Bluestreak cleaner wrasse
Labroides dimidiatus
— Where the name comes from
Labroides means “resembling Labrus”, the wrasse genus, which itself comes from the Latin labrum, the lip. Dimidiatus means “halved”, for the black band running from snout to tail. It is ten centimetres long and it holds the social workings of a coral reef in its hands.
— Facts
- Group
- Fish · Actinopterygii · Chondrichthyes
- Order
- Perch-likes
- Habitat
- Coral reefs, at fixed posts known as cleaning stations
- Range
- The tropical Indo-Pacific, from the Red Sea to Polynesia
- Size
- 8–14 cm, 10–20 g
- Diet
- Parasites, mucus and dead tissue taken from other fish
- Lifespan
- 4 years
— Characteristics
- 01
It works at fixed stations where its clients queue up.
- 02
It enters the mouths and gills of predators that could eat it.
- 03
It performs a swaying dance to invite clients to stop.
— What sets it apart
In 2019 it became the first fish to pass the mirror test. Marked with a coloured spot under the throat, visible only in reflection, it spent a long time in front of the mirror and then tried to scrape the mark off by rubbing on the bottom, repeatedly and only when the mirror was present. The result divided researchers — some argue the test measures something else in an animal so unlike us — but it reopened the question of whether self-recognition belongs to a handful of mammals and two birds.
