Sinustrombus taurus are known primarily from the Marshall and the Marianas Islands. In the Marshalls, they have a very patchy distribution. We saw none in three years of searching at Enewetak Atoll. On a short research trip to Rongelap in 1982, we looked where they had been reported more than 22 years before (Abbott (1960)), and there was still a healthy population. At Kwajalein, there are a few large lagoon pinnacles in the northern half of the atoll where this species is not especially rare, usually distributed in pairs or sometimes groups of three on sand and rubble at depths of about 8-10m. Also, at some spots along the northern atoll interisland reefs, they occasionally form taurus "herds" where 50 or more specimens distributed usually in pairs might be counted in an area of sand, rubble, and Halimeda a hundred meters or so in diameter. Such a herd might last a year or two in an area then disappear. Another place where specimens are occasionally seen is on sand and rubble at the bases of some large midlagoon pinnacles at depths of 30 to 40m. Curiously, at Kwajalein they are nearly absent from the southern half of the lagoon. A few were once spotted in a Halimeda patch on a lagoon sandspit near North Loi island in the southern Kwajalein Atoll. Also, a couple of specimens have been found on the seaward reef, but they are very rare there. Most shells are heavily encrusted and often bear shell-damaging cap shells or vermetid "worm" (mollusk) tubes. Immediately below is a pair of moderately encrusted specimens on a typical sand and algae substrate.
The next three photos show a younger shell with brighter than usual coloration.
This specimen is still thickening up its outer lip and filling in its spine.
Below, a group of three is well camouflaged on a sand, rubble, and algae substrate.
Egg masses, like that just below the specimen below, are mixed up with mucus and sand and often buried under the top layer of sand. The longer spine on this female is broken off, a common flaw in the shell.
A juvenile.
Created 1 October 2009
Updated 21 March 2020