Yes, on most
healthy male synos it is hard to miss from the side, a male that is not in good condition may not be as developed but the fish you were photographing looked to be in top shape.

- boo.jpg.jpg (15.07 KiB) Viewed 2385 times
There are some reophilic synos such as my
which have a bit of a ridge beside the area which makes it more difficult to see but most IMO should be as the above.
Birger