It feeds exclusively on plankton by picking out individual food items with their protractile mouths. Head shows a short snout and a small protractile mouth. The mouth is also usually not truly protractile. This species reaches up to in length and has an unusual protractile mouth. The large, oblique mouth is protractile with a projecting lower jaw. Wrasses have protractile mouths, usually with separate jaw teeth that jut outwards. They have protractile mouths, usually with separate jaw teeth that jut outwards. Prominent features of the shortnose sturgeon are the scutes, protractile tube-like mouth, and chemosensory barbels. The mouth is protractile, and the lower jaw juts out. It has a small protractile mouth with a black, burglar-like mask around its eyes. The fish's protractile mouth helps it dig for chironomid larvae, "Tubifex" worms, bivalves, and gastropods.