SuperDelta Big Ears Female Betta Mix (Betta splendens)

SuperDelta big ears female betta at a glance

This is one female Siamese fighting fish, Betta splendens, from a domestic line bred for two fin traits at once: the enlarged, fan-like pectoral fins that breeders call big ears and a broad, wide-spreading SuperDelta tail. She comes from a colour mix, so her exact shade and pattern are not picked in advance. The first thing to settle is where she will live. Ornamental bettas are territorial, and many do best as the only betta in a heated, filtered and planted aquarium that is ready before she arrives.

Big ears, sometimes sold as dumbo, describes the oversized pectoral fins just behind the gill covers. A big-ear betta shows them off as she hovers, turns and investigates the planting, which is a large part of the appeal. SuperDelta is a breeders' name for a tail with a wide spread that stops short of the full half-circle expected of a halfmoon. Both names are trade descriptions of fin form rather than scientific categories, and a female's fins normally stay shorter than those of a male from a similar line, because male bettas develop more extended fins.

Key facts for planning

• Species: Betta splendens, a labyrinth fish in the gourami family, Osphronemidae
• Adult length: about 7 cm for the species
• Everyday water: 24–28 °C, pH 6.0–8.0 and 5–12 dGH, aiming for 26–28 °C
• Aquarium: at least 20 litres for one fish; a 45 × 30 cm base, about 41 litres, gives more margin
• Keeping: alone, or in a group of at least four females in 60 litres or more
• Diet: a quality betta pellet or flake, with small frozen or live foods for variety
• Care level: intermediate in our assessment
• Breathing: takes air from the surface, so the surface must stay reachable

What you receive

One purchase supplies one live female betta. The 7 cm figure is the length the species reaches when grown, so she may arrive smaller and still be filling out. Sex is guaranteed only when the exact product or selected option explicitly states male or female. This SuperDelta Big Ears Female Betta Mix listing is sold as female. You do not need to work out her sex from her colour or fins; it is part of the offer itself.

The photographs show the SuperDelta big ears form with a blue-grey body, a rust-toned head and pale, fan-shaped fins. Gallery images have been digitally enhanced to improve image quality. Natural colour, pattern, size and maturity can vary between live animals. Because she is chosen from a mixed colour batch, the fish you receive may carry a different body colour or fin shade from the one pictured, while the fin type stays the reason to choose this line.

Wild Betta splendens come from the Mekong basin, where FishBase records them in standing floodplain water, canals, rice paddies and larger rivers. Aquarium bettas are the product of long domestic breeding, and genome research on domestic bettas has mapped the variation behind their colours, fins and body size. If you would like to compare her with other domestic and wild bettas before deciding, browse our betta collection.

The wild form is rarely seen in the hobby. Ornamental lines have been bred for vigour and appearance over many generations, and some have been crossed with related Betta species. The IUCN lists wild Betta splendens as Vulnerable; that assessment describes wild populations rather than domestic fish such as this one.

Setting up her aquarium

Get the aquarium right first and almost everything else about keeping her becomes easier. A female betta is small, but she needs stable heat, clean water and furnishings that suit her long, delicate fins.

How much space to give her

The UK trade body OATA recommends an aquarium of at least 20 litres for a single male betta and at least 60 litres for a group of females. Tropical Fish Co uses the same 20 litres as a minimum starting screen for one domestic betta. Seriously Fish suggests a base of 45 × 30 cm, about 41 litres, for a single male or a pair, and does not support keeping this species in tiny aquaria or small jars. FishBase adds that holding males in very small containers should be discouraged.

For one female, treat 20 litres as the floor and something nearer 41 litres as the comfortable choice. Larger volumes hold temperature and water quality more steadily, and decor takes up real space, so check the actual filled volume and internal dimensions rather than the name on the box. Two 2024 behaviour studies on male bettas point the same way: tiny bowls restricted normal swimming, and a furnished 19.3-litre tank produced better behaviour than smaller or bare set-ups.

