Can Rachov's Killifish (Annual) and Wrestling Halfbeak Live Together?

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

Yes, Rachov's Killifish (Annual) and Wrestling Halfbeak are ideal tank mates. Both species share compatible water parameters and peaceful temperaments, making them well-suited for a community aquarium. They occupy different areas of the water column, which reduces competition for space. A minimum tank size of 55 litres is recommended.


At a Glance

Rachov's Killifish (Annual)

Nothobranchius rachovii

Wrestling Halfbeak

Dermogenys pusilla

🐠Family Group
Rachov's Killifish (Annual)
Killifish
Wrestling Halfbeak
Livebearers
Temperament
Rachov's Killifish (Annual)
Mostly Peaceful (3/10)
Wrestling Halfbeak
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Rachov's Killifish (Annual)
20–26°C
Wrestling Halfbeak
24–28°C
pH Range
✓ Compatible
Rachov's Killifish (Annual)
6–7.5
Wrestling Halfbeak
7–8.5
Hardness (dGH)
✓ Compatible
Rachov's Killifish (Annual)
4–12
Wrestling Halfbeak
10–20
Water Type
✓ Compatible
Rachov's Killifish (Annual)
Freshwater Only
Wrestling Halfbeak
Brackish Tolerant
Flow Preference
✓ Compatible
Rachov's Killifish (Annual)
Low
Wrestling Halfbeak
Moderate
Min Tank Volume
Combined: 55 L
Rachov's Killifish (Annual)
19 L
Wrestling Halfbeak
55 L
Swimming Level
✓ Different zones
Rachov's Killifish (Annual)
MiddleBottom
Wrestling Halfbeak
Top
🏷️Behavior Tags
Rachov's Killifish (Annual)
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)
Wrestling Halfbeak
Jumper (Lid Required)Hyperactive / Fast SwimmerFry PredatorAggressive to same species/look-alikes
Stocking calculator

Can your tank handle Rachov's Killifish (Annual) 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.

Rachov's Killifish (Annual)
Wrestling Halfbeak
Test both in my tank

Behaviour & Temperament

Rachov's Killifish (Annual) 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 Rachov's Killifish (Annual).

In terms of spatial distribution, Rachov's Killifish (Annual) prefers the Middle (Open Water) and Bottom (Substrate) zones, whereas Wrestling Halfbeak occupies the Top (Surface) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Worth noting: Rachov's Killifish (Annual) 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 26°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

Both fish can tolerate a pH between 7 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 10–12 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Rachov's Killifish (Annual) and Wrestling Halfbeak together, plan for an aquarium of at least 55 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: Soil / Nutrient Rich, Leaf Litter/Blackwater, Plants - Densely covered, Plants - Floating. 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 Works in Practice

Rachov's Killifish (Annual) 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 Rachov's Killifish (Annual) and Wrestling Halfbeak.

Show 20 more tank sizes

Frequently Asked Questions

Can Rachov's Killifish (Annual) and Wrestling Halfbeak live together?

Yes. Rachov's Killifish (Annual) 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 Rachov's Killifish (Annual) and Wrestling Halfbeak need?

A minimum of 55 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 Rachov's Killifish (Annual) and Wrestling Halfbeak together?

Keep the aquarium between 24°C and 26°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Rachov's Killifish (Annual) or Wrestling Halfbeak aggressive?

Rachov's Killifish (Annual) 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 Rachov's Killifish (Annual) and Wrestling Halfbeak need?

Both species overlap in the 7–7.5 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
April 28, 2026
Last updated
April 28, 2026
Issues or corrections?
Contact the editorial team

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