Usually no. There are some males that are monsters (like my ghost boy) and some females that get really big, but size couldn't be used as a sex indicator.
The only outward indicator of sex in corns that I know of is tail length/taper. Supposedly, males have a shorter tail with a sudden taper at the base and females have long slim tails with constant tapering. Of course, it's not a true indicator as only probing and popping can be.
**Adriana - White 'N Nerdy!**
1.0 BP 'SunSpot', 0.1 Corn 'Freya', 1.0 IJ BTS 'Topaz', 1.0 ND bunny 'Licorice'
well I probed my big corn and a known female and a known male. the big corn is definitely a female... no doubt about it. the probe stopped dead at 4 scales. With he male although MUCH smaller (using the same probe) went very deep with absolutely no effort.
Man, the known female had 19 eggs last time... and she is literally half the size and weight of my big girl!!!!