Marble Sailfin Molly (Poecilia velifera)

Marble Sailfin Molly is the black, white and silver patterned aquarium trade form offered here under the species name Poecilia velifera. Each selected quantity supplies one live, unsexed fish at approximately 6-7 cm. It is not a guaranteed male, female, pair or group. The fish may still be developing its adult pattern and fins, so a young individual should not be expected to arrive with the fully raised sail seen on a mature displaying male.

This is a larger, active livebearer for a mature hard-water aquarium, not a small-tank substitute for a platy or guppy. Plan a long tank from about 100 cm and 160 litres for a carefully managed small group, with 120 cm and 200 litres or more preferred for mature adults, mixed sexes or a community. Keep the water mineral-rich and alkaline, use strong biological filtration, leave open swimming room and include sturdy planting or decor that breaks lines of sight.

Marble Sailfin Molly care at a glance

Question	Practical answer for this listing
What do I receive?	One live, unsexed fish per selected quantity
Approximate dispatch size	6-7 cm; a live size band, not an exact measurement or age
Expected adult scale	Commonly around 8-12 cm in the supplied care data; published species records reach 15 cm total length
Normal temperature target	24-27°C; acclimated range 23-29°C
pH	7.2-8.0
Hardness	About 12-25 dGH as a practical target; supplied range 10-30 dGH
Minimum planning point	100 cm long and about 160 litres for a carefully planned small group
Preferred mature setup	120 cm long and 200 litres or more
Diet	Omnivorous, with substantial algae and plant content plus modest animal protein
Care level	Moderate: forgiving only when hardness, space and filtration are right

Gallery and quantity note: the four existing gallery images are illustrative, aquarium references based on this trade form. They are not photographs of the exact individual dispatched and do not guarantee sex, mature dorsal height, body pattern or colour balance. One image shows two fish for social context; the live Shopify selector still supplies one unsexed fish per quantity. Every animal is individually patterned, and black, white, silver and blue-toned areas can differ substantially.

What exactly is a Marble Sailfin Molly?

The clean scientific entity for this listing is Poecilia velifera, a poeciliid livebearer described by Regan in 1914. “Marble” describes the domestic black-and-light colour pattern. It is not part of the Latin name and does not create a separate species. The NCBI Taxonomy record for Poecilia velifera and the FishBase species profile both keep the species in the family Poeciliidae.

Common names need care. Retail pages use “sailfin molly,” “marble molly” and “marble sailfin” for several domestic lines, sometimes labelled P. velifera, P. latipinna, P. sphenops or simply Poecilia sp. This page follows the current P. velifera identity attached to this fish. It does not claim DNA verification, wild locality, strain purity or that a domestic ornamental form is identical in every trait to a wild Yucatan population.

Name and evidence boundaries

Term	What it means here	What it does not prove
Poecilia velifera	The species identity used for this listing	A DNA result or certified wild collection locality
Marble	A domestic black, white, silver and variable patterned trade form	A separate species or a fixed identical pattern
Sailfin	The tall dorsal-fin character, most developed in mature displaying males	That every unsexed 6-7 cm fish is male or already has a full sail
One quantity	One live unsexed fish	A pair, trio, sexed group or the number of fish pictured

Natural range, habitat and conservation context

FishBase places the species in the Yucatan-Quintana Roo and lower Usumacinta-Laguna de Terminos systems of Mexico. It occurs in fresh and brackish environments rather than being restricted to one salinity. Wild habitat information helps explain why this fish values dissolved minerals, stable chemistry, warm water, oxygen exchange and room to browse, but an aquarium should reproduce the useful environmental functions rather than trying to copy a coastline with random salt additions.

Wild P. velifera is reported as Vulnerable in the conservation assessment referenced by FishBase. That status belongs to wild populations and should encourage responsible ownership: never release aquarium fish, fry, plants or water outdoors. It does not establish how an individual ornamental fish was produced. This listing therefore makes no unsupported captive-bred or wild-caught claim.

In nature, adults take plant matter as well as worms, crustaceans and insects. Their upturned mouth and constant browsing make sense in a bright, mature aquarium with biofilm, algae-coated surfaces and regular vegetable-rich food. A spotless but biologically immature tank is less suitable than a well-maintained established system.

