Poecilia reticulata female rainbow

Meet the rainbow female guppy

The rainbow female guppy (Poecilia reticulata) is a small freshwater livebearer in the Poeciliidae family. FishBase records its native range across Venezuela, Barbados, Trinidad, northern Brazil and the Guianas, although guppies have also been introduced far beyond that range. Females reach 5 cm standard length, and this fish suits a prepared beginner who can provide a mature, filtered aquarium rather than an uncycled bowl. Plan for a social group of five or more in an aquarium at least 60 cm long, with open swimming room, cover and a deliberate population plan.

Keep the aquarium at 22–28°C, pH 7.0–8.0 and general hardness of 9–18 dGH. These routine values are the overlap of FishBase's recorded ranges, the Seriously Fish species profile, OATA's guppy-and-molly guidance and the routine policy in our complete Guppy Care Guide. Ammonia and nitrite should both remain at zero.

Eschmeyer's Catalog of Fishes accepts the name Poecilia reticulata. “Rainbow” describes the selected aquarium appearance rather than a separate species. This peaceful fish works best for a keeper ready to test water, maintain the filter, monitor social pressure and respond if fry appear.

Decide whether this guppy fits your aquarium

Choose this guppy when the aquarium is already mature, mineral-bearing and long enough for a small social group. The easy care rating reflects its broad aquarium adaptability, not permission to skip cycling, testing or population planning. Guppies produce waste continuously, and a mixed or previously mixed female group may add fry, so spare biological capacity matters.

The adult group, existing animals, filtration, footprint and test results must be considered together. A nominal volume cannot show whether every fish has room to swim, reach food and move away from persistent pursuit. If one fish repeatedly hides, misses food or develops fin damage, treat that behaviour as a reason to change the arrangement rather than add more fish.

Understand the female offer and dispatch size

One purchase supplies one live female fish. The dispatch size is 3–4 cm, while the aquarium must be planned around the 5 cm adult standard length. Dispatch size describes the fish when sent and is not a permanent space requirement.

Sex is guaranteed only when the exact product or selected option explicitly states male or female. This Poecilia reticulata female rainbow listing is sold as female.

The gallery images are representative of this type of animal rather than photographs of the exact animal supplied, so colours can look slightly different from the live animal. Rainbow females may show individual differences in iridescence, body colour and tail pattern without changing their identity as Poecilia reticulata.

Build the intended social group deliberately rather than treating several separate purchases as a balanced ratio. A female-only plan prevents new mating within that group, but a female that encountered a male earlier may later produce fry. If comparing other colours or stated sexes, browse the current guppy collection and assess each exact offer separately.

Plan the aquarium around the adult length

Use an aquarium at least 60 cm long for one small guppy group. Our conservative house policy combines FishBase's 60 cm aquarium note and group of five or more with OATA's 45-litre starting point for a small group of smaller livebearers. Length matters because it gives the fish usable horizontal swimming room and more opportunity to move away from courtship or competition.

Understand the size figures

The adult planning length is 5 cm standard length for the sold female sex, as recorded by FishBase. Seriously Fish gives an aquarium base of 45 × 30 cm at about 41 litres. Standard length excludes the tail fin, and domestic finnage varies, so a broad tail should not be added to the body-length figure as though every fish had an identical total length.

Screen the whole aquarium

• Length: provide at least 60 cm of aquarium length under our house policy.
• Footprint: preserve open horizontal swimming room after plants and ornaments are installed.
• Filtration: allow for the adult group, existing livestock and possible fry rather than only the initial fish.
• Social plan: start with five or more only where sex mix, test results and capacity allow.
• Separation: keep a mature alternative space ready for persistent pursuit, injury or population management.

A tank near 41–45 litres may meet a published volume or footprint reference yet still fail the 60 cm length screen. Conversely, a larger volume is not an automatic entitlement to add fish. Check internal dimensions, mature filtration, other occupants and observed behaviour before setting the group size.

