Its about a 1/4 inch... found it in the creek while looking for scuds ..there's another one that is about 1/8th of an inch but i cant find it. housed in my 3 gallon atm. any info would be great!
i have only experience with brook sticklebacks....which i will say are one of the most evil native fishes ive ever had. Threespines around me are on the coast and in salt. they are less aggressive but still aggressive. ive never kept them, only collected them.
I currently have a couple, two tiny ones and one around 3" they started off as feeders for my sunfish and were caught in saltwater, but survived in fresh. The 3" lives with a bass fry and eats flakes and bits of market shrimp.
They make very cool pets and dont work out well as feeders, my bass tried to eat one several times and it spiked him and lodged it self in its mouth with its spikes. He is now terrified of it.
te sculpin would probably spit it out if i got it, the sticklebacks a pretty agressive, i have mine eating prawn and smelt fry. here is a crappy pic of him