Watch out for the Bull!

by Richard Salisbury

One of Guam's truly rare shells is Strombus taurus Reeve, 1857 (Fig 1 & 2). This is a large 3 to 4 inch Conch shell. Under its mossy periostracum is a beautiful lavender or pink shell spotted and striped with a chocolate brown. This coloration makes it stand out among all other Strombus. The peculiar elongate finger and thick heavy shell are distinctive characteristics. This species is limited in its range to the Marshall and Marianas Islands.

I have only a limited knowledge of the habitat of this species. I have found only one living and one dead specimen. Both were in deep water (over 90 feet) on a gently sloping reef. Small clusters were sparcely scattered about.

Underwater gullies, filled with sand, intersect the reef. I have heard that the Strombus live at greater depths, only common into shallow water at certain times of the year. Reportedly, they are sometimes found in colonies. Perhaps this is for the purpose of laying eggs. I can only dream of seeing such a herd.

Several Strombus taurus have been found in shallow reef lagoons. I can only guess how and why these shells came to be stranded there. Most of these shallow water shells have been heavily corroded.

The "Bull Conch" remains quite high on my list of Guam shells and perhaps it should be on your list also.