Use a worked capacity check

For a nominal 60-litre aquarium, first confirm that its internal length is at least about 60 cm. Then subtract the space occupied by deep decor, bulky equipment and the established territories or social groups of existing fish. Confirm zero ammonia and nitrite before adding guppies, and leave enough filtration capacity for normal feeding and possible fry. If the aquarium is shorter than 60 cm, already supports another full group or shows unstable test results, the litre label alone does not make it suitable.

Keep the water stable and mineral-bearing

Keep this guppy at 22–28°C, pH 7.0–8.0 and 9–18 dGH. These routine values are the overlap of FishBase's recorded ranges, the Seriously Fish species profile, OATA's guppy-and-molly guidance and Tropical Fish Co's routine guppy policy.

Measure the water you actually use

Test the aquarium and source water rather than relying on a regional reputation for “hard” or “soft” tap water. Supplies can differ between areas and may change when water companies blend sources. Use the aquarium water chemistry guide to understand each measurement, then compare the measured values with the guppy range.

If temperature drifts outside the routine range, check the heater, thermometer and room conditions before making a gradual correction. If pH or hardness differs, identify the source-water value first and change conditions gradually. Do not add salt simply because the species can occur in brackish environments. Any mineral or salt addition needs a measured purpose and a compatibility check for every fish, invertebrate and plant in the aquarium.

Interpret changes as a pattern

Compare each result with the previous reading and with the tap water used for replacement. A sudden pH shift alongside detectable ammonia or nitrite calls for an immediate check of filtration, recent additions and maintenance. A consistent hardness outside 9–18 dGH calls for a stocking decision based on the actual source water, not repeated unmeasured chemical correction. Record the date, temperature, pH, hardness and nitrogen readings so gradual drift is visible before fish behaviour changes.

Build biological filtration before adding fish

Add this guppy only after the aquarium has a functioning biological filter and repeated tests show zero ammonia and zero nitrite. The RSPCA explains that fish release toxic ammonia; filter bacteria convert it to nitrite and then to safer nitrate. A running filter is therefore part of the animal's life-support system, not just a way to make the water look clear.

If this is your first aquarium, prepare and mature the tank before livestock arrives. Do not judge maturity by elapsed time alone. Test results must show that the biological filter can process waste, and stocking should increase slowly so the bacterial population can respond to greater feeding and waste production.

Follow a measurable weekly routine

1. Test ammonia, nitrite and nitrate at least once each week.
2. Change 25% of the water at least once every week, using a siphon to remove settled waste from the gravel.
3. Treat replacement tap water with a conditioner that removes chlorine or chloramine.
4. Bring replacement water towards suitable aquarium conditions and avoid sudden changes.
5. Check the filter for restricted flow or blockages.
6. Rinse dirty filter media lightly in removed aquarium water rather than under the tap.
7. Record unusual readings, maintenance and livestock changes so a pattern is easier to identify.

Clean mature filter media only by rinsing it lightly in removed aquarium water so fewer beneficial bacteria are lost. Chlorine or chloramine can damage the bacterial population, while excessive cleaning can reduce the filter's capacity just as the fish continue producing waste. After adding fish, increasing food or discovering fry, watch the next test results closely. Detectable ammonia or nitrite calls for immediate investigation of stocking, feeding, filter function and water-change needs.

Provide cover without losing swimming room

Arrange the aquarium with open horizontal swimming space, planted cover and places where one fish can move out of another's direct line of sight. Guppies appreciate planted aquariums and floating vegetation, but the layout must still let the whole group swim and feed freely. Fit a secure cover to the aquarium.

Balance structure and access

• Open water: preserve a clear swimming route along the aquarium's length.
• Plants: use live or suitable artificial plants to create shelter and visual breaks.
• Surfaces: avoid sharp ornaments or rough artificial plants that may damage fins.
• Flow: avoid strong current; long-finned fish should not be pinned, exhausted or kept away from food.
• Intakes: check that a filter intake cannot trap small fish or fry.
• Observation: change the layout if one fish remains cornered, excluded or unable to rest.

