Can Molly (Sailfin/Black/Dalmatian) and Wrestling Halfbeak Live Together?

Reviewed by Guidarium Editorial DeskUpdated April 28, 2026
Ideal Tank Mates

Yes, Molly (Sailfin/Black/Dalmatian) and Wrestling Halfbeak are ideal tank mates. Both species share compatible water parameters and peaceful temperaments, making them well-suited for a community aquarium. A minimum tank size of 75 litres is recommended.


At a Glance

Molly (Sailfin/Black/Dalmatian)

Poecilia sphenops

Wrestling Halfbeak

Dermogenys pusilla

🐟Family Group
Molly (Sailfin/Black/Dalmatian)
Livebearers
Wrestling Halfbeak
Livebearers
Temperament
Molly (Sailfin/Black/Dalmatian)
Mostly Peaceful (3/10)
Wrestling Halfbeak
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Molly (Sailfin/Black/Dalmatian)
24–28°C
Wrestling Halfbeak
24–28°C
pH Range
✓ Compatible
Molly (Sailfin/Black/Dalmatian)
7.5–8.5
Wrestling Halfbeak
7–8.5
Hardness (dGH)
✓ Compatible
Molly (Sailfin/Black/Dalmatian)
12–30
Wrestling Halfbeak
10–20
Water Type
✓ Compatible
Molly (Sailfin/Black/Dalmatian)
Brackish Tolerant
Wrestling Halfbeak
Brackish Tolerant
Flow Preference
✓ Compatible
Molly (Sailfin/Black/Dalmatian)
Moderate
Wrestling Halfbeak
Moderate
Min Tank Volume
Combined: 75 L
Molly (Sailfin/Black/Dalmatian)
75 L
Wrestling Halfbeak
55 L
Swimming Level
Shared: 1 zone
Molly (Sailfin/Black/Dalmatian)
TopMiddle
Wrestling Halfbeak
Top
🏷️Behavior Tags
Molly (Sailfin/Black/Dalmatian)
Hyperactive / Fast SwimmerFry PredatorAggressive Eater (Starves shy fish)
Wrestling Halfbeak
Jumper (Lid Required)Hyperactive / Fast SwimmerFry PredatorAggressive to same species/look-alikes
Stocking calculator

Can your tank handle Molly (Sailfin/Black/Dalmatian) and Wrestling Halfbeak?

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.

Molly (Sailfin/Black/Dalmatian)
Wrestling Halfbeak
Test both in my tank

Behaviour & Temperament

Molly (Sailfin/Black/Dalmatian) is a generally mild-mannered species (3/10), while Wrestling Halfbeak is generally mild-mannered (4/10). This modest difference means Wrestling Halfbeak may occasionally assert dominance over Molly (Sailfin/Black/Dalmatian).

Molly (Sailfin/Black/Dalmatian) and Wrestling Halfbeak both frequent the 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.

Worth noting: Wrestling Halfbeak is a known jumper, so a tight-fitting lid is essential.

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 8.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 12–20 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Molly (Sailfin/Black/Dalmatian) and Wrestling Halfbeak 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.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

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

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

Why This Pairing Works in Practice

Molly (Sailfin/Black/Dalmatian) and Wrestling Halfbeak work best when the tank gives each fish enough room to use its preferred level of the aquarium and enough cover to avoid constant visual contact. The score matters, but the real-world success usually comes from matching their pace, keeping water stable, and resisting the urge to crowd the tank just because the pair looks safe on paper.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Molly (Sailfin/Black/Dalmatian) and Wrestling Halfbeak.

Show 17 more tank sizes

Frequently Asked Questions

Can Molly (Sailfin/Black/Dalmatian) and Wrestling Halfbeak live together?

Yes. Molly (Sailfin/Black/Dalmatian) and Wrestling Halfbeak are considered ideal tank mates. Their water parameters, temperaments, and behaviour profiles are well matched for a community aquarium.

What size tank do Molly (Sailfin/Black/Dalmatian) and Wrestling Halfbeak 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 Molly (Sailfin/Black/Dalmatian) and Wrestling Halfbeak 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 Molly (Sailfin/Black/Dalmatian) or Wrestling Halfbeak aggressive?

Molly (Sailfin/Black/Dalmatian) is generally mild-mannered (3/10) and Wrestling Halfbeak is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Molly (Sailfin/Black/Dalmatian) and Wrestling Halfbeak need?

Both species overlap in the 7.5–8.5 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
April 28, 2026
Last updated
April 28, 2026
Issues or corrections?
Contact the editorial team

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