Lightning Whelk
Organisms / Invertebrates / Mollusks
Busycon contrarium    Intertidal Zone on Lulu Key

3/17/04   Photographed by: Carrie Roonsenberg

Descriptive Information - Observations from two groups
  • Field Marks: #1)Lighting Whelks display an anterior spiral with knobby protrusions. The shell tapers posteriorly with a long white, or cream, colored opening. The snail, itself, is either dark brown or black. The shell has dark brown, vertical lines. #2)The shell of the Lightning Whelk is a beautiful spiral that turns to the left, consisting of two main colors. A light tan color makes up the majority of the top of the shell along with beautiful brown stripes about 2.5 cm apart. The rest of the shell is the brown color except for a light tan stripe that travels across the middle of the shell at a bit of a diagonal. The shell texture included horizontal ridges spanning across the shells' surface. The mantle of the mollusk inside the shell was black in color and the shell that it pulls up against was a deep brown.
  • Size: #1)8 –10 inches #2)Approximate field measurements were taken for the Lightning Whelk and the observed is the following:
    • Total Length- 5 inches
    • Foot length – 1.5 inches
    • Shell width—2.5 inches
  • General Habitat: #1)Lightning Whelks are found in low-tide zones up to 10 feet deep and live on shell, sand, or mud bottom #2)The Lightning Whelk inhabits anywhere from the low tide line to 10 feet deep and can be found on the surface of sand, mud, or shell bottoms.
  • Range: #1)Costal and Marine regions.
  • Field Observations: #1)The Lighting Whelk was observed in the oyster bed at a depth of 2 – 21/2 feet. Attached primarily to the anterior dorsal side of the Lightning Whelk shell were Ivory Barnacles, as well as green algae. When removed from the water, the foot and body of the muscle ejected a stream of water and pulled back into the shell. Upon this occurrence the door to the shell shut. In the groove of the shell, extending posteriorly, there is a projection of the muscle body, which can be contracted or lengthened. Over a period of twenty minutes the mollusk became acclimated to our touch and no longer released water. After an initial five minutes the mollusk did not retreat as rapidly; this time period increased until the mollusk no longer responded. We also observed Lightning Whelk egg cases; they were located in a depth of approximately 2 1/2 feet. The cases were attached similar to beads on a string. The group of cases was coiled and about10 inches long. Each individual case contained an air pocket and was approximately 1 in. across. The sides of the case were not smooth, but made up of short linear segments. The observed egg cases were a transparent ivory color. #2) We were drowned in thought, surrounded by indescribable beauty that screamed praise when we spotted a shell that had a dazzling coloration, and a beautiful spiral for which the architect was the most admirable. It turned out to be a Lighting Whelk. We were captured by its beauty, and decided to further examine the flawless design. It was about five inches long and about two and a half inches wide. When we pulled it out of the water, it extended its foot and the entire mantle outward, as if it was screaming out of fear and discomfort. When we applied pressure to its mantle it squirted water out so that it would be able to contract itself and fit back into its shell. We also observed that when we put it out in the sun and held up in the air, it fully extended and stretched out, we hypothesized that it might be searching for a solid base to feel secure. Our observation of the Lighting Whelk further emphasized the amazing creativity of the designer and architect that so carefully put together a master piece, a work of art that naturally developed colors ever so pleasant to the eye.
  • Sources:#1) Alden, Peter, Rick Cech, Gil Nelson. National Audobon Society: Field Guide to Florida. Alfred A. Knopf: New York. 1998. p 201. #2)National Audubon Society Field Guide to Florida (pg 201)



            (This page developed by: Amy and Carrie Roosenberg, Grigoriy Arutyunyan and Steve Kempton)