Appearance, pattern and adult development

The appeal is the contrast: irregular black patches and speckling over a pale silver, white or cream base, sometimes with blue or warm metallic highlights. Pattern boundaries may sharpen as the fish settles and grows, but no two individuals are identical. Stress, transport, social status, lighting, substrate, diet and maturity can all change how dark or bright a fish appears from one day to another.

Mature males are generally slimmer and develop a gonopodium, the modified anal fin used in reproduction. Their dorsal can become much taller and more dramatic during display. Females usually retain a fan-shaped anal fin and a fuller body. Juveniles can be difficult to sex confidently, and a reference image of a mature male is not evidence that an unsexed fish will become male.

FishBase records a published maximum of 15 cm total length, while the current supplied care data gives 8-12 cm. That difference is useful rather than contradictory: domestic aquarium fish vary, and published maximum length is not the same as the size every individual reaches. The safe planning decision is to house the fish for the larger possibility instead of choosing a tank around its 6-7 cm arrival size.

How appearance can change

Feature	At approximately 6-7 cm	With maturity
Dorsal fin	May still look modest or partly developed	Mature males can show a much taller display sail
Sex	Not guaranteed by this listing	Gonopodium or fan-shaped anal fin becomes clearer
Marble pattern	Individual and potentially still changing	Contrast and coverage may strengthen or shift
Body depth	Young fish can look comparatively slim	Females often become fuller; adult body mass increases
Colour in photographs	Depends on light, camera and stress	Never a guarantee of the exact dispatched fish

Tank size and long-term space planning

A small molly at the shop counter can make a 60- or 90-litre aquarium look plausible. That is poor long-term planning for true P. velifera. The adult fish is long, deep-bodied and active, and a male needs room to raise the dorsal without constant contact with tank mates. Females also need distance from persistent courtship. Length and front-to-back depth matter more than a tall decorative column of the same volume.

Use about 100 cm of tank length and 160 litres as the starting point for a carefully managed small group. A 120 cm aquarium of 200 litres or more is the better choice for mature adults, mixed sexes or companion fish. Increase that again when combining several large livebearers, when filtration is modest, or when decor reduces swimming space. The RSPCA aquarium guidance explains why larger volumes are more stable and why surface area, biological filtration and adult fish size all matter.

Footprint-led planning examples

Setup	Planning point	Reason
Temporary quarantine or observation	A mature appropriately sized hospital system, not a permanent small home	Short-term management has different goals from lifelong housing
Carefully planned small same-species group	About 100 cm and 160 litres or more	Swimming room, social distance and water stability
Mature mixed-sex group	Prefer 120 cm and 200 litres or more	Courtship pressure and adult body size
Hard-water community	120 cm and 200 litres is a sensible starting point; stock conservatively	Companions add waste and compete for the same swimming space
Fry-producing group	Main tank plus a separate cycled grow-out plan	Numbers can increase quickly and adults may eat fry

Do not use litres alone. A short, tall 200-litre aquarium can offer less useful swimming length than a lower 180-litre tank with a broad footprint. Keep open lanes through the middle and upper levels, and avoid filling the entire front with rockwork. The fish should be able to cruise, turn and move away from another individual without being trapped against glass.

Temperature, pH, hardness and nitrogen waste

The central care requirement is mineral-rich water. Aim for a stable 24-27°C, pH 7.2-8.0 and roughly 12-25 dGH. The current supplied range is 23-29°C, pH 7.0-8.0 and 10-30 dGH. FishBase reports 25-28°C, pH 8 and 13-19 dH. Those sources overlap around warm, hard, alkaline conditions; the practical target stays comfortably inside that overlap.

Measure your tap water before buying. “High pH” and “hard water” are related but not interchangeable. General hardness reflects dissolved calcium and magnesium; carbonate hardness helps resist sudden pH change. A tank can show an acceptable pH reading while still being short of the minerals mollies use. If your source water is soft, plan remineralisation with a measured aquarium mineral product and test the result. Do not chase numbers with abrupt chemicals after the fish arrives.

