Can Espei Rasbora (Lambchop Rasbora) and Molly (Sailfin/Black/Dalmatian) Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 4, 2026
Possible with Caution

Keeping Espei Rasbora (Lambchop Rasbora) and Molly (Sailfin/Black/Dalmatian) together is possible but requires caution, though some care is needed. Provide a spacious tank of at least 75 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Espei Rasbora (Lambchop Rasbora)

Trigonostigma espei

Molly (Sailfin/Black/Dalmatian)

Poecilia sphenops

🐠Family Group
Espei Rasbora (Lambchop Rasbora)
Cyprinids
Molly (Sailfin/Black/Dalmatian)
Livebearers
Temperament
Espei Rasbora (Lambchop Rasbora)
Peaceful (1/10)
Molly (Sailfin/Black/Dalmatian)
Mostly Peaceful (3/10)
Temperature
✓ Compatible
Espei Rasbora (Lambchop Rasbora)
23–28°C
Molly (Sailfin/Black/Dalmatian)
24–28°C
pH Range
✓ Compatible
Espei Rasbora (Lambchop Rasbora)
5.5–7.5
Molly (Sailfin/Black/Dalmatian)
7.5–8.5
Hardness (dGH)
✓ Compatible
Espei Rasbora (Lambchop Rasbora)
1–12
Molly (Sailfin/Black/Dalmatian)
12–30
Water Type
✓ Compatible
Espei Rasbora (Lambchop Rasbora)
Freshwater Only
Molly (Sailfin/Black/Dalmatian)
Brackish Tolerant
Flow Preference
✓ Compatible
Espei Rasbora (Lambchop Rasbora)
Low
Molly (Sailfin/Black/Dalmatian)
Moderate
Min Tank Volume
Combined: 75 L
Espei Rasbora (Lambchop Rasbora)
38 L
Molly (Sailfin/Black/Dalmatian)
75 L
Swimming Level
Shared: 2 zones
Espei Rasbora (Lambchop Rasbora)
MiddleTop
Molly (Sailfin/Black/Dalmatian)
TopMiddle
🏷️Behavior Tags
Espei Rasbora (Lambchop Rasbora)
Nano / Bite-sized (Predation Risk)Hyperactive / Fast Swimmer
Molly (Sailfin/Black/Dalmatian)
Hyperactive / Fast SwimmerFry PredatorAggressive Eater (Starves shy fish)
Stocking calculator

Can your tank handle Espei Rasbora (Lambchop Rasbora) and Molly (Sailfin/Black/Dalmatian)?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Espei Rasbora (Lambchop Rasbora)
Molly (Sailfin/Black/Dalmatian)
Test both in my tank

Behaviour & Temperament

Espei Rasbora (Lambchop Rasbora) is a peaceful species (1/10), while Molly (Sailfin/Black/Dalmatian) is generally mild-mannered (3/10). This modest difference means Molly (Sailfin/Black/Dalmatian) may occasionally assert dominance over Espei Rasbora (Lambchop Rasbora).

Espei Rasbora (Lambchop Rasbora) and Molly (Sailfin/Black/Dalmatian) both frequent the Middle (Open Water) and Top (Surface) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Water Parameters

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

Both fish can tolerate a pH between 7.5 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 12–12 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Espei Rasbora (Lambchop Rasbora) and Molly (Sailfin/Black/Dalmatian) together, plan for an aquarium of at least 75 litres with a minimum length of 60 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Plants - Densely covered, Leaf Litter/Blackwater, Established Algae (Otocinclus). Meeting these requirements will help both species thrive.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Why This Pairing Needs Extra Planning in Practice

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Espei Rasbora (Lambchop Rasbora) and Molly (Sailfin/Black/Dalmatian) need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Espei Rasbora (Lambchop Rasbora) and Molly (Sailfin/Black/Dalmatian).

Show 17 more tank sizes

Frequently Asked Questions

Can Espei Rasbora (Lambchop Rasbora) and Molly (Sailfin/Black/Dalmatian) live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 75 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Espei Rasbora (Lambchop Rasbora) and Molly (Sailfin/Black/Dalmatian) need?

A minimum of 75 litres (tank length at least 60 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Espei Rasbora (Lambchop Rasbora) and Molly (Sailfin/Black/Dalmatian) together?

Keep the aquarium between 24°C and 28°C. A target of around 26.0°C sits comfortably within both species' preferred ranges.

Are Espei Rasbora (Lambchop Rasbora) or Molly (Sailfin/Black/Dalmatian) aggressive?

Espei Rasbora (Lambchop Rasbora) is peaceful (1/10) and Molly (Sailfin/Black/Dalmatian) is generally mild-mannered (3/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Espei Rasbora (Lambchop Rasbora) and Molly (Sailfin/Black/Dalmatian) need?

Both species overlap in the 7.5–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 4, 2026
Last updated
May 4, 2026
Issues or corrections?
Contact the editorial team

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