That's the juvenile pattern for a number of lugubris-types. Until it gets larger and takes on a mature color pattern it would be difficult to say with any certainty which of the many lugubris types it is.
By far, the most common would be Crenicichla sp. "venuzuela". That would be my guess, but it could easily be any of a number of other lugubris-types.
By far, the most common would be Crenicichla sp. "venuzuela". That would be my guess, but it could easily be any of a number of other lugubris-types.