Water target and action points

Measure	Target	Action if outside target
Temperature	24-27°C stable	Adjust gradually with a thermostatic heater; avoid daily swings
pH	7.2-8.0	Check KH and source water before using pH-changing products
GH	About 12-25 dGH	Use a measured remineralisation plan if source water is soft
Ammonia	0 mg/L	Stop feeding, test the filter cycle and make matched emergency water changes
Nitrite	0 mg/L	Treat as urgent; reduce load and restore biological filtration
Nitrate	Keep low and stable	Review stocking, feeding, plant growth and water-change schedule

A clear tank is not automatically a safe tank. Test ammonia, nitrite, nitrate, pH, GH and KH with appropriate kits. Mature filtration must be running before livestock is added. The RSPCA recommends fishless cycling and identifies zero ammonia and zero nitrite as essential. For a fish that eats actively and can become large, generous filter capacity and regular partial water changes are more dependable than relying on “hardy fish” reputation.

Do Sailfin Mollies need aquarium salt?

No routine salt dose is required for this freshwater sale. The species can occur across fresh and brackish environments, but euryhaline does not mean every aquarium should be salted. A controlled study of P. velifera across different salinities found greater reproductive success and larger males in freshwater than in the saline treatments used. The abstract is available through Europe PMC's record of the salinity study.

Sodium chloride also does not supply calcium, magnesium or carbonate hardness. Adding salt to soft water can leave the core mineral problem unsolved while making the aquarium less suitable for plants, invertebrates or companions. Use GH/KH testing and a proper remineralisation method when minerals are low.

Salt, hardness and treatment are different decisions

Need	Appropriate response	Common mistake
Soft source water	Measure GH/KH and remineralise deliberately	Adding unmeasured salt and assuming hardness is fixed
Normal freshwater maintenance	Stable hard alkaline water, filtration and water changes	Keeping permanent salt without a defined reason
Suspected disease	Diagnose water and symptoms; seek qualified advice	Using salt as a universal medicine
Planned brackish system	Use a marine salt mix, refractometer and brackish-compatible stock	Adding “a spoonful” without measuring salinity

Salt can have a role in a diagnosed treatment or a deliberately designed brackish aquarium, but those are separate projects. Check every tank inhabitant, plant and medication interaction first. Never change salinity rapidly around a newly transported fish.

Filtration, oxygen and maintenance

Use a mature filter with enough biological media for a large, enthusiastic omnivore. An external canister, spacious internal filter or well-designed sump can all work. The exact brand matters less than proven cycle capacity, easy maintenance and good distribution. Aim for steady circulation around the aquarium without forcing the fish to swim against a narrow high-speed jet all day.

Keep the surface moving. Warm water holds less oxygen than cool water, and a group of active livebearers can place significant demand on the system. A spray bar, outlet angled toward the surface or air stone can improve gas exchange. Leave open access to the upper water and avoid a thick unbroken surface film.

Change a measured portion of water regularly with dechlorinated replacement water matched for temperature and mineral profile. A weekly routine around 25-40% is a sensible starting point, then adjust from test results, stocking and feeding. Never rinse all biological media under chlorinated tap water or replace every filter cartridge at once. Clean mechanical waste without destroying the bacterial population that processes ammonia.

Simple maintenance rhythm

Frequency	Check	Purpose
Daily	Temperature, breathing, appetite, posture, aggression and equipment flow	Catch rapid changes early
Weekly	Ammonia/nitrite after any concern, nitrate trend, partial water change, visible waste	Control dissolved and solid waste
Regularly	pH, GH and KH, especially after source-water or remineralisation changes	Prevent slow mineral drift
As needed	Rinse mechanical media in removed aquarium water	Restore flow without sterilising the filter
Before adding fish	Confirm cycle, final adult stock, water overlap and spare capacity	Avoid using livestock to test an immature system

Substrate, plants, lighting and cover

Fine gravel or sand both work. Choose a substrate that is easy to clean and compatible with the mineral strategy; limestone-based material can raise hardness, but its effect should be tested rather than guessed. Darker substrate often makes pale marbling look stronger, while very bright bare glass can leave a new fish washed out and exposed.

Use robust plants that tolerate hard alkaline water. Vallisneria, Java fern and some Anubias are practical starting points, but check each plant against your actual hardness and lighting. Dense planting at the sides and rear creates retreat routes; open central water lets the fish cruise and display. Wood and stone can add structure, provided there are no sharp edges that can damage a tall dorsal.

