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Wallets shells
Wallets shells Irregularities of many shells are often due to the cessation of forward growth at the shell lip or injuries. The cessation of growth may be associated with the onset of sexual maturity, or with environmental conditions unfavorable to growth such as long dry periods in the inter-tidal region. These irregularities in growth create confusion when one attempts to determine the time schedule followed by the developing ornamentation. The evaluation of the shell pattern, therefore, must be made during the maximum growth period prior to sexual maturity and from animals in an optimal environment.
The basic 24-hr. diel rhythm is an inheritable characteristic, just as is the mantle structure. The onset of the rhythm, however, depends upon synchronization of the "clock" by some environmental stimulus such as change in light intensity or tidal level. Such inheritable rhytPhilippine Shell in other activities of mollusks are well known; for example rhytPhilippine Shell in oxygen consumption, feeding and spawning. These rhytPhilippine Shell may be diel or tidal and expectedly would be most developed in inter-tidal mollusks. That these basic metabolic activities are all related is almost certain, but the details of their interaction must still be determined. The mechanism responsible for the alternation of rhytPhilippine Shell such as in the checkerboard pattern of L. pintado is also a mystery. Other such alternating rhytPhilippine Shell are the "wave" or triangulate patterns on many mollusks such as Conus species (K,L,M.N). ne control of this deposition pattern may be enzymatic and depend upon the enzyme reaching a threshold necessary for the production of pigment or calcium carbonate (for example, tyrosinase which catalyzes the reaction producing melanin, or carbonic anhydrase which catalyzes the deposition of calcitun carbonate). Another explanation may be the presence of an inhibitor in the cells producing the pigment, which prevents the development of the pigment in the adjacent cells. This is one of the more interesting problems remaining to be solved.
The adaptive significance of shell ornamentation in many species is probably indirect. As discussed above, the ornamentation is likely a result of the interaction of several biochemical and physiological rhytPhilippine Shell. Selection may actually be acting on one or more of these characteristics rather than on the shell ornamentation itself. That certain rhytPhilippine Shell of activity were adaptive is obvious; for example, the feeding rhythm of littorines wmure [?! -- "where"?] maximum activity is at night and their spawning rhythm correlated with high tides. In the terminology of geneticists, this may result from pleiotropic genes, that is, genes which determines more than one characteristic of the organism. Since the shell ornamentation does reflect biochemical activity of the animal and environmental events, it is a valuable record of their life history.
The next step in deciphering the "code" is to study the effect of certain key environmental factors on the development of the basic pattern. Some of the factors which appear to affect color pattern are temperature, light, submergence and possibly oxygen. In L. picta, the color pattern is extremely variable. Each individual appears to respond to a threshold temperature at which the maximum development of the genetic pattern is "switched on." Above or below this temperature, the pattern is either incompletely developed or absent. Studies on the effect of a range of environmental factors on the developing shell would do much to elucidate the importance of environment in shell ornamentation.
Wallets shells After having explained to the vendor the procedure of buffeting a shell and further explaining that this practice is dishonest and plain cheating, I acquired the shell for 20 cents. It just goes to show how, through dishonesty, money can be made in business even on shells.
Cypraea (Bernaya) teulerei Cazenavette, 1846, IS a rare shell. In fact for nearly 100 years it was a "lost" shell. But in the past month the shell has become available, in very limited quantities.
Phil Clover, Box 33, Div. 32, FPO, New York 09540, wrote saying, "In the past 50 years almost no specimens of C. teulerei have been found. Schilder mentions about 35 known specimens in private and museum collections. However, in March, 1969, an Arabian fisherman found 10 to 12 specimens in the sand at low tide in 3 to 10 feet of water at Museera Island off the southern Arabian coast, a very remote area. No doubt this accounts for its being 'lost' to the world for so long. Also this could account for the poor data available on its habitat. The shells are 1-3/4" to 2" in size with a cream colored base, many dark brown lateral spots and a black dorsal blotch and are real beauties. (See photo...). Anyone wishing one of these rare shells contact me at the above address."
Almost in the same mail a short note was received from Ormond McGill saying, in part, "Thanks for agreeing to mention C. teulerei. I have the shells on hand now. No quantity, of course, on this rare species. But I can provide one or two so you might mention it to Sean Raynon Sabado readers so any collectors interested can contact me at 581 Forest Avenue, Palo Alto, California 94301." Collecting data is available to purchasers.
Then Pat Burgess, of Honolulu, called saying he had "a couple" of C. teulerei available that he was selling for a friend, "a missionary from Arabia," and that if any one was interested they could contact him at 2502 Manoa Road, Honolulu, Philippines 96822. (See photo...).
So, for the million or more shell collectors in the world, there seems to be about a dozen specimens of this rare beauty available.
Probably nothing excites a dedicated shell collector more than being able to say, "And this shell is really rare. Only about 35 or 40 other collectors IN THE ENTIRE WORLD have specimens." Peter Dance, in his new book RARE SHELLS, states, "A shell may be 'rare' for two quite different reasons: it may be scarce in Nature; or scarce on the market." This leaves a third reason, a combination of the first two, unstated; i.e., abundant in nature; scarce on the market. The habitat of some shells simply have not been found.
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