Jansen Wrasse (Thalassoma jansenii) Care
The Jansen Wrasse, Thalassoma jansenii, is best kept in a FOWLR (Fish Only with Live Rock) aquarium of 100 gallons or more with a tight fitting cover. They can reach a length of 8″ and need large areas to swim in and plenty of rock work as hiding places along with a deep sand bed of 4″ or greater for juveniles. They are very active fish and need tank-mates that are larger and somewhat aggressive to hold their own against the Jansen Wrasse. Some fish to consider with these guys are angelfish, some semi-aggressive trigger fish, moray eels, angelfishes, hawkfish and groupers.
They are know to move rocks and bottom living corals in order to find prey along with disturbing existing sand beds by blowing streams of water looking for food, so ensure the rock work and structures are secure. While they do not eat corals or plants they are known to eat snails, tubeworms, sea stars, cucumbers, urchins, crabs, and shrimp and will also eat smaller fishes, even those slightly larger by first grabbing them and then bashing them against rock work or the side of the tank, then consuming the pieces.
The Jansen Wrasse will quickly burrow into the sand if frightened, and occasionally for sleeping at night.
Only keep one male fish per aquarium.
These fish are carnivores and will eat most regular fortified aquarium food such as finely chopped frozen or fresh meaty foods. You can feed them brine, mysis, squid, shrimp, clam and flake and pellet foods two to three times a day.