By Tom Whitfield
Avoid: Tiger barbs (fin-nip), male bettas (attack guppy tails in some lines), angelfish (eat adult guppies once grown), dwarf cichlids (territorial).
Rare and show-strain guppies in stock
Female Red Cap guppy. Female strains carry the same genetic colour markers as males but with understated patterning. Photo: Tropical Fish Co warehouse.
If you're past the beginner stage and want rarer lines, we stock Moscow Blacks (female 6744 pictured in stock), albino strains, elephant-ear lines, and the occasional double-sword. These sell fast — check the livebearer hub weekly for the full refresh.
Guppy colour-strain genetics — what breeds true, what doesn't
If you want a stable colony of a specific colour strain, the genetics matter. Not every strain breeds true; mixing lines regresses quickly to wild-type brown-grey.
| Strain | Breeds true? | Mixing risk | Notes |
|---|---|---|---|
| Fire Red Cherry (wild-type red) | ✓ Dominant line | Low | Established trait, dominant |
| Moscow Black | Partial | High if mixed with non-Moscow | Recessive modifier, needs closed line |
| Endler's (pure Poecilia wingei) | ✓ Only with pure Endlers | Critical — hybridises with guppy | Keep species-separate |
| Half-moon tail | Partial | Moderate | Tail gene often throws mixed |
| Elephant Ear (pectoral modification) | Partial | Moderate | Dominant but incomplete penetrance |
| Albino / Gold | ✓ Recessive line | Low if closed | Shows only when both parents carry |
| German Sunset | Partial | High | Multiple modifiers; line-breed required |
| Green Moscow | Partial | High | Needs strict selection |
Single-strain tanks breed true. Mixed-strain tanks produce interesting F1 hybrids and then regress. The BLA club scene below is where serious strain-work happens in the UK — pure lines get traded at meets rather than through retail.
Colour-strain compatibility matrix
| Strain A → keeps with strain B? | Fire Red | Moscow Black | Endler | Fancy Mix |
|---|---|---|---|---|
| Fire Red | ✓ Same | ✗ Regresses | ✗ Hybrids | ✓ But weak breeds |
| Moscow Black | ✗ | ✓ Same | ✗ | ✗ |
| Endler | ✗ | ✗ | ✓ | ✗ |
| Fancy Mix | ✓ Generic | ✗ | ✗ | ✓ Mutt |
The horizontal axis is which strain you're adding; vertical is what's already in the tank. Most boxes are "no" — guppy genetics don't play well with mixing if you care about strain stability.
UK guppy community — clubs, forums, and friends
One thing Google rarely surfaces: buying guppies is a LOT more fun when you have people to share strains with. The UK has a surprisingly active guppy community once you know where to look.
Formal clubs
- British Livebearer Association (BLA) — runs meetups, publishes a strain-judging guide, hosts an annual show. The primary UK organisation for serious guppy and livebearer keepers [6].
- International Fancy Guppy Association (IFGA) UK chapter — for show-strain keepers competing at international standard.
- Federation of British Aquatic Societies (FBAS) — umbrella body covering ~70 regional UK fishkeeping clubs, many of which run dedicated livebearer sections.
Where the everyday community actually lives
- r/Aquariums + r/livebearers on Reddit — 2M+ members combined, helpful UK-specific threads every week
- "UK Aquarists" Facebook group — 40K+ members, quick answers on UK water chemistry and shop recommendations
- Fishkeeping.co.uk forum — smaller, older, higher signal-to- noise ratio than Facebook
- YouTube channels — Tom's own channel ("Tiny Tanks, Slow Pace") leans nano + beginner; Aquarium Co-Op is US-based but their livebearer advice translates directly
Finding local friends who breed guppies
If you want rare strains (Moscow blacks, dragon-skin, panda-pied), your best bet is the BLA meetups where hobbyists trade breeding pairs at cost rather than through commercial retail. A pair of pure-strain Moscow Blacks goes for £20–£40 at a club meet vs £60+ through specialist retailers.
When your guppies arrive — our UK delivery protocol
Guppies are one of the hardiest shippers in the hobby. Even so, the acclimation protocol matters — these are tank-bred fish that will have seen a narrow water-chemistry range their whole lives [7].
- Open in a dim, quiet room. Guppies stress less than cardinals on arrival but still benefit from low light.
- Float 15 minutes sealed. Temperature equalisation.
- Drip-acclimate 30 minutes. Guppies don't need the 45-minute deep drip that cardinals need — their tolerance is wider.
- Net into the tank. Don't pour the bag water in.
- Lights off 1 hour. Let them find cover.
- No feeding for 12 hours. Resume normal feeding the next morning.
Live arrival guarantee: photograph the unopened bag within 2 hours if any fish arrive dead. We refund or replace at our cost.
What to look for when you buy live guppies
Healthy guppies tell you they're healthy before you buy. Here's the 30-second visual check:
- Fins upright and flowing. Clamped fins pressed against the body = stress or beginning of disease.
- Active mid-water swimming. Guppies park at the surface, not the bottom. Bottom-sitting = ammonia poisoning or swim-bladder issue.
- Bright, saturated colour. Washed-out colour = stress or poor husbandry at the supplier. Walk away.
- Straight spine. Curvature (scoliosis) is common in ornamental-bred guppies and shortens lifespan considerably.
- No white spots (ich) or velvet (gold dust). Check under bright tank lighting before buying.
My first guppies came from a pet-shop chain with 40 fish in a small overstocked tank. All six died within a month. The lesson — still true today — is that pet-shop chains buy from central wholesalers where one tank infection cross-contaminates every species in the shop. Specialist retailers quarantine species-by- species. It's a £5 price difference and a 10-fold survival difference on the first month.
Ready for more?
If you're new to the whole hobby, our best beginner tropical fish guide positions guppies alongside the other nine species I'd recommend for a first tank.
For a single-species deep-dive on guppy care, breeding, and strain genetics, the guppy care guide is where to go next. If you decide a nano tank suits your space better, consider Endler's livebearers as the sharper, smaller alternative.
Already know what you want? The full in-stock livebearer range is at the livebearers hub.