More decoration is not automatically better. Dense structure can block usable swimming room or hide continuing pursuit from view. Place cover around open areas so a fish can break visual contact without disappearing into an inaccessible space. Watch how the group uses the aquarium after each layout change rather than assuming the intended shelter has worked.

Dense plants can increase fry survival. That may help a deliberately managed breeding plan, but it can also raise the population and filtration load. Choose the amount of cover together with the plan for housing and responsibly rehoming young fish; plants do not replace that decision.

Check the layout from the fish's route

Trace a clear path along the length of the aquarium and make sure plants or ornaments do not turn it into narrow dead ends. Observe the group at feeding time and during normal swimming. If every fish can cross the tank, approach food and leave another fish's line of sight, the layout is serving both movement and refuge. If one area traps a fish against glass or strong flow, move the obstruction or redirect the outlet and watch the result.

Feed a complete omnivore diet in measured portions

Use an appropriately sized, nutritionally complete omnivore flake or granule as the staple food. Add safe compatible variety rather than building the diet around one treat. FishBase records zooplankton, small insects and detritus in the wild diet, while Seriously Fish describes wild fish as primarily insectivorous and notes that aquarium strains accept most foods offered.

Build variety around the staple

• Offer a complete flake or small granule sized for the fish's mouth.
• Add small live or frozen items such as daphnia, small bloodworm or tubifex as compatible variety.
• Include a safe algal component within a balanced omnivore routine.
• Use biosecure aquarium foods rather than collecting food or detritus outdoors.
• Make sure shy fish reach food before the portion is finished.

OATA's guppy-and-molly feeding guidance says guppies should be fed only what they can eat within a few minutes, once a day. Start with a small measured portion, observe the whole group and stop before food settles. Remove uneaten food because it breaks down into waste and increases the load on the biological filter.

Respond to what you see

If food repeatedly reaches the substrate, reduce the next portion or use a better-sized food. If one fish misses meals, spread a small portion across more than one point and check for chasing, illness or unsuitable particle size. A sudden loss of appetite is a health warning, especially when accompanied by hiding, altered breathing or unusual swimming.

Fry need food small enough for their mouths and especially close water-quality monitoring. Before raising young deliberately, prepare a mature nursery system with safe filtration and sufficient capacity rather than moving them to an uncycled container.

Review the portion against water quality

A suitable portion leaves no persistent food and lets each fish feed without frantic competition. Check the aquarium after the feeding window: settled flakes, swelling granules or repeated leftovers mean the portion or particle size needs reducing. If nitrate rises faster after a feeding change, compare the new quantity with the previous routine and confirm that the filter remains clear and functional. Increase variety by substituting part of a portion, not by adding an unmeasured extra meal.

Plan the social group and possible fry

Keep five or more guppies where aquarium capacity, sex planning and other livestock allow. FishBase gives a group of five or more, while OATA advises at least three and suggests two females per male in mixed groups. Tropical Fish Co uses the more conservative five-or-more policy because a social plan must account for adult fish, filtration, feeding access, pursuit and possible fry.

Choose the group deliberately

No ratio guarantees a calm group. Watch whether every fish can feed and use open water without repeated cornering, hiding or fin damage. Keep a mature separation option ready; adding more fish is not the automatic answer to a persistent interaction.

Guppies are livebearers. Seriously Fish notes that a female can retain viable sperm after earlier contact with a male, so a later brood may appear without a male currently present. Prepare for that possibility before adding female guppies. If fry arrive, monitor ammonia and nitrite closely, protect filter intakes and assess capacity before deciding which young can remain.

Use behaviour as the checkpoint

• Calm group: all fish swim, feed and rest without one individual being persistently excluded.
• Social pressure: repeated pursuit, cornering, missed food or damaged fins requires intervention.
• Growing population: review filtration, swimming room and rehoming plans before young mature.

Never release guppies, fry, plants, aquarium water or other aquarium life outdoors. Rehome livestock responsibly and dispose of aquarium water where organisms cannot reach ponds, drains connected to natural water or other watercourses.

