Ratio
---------- Average
eye to lips 6.049
lips 13.367
eye to head 16.276
dorsal fin 9.250
depth at dorsal 6.072
peducnle 17.544
tail fin 8.314

The two most closest ratios were the dorsal fin and the distance from the eye to the lips.



Fishbase.com did not have morphometrics for the northern hog sucker, so I tried working some up on my own. The Red lines on my image represent the measurements I took on DT's and my fish. the ratio is =total length/ length of segment. That way a fish that has a "eye to lips measurement" of 2 inches would be ~12" long.

I tried to focus on measurements that were both easily defined and represented well in pictures. Pelvic and pectoral fins were out because these are usually not held perpendicular to the camera. Measurements on the body and head seemed like they would be more consistent.

E.Sub, this might make it easier for you to measure your slanted fish. Maybe you could compare the length of one of your left hand fingers to the the length of the dorsal fin? Or the width of your finger in the second photo to the eye to lip distance?