Species · Shrimp & snails
Mystery Snail
Pomacea bridgesii
The big, friendly, colourful snail that grazes leftovers and — unlike other apple snails — leaves healthy plants alone. Needs calcium for its shell and an air gap to breathe.
Difficulty: BeginnerShrimp / invert tank✓ Fact-checked care guide
Quick facts
| Adult size | ~5 cm / 2 in |
|---|---|
| Minimum tank | ~40 L / 10 US gal (a big snail with a real bioload) |
| Temperature | 22–26 °C / 72–79 °F (within the range of 20–28 °C / 68–84 °F) |
| pH | 7.6–8.4 (alkaline) |
| Hardness | Hard — KH ~12–18; needs calcium for its shell |
| Filtration & flow | Any cycled tank; leave an air gap above the water (it breathes air) and a lid |
| Diet | Omnivore scavenger — leftovers, algae, blanched vegetables + a calcium source |
| Social | Keep singly or in a group; peaceful with everything |
| Temperament | Completely peaceful |
| Lifespan | 1–2 years |
Overview
The mystery snail (Pomacea bridgesii, the spike-topped apple snail) is a big, personable, brightly-coloured snail — gold, ivory, blue, black — that trundles around grazing leftovers and algae, and is genuinely fun to watch.
Its best trait: unlike its larger apple-snail relatives, it generally leaves healthy live plants alone, so you get a big cleanup snail without a shredded planted tank.
Water & tank
Mystery snails want hard, alkaline water — pH 7.6–8.4 with KH around 12–18 — at 22–26 °C / 72–79 °F, because they need plenty of calcium to build and hold their large shell; soft, acidic water dissolves it.
Two setup essentials: leave an air gap above the water and keep a lid, because they have both gills AND lungs and regularly surface to breathe air (and can climb out). Give them ~40 L / 10 US gal — they have a real bioload for a snail.
Feeding
An omnivore scavenger — it grazes leftovers, algae and biofilm, and appreciates blanched vegetables (courgette, spinach) and a calcium source (cuttlebone, or a mineral supplement) for shell health.
Behaviour & tankmates
Completely peaceful and safe with fish, shrimp and plants — a great community scavenger. Avoid snail-eaters and copper.
What to expect
A busy, curious grazer that often climbs to the surface for air and may cruise the glass upside-down at the waterline. Females lay distinctive pink egg clutches ABOVE the waterline — remove them if you don't want more snails.
Myths, kindly busted
“Mystery snails eat aquarium plants like other apple snails.”
P. bridgesii generally leaves healthy live plants alone — one of the few apple snails safe for a planted tank.
“It can live fully submerged with no air gap.”
It breathes air with a lung as well as gills and needs to reach the surface — leave an air gap above the water (and a lid, as it climbs).
When to act
We triage, not diagnose — but these are worth a closer look (starting with a water test):
- A pitted, cracked, or thinning shell — water too soft/acidic or short on calcium; raise KH/hardness and add a calcium source.
- A snail sealed shut and inactive for days, or floating and foul-smelling (dead) — test the water (and rule out copper).
Sources & further reading
- Aquarium Co-Op — Mystery Snail (Pomacea bridgesii) care — Adult ~2 in / 5 cm; temperature ~68–84 °F / 20–28 °C; pH 7.6–8.4; KH ~12–18 (calcium for shell); breathes air (needs air gap + lid); lays pink egg clutches above the waterline; leaves healthy plants alone; lifespan 1–2 yr.
Written & fact-checked by The Finfern Team against the sources above — kind, general guidance, not a diagnosis. If something looks wrong, test your water and, if it persists, contact a fish-savvy vet.
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