Eastern Mosquitofish

Gambusia holbrooki

Eastern Mosquitofish is a middle-to-top swimmer.

AggressiveMiddle to top swimmerBeginner – Intermediate

Save this fish or add it directly to one of your aquariums.

Need help with Eastern Mosquitofish?

Explore compatibility, care or problems using this guide and your aquarium’s conditions.

Quick facts

Adult size: ≤ 3.1" (≤ 8 cm)
Aquarium size: 11 US gal (40 L) or larger / ≥ 11.8" (≥ 30 cm) minimum length
Care level: Beginner – Intermediate
Temperament: Aggressive
Swimming zone: Middle to top swimmer
Temperature: 59–95°F (15–35°C)
pH: 6–8.5
GH: 5–15 dGH
Diet: Omnivore
Lifespan: up to 2 years

Care requirements

Care level: Beginner – Intermediate.

Lifespan: up to 2 years.

Aquarium size and space needs

Minimum aquarium size: 11 US gal (40 L) or larger / ≥ 11.8" (≥ 30 cm) minimum length. Plan the layout and stocking within that limit.

Water parameters

Suitable water: temperature 15–35 °C, pH 6–8.5, GH 5–15 dGH.

Temperament and compatibility

Eastern Mosquitofish is aggressive and needs carefully selected companions.

Swimming zone and behavior

This fish uses the middle to upper part of the aquarium, so leave enough open swimming space for movement and feeding.

Feeding

As an omnivore, Eastern Mosquitofish should receive a varied diet rather than one repeated food type.

Before adding this fish

Plan for an aquarium of 11 US gal (40 L) or larger / ≥ 11.8" (≥ 30 cm) minimum length.
Choose other fish carefully around this temperament.
Offer a varied diet suited to this species’ documented feeding habits.

Natural habitat and origin

Origin: United States.

Important notes

Controlled 2025 research directly demonstrates attacks and fin damage to similarly sized guppies: do NOT mark Eastern Mosquitofish generically peaceful or community-safe. Do not release this invasive species into local waters.

Similar fish profiles

Use these profiles to compare fish with similar care level, size, temperature range, or swimming behavior.

Black-Bellied Limia Limia melanogaster Same family Similar care level Same swimming zone Beginner – Intermediate ≤ 2" (≤ 5 cm) 72–82°F (22–28°C) African Butterfly Cichlid Anomalochromis thomasi Similar care level Bottom dweller Similar diet Beginner – Intermediate ≤ 3.1" (≤ 8 cm) 73–81°F (23–27°C) Anus Spot Lampeye Killifish Poropanchax stigmatopygus Same family Similar care level Same swimming zone Intermediate ≤ 0.9" (≤ 2.4 cm) 72–79°F (22–26°C) Avacado Pufferfish Auriglobus modestus Similar care level Same temperament Bottom dweller Intermediate – Advanced ≤ 3.9" (≤ 10 cm) 73–82°F (23–28°C) Black Sharkminnow Labeo chrysophekadion Similar care level Same temperament Bottom dweller Intermediate – Advanced ≤ 35.4" (≤ 90 cm) 68–79°F (20–26°C) African Moon Tetra Bathyaethiops caudomaculatus Similar care level Same swimming zone Similar diet Beginner – Intermediate ≤ 3.1" (≤ 8 cm) 75–77°F (24–25°C)

FAQ

How large does Eastern Mosquitofish get?

Eastern Mosquitofish reaches ≤ 3.1" (≤ 8 cm).

What aquarium size does Eastern Mosquitofish need?

Use an aquarium of at least 11 US gal (40 L) or larger / ≥ 11.8" (≥ 30 cm) minimum length.

Is Eastern Mosquitofish peaceful?

Eastern Mosquitofish should be planned cautiously with compatible fish only, because aggressive behavior can limit companion options.

What temperature is suitable for Eastern Mosquitofish?

Keep it between 15 to 35 °C.