Species profile
Shortfin Molly
Poecilia sphenops
Peaceful
Easy care
100 L minimum aquarium
5–10 cm adult size
Top mid
Minimum group: 4
About this species
General notes for hobby use.
Short-finned molly suited to hard alkaline water. Pure Poecilia sphenops is adaptable, but many commercial mollies have mixed ancestry and should not automatically be assumed to be genetically pure.
Water parameters
Suggested general range for long-term care.
Temperature
18–28 °C
pH
7.5–8.5
GH
8–25 dGH
KH
Not yet documented
Flow preference
Low–moderate
Data confidence
Verified
Behaviour
General behaviour traits used by TanksConnected compatibility checks.
Minimum group size
Minimum group: 4
Tank zone
Top mid
Territory level
Low
Predation risk
Fry
Bioload factor
1.2
Keep in a social group with females outnumbering males. Courtship is persistent and adults may eat fry. Avoid soft acidic conditions for long-term maintenance.
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
Not yet documented
Diet type
Omnivore
Minimum aquarium volume
100 L
Minimum footprint
80 × 35 cm
Accepted scientific name
Poecilia sphenops
Alternative names
Sphenops Molly, Common Molly, Short-finned Molly
Native range
Central and northern South America from Mexico to Colombia.
Natural habitat
Uses varied fresh and sometimes mineral-rich waters. Plant cover and open grazing space are useful; stable mineral content is important.
Diet & feeding
A strong plant/algal component is important. Use algae/spirulina-rich foods with quality flake/pellets and modest frozen foods.
Breeding & sexing
Research-backed guidance for identifying sexes and reproductive behaviour.
Sexing
Males are generally smaller and possess a gonopodium; females are larger and deeper-bodied.
Breeding
Livebearer. Females produce free-swimming young and can store sperm; dense plants improve fry survival.