All fish / Rivulidae

Blue Sword Rivulus

Laimosemion xiphidius

Also known as rivulus xiphidius, xiphidius rivulus, blue rivulus, blue sword killifish, rivulus xiphidium, laimosemion xiphidium, リヴルス・キフィディウス

This small killifish has a slim body with bright blue flanks crossed by deep red stripes. Males also have a fine blue edge running along the tail. It lives in shaded, very soft and acidic forest streams, and keepers value it as one of the most colourful non-annual killies.

Care at a glance

Care level

Hard

Temperament

Peaceful

Adult size

4 cm

Temperature

22 to 26 °C

pH

4.5 to 6.5

Smallest tank

20 litres

Keep as

Pair or one male with two or three females

Diet

Carnivore: small live foods such as daphnia, mosquito larvae, bloodworm and fruit flies; frozen foods taken once settled

Swims

Top of the tank

Lifespan

2 to 3 years

Water

Freshwater

Wild range

Upper Maroni and Oyapock drainages of French Guiana and Suriname, also northern Brazil (Amapá)

Breeding

It is a non-annual species that lays single eggs among plants or spawning mops over several weeks. The eggs take about two weeks to hatch in soft, acidic water, and the fry are small, so breeding is possible but takes some effort.

Good to know

It jumps very well, so the tank needs a tight-fitting lid. It does poorly in hard or alkaline water and is best kept on its own or with very small, calm fish.