Lethrinus nematacanthus Bleeker, 1854 Lethrinus genivittatus, the longspine emperor, threadfin emperor, lance emperor or lancer,[2] is a species of fish in the genus Lethrinus, and family Lethrinidae.

[3] It was first described by Achille Valenciennes in 1830.

The IUCN classifies it as being of least concern.

[1] It lives in marine and brackish water and is native to the Indo-West Pacific.

This Acanthuriformes-related article is a stub.