Tequila splitfin
Zoogoneticus tequila
The Tequila splitfin features a slender body with vibrant green-blue iridescence and long, flowing fins.
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About the Tequila splitfin
This is a little Mexican goodeid livebearer where the males get that awesome orange crescent in the tail and will spar and posture like tiny cichlids. They do best in a planted tank where they can duck into roots and stems, and once they're settled they'll breed steadily and you'll see lots of interesting social behavior.
Also known as
Quick Facts
Size
8 cm
Temperament
Semi-aggressive
Difficulty
Intermediate
Min Tank Size
20 gallons
Lifespan
3-5 years
Origin
North America (Mexico)
Diet
Omnivore leaning carnivore - small frozen/live foods (daphnia, bloodworms, insect larvae) plus quality flakes/pellets
Care Notes
- Give them a longer tank with lots of swimming room and some dense plants or rock piles to break up sightlines - they spar and chase when the tank is too bare.
- They do best in cooler, harder/alkaline water: roughly 20-24°C (68-75°F) and pH about 7.0-8.0; avoid consistently high temperatures (above ~24°C) long-term.
- Keep the water clean with steady filtration and regular water changes because they are active eaters and can turn a small tank into a nitrate factory fast.
- Feed a mix: good quality flake or small pellets as a base, plus spirulina/veg-based foods and frequent frozen/live stuff like daphnia, brine shrimp, or bloodworms; small portions 1-2 times a day keeps them from getting chunky.
- Stock them in groups, not pairs - something like 1 male to 2-3 females reduces nonstop male harassment and gives the girls a break.
- Tankmates: stick to other peaceful, cooler-water fish that are not slow or long-finned (think small livebearers, ricefish, hillstream-type fish); avoid bettas, guppies with fancy tails, and anything that wants tropical 78-80F.
- Breeding is straightforward livebearer stuff - lots of cover and floaters helps fry survive, but adults will snack on babies if they are easy to spot; move pregnant females or pull fry if you want numbers.
- Watch for fin nipping and torn fins from bullying, plus skinny fish from being outcompeted at feeding time - spreading food out across the tank helps a ton.
Compatibility
Good Tankmates
- Platies and swordtails - active but usually not jerks, and they are tough enough to not get stressed by the splitfins' nonstop movement
- Peaceful bottom crews like Corydoras or bristlenose plecos - they stay out of the splitfins' way and keep the floor moving without drama
- Small loaches like kuhli loaches - they mind their own business, mostly come out later, and dont compete much for the same space
Avoid
- Tropical livebearers typically kept warm (e.g., many guppy/Endler setups) unless you intentionally run the tank cooler and accept potential temperature mismatch
- Most tropical tetras commonly kept at higher temperatures (mid/upper 20s°C) due to temperature mismatch; choose cool-tolerant species if mixing
- Warm-water/tropical community fish that prefer sustained higher temperatures (e.g., many rainbowfish species) due to temperature mismatch with tequila splitfins' cooler-water preference
- Anything nippy like tiger barbs or serpae tetras - splitfins are busy fish and can get their fins checked all day in a mixed tank like that
- Aggressive cichlids (convicts, jewels, most Central American types) - they will turn the tank into a boxing ring, and the splitfins will get pushed around or picked off
- Big predatory stuff like larger catfish or knife fish - if it can fit a young splitfin in its mouth, it will eventually try
- Slow fish with fancy fins like bettas and fancy guppies - tequila splitfins can be pushy at feeding time, and the slow pretty fish always lose that contest
Where they come from
Tequila splitfins are a little slice of fishkeeping history. They come from the Teuchitlan River system in Jalisco, Mexico (near the town of Tequila), and in the wild they got hammered by habitat changes and introduced fish. A lot of the ones in the hobby trace back to conservation breeding lines, which is pretty cool and also a good reason to keep them thoughtfully.
If you can, ask what line your fish are from and avoid mixing lines unless you know what you are doing. A lot of hobbyists try to keep bloodlines separate for conservation value.
Setting up their tank
Think of them like tougher livebearers that still appreciate clean, stable water. I have had the best luck giving them some swimming room and lots of cover so the females can take a break from attention.
