A portion of the mantle on a Cypraea vitellus Linnaeus, 1758.
In the preceding issue, an observation that gravid cowries show a preference for quiet-water areas was being made. This is reasonable to expect in an animal which has become integrated into its habitat. This writer/diver is well aware of the currents which at times sweep the offshore areas of O'ahu. This diver also recalls the prodigious numbers of swarming, swimming, swirling tiny critters which gathered around the dive light when pausing – during summertime night dives – at the bottoms of sinkholes and craters in Makua's off-shore areas. The density of such minute life forms was much less in the ‘open’ areas, which were subject to currents caused by tidal effects, tradewind action, and ocean swells.
Among the species of Cypraea which this observer has seen on eggs laid in aquariums are; C. controversa Gray, C. helvola Linn., C. schilderorum Iredale, and C. vitellus Linn. In the open ocean, all of the previous (except vitellus) have been spotted on clutches of eggs as well as C. teres Gmelin (including the form "alisonae Burgess"), C. fimbriata Gmelin, C. sulcidentata Gray, C. tessellata Swainson, C. maculifera Schilder, C. gaskoini Reeve, C. leviathan Schilder and Schilder, and C. chinensis Gmelin.
(A seemingly associated observation is that on one occasion—the only time for any species of cowry seen by this collector—a cowry which was still in the ‘juvenile’ bulla stage was seen on a clutch of eggs. This was at Makua, of course, in 30 feet of water, under a small, dead clump of coral at the top of a trench. That trench was itself comprised of a series of elongated, interlinked holes. Either this specimen of C. isabella was an anomoly which had failed to curl its labial edge or this species reaches sexual maturity—possibly other species, too—at an earlier point in their growth than is generally believed.)