Moderate lighting on a timer gives a predictable day-night rhythm and can support a little natural algae for browsing. Avoid leaving bright lights on late into the night. Add floating cover only where it does not smother surface movement. A lid is recommended because startled livebearers can jump, and it also reduces rapid heat loss. Secure cable and pipe gaps.

What should a Marble Sailfin Molly eat?

Feed as an omnivore with a strong grazing component. A quality spirulina-rich flake, wafer or appropriately sized livebearer pellet can form the staple. Add blanched courgette, spinach or other fish-safe vegetable matter in controlled portions. Frozen or live daphnia, Artemia and similar invertebrate foods provide useful variety, but rich animal protein should not displace plant content.

Offer small meals once or twice a day that are consumed promptly. A fish that is always ready to eat is not necessarily underfed; mollies are persistent browsers and quickly learn to solicit food. Remove uneaten vegetables before they soften and foul the water. Use body condition, waste, nitrate trend and appetite to adjust the ration.

Balanced weekly feeding pattern

Food role	Examples	How to use it
Vegetable-rich staple	Spirulina flake, quality livebearer pellet, algae-based wafer	Most routine meals in small portions
Fresh plant supplement	Blanched courgette or spinach	Small clean piece; remove leftovers
Animal-protein variety	Daphnia, Artemia, modest bloodworm	Several small meals per week, not the entire diet
Natural browsing	Biofilm and soft algae on safe surfaces	Useful enrichment, not a replacement for complete food
Fry food	Powdered quality food and newly hatched Artemia	Only when a separate fry plan is ready

Watch every fish eat. A dominant individual can take the first food while a subordinate remains thin. Spread small portions across more than one area and make sure slow companions receive their share. Sudden appetite loss is a reason to test water immediately, not an invitation to keep adding different foods.

Temperament, social structure and group planning

This is an active social livebearer rather than a tight shoaling fish. It can live in a compatible community or a planned molly group, but social structure matters. Males may display to one another and pursue females repeatedly. In a sexed group, one male to two or three females is commonly used to spread courtship pressure. This listing is unsexed, so ordering three does not guarantee that ratio.

If you cannot select sexes, provide more footprint, dense side cover and a cycled separation option. Observe who is eating, who is hiding and whether one fish is constantly chased. A raised dorsal and brief display can be normal; relentless pursuit, clamped fins, torn fins, loss of appetite or a fish pinned behind equipment is not.

The RSPCA guidance on keeping fish together emphasises species, water quality, behavioural needs and compatibility. Use those four checks rather than assuming that every fish described as “peaceful” belongs in every community.

Compatible tank mates and combinations to avoid

Choose companions that tolerate the same warm, hard, alkaline water and are large and confident enough to share space without bullying or being bullied. Platies and swordtails may work in a large hard-water aquarium. Other robust mollies share chemistry, but different domestic lines can interbreed, so do not mix them in a project where parentage matters. Some rainbowfish can fit the chemistry and activity level when temperature, adult size and group needs overlap.

Avoid fish that require soft acidic water, very cool water or unusually high sustained temperatures. Slow long-finned fish can lose food or have fins investigated. Persistent fin nippers can damage the dorsal. Tiny fish and shrimplets may be stressed or eaten opportunistically, while large cichlids may injure or swallow the molly. Compatibility is a whole-tank decision, not a list of names.

Compatibility decision guide

Candidate	Decision	Why
Platies and swordtails	Often workable with enough space	Similar hard-water preference, but add bioload and breeding activity
Other mollies	Workable for display; caution for breeding	Shared care, but crossbreeding can obscure line identity
Hard-water rainbowfish	Case by case in a large aquarium	Match exact temperature, adult size, group and swimming-space needs
Soft-water tetras or dwarf cichlids	Usually avoid	Water chemistry compromise can leave one side chronically stressed
Fin nippers	Avoid	The tall male dorsal is vulnerable
Shrimp colonies	Adults may coexist; young are at risk	Small shrimplets can be eaten
Large predatory fish	Avoid	Injury or predation risk

For alternatives and same-category context, browse the Molly fish hub or the broader livebearer collection. Read each product's adult size and water range rather than treating a shared category as automatic compatibility.

How can males and females be distinguished?

