Red Cap Female Guppy (Poecilia reticulata)

Meet the Red Cap Female Guppy

The Red Cap Female Guppy (Poecilia reticulata) is a peaceful freshwater livebearer in the family Poeciliidae. FishBase records the species across Venezuela, Barbados, Trinidad, northern Brazil and the Guyanas, while the aquarium trade has developed many ornamental varieties. This female reaches 6 cm standard length and suits a prepared beginner with a mature, filtered aquarium, tested mineral-bearing water and a plan for its social and reproductive needs.

Red Cap is the colour-form name for this offer rather than a separate species. The adult body size matters more than the dispatch measurement when planning space, filtration and companions. Standard length measures the body without the tail fin, so provide for the full adult fish and its social group instead of choosing an aquarium around the smaller arrival size.

Wild guppies occupy varied habitats, including vegetated springs, lakes, streams, ditches and canals. FishBase records zooplankton, small insects and detritus in their diet. In an aquarium, use those feeding habits to choose a complete small-fish food with suitable animal and plant variety rather than trying to reproduce material collected from the wild.

The accepted scientific name remains Poecilia reticulata. Eschmeyer’s Catalog of Fishes records the accepted name, authorship and type locality. Use the scientific name when checking water, adult size or compatibility advice, because colour-form names describe appearance rather than different husbandry requirements.

Decide whether your aquarium fits

This guppy suits a keeper who can maintain a social group in a stable aquarium at least 60 cm long. Tropical Fish Co uses five or more guppies as its conservative group policy where sex mix, filtration, water tests and other livestock allow. A mature biological filter, zero ammonia and nitrite, neutral-to-alkaline water and enough mineral content are essential parts of that plan.

The 22–28°C, pH 7.0–8.0 and 9–18 dGH routine is the overlap of FishBase, Seriously Fish and the Tropical Fish Co guidance. It gives a clear operating range inside the species values rather than asking the fish to live at the edge of one reference. Test the aquarium itself, because room temperature and local tap-water descriptions cannot replace measured water values.

Guppies are peaceful, but that does not make every community combination safe. Allow for the adult size and social group of every species, assess feeding competition and exclude fish known to nip fins. Keep a separation option ready if pursuit, hiding, missed feeding or damaged fins show that the observed combination is not working.

Understand the female offer and gallery

One purchase supplies one female fish. Use the live size selector to choose 2-3 cm or 3-4 cm. These labels describe the approximate dispatch size rather than a promise of age or reproductive stage. The size you select is the size supplied, not the adult size. Plan every aquarium, group and tank-mate decision around the 6 cm adult standard length.

Sex is guaranteed only when the exact product or selected option explicitly states male or female. This Red Cap Female Guppy listing is sold as female. The offer does not make a claim about pregnancy, earlier mating or whether fry may later appear.

Some gallery images have been digitally enhanced to improve image quality. They show the listed type of animal rather than guaranteeing the exact markings of the individual supplied, so natural colour and pattern can vary. One scene shows two fish, but the purchase unit remains one female. Use the written identity and care requirements for planning rather than treating the number of animals in a representative scene as an order quantity.

Individual colour placement and intensity may differ from the representative scenes. The visible Red Cap direction includes warm red-orange colour around the head, with related colour shown on the tail in the gallery. Compare other forms through the current guppy collection, while keeping the same adult-space, group and water checks for Poecilia reticulata.

Plan space for the adult group

Plan for a female reaching 6 cm standard length. Seriously Fish records 60 mm standard length and gives a 45 × 30 cm aquarium base, approximately 41 litres, as its species reference. FishBase gives a 60 cm minimum aquarium length and a group of five or more. Tropical Fish Co therefore uses a mature, filtered aquarium at least 60 cm long for one small guppy group, then adjusts the plan for sex mix, existing livestock, filtration and water-test results.

A nominal volume is not a stocking allowance. Two aquariums carrying the same litre label may have different lengths, footprints, filter capacity and usable swimming room. Measure the internal dimensions, confirm at least 60 cm of aquarium length and consider how much space remains after substrate, decor and the needs of every other social group.

