Ladder Horn Snail
Synonym(s): Cerithidea scalariformis
A frequent marine mollusk of estuaries, mangrove swamps, salt marshes and tidal creeks along most of Florida's coastal areas. The range extends up the Atlantic coast to include Georgia and South Carolina. Also found in the West Indies and Bermuda.
Horn snails have a narrowly elongated spirally-coiled shell of from 10 to 15 ribbed whorls with adults having a flared, thickened outer lip. Ladder horned snails (Cerithideopsis scalariformis) are up to 33mm (~1-1/4 in.) long with the ribs on the two smallest whorls remaining distinct. Coloring is whitish to various shades of gray.
Breeding takes place in the fall resulting in jelly-clad spirals of bright green eggs which hatch into juveniles after about three weeks. There is no larval stage. Juveniles mostly live underwater with adults remaining above the high water mark. They feed on microalgae and detritus.
The other species of this genus in Florida is C. costata. Costate horned snails are much smaller, with a maximum length of 21mm (~13/16 in.) and the ribs of the two smallest whorls being less distinct than the others.
Cerithideopsis scalariformis is a member of the Potamididae - Horn Snails family.
For more information on this species, visit the following link:
iNaturalist page for this species
Date record last modified: Jul 27, 2022