Manage arrival and health changes promptly

Prepare and test the mature aquarium before the fish travels. OATA's guppy-and-molly guidance calls for zero ammonia and zero nitrite before fish are introduced. Arrange for someone to be present to receive the parcel, and open and inspect it on the day it arrives.

Follow the store arrival steps

1. Start filming before the parcel is opened, showing the parcel still sealed, the continuous opening and the fish still inside the bag.
2. Float the bag for 20–30 minutes before releasing the fish.
3. Release the fish without pouring the bag water into the aquarium.

These steps come from the current delivery and Live Arrival Guarantee policy. Fish are hand-bagged in pure oxygen and placed in an insulated poly box, with a heat pack when weather conditions call for one.

Check the fish and aquarium together

A settled guppy should swim steadily, breathe regularly, hold open undamaged fins, maintain a normal body profile and feed consistently. Warning signs include surface gasping, sitting on the bottom, erratic swimming, loss of balance, clamped or damaged fins, unusual hiding, white spots, fluffy growths, wounds, sudden colour change or reduced appetite.

If behaviour or appearance changes, test ammonia, nitrite, nitrate, pH and temperature immediately. Inspect filter flow, heater operation, recent maintenance, food, additions and social behaviour. RSPCA fish-health guidance supports prompt water-quality checks and veterinary escalation. Do not select salt, heat or medication from one symptom alone.

Use quarantine as prevention

Run quarantine as a separate, biologically supported and tested system with dedicated equipment. The MSD Veterinary Manual recommends at least 30 days of isolation, with longer periods where indicated. Keep ammonia and nitrite at zero throughout rather than relying on the calendar.

When diagnosis or treatment is needed, use the OATA fish-vet directory to find qualified help. Record test results, symptoms and photographs so changes can be described accurately. A timely water-quality response can remove an immediate stressor while professional advice addresses the cause.

Screen every tank mate before combining groups

This guppy is peaceful, but peaceful behaviour does not make every community combination safe. Seriously Fish says it does well in a quiet community tank with other livebearers, rasboras, corydoras, small loricariids and tetras. Treat those as kinds to assess, not universal approvals, because exact species, adult size, water needs and behaviour still matter.

Use the same six checks every time

1. Water: choose a shared working range for temperature, pH and hardness rather than holding either animal at an extreme.
2. Adult size: make sure neither animal can swallow, trap or injure the other.
3. Fins and temperament: assess fin-nipping, territorial behaviour, courtship and pursuit.
4. Space: include the full social group and usable footprint for both species.
5. Food: confirm that every animal can reach an appropriate diet without exclusion.
6. Separation: have a mature alternative space if observed behaviour changes.

Avoid tiger barbs, serpae tetras and any other fish that might nip guppy fins, including barbs. Seriously Fish specifically names tiger barbs and serpae tetras as unsuitable fin-nipping companions. The rule is based on the risk to the guppy's fins rather than assuming that every fish sold under a broad community label behaves alike.

After introducing a compatible group, watch feeding access, swimming, hiding, pursuit and fin condition. Repeated cornering, missed meals or new damage means the combination needs intervention. Do not wait for severe injury simply because the water values overlap.

Apply the compatibility screen to common choices

Quiet rasboras, corydoras, small loricariids, compatible livebearers and non-fin-nipping tetras may work when their exact water values, adult size, group needs and footprint fit the aquarium. Check the needs of both social groups; a tank large enough for one group is not automatically large enough for two.

A betta and guppy combination is not a sensible default. Individual display, territorial and long-fin interactions vary, and more plants or volume cannot guarantee safety. Use a different plan unless the exact animals, aquarium and separation arrangements have been carefully assessed.

Compare complete groups, not single fish

For a proposed corydoras community, calculate space for the corydoras group and its bottom footprint before reserving the open upper area for guppies. For another livebearer, include its adult size, group plan, sex pressure and possible fry in the filtration calculation. With tetras or rasboras, assess the complete shoal and confirm that its working water range overlaps 22–28°C, pH 7.0–8.0 and 9–18 dGH. A single compatible-looking fish is not a substitute for meeting the social needs of both species.