Use an adult-stock calculation

• Start with five guppies: this is the store’s conservative social policy where aquarium capacity and the sex plan allow.
• Add existing livestock: count each companion at its adult size and include its full group requirement.
• Allow for possible fry: a female may later produce young after an earlier mating, so keep a population response ready.
• Watch the fish: persistent pursuit, exclusion from food, hiding or fin damage means the plan needs intervention.

Do not use a smaller aquarium because the selected fish is 2-3 cm or 3-4 cm at dispatch. Growth, social needs and biological waste continue after arrival. More water can improve stability and provide options, but it does not remove the need to test the aquarium or create an automatic entitlement to add more fish.

Keep open swimming room alongside planted cover and sight breaks. Guppies appreciate vegetation, including floating plants, while strong currents should be avoided. Arrange the return flow so the fish can hold position, feed and move through the aquarium without being pinned or exhausted.

Hold water inside the shared range

Keep the aquarium at 22–28°C, pH 7.0–8.0 and 9–18 dGH. These routine values are the overlap of FishBase, Seriously Fish and the Tropical Fish Co Guppy Care Guide. OATA’s guppy-and-molly sheet gives 20–28°C, pH 7.0–8.0 and 8–18 dGH for the group; these are broad planning values, not a species-specific optimum.

Maintain zero ammonia and zero nitrite. OATA also advises that nitrate should not exceed 20 mg per litre above the normal tap-water level. Record the source-water result as well as the aquarium result so a rising trend is not hidden by an assumption about local tap water.

Use the water chemistry guide to understand each test and the water matcher to compare measured values with this routine. Test strips or liquid kits must be in date and used according to their own instructions. A clear-looking aquarium can still contain toxic nitrogen compounds.

Change water conditions gradually. Treat replacement tap water with conditioner before adding it, and keep the replacement reasonably aligned with the aquarium’s temperature and chemistry. Guppies occur in fresh and brackish environments, but this does not make routine salt addition necessary. Add minerals or salt only for a measured purpose that is compatible with every fish, invertebrate and plant in the aquarium.

Establish filtration, cover and usable swimming room

Use a fully established biological filter before adding the guppy. The RSPCA explains that fish release toxic ammonia, which a working biological filter converts through nitrite and eventually into safer nitrate. Confirm the filter’s performance with repeated water tests rather than relying on how long the aquarium has contained water.

If this is your first aquarium, follow the first tropical tank guide and complete the maturation process before livestock arrives. A newly filled tank, a newly installed filter or a complete media replacement is not ready merely because the heater has reached the right temperature.

Arrange the aquarium around normal movement

• Provide open water: leave a clear horizontal swimming route through the aquarium.
• Add cover: use live plants where possible, including planted margins or floating vegetation.
• Break lines of sight: arrange cover so a pursued fish can move away without becoming trapped.
• Control flow: avoid a strong current and spread or baffle the return if fish struggle to hold position.
• Keep decor safe: OATA recommends avoiding sharp objects that could damage long fins.

Sand or aquarium gravel can be used, and plants or suitable ornaments provide shelter. Leave enough access to remove debris during maintenance. Cover should create choices without blocking the swimming area or preventing every fish from reaching food.

Choose filtration for the completed adult community rather than the first fish added. Seriously Fish gives a turnover of four to five times aquarium volume per hour for its approximately 41-litre reference, equivalent to a filter rated around 165–205 litres per hour. Treat that as a setup calculation for that aquarium size, then account for actual media, flow loss and stock load.

Inspect the outlet and intake during routine care. A blocked filter reduces circulation and biological performance, while a forceful narrow outlet can exhaust a small fish. Any decline in flow, surface gasping or abrupt change in swimming should prompt immediate checks of water values and equipment.

