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Southwest Florida Shells with Emphasis on Sanibel & Captiva

By José H. Leal

Family Muricidae

Calotrophon ostrearum

(Conrad, 1846)

Mauve-mouth Drill

Shell size to 29 mm; shell fusiform, with six whorls. Shell sculpture of strong axial ribs crossed by spiral cords. Shoulder forming angle, raised. Suture well-defined. Color light-brown to pink. Aperture color sometimes mauve. Generally similar to Urosalpinx perrugata, differing by thinner and more elongate shell, more elongate anterior canal, well-formed umbilicus, and color of aperture. The supplementary photos, all taken by Amy Tripp on Kice Island, Collier County, show Mauve-mouth Drills feeding on coquinas (Donax variabilis), and egg capsules (arrows) laid on a Horse Conch egg capsule. The capsules on the bottom (lower arrow) are spent.