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Southwest Florida Shells with Emphasis on Sanibel & Captiva

By José H. Leal

Family Neritidae

Neritina usnea

(Röding, 1798)

Olive Nerite

A rare find locally on Sanibel-Captiva, the Olive Nerite is relatively common in other parts of Florida and the Gulf of Mexico. The species is very variable in color and shape, but usually presents a pattern of closely set, wavy axial (“vertical”), dark lines against a light-olive background. The species prefers to live in brackish water areas. The 16 mm shell in the photos was found on the beach on Captiva by Kimberly Nealon, on the first weekend after Hurricane Irma in September 2017. It probably washed from the back-bay areas or was possibly transported from the Caloosatchee estuary by the recent freshwater releases prompted by Irma. Another shell of this species present in the Museum collection was collected on the Sanibel "River" in 1958.