The other day I was reading the Reel Report (Fishing column in the Galveston Daily News) about how Hot the crabbing was around San Leon. The writer goes on to say what folks use for crab bait and as usual, chicken necks were the go to bait. He also mentioned that Fish Carcasses were used too..i.e. fish heads etc. but here is the Need to Know thing. It is against the law to use GAME FISH remnants of any kind for bait. I emailed the writer this in hopes he would add this bit of info in his next day column so folks would be aware but he never did.
Be safe out there, stay hydrated,and remember to take a Kid Fishin'

There's plenty of non-game species to use for crab bait. Jack crevalle comes to mind.

Hardheads always seem plentiful for me, I have even used mullet heads from the cast net. I would suggest running the string through the fish mouth and out its neck to secure it.

I have fed a gold spoon through mullet heads and pitched them into trapped pools around some back lakes and pulled up bunches of bait crabs. Half don't need a net as they seem to be really hungry.

Every crabber in seadrift would get busted then. They all use parts from the cleaning table for their traps. As do I when mama gets the crab urge.

I am pretty sure that is freshwater only. If that was the case they would have to classify every fish that swims in the ocean.
I have seen guides use every type of fish except for maybe redfish for cut bait.
Been on shark fishing trips where they use sailfish and tuna remains from cleaning tables.
Caught a ton of trout on golden croakers.

I've seen remnants from GAME FISH being put in 5 gallon buckets and was to go to the crabbers (so the bait shop staff said). This was at the TC Dike. But......!!