Lambis, the "Scorpion" Conch

The shallow-marine gastropod genus Lambis Röding, 1758 belongs to family Strombidae, which makes up the “true conchs” of the world. 

Three of the 10 living species (not including 14 hyrbrid “species”) of Lambis are illustrated in this post. They all live in very shallow waters in the Indo-Pacific, and, in much less common cases, the Red Sea. Their shells are large and thick, with many long, hollow digitations along the side of the shell, and knobs or protuberances can be present on the dorsum (top) of the shells. In addition, they all have a “peep-hole” notch (called the strombid notch) for the right eye. Their anterior end has a short or long anterior canal.

 

Lambis scorpius (Linnaeus, 1758), height 11.3 cm, width 5.5 cm, thickness 3 cm; three views: ventral, dorsal, and right side, in that order. This moderately common species lives in coral-reef areas in the Indian Ocean and Western Pacific regions. Its knobby digitations help this gastropod “blend in” with the rubble it lives in.

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Lambis lambis (Linnaeus, 1758), height 15 cm, width 8.5 cm, thickness 5.5 cm. Three views: ventral, dorsal, and right side, in that order. This Indo-Pacific species lives in mangroves or on reef flats from low tide to 5 m depths.

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Lambis millepeda (Linnaeus, 1758), height 14.5 cm, width 5.5 cm, thickness 3 cm. Three views of one specimen: dorsal, ventral, and right side, in that order. An internal view (cut section) of another specimen. This Indo-Pacific species lives on sand and rubble in shallow waters. This specimen is from Marshall Islands, Jaluit Atoll.

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Lambis is known with certainty only from the Recent record. This geologic range of this genus has been reported in some online databases as being Paleocene to Recent, but these reports are taxonomically out-of-date and incorrect. The current consensus among most experts is that these Paleocene and Eocene reports pertain to the gastropod Sulcogladius goniophora (Bellardi, 1852) of Eocene age from Western Europe and Pakistan. That species belongs to family Rostellariidae. A few experts have put forth the concept that Sulcogladius belongs in the Rostellariidae genus Rimellopsis Lambiotte, 1974.