixed ancestry, describe them honestly rather than assigning a pure species or locality name from appearance. The word assorted refers to colour variety here; it is not a lineage certificate.

Treat shrimp compatibility as conditional

No fish is guaranteed shrimp-safe. Adult shrimp may coexist in a suitably planned aquarium, but small shrimp and young can be eaten, while feeding competition can occur at any size. Dense moss and other cover may reduce exposure but cannot guarantee survival. Check the shrimp’s own temperature, mineral and social requirements before combining it with Endlers.

Do not use shrimp as a substitute for maintenance. They do not remove the need for controlled feeding, gravel cleaning, conditioned water changes or filter care. When shrimp breeding is the priority, a fish-free aquarium avoids the predation risk created by Endlers.

Separate breeding goals from community goals

Seriously Fish recommends a species aquarium when breeding Endlers is the aim. This removes many predation and hybridisation variables but does not remove the need to manage courtship, waste and crowding. Dense cover can increase fry survival, so match planting to the number of young fish the aquarium can support.

For a peaceful display, start with a conservative Endler group and add only companions that pass every part of the screen. Avoid combining several social species merely because each is small. Their minimum groups, swimming areas and feeding demands accumulate even when their individual body lengths do not.

Observe individuals rather than relying on category labels. One fish that repeatedly prevents another from feeding can make an otherwise plausible combination unsuitable. Rearrange sight breaks where that addresses pursuit, but use a mature separation aquarium if the behaviour continues or physical damage appears.

Never release unwanted fish, hybrids, fry, shrimp, plants or aquarium water outdoors. Prevent uncontrolled reproduction where possible and arrange permanent suitable care or responsible rehoming before capacity is exceeded.

Answer the key buying questions

How big does an Assorted Endlers Guppy get?

Plan for an adult standard length of 2.0 cm; standard length excludes the tail.

What size aquarium does an Assorted Endlers Guppy need?

Use a mature filtered aquarium of at least 45 litres for a small group under OATA guidance and at least 60 cm long under our conservative house policy.

How many Poecilia endler should I keep together?

Plan five or more where capacity and sex planning allow; OATA’s lower group starting point is at least three guppies.

Does an Assorted Endlers Guppy suit beginners?

It can suit a prepared beginner who provides a mature filtered aquarium, tested stable water, a social plan and capacity for possible fry.

What does it eat?

Assorted Endlers Guppy is omnivorous; feed an appropriately small complete flake or granule with algal content once daily, offering only what it finishes within a few minutes.

What temperature and pH does it need?

Keep it at 24–28°C, pH 7–8 and 15–18 dGH, the overlap between Seriously Fish species guidance and OATA guppy-and-molly guidance.

Is this fish aggressive or likely to nip fins?

Endlers are social, but courtship, pursuit and territorial behaviour need monitoring; avoid keeping them with fish that may nip their fins.

Which animals can live with this fish?

Consider dwarf corydoras, small peaceful rainbowfish or peaceful tetras only after checking water, adult size, group space and feeding; avoid predators, fin-nippers and common guppies, and treat shrimp as conditional because small shrimp and young may be eaten.

How does it arrive alive in the UK?

Film every delivery continuously from the sealed parcel as it is opened, with the fish still inside the bag. Someone must be present to receive the parcel; float the bag for 20–30 minutes, then release the fish without pouring bag water into the aquarium.

Check the care and identity references

• FishBase: Poecilia wingei — accepted identity, family, distribution, maximum recorded length and conservation category.
• Seriously Fish: Poecilia wingei — aquarium footprint, water, diet, behaviour and compatibility guidance.
• OATA: guppies and mollies — UK group husbandry for water, social care, feeding and maintenance.
• RSPCA: aquarium environment — biological filtration and waste processing.
• RSPCA: pet fish health — behavioural and physical warning signs.
• Eschmeyer’s Catalog of Fishes — valid scientific name and family placement.
• Poeser, Kempkes and Isbrücker, 2005 — original description, locality and measured specimens.
• Schories, Meyer and Schartl, 2009 — species distinction and overlapping morphology.
• Arbuatti, Della Salda and Romanucci, 2013 — spinal deformities observed in one captive line.
• Hernández-López and Luna-Vivaldo, 2021 — limited laboratory observations of reproduction and early life.