The anal fin is the most dependable visible clue. Mature males develop a narrow gonopodium; females retain a broader fan-shaped anal fin. Males often carry the larger dorsal and a slimmer profile, while females are generally deeper-bodied. Body shape alone can mislead after feeding, during growth or in a gravid female, so use the anal fin and behaviour together.

Male and female indicators

Feature	Male tendency	Female tendency
Anal fin	Narrow gonopodium when mature	Fan-shaped anal fin
Dorsal	Often taller and raised during display	Usually less exaggerated
Body	Often slimmer	Often fuller and deeper
Behaviour	May display and pursue	May seek cover from persistent courtship
This listing	Unsexed: neither outcome is guaranteed

Do not infer sale sex from the first gallery image. It is an illustrative male-type reference. If a specific sex is essential to an existing group, contact the team before ordering and treat any response as availability-dependent rather than guaranteed by this Default Title listing.

Breeding, pregnancy and fry management

Mollies are livebearers: fertilisation is internal and females give birth to free-swimming young rather than laying an external clutch. A female can store sperm and produce later broods after separation from a male, so an apparently all-female purchase does not always prevent fry. This is one reason every mixed or unsexed group needs a population plan before fish are added.

Stable hard water, vegetable-rich nutrition, clean warm conditions and low social stress support reproduction. Gestation and brood size vary with female size, age, temperature, health and line, so the product does not promise a calendar or fry count. Dense fine-leaved plants give some young a chance to hide, but adults may eat fry. A separate mature grow-out aquarium gives more control than a cramped floating breeder box.

Before allowing a group to breed

Question	Plan before purchase
Where will fry live?	A cycled grow-out tank with suitable filtration and food
How will numbers be controlled?	Sex separation where reliable, careful rehoming and no outdoor release
Will lines be kept identifiable?	Do not mix different molly forms if parentage matters
Can females escape courtship?	Use a larger footprint, plants, sight breaks and a sensible sex ratio
Can fry eat safely?	Provide fine complete foods several times daily without fouling the water

Never release unwanted fry or aquarium water into a pond, stream or drain connected to natural water. Rehome responsibly through experienced aquarists or retailers. The conservation status of wild P. velifera does not make domestic release helpful; introduced ornamental fish can spread disease, hybridise or disrupt local ecosystems.

Health signs, shimmying and first checks

A settled healthy fish should swim steadily, browse, respond to food, breathe without obvious effort and hold its fins naturally. Pattern intensity alone is not a health test. Newly arrived fish can temporarily look pale, but continued clamping, rocking in place, rapid breathing, flashing, isolation, damaged fins, white spots or appetite loss require investigation.

“Shimmying” describes rocking or trembling without normal forward movement. It is a symptom, not a single disease. In mollies it is often associated with environmental stress, especially unsuitable mineral content, unstable temperature or poor water quality. Test ammonia, nitrite, nitrate, pH, GH, KH and temperature before reaching for medication. Correct changes gradually with matched water.

Do not medicate the display tank blindly. White spots, excess mucus, ulcers, wasting and breathing problems can have different causes and treatments. Some medicines affect biological filters, plants or invertebrates. The RSPCA fish-health checklist is a useful starting point; persistent or serious signs need advice from an experienced aquatic professional or aquatic veterinarian.

Symptom-first response

Observation	Check first	Avoid
Rocking or shimmying	GH, KH, pH, temperature, ammonia and nitrite	Assuming salt is the automatic cure
Rapid breathing	Oxygen, temperature, ammonia, nitrite and gill irritation	Increasing temperature without diagnosis
Clamped or torn fins	Aggression, sharp decor, water quality and infection	Adding more fish before the cause is known
Loss of appetite	Water, bullying, constipation, infection and recent transport	Leaving multiple uneaten foods to decay
White spots or excess mucus	Confirm signs and seek treatment guidance	Mixing medicines or overdosing

Preparing for delivery and acclimation

Prepare the aquarium before dispatch. Confirm the nitrogen cycle, temperature, pH, GH and KH; finish major aquascaping; and make sure the lid, filter and heater work. Compare your water with the care range rather than trying to correct it while the fish is in transit. Keep lights low on arrival and follow the current instructions supplied with the order.

Use the site's full new-fish acclimation guide and current delivery and Live Arrival Guarantee page. Do not add transport water to the aquarium. Avoid a heavy meal immediately after arrival; offer a small familiar food once breathing and swimming are steady. Check the fish regularly through the first week without repeatedly chasing or netting it.