Filter, heater and lid

• Filter: the RSPCA says no fish should be kept without a well set up and maintained filter, because a working biological filter lets beneficial bacteria turn toxic ammonia into nitrite and then into safer nitrate. Bettas come from sluggish water, so Seriously Fish favours gentle movement from a filter like an air-powered sponge; for a tank of about 41 litres it suggests a filter rated around 80–125 litres per hour.
• Heater: in the UK a thermostatic heater is needed all year. Check the result with a separate thermometer rather than trusting the dial.
• Lid: use a secure cover with a small air gap beneath it. Bettas can jump, and the warm, humid air above the water is the air she breathes.

That last point matters. Bettas carry a labyrinth organ that lets them gulp atmospheric air at the surface, but OATA is clear that this does not mean they need less care or less filtration than other fish. Keep the surface reachable, with no decor or dense floating mat sealing it off.

Cycling before she arrives

Clear water is not the same as a mature aquarium. Fishless cycling builds the filter bacteria first, and fish should only go in after ammonia and nitrite have risen and fallen back to zero. OATA warns that stocking too quickly can cause new tank syndrome, when there are not enough nitrifying bacteria to handle the extra waste. If this is your first heated aquarium, work through our guide to setting up a first tropical tank and give the filter time to mature before you order.

Water values and testing

Stable water matters more than chasing a perfect number. These are the values to hold her in:

Where these numbers come from

FishBase records the wild species at 24–30 °C, pH 6.0–8.0 and 5–19 dH, which describes where the fish lives in nature rather than an aquarium target. Seriously Fish gives 22–30 °C, pH 6.0–8.0 and 1–15 dGH, noting that wild-collected fish probably prefer pH 5.0–7.0 while ornamental strains are unfussy across 6.0–8.0. OATA's betta care sheet suggests 20–28 °C, pH 6.0–8.0 and 4–12 dGH for tank-reared fish. The everyday range in the table is where those sources agree, and Tropical Fish Co uses 26–28 °C as a practical target for a typical domestic betta.

Her line is domestic, so there is no reason to acidify or soften water that already sits steadily inside the range. Sudden swings are the real risk. Adjust slowly if you must adjust at all, and never change pH or hardness simply to land in the middle of a published range.

Holding the temperature

UK rooms cool sharply overnight and in winter, which is why the heater stays on all year. Size and fit it using the manufacturer's guidance for aquarium volume, installation, minimum water depth and room temperature, rather than a universal watts-per-litre rule, then confirm the result with the separate thermometer over a day or two before she arrives. If the reading drifts outside 24–28 °C, find the cause before changing the setting.

Testing and UK tap water

UK tap water varies from region to region, and chlorine or chloramine must be neutralised with an aquarium conditioner before it reaches her tank. Test ammonia and nitrite at least once a week, and more often while the aquarium is young. Our aquarium water parameters guide explains what each test tells you, and the water parameter matcher lets you compare your own readings with the ranges above.

Planting, cover and fin-safe decor

Bettas are at their best in a well-planted, shady aquarium with plenty of cover near the surface. Seriously Fish suggests tall stem plants, floating plants such as Salvinia or Riccia, tropical lilies from the genus Nymphaea and Cryptocoryne. Driftwood works well, with Microsorum ferns or Taxiphyllum moss attached to it.

Shelter and leaf litter

Small clay plant pots or short lengths of smooth plastic pipe give her somewhere to retreat. A layer of dried leaf litter adds cover and encourages microbe colonies as it breaks down, and the tannins it releases are considered beneficial.

Protecting big fins

Her enlarged pectorals and wide tail are easy to tear on sharp or rough decor. Choose smooth wood, rounded stone and soft-leaved plants, and avoid ornaments with narrow openings that could trap a body. Very long fins can also change how an individual copes with current and clutter, so watch her swim: if she is pushed around or cannot rest, reduce or spread out the outflow without switching off the filter. A 2024 study found that in the same 19.3-litre volume, a bare tank produced more hovering, repetitive swimming and wall interaction than a furnished one, so meaningful structure is part of her welfare, not decoration.

Leave some open water at the front for her to swim and display, and keep at least part of the surface clear of floating plants so she can always reach the air.

Feeding a female betta

In nature FishBase describes Betta splendens feeding on zooplankton, mosquito larvae and other insect larvae, and Seriously Fish expects wild fish to take small aquatic and land invertebrates. In the aquarium, OATA calls bettas omnivorous and happy to take most food types.