Keep guppies and Endler lines distinct when identity matters

Endler's livebearer is Poecilia wingei, a separate species supported by its formal description and current status in Eschmeyer's Catalog of Fishes. Guppies and Endlers can hybridise. If preserving a documented line matters, avoid mixing them: house them separately and do not represent hybrid descendants as pure examples of either species.

Answer common questions before choosing this guppy

How big does Poecilia reticulata female rainbow get?

It reaches 5 cm standard length as an adult female. Standard length excludes the tail fin, so plan the aquarium around the 5 cm body measurement while allowing room for variable domestic finnage.

What size aquarium does Poecilia reticulata female rainbow need?

Use a mature, filtered aquarium at least 60 cm long for one small group. Seriously Fish gives a 45 × 30 cm base at about 41 litres, while Tropical Fish Co applies the more conservative 60 cm length screen.

How many Poecilia reticulata female rainbow should I keep together?

Keep five or more where aquarium capacity and the sex plan allow. FishBase gives a group of five or more, and Tropical Fish Co uses that conservative policy while OATA's lower group guidance is at least three.

Is Poecilia reticulata female rainbow suitable for beginners?

Yes, it can suit a prepared beginner and carries our easy care rating, but it needs a mature filtered aquarium, zero ammonia and nitrite, stable mineral-bearing water, weekly maintenance and a population plan.

What does Poecilia reticulata female rainbow eat?

Feed an appropriately sized complete omnivore flake or granule as the staple, with safe algal and small invertebrate variety. OATA's guppy-and-molly guidance says to feed once daily and only what the fish consume within a few minutes.

What temperature and pH does it need?

Keep it at 22–28°C, pH 7.0–8.0 and 9–18 dGH. These routine values are the overlap of FishBase's recorded ranges, Seriously Fish, OATA's guppy-and-molly guidance and Tropical Fish Co's routine guppy policy; ammonia and nitrite should remain at zero.

Is this fish aggressive or likely to nip fins?

It is peaceful, but courtship or social pursuit can still pressure another guppy. Guppy fins are vulnerable to nippers, so avoid tiger barbs, serpae tetras and any other fish that might nip fins, including barbs.

Which animals can it live with?

It may share a quiet community with compatible livebearers, rasboras, corydoras, small loricariids and non-fin-nipping tetras. Check the exact species for matching water, adult size, group space, feeding and behaviour; small shrimp or young may be eaten.

How does this fish arrive alive in the UK?

It is hand-bagged in pure oxygen and placed in an insulated poly box, with a heat pack when weather calls for one, then carried by a tracked licensed live-animal service. Be present to receive the parcel and open it the same day: start filming before opening it, showing it sealed, the continuous opening and the fish still in the bag, then float the bag for 20–30 minutes and never pour bag water into the aquarium.

Consult the reference library

• FishBase: accepted identity, family, native distribution, environmental range, adult length, wild habitat, diet and aquarium group note.
• Seriously Fish: aquarium dimensions, water ranges, diet, behaviour, named community companions, sex differences and reproduction.
• OATA guppy-and-molly sheet: group water values, aquarium planning, feeding, maintenance, social ratios and health observations.
• RSPCA aquarium environment guidance: biological filtration and the conversion of ammonia through nitrite to nitrate.
• RSPCA fish health and welfare: normal condition, warning signs, water-quality checks and veterinary escalation.
• Eschmeyer's Catalog of Fishes: accepted scientific names and taxonomic status for Poecilia reticulata and Poecilia wingei.
• MSD Veterinary Manual: biosecure quarantine, water-quality-led investigation and isolation duration.
• OATA fish-vet directory: access to qualified fish veterinary help in the UK.
• Poeser, Kempkes and Isbrücker: formal description of Poecilia wingei as a distinct species.