Molly

Mollies are fish from coastal streams and inlets around Mexico, often bred into interesting shapes and colours, particularly with black, speckled, and golden varieties.

Snapshot

Maintenance

Generally quite a hardy fish; requires at least a 25L tank, ideally with some salt added.

Sociability

Mollies are peaceful fish, and care should be taken when housed with more aggressive species.

Ego

They have a reputation for nipping the fins of longer-finned fishes.

Greed

Mollies aren't too greedy and will get by on a flake or two of food per day.

Celebrity doppelgänger

Taylor Swift

Pimp my tank

Mollies like all sorts of aquascaping for their tank, with plenty of room to swim and hide.

Popular names

Holly, Wally, Ollie

Health & Care

Although mollies are technically freshwater fish, in the wild they live in brackish water, at inlets or coastal reasons. Because of this, it is common to add marine salt to the water, to maintain an optimum pH level and keep parasites and fungus away.

Key Facts

AVERAGE LIFESPAN
5 years
AVERAGE SIZE
8 - 12 cm

Common Conditions

Popeye

Exopthalmia can have a variety of causes, from gas embolism manifesting in the eye, internal bacterial infections or as a secondary symptom from injury, or even stress. It’s hard to treat until the cause is identified.

Average vet fees: £5 - 100

Fin Rot

Fin rot is a disease of the fin, a bacterial infection spreading from damage. It can often be cured by ensuring a clean environment for the fish, but sometimes a virulent strain of bacteria will need antibacterial medicine or antibiotics.

Average vet fees: £10 +

Tip for first-time owners

Mollies are rapid breeders and growing a big family of them can be a fun project.

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