Feed for insect and detritus foraging

Use an appropriately sized, nutritionally complete omnivore flake or granule as the staple. FishBase records zooplankton, small insects and detritus in the wild diet, while Seriously Fish describes wild guppies as primarily insectivorous and notes that aquarium fish accept most offered foods. Choose a staple containing suitable animal ingredients with compatible plant or algal variety rather than relying on one treat.

OATA’s group guidance is to feed once a day and offer only what the fish can eat within a few minutes. Begin with a small measured portion, watch every fish and reduce the next portion if food reaches the substrate uneaten. Excess food breaks down into waste and increases the demand on the biological filter.

Distribute food so quieter fish can take part. A peaceful species can still experience competition when one individual reaches every particle first. Watch body condition and feeding response across the whole group instead of judging the ration from the fastest fish.

Remove leftovers before they degrade water quality. If appetite falls, check temperature, ammonia, nitrite, social pressure and the fish’s breathing or swimming rather than adding several rich foods. A sudden feeding change can be an early warning sign, especially when accompanied by hiding, clamped fins or altered respiration.

Fry require food sized for their mouths and closer attention to water quality. Decide how young fish would be housed before attempting to raise them; an adult ration crushed without control can create heavy waste in a small nursery.

Plan the female group and possible fry

Keep five or more guppies where aquarium capacity and the sex plan allow. FishBase gives a group of five or more, while OATA suggests at least three guppies or mollies and two females to each male in mixed groups. Tropical Fish Co applies the more conservative five-plus group policy, then screens the aquarium for adult stock, filtration, test results and behaviour.

A female-only group prevents new mating inside that group, but it does not rule out later fry. Seriously Fish states that a female can preserve viable sperm and may produce young for six months or more without a male present. Treat this as a population-planning possibility rather than a statement about this individual.

Choose the group before adding fish

• Female-only: avoids new mating within the group, although earlier mating may still lead to young.
• Mixed sex: OATA suggests two females to each male, but the group still needs monitoring for persistent pursuit.
• Existing guppies: count them only when water, adult space, health and observed behaviour make the combined group suitable.
• Unexpected fry: prepare mature filtered capacity and a responsible long-term housing or rehoming plan.

Do not assume colour identifies sex. Seriously Fish describes a mature male’s gonopodium as a narrow, modified anal fin and notes that females are larger and plumper, while aquarium-bred females may still show intense tail colour. The offer’s stated sex is the relevant purchasing assurance.

Use planted cover and sight breaks, then observe the result. Repeated pursuit, cornering, hiding, missed meals or physical damage means intervention is needed. Move the affected fish only to a suitable mature system or safe separation space with stable heat, filtration and water quality.

Never release guppies, fry, plants, snails or aquarium water outdoors or into a surface-water drain, pond or natural waterway. FishBase records introductions far beyond the native range and reports negative to neutral effects on native fishes. Rehome surplus animals responsibly and dispose of aquarium water where organisms cannot reach natural watercourses.

Maintain the aquarium every week

At least once every week, change 25% of the aquarium water. This is OATA’s maintenance guidance for guppies and mollies. Use a siphon to remove settled waste, treat replacement tap water with conditioner before adding it and keep changes gradual enough to preserve stable temperature and chemistry.

Test at least once per week for ammonia and nitrite, with both remaining at zero. Track nitrate against the source water and keep it no more than 20 mg per litre above the normal tap-water level. Increase checks whenever livestock is added, feeding changes or fish show unusual behaviour.

Protect the biological filter

• Check the filter for blockages and confirm that its flow remains effective.
• If the filter needs cleaning, do not run it under the tap.
• Rinse it lightly in aquarium water removed during the partial water change.
• Avoid replacing all mature biological media together.

Watch swimming, breathing, colour, temperament, body condition, fins, scales and appetite. OATA lists surface hanging, bottom sitting, erratic swimming, altered gill movement, darker or paler colour, increased hiding, white spots, fluffy growths, lost fins or scales and reduced feeding as changes that need attention.

Test water first when a health change appears. Inspect the heater, filter, recent maintenance, feeding and social behaviour, then keep notes or photographs of the signs. The RSPCA fish health guidance supports checking water quality and seeking veterinary help for concerning changes.

