For the longest time I thought this fish was a female due to the fin shape and behavior, but now I'm thinking male. I was able to vent her(him?) today and am hoping for your opinions....
You can't sex EBJD by finnage because their fins are deformed. Neither can you sex them by gill plate color because both sex show the same color. Venting is the only way to go if you know what your are doing. I am no good at vening but try to compare the unknown fish with a fish of known sex side by side. Another clue I use is to compare the two holes. If both holes have the same size, it's male. If the rear hole is bigger, it's a female. Remember the position of the genitial and AO for fish is the reverse for human so you don't mess up which hole to target.
Do you have any more pics of the vent? Like ones a little more to the side? Its hard to see the shape of the vent.