I agree that getting all the air out the bags help big time! Like others have said, use the bigger ones. I have found the ones that are 6" or bigger work best. I dont crowd the shad together also. I law them flat get the air out, seal and use later. Try it!! Small one get mushy instantly! I might try the using frozen method and letting them thaw in the water.

I freeze threadfin shad and still usable. After I catch, I put them on a towel to dry them out. Then put them in bag with pickling salt, get all air out then as much as possible spread them apart. When using them keep them in bag but on top of ice. I've had them last all day.

Dry them(paper towels) and vacuum seal them if your serious about quality bait and longevity

I vacuum seal mine.

I vacuum seal but with a twist, I put them dried and stacked in 1/2 gal mason jar or quart jars use the lid sealer on my vacuum sealer. I normally pack what I think I'll need per trip, works great for me.

Me too, it works great.

I have used this method and it does work. Any size or type. Frozen solid in seconds. You need a glove its so cold ! Saltyvarmintr
http://discovercatfishing.com/2011/09/freezingpreserving-baitfish-for-catfishing/

Glad you say it works so well. I always tell myself next time im stocking up for the freezer im going to try it but I always get lazy and never do. Hopefully your response will be a little motivation for me next time to give it a try.

Thank you for the link to preserving bait. I think everyone can benefit from this.

Glad I could contribute. I've learned a lot from this site. Good Guys all.
Thanks to all of you for sharing. Saltyvarmintr