Use a separate, biologically supported quarantine system with dedicated equipment where disease transfer is a concern. The MSD Veterinary Manual recommends at least 30 days of quarantine, with longer isolation where indicated. Quarantine still requires stable heat, filtration, cover, feeding and water testing; a small uncycled container is not a safe substitute.

Do not select salt, heat changes or medication from one symptom. Similar outward signs can have different infectious, environmental or social causes. Use the OATA fish-vet directory when qualified diagnosis or treatment direction is needed.

Follow the arrival procedure and first-month checks

Prepare the mature aquarium before the parcel arrives. Confirm the heater, filter and water tests, and make sure someone is present to receive the live fish. Follow the current delivery and Live Arrival Guarantee policy for the reporting requirements that apply to the order.

On arrival

1. Receive the parcel in person; live fish cannot be left unattended.
2. Start filming while the parcel is still sealed and the outer box is visible.
3. Open the parcel in one continuous take and show the fish inside the sealed bag before anything is disturbed.
4. Float the bag for 20–30 minutes before releasing the fish.

The fish is hand-bagged in pure oxygen and placed in an insulated box, with a heat pack when the weather calls for it. Keep the packaging while the condition of the fish is assessed and include the continuous unboxing video and order number with any Live Arrival Guarantee claim.

First-week checkpoints

• Swimming: look for controlled movement rather than surface hanging, bottom sitting or erratic swimming.
• Breathing: compare gill movement with the rest of the settled group.
• Feeding: offer a modest familiar ration and confirm that the new fish can reach it.
• Fins and body: check for intact scales, undamaged fins, spots, growths or wounds.
• Water: test immediately if behaviour, breathing or appetite changes.

OATA advises increasing aquarium population slowly because filter bacteria must respond to each rise in waste and feeding. Do not use the arrival as a reason for a major rescape, complete filter clean or several additional fish at the same time.

During the first month, keep the weekly 25% water change and testing routine, track interactions and check whether every guppy feeds. Persistent hiding, pursuit or damage calls for separation and a revised stocking plan rather than waiting for the fish to adapt indefinitely.

Screen every community companion

Choose companions only after their temperature, pH, hardness, adult size, group requirement, feeding behaviour and aquarium footprint have been checked against the complete guppy plan. Compatibility remains a conditional decision because the same species combination can behave differently as stocking, sex mix and aquarium layout change.

Seriously Fish describes Poecilia reticulata as very peaceful and lists other livebearers, rasboras, corydoras, small loricariids and tetras for a quiet community. Treat those as kinds to assess, not universal approvals. The exact companion must fit 22–28°C, pH 7.0–8.0 and 9–18 dGH, have enough room for its own adult group and allow every fish to reach food.

Keep fin-nipping species out of the aquarium. Seriously Fish says not to keep guppies with fin-nipping species, and OATA likewise says guppies should not be kept with species that might nip their fins. More planting does not cancel that instruction.

Assess invertebrates individually. The Tropical Fish Co guide explains that adult invertebrates are too broad a category for a promise and that small shrimp or young may be eaten. Check the exact invertebrate’s water chemistry, adult size and vulnerability, and use a dedicated setup when preserving every juvenile is the priority.

Respond to observed behaviour, not labels

A peaceful label describes the usual species temperament, not the outcome of every aquarium. Watch whether all fish can swim normally, reach food, use cover and rest without repeated pursuit. Hiding more than normal, missed feeding, torn fins or a fish being held in one corner means the community needs intervention.

Work through the decision in order

1. Check water: confirm temperature, pH, hardness, ammonia and nitrite before treating the problem as purely social.
2. Check space: include the adult size and full social group of every species, not just the guppy.
3. Check behaviour: identify which animal is pursuing, excluding or nipping rather than relying on a community-fish label.
4. Check feeding: spread an appropriate portion and confirm that each fish eats.
5. Separate safely: use a mature filtered option if damage or persistent pressure continues.