A separate mature quarantine aquarium is the most controlled way to observe new livestock before it joins an established community. It must be cycled, heated and chemically compatible; an empty uncycled container is not safer. Use dedicated equipment where possible and never share wet nets or siphons without cleaning.

How does this fish compare with other Molly types?

Common names overlap, so compare the full label, adult size and body form. P. velifera is the larger Yucatan sailfin identity used here. P. latipinna is also called Sailfin Molly and can look similar. P. sphenops underlies many shorter-finned common and fancy mollies. Balloon forms have a shortened body shape and should not be treated as a size guide for a normally proportioned sailfin.

Useful retail comparison

Trade label	Typical identity	Main planning difference
Marble Sailfin Molly on this page	Poecilia velifera trade form	Plan for a large active sailfin and variable marble pattern
Dalmatian Sailfin Molly	Often P. velifera or another domestic sailfin line	Similar scale; pattern and exact taxon must be checked per listing
Silver Marble Sailfin	Often sold as P. latipinna	Related hard-water care, but not the same species identity
Common or Black Molly	Frequently P. sphenops or domestic hybrid ancestry	Usually less exaggerated dorsal and often smaller-bodied
Balloon Molly	Short-bodied domestic form	Different body shape and swimming considerations; not a natural comparison for adult length

Compare the current Dalmatian Sailfin Molly, Goldleopard Sailfin Molly, Silver Marble Sailfin Molly and Assorted Molly to see how trade form, species label, adult planning and pattern differ. Availability and live price belong to each product selector.

Ordering, live price and current offers

The title and care information identify the fish; the selector is the live authority for price and stock. This prevents an old number embedded in a long description from surviving after availability changes. One selected quantity adds one unsexed fish. Choose the number only after calculating adult space, likely sex uncertainty and the aquarium's remaining biological capacity.

UK livestock orders are covered by the published Live Arrival Guarantee when its current conditions are met. Read the returns and Live Arrival Guarantee terms before dispatch so you know the evidence and contact window. The code WELCOME10 may provide 10% off eligible orders; check current eligibility and terms at checkout rather than assuming every customer or basket qualifies.

The strongest buying decision is a prepared aquarium, not a promotional code. Test the water, confirm a responsible adult-space plan, choose compatible stock and make sure someone can receive the delivery. If the current aquarium is soft, acidic or too small, solve that first or select a species suited to the water you already keep stable.

Source-backed care and evidence limits

This page separates facts about the species from promises about one retail animal. Taxonomy, published range, maximum length and broad ecology come from scientific databases. Temperature, pH, hardness, dispatch size and current quantity are reconciled with the live product record. Tank dimensions and husbandry recommendations are welfare-led planning decisions based on the adult scale and need for stable water; they are not presented as a universal legal minimum.

Where key statements come from

Topic	Evidence used	Boundary retained
Accepted species identity	NCBI Taxonomy and FishBase	No DNA or wild-locality certificate
Range, habitat, diet and maximum	FishBase	A published maximum is not every adult's final length
Salinity evidence	Peer-reviewed reproduction study record	Does not make one treatment a universal medical protocol
Aquarium stability and cycling	RSPCA aquarium guidance	Exact stock still determines required capacity
Compatibility method	RSPCA fish-company guidance	No universal peaceful-fish list
Health observation	RSPCA fish-health guidance	Online content cannot diagnose an individual fish

Frequently asked questions

Is this listing for one fish or a pair?

One selected quantity supplies one live, unsexed fish at approximately 6-7 cm. The gallery includes a two-fish illustrative scene, but that image does not define the quantity. A pair, sex ratio or breeding group is not guaranteed.

Is the fish guaranteed to be male?

No. The Default Title offer is unsexed. Mature males usually develop a gonopodium and the most prominent sail-like dorsal, while females retain a fan-shaped anal fin. A male-type reference image is not a sex promise.

How large can Poecilia velifera become?

The supplied care information gives around 8-12 cm, while FishBase records a published maximum of 15 cm total length. Plan the aquarium for a large adult rather than for the 6-7 cm arrival size.

What tank size does a Marble Sailfin Molly need?

