Common name: Jansen's wrasse
General information
Jansen's Wrasse, Thalassoma jansenii, is a vibrant and active fish species that adds both color and dynamism to a saltwater aquarium. Known for their striking coloration, which typically includes a mix of green, blue, and yellow hues, these wrasses are a favorite among aquarists. They are part of the Labridae family, which is known for the cleaning behavior some species exhibit, although this particular behavior is not prominent in Thalassoma jansenii.
Details
- Recommended minimum volume
- 300 liter (79 gallons)
- Salinity
- S.G. 1.020 to 1.025
- Temperature
- 24 to 28 °C (75 to 82 °F)
- Acidity
- pH 8 to 8.4
- Average size
- 30 cm (1′)
- Care level
- Moderate to easy Needs ample swimming space
- Diet
- Omnivore Varied diet of meaty foods and algae
- Social
- Harem Males may be territorial
- Reefsafe
- Yes
- Aggression
- Semi aggresive Can be territorial, especially males
- Captive bred
- No
Taxonomy
- KingdomAnimalsAnimalia
- PhylumChordatesChordata
- ClassRay-finned FishesActinopterygii
- OrderPerch-like FishesPerciformes
- FamilyWrassesLabridae
- GenusLunar WrasseThalassoma
- SpeciesJansen's wrasseThalassoma jansenii (Bleeker, 1856)
- SynonymsJulis jansenii Bleeker, 1856
Care
Jansen's Wrasse is a hardy species that requires a well-established aquarium with plenty of swimming space and rockwork for hiding. They are known to jump, so a tightly fitting lid or screen is essential to prevent escape. These wrasses are not picky eaters and will accept a variety of meaty foods, including frozen mysis shrimp, brine shrimp, and quality marine flake and pellet foods. It's important to maintain high water quality and stable parameters to keep them thriving.
Reproduction
In the wild, Thalassoma jansenii exhibits protogynous hermaphroditism, where individuals start life as females and can change to males if the dominant male is removed. This is a common trait among wrasses. In the aquarium, breeding Jansen's Wrasse is quite challenging and rarely achieved, as it requires precise conditions and a large, species-specific setup.
Habitat
Jansen's Wrasse is found in the Indo-Pacific region, from Indonesia to the Philippines, and north to southern Japan. They typically inhabit coral reefs and rocky areas where they can forage for small invertebrates. They are usually seen at depths ranging from shallow waters to about 40 meters deep.