by Timothy A. Pearce
There really is a Christmas Island. It is in the Indian Ocean about 250 km (155 mi) SW of Java and it is administered by Australia. Christmas Island, which was uninhabited by humans until the late 1800s, has a highly endemic flora and fauna, reflecting little human disturbance. Nearly two-thirds of the island is designated as a national park.
Carnegie Museum of Natural History has two species of sea snails from Christmas Island. Neither of these species is endemic to the island, and neither is rare.
Money Cowries from Christmas Island
These Moneteria moneta (Fig. 1), also known as money cowries, are from Christmas Island. They were donated to the museum by Casimir Potyraj, Jr. in September of 2012, although we don’t know when they were collected. These specimens are smaller than average M. monetaria. This species of cowry is used as decoration and was used as currency in many islands of the south Pacific Ocean region into the 1800s. Both the genus and the species names, Monetaria moneta, reflect their use as currency. This species occurs broadly in tropical areas of the Indian and Pacific Oceans, but not in the Atlantic. Monetaria moneta is in the cowry family, Cypraeidae, a group of snails appreciated around the world for their shiny, colorful shells, that look like they have a zipper underneath.
Castor Bean Shells from Christmas Island
This Drupa ricinus (Fig. 2), also known as the castor bean shell, is also a sea snail from Christmas Island. It came to Carnegie Museum of Natural History by way of the British Museum of Natural Science on July 25, 1935. It’s unclear whether that was the date the British Museum gave it to us, or the date it was collected; my guess is the former. Like the Monetaria moneta, Drupa ricinus also occurs broadly in tropical areas of the Indian and Pacific Oceans, but not in the Atlantic. Drupa ricinus is in the murex family, Muricidae, which includes snails that produce the purple dye prized by the Romans and Phoenicians.
Every day is Christmas on Christmas Island! We wish Merry Christmas to all the creatures there.
Timothy A. Pearce, PhD, is the head of the mollusks section at Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.
Carnegie Museum of Natural History Blog Citation InformationBlog author: Pearce, Timothy A.
Publication date: December 20, 2021