Use a long aquarium from about 100 cm and 160 litres for a carefully managed small group. A 120 cm tank of 200 litres or more is preferred for mature adults, mixed sexes or a community. Stock and filtration can require more.

What temperature should I use?

A stable 24-27°C is the practical target. The current care range is 23-29°C. Stability and oxygenation matter more than aiming at the warmest possible number.

What pH and hardness are appropriate?

Aim for pH 7.2-8.0 and about 12-25 dGH, within the broader supplied range of pH 7.0-8.0 and 10-30 dGH. Test GH and KH as well as pH; high pH alone does not prove adequate minerals.

Do I have to add aquarium salt?

No routine salt dose is required for this freshwater listing. The species tolerates salinity, but salt does not replace calcium, magnesium, carbonate hardness, filtration or diagnosis. Use salt only for a defined brackish plan or qualified treatment advice.

Can this fish live in soft water?

Chronically soft water is not recommended. If your source water has low GH/KH, use a measured remineralisation plan before purchase or choose a species suited to your existing stable chemistry. Avoid sudden pH correction after arrival.

What does a Sailfin Molly eat?

Use a vegetable-rich omnivore diet: spirulina flake or quality livebearer pellets, small portions of fish-safe greens, and modest daphnia, Artemia or similar foods. Avoid an animal-protein-only diet and remove leftovers.

Are Sailfin Mollies beginner fish?

They are resilient in the correct water, but this larger form is better classed as moderate care. Beginners can succeed after cycling a spacious aquarium and learning GH/KH testing; a small new soft-water tank is not suitable.

Can I keep one on its own?

It is not a strict shoaling fish, but it benefits from social and environmental activity. A compatible hard-water community or a planned molly group is preferable to isolation in a bare tank. Never add random companions solely to create company.

How many females should be kept per male?

Where sexes are known, one male with two or three females is commonly used to spread courtship pressure. This offer is unsexed, so ordering several fish does not guarantee that ratio. Provide space and a separation plan.

Can different Molly varieties breed together?

Domestic molly forms can interbreed. That may be acceptable in a display aquarium, but it obscures strain and parentage. Keep forms separate if you intend to preserve an identifiable breeding line.

Will they eat algae?

They browse soft algae and biofilm, but they are not a substitute for maintenance and should not be bought as a cleaning tool. Provide a complete vegetable-rich diet and manage light, nutrients and water changes directly.

Are the gallery images the exact fish I will receive?

No. They are protected illustrative, reference scenes for the trade form. The dispatched fish is a live individual whose sex, pattern, dorsal development and colour balance can differ. Existing images remain for visual context, not exact-stock identification.

How long do Sailfin Mollies live?

Plan for a multi-year commitment. Aquarium sources often quote several years, but age at purchase, sex, genetics, temperature, water quality and care all alter outcome. This listing does not guarantee an exact lifespan.

What causes a Molly to shimmy?

Shimmying is a symptom, often linked with environmental stress. Test ammonia, nitrite, temperature, pH, GH and KH first. Do not assume that permanent salt or a random medication is the answer.

Can this fish live with guppies, platies or swordtails?

Platies and swordtails often share suitable hard-water conditions in a large aquarium. Guppies can be more delicate and long-finned. Check exact temperature, adult size, behaviour, filtration and available space before mixing any livebearers.

Will a female arrive pregnant?

It is possible because female livebearers can store sperm, but sex and reproductive state are not guaranteed. Anyone keeping unsexed or female mollies should have a fry and population plan before purchase.

What should I do before ordering?

Confirm a mature cycled tank, 24-27°C, hard alkaline water, zero ammonia and nitrite, sufficient adult footprint, compatible stock and a delivery recipient. Read the acclimation and Live Arrival Guarantee terms before dispatch.

Useful next steps

Use the dedicated Molly fish care guide for category-wide preparation, then return to this page for the larger P. velifera boundaries. Browse the Molly hub to compare current live stock or the livebearer hub for related hard-water groups. For arrival day, keep the acclimation guide, delivery information and Live Arrival Guarantee terms available.

Choose this fish when you can provide the space, mineral-rich water and filtration that let a sailfin mature properly. The reward is an active, individually patterned livebearer with a striking display profile, but the responsible decision begins with the adult aquarium rather than the photograph or juvenile size.