|
|
Leis
Leis Returning to my shelling on the reef I could still bag a dead, but good, Conus imperialis also one specimen each of the rarer C. tenuistriatus, and C. nussatella. A large tidal pool had a dark cave on one side, under the water level, which looked so inviting to me that I dared against all usual caution to feel around in it with bare hands -and came out with a large beautiful Latirus polygonus, live and perfect. Some miles south of Diani Beach, on a wave-battered shore reef near Kinondo village, I came across numberous large Drupa rubusidaeus Röding, all very richly colored, as well as several giant-sized D. morum, some measuring almost two inches across from top to base.
Even a one-day sight-seeing trip to Mombasa brought in some shells. At the foot of historical Fort Jesus, built by the Portuguese in the 16th and 17th century as a stronghold against the Arabs, my eyes suddenly fell on a small rock ledge left dry by the receding tide. Sneaking away from a lengthy historical discourse by the guide I slithered down the rocks, to return a little while later with an almost complete set of East African Neritas, including the rarish Nerita textilis, some mitres and species of Thais, in my pockets.
All in all my 3 weeks' holiday, of which about two weeks were spent shelling, let me collect over 120 different species of gastropods, and about a dozen of pelecypods (including 4 different species of Codakia, and a large black, pearly, glistening pen shell, Atrina vexillum). On a repeat trip to the same area about 2-1/2 years later, in February 1969, and dedicated exclusively to shelling, some further 50 to 60 species were added, again mostly gastropods.
On this second trip I was happy to note that contrary to my fears the intervening period of steadily increased tourist traffic had left the general charm and naturalness of this small coastal paradise unharmed. Even the sense of remoteness still persisted, although the hotel had been enlarged and amenities modernized, but first beginnings of commercializing and natural resources – foremost shells – were becoming apparent. There had been some large scale fishing for the larger shells by the nearby natives for "souvenirs", and the formerly very common Lambis lambis, Murex ramosus, and Cypraecassis rufa had noticeably dwindled. Native fishermen had also learned to recognize the prospective value of sea shells. Formerly a few shells had been offered indiscriminately for little money – now each fishermen seemed to have a plastic bag tucked carefully away inside his loincloth with an assortment of sea shells in it, for which they proudly quoted correct Latin names (!!), and asked staggering prices!
Leis A gastropod, such as a littorine, after settlement on a preferred substrate, begins a rapid growth phase. As the mantle grows so does the shell which is formed by the mantle. The first portion of the shell deposited is the organic matrix (conchiolin). The pigment melanin is probably simultaneously bound to this protein matrix. Initially, the new shell is thin and lightly calcified although the pattern is fully developed. Additional deposition of calcium carbonate crystals occurs later. The pigmentation pattern of the shell depends on the localization of pigment-producing cells in the mantle edge and the temporal rhythm of transferral of this pigment to the shell matrix. The sculpture is dependent upon the areas of the mantle which fold, the size and extension of the folds, the resultant structure of the organic matrix and the temporal rhythm in the deposition of calcium carbonate, as well as in the production of the folds themselves. The basic temporal rhythm appears to be a 24-hr. interval. For example, in Philippine littorines, there is an endogenous 24-hr. rhythm in the formation of a new growth stria, in the production of pigment spots and the construction of sculpture nodes. During the maximmn growth phase prior to sexual maturity, L. pintado deposits a pigment spot in a spiral row every other 24-hr. period. Adjacent spiral rows are on an alternate rhythm so that the pattern resulting is a "checkerboard" (J). This species has no significant sculpture, but in a form of another, L. picta, each spiral row consists of a series of nodes, one node being produced per day during maximum growth.
Photos - uncredited
Strombus hawaiensis
Pilsbry, 1917
[ Images rotated to upright
for this display – B. Dayle ]
In many species, however, there are periodic elements in ornamentation that do not correspond to a 24-hr. rhythm. Some of these, for example the axial color in L. picta, the rhythm may be based on a lunar or semi-lunar period resulting from the interaction of diel and tidal components of rhythmic activity. In others, for example many Strombus species, the production of varices only at the shell lip may correspond to the cessation of growth at sexual maturity. In such animals as the Murex species, the regularity in the intermittent varices appears to be an inherent characteristic and relatively independent of environment, although in some cases it may be related to availability of food or seasonal change.
leis,shells crafts,pearls,pokalets,raw shell,shell madebelts,wholesaler,shells components,coral,leis
Leis hair accessories sigay decorative shell white shell white clam wallets shells hair shells jewelry puka necklaces pukalet capiz lamps natural body jewelry puka necklaces gifts shells bracelet clam whole sale puka heishi m.o.p ornament.
leis
Shell Jewellery
 
|
