Thalassoma jansenii | L

Thalassoma jansenii, commonly known as Jansen’s Wrasse, is a large and colourful wrasse species prized for its striking appearance and active behaviour. This species is best suited to experienced marine aquarists due to its size and temperament.

In captivity, Thalassoma jansenii requires a minimum tank size of 250 litres to provide ample swimming space and reduce territorial aggression. They thrive in well-established aquariums with plenty of live rock for hiding and foraging.

Temperamentally, this wrasse can be semi-aggressive, especially towards smaller or more passive tank mates. It is advisable to house them with similarly sized or robust species to avoid conflicts. They are generally not reef safe as they may nip at invertebrates and small fish.

The diet of Thalassoma jansenii should be varied and carnivorous, including high-quality frozen or live foods such as mysis shrimp, brine shrimp, and finely chopped seafood. Supplementing with pellet or flake foods formulated for marine carnivores can help ensure balanced nutrition.

Lighting and water flow requirements are standard for marine fish: moderate lighting and moderate water flow to mimic their natural reef environment. Placement in the aquarium should allow for open swimming areas as well as rockwork for shelter.

Origin details are not provided, but like other wrasses, they are native to tropical marine environments. Maximum size can reach up to 20 cm in length, making them a prominent feature in any large marine aquarium.