Blackfin Pearl Killifish

Overview

Blackfin Pearl Killifish (Austrolebias nigripinnis) is a bottom-to-middle swimmer for aquariums where the layout leaves enough open substrate area and the water stays stable.

Use these values as planning checks, then make sure the aquarium still has room for behavior, group needs, and calm community fish.

Care requirements

With a Beginner – Intermediate care level, Blackfin Pearl Killifish is approachable, but it still needs stable water, clean substrate, and a well-planned stocking group.

Because it uses the lower to middle part of the aquarium, leave enough open substrate area instead of crowding that part of the aquarium.

Plan the aquarium around the group, not just one individual.

With a lifespan of up to 5 years, this is a fish to plan for long term rather than an impulse addition.

Aquarium size and space needs

An aquarium of 120 L or larger can be a reasonable starting point, but it should not be read as permission to overstock.

At up to 5 cm, Blackfin Pearl Killifish stays small, but a group still needs room to move, feed, and avoid constant competition.

Uses the lower to middle part of the aquarium, so leave enough open substrate area for movement and feeding.

A group of 6 or more should have enough open substrate area for movement and feeding.

Water parameters

The temperature range for this fish is 17 to 23 °C, which fits many tropical freshwater aquariums. Choose other fish with overlapping temperature needs.

The pH range for this fish is 6 to 7. That points to acidic to neutral water, but stability is more important than sudden corrections.

The GH range for this fish is 5 to 20 dGH. That gives some flexibility, but sudden changes are usually more stressful than a stable value that is slightly imperfect.

The KH range is 1 to 8 dKH. Use it as a general stability reference rather than a reason for aggressive adjustments.

Temperament and compatibility

Blackfin Pearl Killifish needs more careful companion choice because the temperament data suggests space, boundaries, or similar-sized fish may matter.

If kept in a group of 6 or more, the aquarium should have enough open substrate area for the group rather than being planned around a single fish.

Because this fish uses the lower to middle part of the aquarium, compatibility is easier when other fish are not all competing for the same swimming space.

Swimming zone and behavior

This fish uses the lower to middle part of the aquarium, so leave enough open substrate area for movement and feeding.

Because this species is best planned as a group of 6 or more, bottom space matters more than body size alone.

Feeding

As an omnivore, Blackfin Pearl Killifish should receive a varied diet rather than one repeated food type.

Because it feeds near the bottom, make sure food reaches the substrate and is not completely taken by faster fish in the open water.

Natural habitat and origin

This profile currently lists the origin as Argentina. Treat this as a broad regional note rather than a complete habitat description.

Before adding this fish

Use this checklist before treating the profile as a match for an existing aquarium.

• Plan for an aquarium of 120 L or larger.
• Make sure the bottom area has enough open substrate for a group.
• Choose other fish with overlapping temperature needs.
• Keep pH stable within the listed range instead of making sudden corrections.
• Choose other fish carefully around this temperament.
• Plan for a group of 6 or more.
• Offer a varied diet suitable for an omnivorous bottom-dwelling fish.