These animals feed upon other mollusks by drilling with the radula and secreting acid to burn through the shell, leaving a small round hole as evidence.  A few feed upon living corals using acid alone.  The animals create a green fluid that dries purple.  Ancient Romans used to crush hundreds of murex to create this royal dye.

Most have spiny shells and attractive colors and are popular with collectors.  They are found in habitats where their favorite prey occurs, including the intertidal zone, estuaries, mudflats, sand, boulders, and reefs to deep water.  Drupes are abundant in shallow water and rocky shores.  Shells are usually heavily encrusted with organisms and better ones may be cleaned by soaking  them in bleach, followed by lots of scraping and scrubbing with a stainless-steel brush.

Lanai Lookout, Oahu

Abundant on rocks in shallow water.  Feeds upon worms and mollusks.  About 3/4 inch.  Hawaii, Indo-Pacific, & the Galapagos.

Makapu'u tidepool, Oahu

Makapu'u tidepool, Oahu

Uncommon under rocks at scuba depths.  Has orange-ringed aperture and longer spines than D. ricinus.  Feeds upon worms and mollusks.  About 3/4 inch.  Hawaii & the Indo-Pacific.

Abundant on hard reef in shallow water to 30 feet.  Feeds upon worms.  About 1.5 inches.  Hawaii & the Indo-Pacific.

Firehouse, Oahu, 40 feet

Firehouse, Oahu, 40 feet

Firehouse, Oahu, 40 feet

Fairly common under rocks at scuba depths.  Aperture is bright pink and yellow.  Attains 2 inches.  Hawaii & the Indo-Pacific.

Fairly common on hard reef in the surf zone in the extreme Northwestern Hawaiian Islands but rare in the main Hawaiian Islands.  Attains 3/4 inch.  East Indian Ocean through Polynesia.

Lanai Lookout, Oahu

Lanai Lookout, Oahu

Fairly common on rocks in the surf zone.  Feeds upon limpets ('opihi).  Attains 4 inches.  Hawaii & the Indo-Pacific.

Diamond Head, Oahu

Diamond Head, Oahu

Fairly common under basalt rock in shallow water.  Feeds upon vermetid snails.  Attains 1 inch.  Hawaii & the tropical Pacific.

Diamond Head, Oahu

Diamond Head, Oahu

Diamond Head, Oahu

Diamond Head, Oahu

Portlock, Oahu

Portlock, Oahu

Abundant on and under rocks in the intertidal zone.  Feeds upon bivalves and dead mollusks.  Attains 1 inch.  Hawaii & the Indo-Pacific.

Uncommon under rocks and among zoanthids in shallow water.  Attains 3/8 inch.  Hawaii & the Indo-West Pacific.

Fairly common under rocks in shallow water.  Feeds upon mussels and other bivalves.  Attains 1 inch.  Endemic to Hawaii.  Closely related to Stramonita turbinoides.  Formerly known as Morula foliacea.

Rare under rocks in shallow water.  Feeds upon mussels and other bivalves.  Has a narrower shell than Stramonita foliacea.  Attains 7/8 inch.  Hawaii & the Marshall Islands.  Formerly known as Morula spinosa.

Common on Pocillopora corals at any depth.  Feeds upon coral polyps.  Attains 2 inches.  Hawaii & the Indo-Pacific.  Formerly known as Drupella elata.

Lanai Lookout, Oahu, 25 feet

Lanai Lookout, Oahu, 25 feet

Portlock, Oahu, 15 feet

Portlock, Oahu, 15 feet

Sea Cave, Oahu, 45 feet

Sea Cave, Oahu, 45 feet

Fairly common on hard reef in the surf zone.  Aperture is light orange.  Attains 4 inches.  Hawaii & the Indo-Pacific.

Makapu'u, Oahu, 8 feet

Makapu'u, Oahu, 8 feet

Fairly common on rocks in the intertidal zone.  Feeds upon limpets ('opihi).  Attains 3 inches.  Hawaii & the Indo-Pacific.   Formerly known as Thais intermedia.

Makapu'u intertidal, Oahu

Endemic to Hawaii.  Fairly common on rocks in the intertidal zone.  Feeds upon nerites and periwinkles.  Attains 1.5 inch.

Makapu'u tidepool, Oahu

Uncommon under rocks at any depth.  Attains 2 inches.  Hawaii & the Tropical Pacific.

Uncommon under rocks in shallow brackish water.  Attains 1/2 inch.  Hawaii & the Indo-Pacific.

Makapu'u tidepool, Oahu

Makapu'u tidepool, Oahu

On Rock-boring Urchin, Makapu'u intertidal, Oahu

Uncommon, parasitic on Rock-boring urchins in shallow water.  Usually attached to underside of host.  Attains 1 inch.  Hawaii & the Indo-Pacific.

Quite rare, parasitic on Shingle urchins on rocky shores.  Usually attached to underside of victim.  Attains 1/2 inch.  Hawaii & the Indo-Pacific.  Some consider this a synonym of Vexilla vexillum.

Rarely collected alive in Hawaii.  Attains 1 inch.  Hawaii & the Indo-Pacific.

Makapu'u tidepool, Oahu

Makapu'u tidepool, Oahu

Abundant under rocks at all depths.  Feeds upon other mollusks.  Attains 3/4 inch.  Hawaii & the Indo-Pacific.  Formerly known as Drupella ochrostoma.  

Kapoho Point, Kailua, Oahu

Kapoho Point, Kailua, Oahu

Fairly common under stones in shallow water.  Feeds upon oysters.  Attains 1 inch.  Formerly known as Muricodrupa funiculus.  Hawaii & the Indo-Pacific.

Common under rocks at any depth.  Preys upon bivalves.  Pale and spotted forms occur together.  Attains 1 inch.  Formerly known as Maculotriton bracteatus.  Hawaii & the Indo-Pacific.

Fairly common under rocks in shallow water.  Feeds upon bivalves.  Attains 3/4 inch.  Hawaii & the Tropical Western Pacific.  Formerly known as Morula dumosa.

Uncommon under rocks at scuba depths. About 1/4 inch.  Hawaii & the Indo-West Pacific.  Formerly known as Morula benedictus.

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