For example, a rasbora species named by Seriously Fish still needs its own group and compatible water. It should not be added if accommodating that group would crowd the 60 cm aquarium. A corydoras species also needs its own adult footprint and group assessment, even though it occupies a different part of the tank.

Mixed guppy sexes create a separate compatibility decision. OATA suggests two females to each male, while the store policy asks keepers to plan five or more fish where capacity allows. Neither figure guarantees low pursuit or manageable reproduction, so observe females for feeding access, body condition and opportunities to move out of sight.

Keep Endler’s livebearer separate when maintaining documented species lines. The formal description of Poecilia wingei and Eschmeyer’s current record treat it as a distinct valid species, while the Tropical Fish Co guide notes that guppies and Endlers can hybridise.

Answer common Red Cap Female Guppy questions

How big does a Red Cap Female Guppy get?

The Red Cap Female Guppy reaches 6 cm standard length. Seriously Fish records 60 mm standard length, so plan the aquarium around that adult body size rather than the 2-3 cm or 3-4 cm dispatch measurement.

What size aquarium does it need?

Use a mature, filtered aquarium at least 60 cm long for the Red Cap Female Guppy under Tropical Fish Co’s conservative house policy. Seriously Fish gives a 45 × 30 cm base and approximately 41 litres as its species reference, while total stock, sex mix, filtration and test results may require more space.

How many Red Cap Female Guppies should I keep?

Keep five or more Red Cap Female Guppies where aquarium capacity and the sex plan allow. FishBase gives a group of five or more, while OATA’s group guidance suggests at least three.

Is the Red Cap Female Guppy suitable for beginners?

The Red Cap Female Guppy suits a prepared beginner and carries an easy store care assessment. It still needs a mature filtered aquarium, zero ammonia and nitrite, tested mineral-bearing water, a social plan and provision for possible fry.

What does it eat?

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

What temperature and pH does a Red Cap Female Guppy need?

Keep the Red Cap Female Guppy at 22–28°C, pH 7.0–8.0 and 9–18 dGH, the overlap of FishBase, Seriously Fish and Tropical Fish Co guidance. Maintain ammonia and nitrite at 0 mg/L.

Is it aggressive, and will it nip fins?

This fish is described by Seriously Fish as very peaceful, but individual interactions still need observation. Avoid fin-nipping species, including tiger barbs and serpae tetras, because both Seriously Fish and OATA say guppies should not be kept with fish that may nip their fins.

Which kinds of animals can it live with?

It may share a quiet community with compatible livebearers, rasboras, corydoras, small loricariids and peaceful tetras after the exact species passes the water, adult-space, group and feeding screen. Small shrimp or other young invertebrates may be eaten.

How does a Red Cap Female Guppy arrive alive in the UK?

Film the sealed parcel before opening it, continue in one take until the fish is visible inside the sealed bag, then float the bag for 20–30 minutes before releasing the fish. Tropical Fish Co packs live fish in pure oxygen inside an insulated box, with a heat pack when the weather calls for it.

Check the public references

• FishBase: Poecilia reticulata — identity, family, distribution, recorded habitat, diet, water occurrence, adult length and aquarium group guidance.
• Seriously Fish: Poecilia reticulata — aquarium dimensions, adult length, water ranges, food, behaviour and named community types.
• OATA: How to look after guppies and mollies — UK group guidance on water quality, social planning, feeding and maintenance.
• RSPCA: Aquarium environment — filtration and biological waste processing.
• RSPCA: Fish health and welfare — health observations and escalation.
• MSD Veterinary Manual: Management of aquarium fish — biosecure quarantine guidance.
• OATA: Find a fish vet — UK fish-vet directory.
• Eschmeyer’s Catalog of Fishes: Poecilia reticulata — accepted name and type locality.
• Description of Poecilia wingei — formal description of Endler’s livebearer.
• Eschmeyer’s Catalog of Fishes: Poecilia wingei — current valid-status record.