The shells of whelks are generally elongated with a wide opening and are frequently incorrectly described as conchs. Whelks have complete shells even when they are in the larval stage. Unlike many other mollusks, whelks never go through a period when they can swim. Instead, the larvae simply crawl away from their egg capsules as fully formed, miniature whelks. Empty whelk shells remain strong for a long period of time and are often in demand by hermit crabs seeking a new home.