Sex ID on Synspilum?

[eyespot]

I bought this synspilum about a year ago at 3 inches and it's now about 8 inches (some keepers on here argue there is a distinction between melanurus and I bought mine as a synspilum). It has blue eyes which isn't a guarantee it's a male but I thought I'd throw that out there. On a slightly unrelated note I owned a 14" dominant male about 25 years ago that developed a healthy nuchal hump and I noticed I rarely ever see adult males with nuchal humps anymore. I'm leaning towards male but I'd like to hear informed opinions.

 

[newworld]

Looks male

 

[roliva]

How is he/she doing?

 

[duanes]

The name synspillum, is no longer considered valid by the scientific community.
DNA test have shown that melanurus and synspillum are the same fish, just location/color variants.
Because melanurus was described first (Gunther 1862) that name takes precedence,
synspillum was not described until 1935 by Hubbs, thus syspillum was dropped. Of course many aquarists are often hardheaded and resist change (and science).
Back in the 80s they were imported as separate species, melanurus often predominantly dark yellow, and black, with a more sleek body shape, and very little blue and red, while the syspillum variant was collected in a different location, sporting the more popular reds and blues, and less sleek shape.
But color or even shape is not always a determiner of being a separate species, it just indicates adaptation of a population to certain separate environments.