Species profile
Merry Widow Livebearer
Phallichthys amates
Peaceful
Easy care
60 L minimum aquarium
4–6 cm adult size
Mid–top
Minimum group: 6
About this species
General notes for hobby use.
A hardy livebearer but not a licence for poor water quality. Stable moderate-to-hard water and planted cover suit it well.
Water parameters
Suggested general range for long-term care.
Temperature
20–26 °C
pH
6.5–8
GH
5–20 dGH
KH
3–15 dKH
Flow preference
Low
Data confidence
Verified
Behaviour
General behaviour traits used by TanksConnected compatibility checks.
Minimum group size
Minimum group: 6
Tank zone
Mid–top
Territory level
None
Predation risk
Fry
Bioload factor
0.7
Peaceful livebearer suited to a planted community. Keep more females than males and provide dense cover for fry and subordinate fish.
Compatibility flags
Quick cautions for common tank-planning issues.
Fin nipper
No
Plant safe
Yes
Shrimp safe
No / caution
Snail safe
Yes
Cave breeder
No
Digs substrate
No
Jump risk
Yes
Natural history & care
Research-backed context for long-term aquarium care.
Lifespan
3–5 years
Diet type
Omnivore
Minimum aquarium volume
60 L
Minimum footprint
60 × 30 cm
Accepted scientific name
Phallichthys amates
Alternative names
Merry Widow Livebearer, Merry Widow, Dwarf Molly
Native range
Central America from Guatemala through Honduras, Nicaragua, Costa Rica and Panama.
Natural habitat
Shallow ponds, ditches, swamps and slow streams with dense vegetation, soft substrate and abundant detritus/algae.
Diet & feeding
Algae, diatoms, detritus and tiny invertebrates; offer varied fine dry foods with plant matter and small frozen/live foods.
Breeding & sexing
Research-backed guidance for identifying sexes and reproductive behaviour.
Sexing
Males are smaller and possess a gonopodium; females are larger and fuller-bodied, especially when gravid.
Breeding
Livebearer. Females produce broods of free-swimming young after internal fertilisation; dense planting improves fry survival.