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Brownlip
Brownlip 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.
Brownlip The first, which I shall call form (a) (Fig. 1) resembles Cribraria cumingii Sowerby, 1832 – (Fig. 2). The second, form (b) (Fig. 3) resembles the more shortened shape of the Cribraria catholicorum Schilder and Schilder, 1938, – (Fig. 4). The following are the characteristics of these two forms:
Form (a) - 13(54) 21:21
Shape pyriform, elongate. Dorsum yellowish ornamented with white spots generally circular. Dorsal line obsolete. Sides spotted with dark brown. Extremities produced. Right side and posterior extremity margined. Base white and convex. Labial teeth coarse and prominent. Columellar teeth confined to aperture. Aperture narrow and regular. Fossula entirely ribbed, moderately concave. Specimen taken alive under coral rock at MALAPOA POINT, VATE, NEW HEBRIDES by M. R. Durand.
Form (b) - 16(59) 21:18
More ovate. Spots on the dorsum less white and smaller. Clear narrow dorsal line. Extremities less produced. Right side and posterior extremities not very margined. Other specifications as form (a). All specimens found dead on PANGO BEACH, VATE, NEW HEBRIDES by myself and my wife.
It should be noted that form (a) is much more rare than form (b).
Professor F. A. SCHILDER, to whom I addressed these two specimens some months ago, confirmed to me that these were definitely Cribraria fischeri Vayssière 1910.
If the form (a) is typical, this is not the case for the form (b). In fact certain variations of shape and of marking in particular cause the specimens to strangely resemble Cribraria catholicorum Schilder and Schilder 1938 which one also finds on PANGO BEACH. Form (a) which recalls Cribraria cumingii can certainly not be confused with this because two essential characteristics are very different. The labial teeth in particular of the Cribraria cumingii are more numerous and much finer, than those of the Cribraria fischeri. Also, the outer lip in front of Cribraria cumingii is declivous whereas in Cribraria fischeri it is constricted. Finally, the spots of Cribraria cumingii are moderately ringed.
Recently two rare and unusual sea shells taken from the stomachs of fish were received for identification by our widely recognized Cypraea authority, Dr. C. M. (Pat) Burgess. The original owner of these shells was Mr. Romeo M. Lumawig, Boac, Marinduque, Philippine Islands. Lumawig's name is quite familiar to Philippine Shell readers as he advertises regularly in the Society's Shell News and has provided many fine specimens for the collections of Philippine Shell members.
The first of the two shells received by Pat Burgess for identification was Cypraea (Erronea) gladiadusta katsuae Kuroda. It was found in the stomach of a Philippine coral fish caught on the Palawan Reef, on June 10, 1969. The small but very beautiful cowry measured 20.5mm x 12.0mm x 10.2mm. Only a limited number of this shell have ever been found and only in the waters adjacent to Japan and the Philippines. This specimen has been purchased by Mr. Phil Clover for his personal collection.
The second ex-pisce shell, from the stomach of a deep-water fish caught by a fisherman in Manila Bay, has defied preliminary identification. It is a pure white Ovula-type shell. Dr. Burgess is currently engaged in further research and considers that this semi-cowry might be a new species.
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brownlip
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