All fish / Labridae

Jansen's Wrasse

Thalassoma jansenii

Also known as jansen's wrasse, jansen wrasse, black and white wrasse, jansens wrasse, jansen's thalassoma, ヤンセンニシキベラ, 詹氏锦鱼

A fast-swimming wrasse that is black with broad white to yellow-green bands, and the head often has a yellow tint. People keep it because it is bold, active and hardy in large fish-only tanks.

Care at a glance

Care level

Moderate

Temperament

Aggressive

Adult size

18 cm

Temperature

24 to 28 °C

pH

8.1 to 8.4

Smallest tank

500 litres

Keep as

Keep singly, or one male with several females in a very large tank

Diet

Carnivore: mysis, krill, chopped seafood, marine pellets and flakes

Swims

Middle of the tank

Lifespan

5 to 10 years

Water

Marine (saltwater)

Wild range

Eastern Indian Ocean and western Pacific: Maldives to Indonesia, Philippines, Fiji and northern Australia

Breeding

It is a protogynous hermaphrodite, so females can turn into males, and pairs spawn in open water. It has not been bred in home aquariums with any regularity.

Good to know

It grows large, swims constantly and will eat small fish, shrimps, crabs and snails, so it is not reef safe for invertebrates. Fit a tight lid because it jumps.