The common name 'sweetlip' is used in the Indian Ocean Territories to describe a couple of emperor species - the orange-striped emperor and the yellowlip emperor.

The common name ‘Sweetlip’ is used in the IOTs to describe a couple of emperor species; the orange-striped emperor (Lethrinus obsoletus) and the yellowlip emperor (L. xanthochilus).  Both species require a lagoon environment for the recruitment phase of their life cycle, so are more commonly found at Cocos (Keeling) Islands and not Christmas Island. 

Sweetlip are believed to spawn after dark, following a local migration to either sheltered lagoons or on the edge of exposed reef. Reproductive activity generally peaks around the time of the new moon. Growth rings on otoliths (ear bones) have been used to determine the age of emperors. Most species appear to live at least 15 years of age and some may reach twice this age.

Yellowlip emperor are heavily targeted by recreational fishers at Cocos (Keeling) Islands, so populations need to be monitored in the future to ensure their sustainability.

Yellowlip emperor, Lethrinus xanthochilus  (Image: Gelblippen-Straßenkehrer)