The “Bull Conch” is a striking classic rarity among the strombids characterised by two posterior spines; it is one of the most coveted conchs of the Pacific Ocean and also one of S. Peter Dance’s 50 “Rare Shells” (1969). Originally described from the collection of Sir David Barclay who kept the then unique specimen in personal collection until his death, and it remained unique for more than a century until its re-discovery in the Marshall Islands by R. C. “Dick” Willis.

Locating its home ground was difficult because when Lovell Augustus Reeve described it he misinterpreted the locality as ‘Amirante Islands’, part of Seychelles in the Indian Ocean; the actual locality appears to be Admiralty Islands in the Pacific Ocean which is much more likely. It is still rare today, mainly known from the Marshall Islands and Mariana Islands.

A herbivorous gastropod, it is usually found on sandy to rubbly bottoms of moderately shallow water around -5~50m in depth. Often found in pairs or threes, rarely one may encounter a large ‘herd’ which is presumably a mating behaviour (known from many strombid species); and ‘herds’ may contain 50 or more individuals.

Usually a rough species with much of the shell encrusted or corroded or damaged by cap shells and worm shells; specimen grade shells are difficult to find. A very heavy shell for its size, its typical shell length is around 90mm but giants are known to exceed 130mm. – Adapted from Dr. Chong Chen’s post