- Tank size: 20 gallons long works nicely for a small group. Bigger is always easier if you want more males or you plan to breed.
- Filtration: moderate flow and plenty of biofiltration. A sponge filter plus a hang-on-back is a nice combo if you are raising fry.
- Temperature: they do great in the low 70s F (around 22-24 C). They do not need hot water like some tropical livebearers.
- Hardness/pH: they generally like harder, more alkaline water. If your tap is on the soft/acidic side, go slow and focus on stability rather than chasing numbers.
- Decor: dense plants (guppy grass, hornwort, java moss), rock piles, and wood all work. Give them line-of-sight breaks.
- Substrate: anything is fine. Dark substrate makes their colors pop, especially the males.
Pack the tank with plants if you want any fry to make it. A loose wad of guppy grass or hornwort near the surface is basically a fry daycare.
They are active and curious, so tight lids matter. They are not notorious jumpers like some killifish, but I have still found the occasional surprise carpet fish when a gap was left open.
What to feed them
These guys eat like livebearers with an extra interest in meaty foods. If you keep them on flakes only, they will live, but they color up and breed better with variety.
- Staples: good quality flake or small pellet (I like a mix of a spirulina-based food and a higher-protein community pellet).
- Frozen/live: daphnia, baby brine shrimp, cyclops, mysis, and bloodworms as a treat.
- Greens: blanched spinach or zucchini now and then, or algae wafers that they can pick at.
- For fry: baby brine shrimp is the fast lane. Microworms and finely crushed flake also work.
Go easy on rich foods like bloodworms. It is easy to overdo it and end up with bloating or messy water. Small portions, more often, works better.
How they behave and who they get along with
Tequila splitfins are lively and a bit pushy, especially the males. They are not mean in the cichlid sense, but they can be relentless with chasing and displaying. In a cramped tank, that turns into stress fast.
- Best group setup: more females than males. I aim for 1 male to 2-3 females if I want peace.
- Temperament: active, always exploring, males spar and posture a lot.
- Good tankmates: other robust, similar-temperature fish that will not get bullied or outcompeted. Think tougher livebearers, many rainbowfish, or medium tetras in the right setup.
- Tankmates to avoid: slow long-finned fish (they can get nipped), tiny nano fish, and anything that needs very warm, soft, acidic water.
If the females are getting hassled, add cover first (plants, rock piles) and then consider reducing males. Rearranging decor can also reset the pecking order.
Breeding tips
They are livebearers, so breeding is more about managing the adults than getting them to spawn. Once the group is settled and well fed, you will start seeing fry show up pretty regularly.
- Pregnancy and fry: females carry for several weeks and drop small batches. It can feel like you get a few fry at a time rather than one huge guppy-style dump.
- Fry survival: adults will eat fry if they can find them. Heavy plants and floating cover make a massive difference.
- Breeding setup: a separate grow-out tank is easiest. Move pregnant females only if you can do it gently and without stressing them.
- Raising fry: feed tiny foods 2-3 times a day and keep the water clean with small, frequent water changes.
If you are trying to keep a specific line, label your tanks and do not mix fish around casually. It is surprisingly easy to lose track once you have a few groups going.
Common problems to watch for
Most issues I have seen with splitfins come from crowding, warm stagnant water, or not enough structure in the tank. They are hardy, but they do not like being stressed all the time.
- Chasing stress: constant harassment leads to clamped fins, hiding, and skinny females. Fix with more space, more cover, and fewer males.
- Fin nipping: usually shows up in under-decorated tanks or mixed with tempting long-finned species.
- Bloat/constipation: often from overfeeding rich foods. Add more fiber, feed smaller portions, and skip a day if needed.
- Ich and other parasite flare-ups: often after new fish or big temperature swings. Quarantine new arrivals if you can.
- Water quality crashes: heavy feeding for fry can foul water fast. Watch ammonia/nitrite and do frequent small water changes.
If you see rapid breathing at the surface or fish gasping, treat it like an emergency: check ammonia/nitrite right away, increase aeration, and do a large water change.
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