A simple feeding plan

• Base food: a good-quality betta pellet or flake, sized so she can swallow it easily. Specialised betta pellets are made for exactly this job.
• Variety: small live or frozen foods such as daphnia, brine shrimp (Artemia), small bloodworm or tubifex. Freeze-dried bloodworm and Artemia also work. Seriously Fish notes that plenty of small live or frozen foods helps bring out full colour and condition.
• Insects: pinhead crickets or Drosophila fruit flies are suitable, ideally after the insects have been fed on fish flake or vegetable matter.

How much and how often

OATA advises feeding bettas only what they can eat within a few minutes, once a day. Seriously Fish warns that bettas seem particularly prone to obesity, so a slim, active fish is the goal. Skip rules based on the size of her eye or a fixed pellet count: pellet sizes and energy content vary between brands, and age, condition and temperature all change how much she needs. Follow the food maker's guidance, watch her body shape, and remove anything uneaten before it breaks down and fouls the water.

If several people feed the tank, pre-measure portions. Before a holiday, arrange a competent carer with measured feeds and written notes, and test any automatic feeder well before you leave rather than trusting it for the first time while you are away.

There is no need for a fixed weekly fasting day. Judge her portions by body shape and appetite instead: a gently rounded belly after feeding is fine, while a fish that grows steadily broader needs smaller meals.

Weekly maintenance

A betta tank stays healthy through a short routine done every week rather than a big clean now and then. OATA notes that bettas can be stressed by even the smallest amounts of ammonia and nitrite, which is why testing and water changes matter so much.

• At least once every week, make a partial water change of 25%, using a siphon to lift solid waste from the gravel.
• Treat all replacement water with tap-water conditioner to remove chlorine or chloramine.
• Test the water at least once a week so ammonia and nitrite never build up.
• Check the filter for blockages. When it needs cleaning, rinse the media lightly in tank water removed during the water change. Do not run it under the tap, as chlorine or chloramine can kill the beneficial bacteria.
• Check the thermometer regularly, and make sure the lid still fits with its air gap intact.

If a test shows ammonia or nitrite

Any detectable ammonia or nitrite needs investigating the same day. Check that the filter is running and has not been over-cleaned, think back over feeding and any recent additions, remove uneaten food, and make a partial water change with conditioned water, avoiding any sudden change in temperature. Keep testing until both readings are back at zero. Nitrate that keeps climbing towards 20 mg per litre above your tap water is a sign that water changes need to keep better pace.

Keep a simple log of test results, water changes and anything unusual. Patterns in the log make problems far easier to spot early.

Arrival and her first days

Your betta is hand-bagged in pure oxygen and packed in an insulated poly box, with a heat pack when the weather calls for it, then carried by a tracked, licensed live-animal courier. You will receive a tracking number and your confirmed delivery date by email. Someone needs to be at the address to receive the parcel, because live fish cannot be left unattended.

Opening the parcel

1. Before you open anything, start one continuous unboxing video showing the parcel still sealed with the outer box visible, and keep filming as you open it until the fish can be seen still inside the sealed bag.
2. Open and inspect the parcel on the day it arrives.
3. Float the sealed bag in her aquarium for 20–30 minutes before releasing her, so the temperatures can even out.
4. Release her into the aquarium without pouring the bag water into your tank.
5. If anything has gone wrong, contact us the same day, with WhatsApp the fastest route, including your order number and the unboxing video, and we will arrange a replacement or refund.

The Live Arrival Guarantee needs that continuous video for any claim, so film every parcel from sealed. The full terms are on our delivery and Live Arrival Guarantee page.

Her first days

Give her time to explore. Healthy fish have clear, bright eyes, undamaged fins, intact scales, no ulcers or bumps and normal swimming. Offer a small amount of food once she is moving around, and remove anything she ignores. Test ammonia and nitrite more often for the first few weeks, because the filter bacteria need time to catch up whenever a new fish adds waste. If you plan a female group, OATA's advice to build up numbers slowly applies here too.

Health checks and when to act

Every fish varies a little in behaviour and appearance, so learn what is normal for her. OATA lists the changes worth watching:

• Swimming: hanging at the surface more than usual, sitting on the bottom or darting erratically
• Colour: turning darker or paler than normal
• Temperament: a change in aggression, or hiding more than usual
• Breathing: gill covers moving faster or slower than normal
• Appearance: white spots, fluffy growths, or loss of fins or scales
• Condition and feeding: weight loss or gain, or reduced interest in food

Remember that she visits the surface to breathe air as a matter of course; it is a change from her usual pattern that deserves attention.

