By hand size, I'd say 15 for the first; 17-18 range for the second. I'm basing that on the "rule of thumb" that if an average man stretches his thumb and pinky apart as far as they will go, it measures about 9". On the first, it looks like that would reach from the nose to back of the dorsal fin, with maybe 2/3 that distance to remaining. On the second, it looks like a thumb-pinky span would to about the mid-point of the fish.

Hard to tell from a photo, though.