Jansen's wrasse (Thalassoma jansenii)

Scientific name: Thalassoma jansenii Bleeker, 1856

The Jansen's wrasse (Thalassoma jansenii) is a marine fish of the family Labridae. In the aquarium it needs water at 24–28°C (75–82°F). Native range: Indo-West Pacific, Maldives to Fiji, north to southern Japan, south to Lord Howe Island.

Jansen's wrasse care at a glance

Temperature: 24–28°C (75–82°F)

Biology

Dorsal spines (total): 8; Dorsal soft rays (total): 13; Anal spines: 3; Anal soft rays: 11. Color pattern remains similar throughout life. Large juveniles and females are mostly black with a single white band and white area below the head to the anus. Males retain the white central band but is more yellow, and develops a second narrow band halfway towards the head. Initial phase white with 3 black bars, the first on upper half of head and anterior body containing a yellow streak at edge of opercle, the second across dorsal fin and ventrally to anus, the third covering most of body and posterior portions of dorsal and anal fins. Terminal male with yellow between black bars. Pectoral fins bluish (Ref 9823).

Source: FishBase, licensed CC BY-NC 4.0.

Species facts

Scientific name: Thalassoma jansenii
Family: Labridae (Wrasses)
Order: Perciformes (Perch-like fish)
Class: Actinopterygii (Ray-finned fishes)
Maximum length: 20.0
Depth range: 1–15 m (3–49 ft)
Environment: Marine; reef-associated; non-migratory; depth range 1 - 15 m, usually 1 - 12 m
Climate: Tropical
Distribution: Indo-West Pacific: Maldives to Fiji, north to southern Japan, south to Lord Howe Island.
Conservation status (IUCN): Least Concern (LC)
Threat to humans: Harmless
Uses: Aquarium: commercial
Resilience: Medium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.)