Busycon perversum (Linnaeus, 1758)

Guide To Northeast Florida Whelks

    Four species of whelks can be found in northeast Florida. These include Busycon carica (Gmelin, 1791) [Knobbed Whelk], Busycon perversum (Linnaeus, 1758) [Lightning Whelk], Busycotypus canaliculatus (Linnaeus, 1758) [Channeled Whelk], and Fulguropsis spirata (Lamarck, 1816) [Pear Whelk]. Of the four, the Lightning Whelk is by far the most common while the Pear Whelk is uncommon to rare. All four can be found living intertidally on the open Atlantic Beaches as well as in more sheltered habitats such as inlets and sounds.
     In the case of the Channeled and Pear Whelks, the old saying "When you've seen one you've seen them all" is appropriate for both species. As a rule neither species varies much in shape and coloration and the shell you find on the beach will look like the picture in your favorite shell book. However,  for a reason not yet explained, the Channeled Whelk will periodically produce a pure white shell even though the coloration of the animal and its operculum is indistinguishable from one which produced a normal shell. Most shell collectors (as well as this web site) call these specimens "albinos." Personal observations since 1998 suggest that about 13% of the sub-adult Channeled Whelks on Duval County beaches have pure white shells. The species is usually not found in sufficiently large numbers to perform meaningful scientific studies. However on 9/23/2000, five of 38 specimens found and examined at Mayport Naval Station Beach in Duval County had pure white shells. [See Image] Subsequent finds/observations over the ensuing five years seem to confirm that approximate ratio.
    Both the Knobbed Whelk and Lightning Whelk are extremely variable species. The shells of each individual species differ considerably in shape, spire height, siphonal canal length, coloration, weight, size and number of knobs/spines, etc.  Fortunately, species identification 99.9% of the time is assured owing to the fact that the Knobbed Whelk is dextral (right handed - opening to the right when held with the spire up) while the Lightning Whelk is sinistral (left handed - opening to the left when held with the spire up). However, both species on rare occasions are known to produce reverse coiled specimens (a shell eagerly sought by collectors and both known from northeast Florida) which can complicate easy identification in some instances. Ultimately when everything else has proved inconclusive, if the color of the animal is known, it can provide the "ace in the hole."  The animal of the Knobbed Whelk is light cream colored while the animal of the Lightning Whelk is black/dark gray. [See Live Animal Images Of All Four Whelk Species] This difference in coloration proved helpful in determining that a specimen recently found in Duval County was in fact a reverse coiled (right handed) Lightning Whelk instead of an abnormal Knobbed Whelk. [See Image] While talking about the color of whelk animals, one might logically inquire whether  there are whelks with normally colored shells that have albinistic animals since it known that a normally colored animal can produce a while shell. Two observations, five years apart, would seem to indicate that the answer is "maybe." [See Image1 & See Image2]