What to do first

Signs are not diagnoses. A torn fin, a white mark or a swollen belly can each have more than one cause, and the MSD Veterinary Manual stresses aquarium history, water analysis and proper diagnostic work over picking a medicine from one symptom. Work through it in order: confirm the temperature and test ammonia, nitrite, nitrate and pH; review recent additions, feeding and equipment changes; and compare her breathing, posture, appetite and fins with her normal pattern. Avoid mixing medicines or raising the temperature on the strength of an internet guess. If signs are severe, persistent or unexplained, speak to an experienced aquatic retailer or use OATA's find a fish vet directory.

A readiness checklist before you order

The Animal Welfare Act 2006 expects every keeper to provide a suitable environment, a suitable diet, the chance to behave normally, appropriate company or separation, and protection from pain, injury, suffering and disease. For a betta, that turns into a practical checklist. Order when every line is true:

• The aquarium holds at least 20 litres of real water and has been cycled without fish.
• Ammonia and nitrite both test at zero.
• The heater and a separate thermometer hold the planned temperature.
• Filter flow is gentle and part of the surface stays open.
• The lid fits securely with a safe air gap beneath it.
• Plants and decor give cover without sharp edges or traps.
• You know whether she will live alone or in a female group, and you have a plan for separating fish if a mix fails.
• Food, conditioner, test kits, a siphon and a bucket kept only for the aquarium are ready.
• Someone can look after the tank while you are away.

If any line is not true yet, finish that step first. A betta that arrives to a ready, stable aquarium settles far more easily than one added to a tank still finding its balance.

Breeding background

Betta splendens is a bubble-nest builder. Breeding is a separate, planned project, and buying a female does not commit you to it. The outline below explains the behaviour you may read about.

• The male builds the nest, in a tube, under a broad leaf or among fine surface plants, and will not usually tolerate the female nearby until it is finished.
• A female ready to spawn turns paler and shows dark bars on her flanks.
• Spawning takes place beneath the nest in the embrace typical of the gourami family.
• Fry need a layer of warm, humid air above the water, or the development of the labyrinth organ can be impaired, which is why breeders use a very tight cover.

FishBase advises keeping the sexes separate except for mating, with only one female brought into a breeding tank of about 20–30 litres. Seriously Fish stresses giving the female plenty of cover. Outside a planned spawning with space for both fish afterwards, keep her away from males.

Alone, in a female group or in a community

Deciding how she will live is the biggest choice you make with this fish. Female bettas are calmer than males, which widens the options, but ornamental strains are still some of the most combative bettas in the hobby.

Keeping her alone

This is the safest default. Seriously Fish advises that the species is best kept alone and not in a standard community, noting that ornamental strains seem more aggressive than any other Betta species and that in most cases only a single individual can be kept per tank. A single female in a well-planted aquarium of 20 litres or more has room to explore, rest among the plants and display those big pectorals without competition.

A group of females

OATA describes females as much calmer than males and able to live in groups of at least four, in an aquarium of at least 60 litres. Because one purchase is one fish, that means buying at least four and setting up the larger tank first. Plant it densely, add plenty of cover, and keep a spare, cycled aquarium ready. Individual temperament varies, and a group that looks settled can change, so watch for one fish being chased, cornered or kept from food.

A calm community

OATA notes that it is easier to mix females into community aquariums than males, but they must be kept in a group and without boisterous or aggressive fish. Seriously Fish accepts that some small cyprinids and loaches from similar natural habitats can work, with proper research before purchase. Screen every candidate for adult size, water overlap, activity, fin-nipping and feeding competition, and remember that the whole community needs space, not just the betta. Male bettas, with their long fins, are often the target of intense fin nipping, and her enlarged pectorals and spreading tail offer fin-nippers the same kind of target. The RSPCA likewise treats compatibility as something to research species by species.

Our Betta fish care guide sets out the screening questions for any tank mate in more depth.

Tank mates to avoid and to approach with care

Use these lists as a starting point, then judge the actual fish in front of you.

