Pretty little axolotl. The main thing I noticed is that the gills are very slightly pointing forward, this may be due to the filter current being a little too strong or that it may be a little stressed. If its the current this can usually be rectified quite easily by a number of ways, if the filter can be turned down..do so..or point the out bit towards the glass so it can diffuse the current. Finally if this fails I ended up attaching an artificial plant to the out bit and this worked!.
Regarding sexing , i am not too sure. What is the axolotl's over all size, it may still be a little to young. Males I find are usually quite easy to sex as they have lumps behind the back legs. My juveniles are approx 9 inches and I am pretty sure I can now tell which ones are males..females are far more coy.