The Thinstripe hermit crab, Clibanarius vittatus, is a common species of hermit crab on the Texas coast. At University Beach, Corpus Christi Bay, virtually every empty gastropod shell is occupied by a hermit crab.

The one on the photo is in a shell of the Shark Eye, Neverita duplicata (Say, 1822).

See more about this species at the Biodiversity of the Gulf of Mexico (BioGoMx) database at:
http://gulfbase.org/biogomx/biospecies.php?species=Spp-59-0520