Species profile
Exclamation Point Rasbora
Boraras urophthalmoides
Peaceful
Moderate care
40 L minimum aquarium
1.5–2.5 cm adult size
Top mid
Minimum group: 12
About this species
General notes for hobby use.
Tiny, timid shoaler. A mature 40 L+ planted setup with a large group is a better welfare target than ultra-small nano minimums.
Water parameters
Suggested general range for long-term care.
Temperature
23–27 °C
pH
5.5–7
GH
0–10 dGH
KH
Not yet documented
Flow preference
Low
Data confidence
Verified
Behaviour
General behaviour traits used by TanksConnected compatibility checks.
Minimum group size
Minimum group: 12
Tank zone
Top mid
Territory level
None
Predation risk
Tiny fry
Bioload factor
0.25
Very peaceful and easily intimidated. Best in a species-focused or similarly tiny calm community.
Compatibility flags
Quick cautions for common tank-planning issues.
Fin nipper
No
Plant safe
Yes
Shrimp safe
Yes
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
40 L
Minimum footprint
45 × 25 cm
Accepted scientific name
Boraras urophthalmoides
Alternative names
Exclamation Point Rasbora, Exclamation Point Boraras
Native range
Mainland Southeast Asia, including Thailand and neighbouring Mekong-associated lowlands.
Natural habitat
Shallow marsh, swamp and vegetated wetland habitat. Use dense plants, botanicals, subdued light and minimal current.
Diet & feeding
Requires very small foods: powdered dry foods, Artemia nauplii, Cyclops and other micro-invertebrates.
Breeding & sexing
Research-backed guidance for identifying sexes and reproductive behaviour.
Sexing
Males are slimmer and usually more intensely coloured; females are fuller-bodied.
Breeding
Continuous/scattered egg layer in dense vegetation; adults provide no care and may consume eggs or fry.