Mauritia arabica (Linnaeus, 1758)
Arabian cowry, 38.2-62.3mm

Mauritia arabica is found in a variety of locations around the atoll, but always in shallow water, usually in areas where there is some water movement. They prefer the rough parts of the intertidal reef, in the shallow surge channels of the reef edge groove and spur system, and under rocks on shallow subtidal reefs, frequently on windward shores. They live under rocks or wedged in crevices. Mauritia arabica is very similar to and frequently confused with Mauritia eglantina. The differences between them are hard to describe, but after examining a lot of specimens, you develop the ability to tell them apart often without even being able to really say why. The one external character often used to distinguish the two is the presence of a dark blotch on the spire of M. eglantina that is lacking on M. arabica; however, sometimes this character is not very clear. Mauritia arabica tends to be smaller, a bit flatter and wider at the base and less cylindrical in shape than M. eglantina. Mauritia eglantina also prefers calmer waters under rocks on the quiet downwind sides of islands, and it is often found deeper. Still, there are areas where the two species overlap, and it often is not easy to tell them apart. Mauritia arabica has been broken up into several subspecies that are distributed from the west central Pacific to the east coast of Africa, and the subspecies found in the Marshalls is Mauritia arabica arabica.

The big reason most cowries hide is there are predators ready to go for them whenever they can. While this cowry was exposed for its photo session, a Cheilinus fasciatus wrasse, which we popularly call "chomper fish," came down and grabbed it, intending to have it for lunch. Swinging the camera at the wrasse caused him to drop the cowry, which was then hidden away to guard against further attacks.

55.3mm, 1971

Mauritia arabica lacks a dark blotch on the posterior end of the shell.

56.05mm, 27 March 2011

This one is a bit enigmatic. By its blotched dorsum, I would tent to call it Mauritia maculifera, but the lack of a columellar blotch rules that out. The base also looks a bit like Mauritia depressa, but that species tends to be wider for its length and flatter, so the marginal color is more easily seen from the top. That really just leaves M. arabica. 49.15mm, 1983

Created 1 April 2008
Updated 2 April 2024

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