Caveat Emptor!! Let The Buyer Beware!!
A large number of Trochoideans are sold to reef aquarists despite having little or no chance of long-term survival in a reef tank. Most of these are collected from the northern shores of Baja California. Although it's south of the United States, the marine environment of the northern part of this peninsula is anything but tropical. Its Pacific side is bathed in waters that are quite cool, and is the home of several Trochoideans that are collected for the reef aquarium hobby. These animals typically have a tolerance for warm conditions, and they are often intertidal animals and can withstand quite hot water - for a while. Prolonged exposure to warm conditions, however, kills them.
Among their many interesting attributes, many marine snails have impressively long life spans. I have counted over 120 annual growth rings on some specimens of Tegula funebralis, a temperate water species. This species is one of the three or four species of Trochoideans collected from cool water areas of Baja California and unethically sold to gullible, or informed, aquarists as a reef aquarium animal under the delightfully ambiguous name of "margarite or margarita snail. Tegula funebralis has a high thermal tolerance for an animal that lives in cold water areas (it ranges northward from Baja and is common in the British Columbian and Alaskan intertidal zones). They normally live a small fraction of one percent of their normal life span, or only a few months, in reef aquaria. Putting these animals in a reef aquarium is both unethical and immoral.
Figure 12. Tegula, two species; Tegula funebralis, left, and Tegula brunnea, right. These cool water species of Tegula are harvested from the coast of either Baja California or California and sold under the name of "margarita" or "margarite" snails. Shells are about ¾ inch (2 cm) in diameter. Image modified from Hickman and McLean, 1990.
This confusion is complicated by various distributors and dealers who just can't seem to grasp "The Phenomenon of a Name," and blissfully attach names seemingly at random to their livestock. A good example of this is in the common name, "Margarite snail." Well folks, I have been studying snails for a long time, and to me a "Margarite snail" is a snail in the genus Margarites. These are small snails, similar in many regards to the grazers we put into our tanks. They are even found in the tropics. However, when they are found in the tropics, they live several thousand feet down in water whose temperature is 39° F. or lower. In other words, there are no snails of the genus Margarites that are found in warm tropical waters. One finds examples of the common North Pacific species, Margarites pupillus (Figure 13), offered for sale and this invariably leads to a quick death for this species if kept in reef aquaria. As with the species of Tegula, with which they share the common name "margarite" snail, they have no place in reef tanks. Still vendors persist in selling them. Go figure...
Figure 13. Margarites pupillus, from Northern Puget Sound, photographed in water that was about 45°F. This species is a cool water animal and should not be purchased for a reef aquarium.
