Butis humeralis

{{Short description|Species of fish}}

{{Speciesbox

| image =Butis humeralis (Valenciennes, 1837).jpg

| taxon = Butis humeralis

| authority = (Valenciennes, 1837)

| synonyms = Eleotris humeralis Valenciennes, 1837

}}

Butis humeralis, commonly known as the dark sleeper or olive flathead-gudgeon, is a fish native to the waters of Indonesia and Indochina. Found in salt, brackish and fresh water, it reaches a standard length of 14.2 cm.{{FishBase | genus = Butis | species = humeralis | year = 2015 | month = 2}} It closely resembles the crazy fish (Butis butis), but is more solid in build and never has two black spots at the base of its pectoral fins.{{cite book|author=Yvonne Sadovy, Andrew S. Cornish|title=Reef Fishes of Hong Kong|publisher=Hong Kong University Press|date=2000|pages=252–53|isbn=9789622094802|url=https://books.google.com/books?id=VWX19IN0630C&q=%22Butis+humeralis%22&pg=PA252}}