Here's a typical Lightning Whelk, Busycon pulleyi Hollister, 1958 from University Beach, Corpus Christi Bay.

The shells of juveniles often show the dark brown axial bands that give the species its common name.

The shell shown here was about 7.5 cm (3 in) long, and was crabbed, as most gastropod shells found in the bay and in coastal waters.

This was just one of many shells of this species that I observed that day. It is a very common species locally.