Keep her away from

• Male bettas, outside a planned spawning
• Fin-nipping species, which target long or wide fins
• Boisterous or aggressive fish
• Fish with trailing finnage or a betta-like body shape, which an ornamental betta may treat as a rival
• Large fish able to injure or eat her
• Species that need very different water

Approach with care

• Small, calm cyprinids and loaches from similar slow, soft waters, only after careful research
• Other females, only as a group of at least four in 60 litres or more
• Shrimp, snails and fry: a betta may investigate or hunt small animals, and some larger or defensive invertebrates can injure her, so treat any such mix as uncertain and be ready to separate them

Signs that a mix is failing

Torn or ragged fins, a fish hiding far more than usual, repeated chasing or a change in aggression all mean the arrangement needs rethinking. Separate fish early rather than waiting for injuries to worsen, and add any new fish gradually, testing ammonia and nitrite as you go so the filter can keep pace.

SuperDelta big ears female betta questions

How big does a SuperDelta Big Ears Female Betta Mix get?

Expect an adult length of about 7 cm. Seriously Fish records 70 mm for the species and OATA gives about 7 cm, so plan her aquarium around that grown size even if she arrives a little smaller.

What size aquarium does one female Betta splendens need?

Start from at least 20 litres of heated, filtered and planted water for one fish, and choose more space where you can: Seriously Fish suggests a 45 × 30 cm base, roughly 41 litres. A group of females needs at least 60 litres.

Can female bettas be kept together?

Many ornamental bettas live best alone. If you want a group, OATA advises at least four females in an aquarium of 60 litres or more, with dense planting, plenty of cover and a spare tank ready in case one fish is singled out.

Is the SuperDelta Big Ears Female Betta Mix suitable for beginners?

She can suit a careful beginner whose aquarium is already cycled, heated and tested before she arrives. We rate her care as intermediate because the heater, mature filter, lid, gentle flow and weekly maintenance all need to be in place from day one.

What does a female Betta splendens eat?

Use a quality betta pellet or flake as the base, with small frozen or live foods such as daphnia, brine shrimp or bloodworm for variety. Feed only what she eats within a few minutes, once a day, and remove leftovers, as bettas put on weight easily.

What temperature and pH does she need?

Keep her water at 24–28 °C, pH 6.0–8.0 and 5–12 dGH, where the FishBase and Seriously Fish ranges overlap with OATA's betta care sheet, and use 26–28 °C as a practical everyday target. Run a thermostatic heater all year and check it with a separate thermometer.

Are female bettas aggressive, and do they nip fins?

Female Betta splendens are calmer than males but still territorial, and ornamental strains can be hard on other bettas. Her enlarged fins can also attract fin-nipping fish, so choose calm companions or keep her on her own.

What kinds of fish can live with a female betta?

No tank mate is guaranteed safe. Seriously Fish lists some small cyprinids and loaches from similar calm, soft waters as possible after careful research, and OATA says females mix more easily when kept as a group away from boisterous or aggressive fish. Avoid male bettas and fin-nipping or long-finned species.

How does a Betta splendens arrive alive in the UK?

She is hand-bagged in pure oxygen and packed in an insulated poly box, with a heat pack when the weather calls for it, then carried by a licensed live-animal courier. Film a continuous unboxing video from the sealed parcel, float the sealed bag for 20–30 minutes before releasing her, and send that video with your order number the same day if anything has gone wrong.

Sources

The care advice on this page draws on these public sources:

• FishBase: Betta splendens species summary, for family, wild habitat, diet in nature, recorded water ranges and maximum length.
• Seriously Fish: Betta splendens species profile, for aquarium size, planting, water, diet, behaviour and breeding notes.
• OATA: How to look after Siamese fighting fish (Bettas), the UK trade care sheet for water values, tank sizes, feeding, maintenance and compatibility.
• RSPCA: Fish environment and filtration, for filter and water-quality welfare guidance.
• RSPCA: Keeping pet fish together, for compatibility principles.
• NCBI Taxonomy: Betta splendens Regan, 1910, for the accepted scientific name.
• Kwon and colleagues (2022): The genetic architecture of phenotypic diversity in the Betta fish, for domestic colour and fin variation.
• MSD Veterinary Manual: Management of aquarium fish, for health investigation.
• OATA: Find a fish vet, for locating specialist help in the UK.