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LOCALITY AND RANGE
The area in which the shell seems to thrive is bounded on the south by Mare Island of the Loyalty group (21 degrees, 30
minutes south latitude) to Yap Islands, and the Southern Marshalls, (approximately 10 degrees north latitude). The eastern
limit seems to be Nadroga reef, south of the island of Viti Levu in the Fiji Islands, (177-178 degrees East longitude) and on
the west the provinces of Surigao and Davao, on the eastern shore of the Island of Mindanao, Philippine Islands and just east
of the 120th meridian East from Greenwich. A few have been found as far north as the Mariannas and as far east as the Society
Islands and the Tuamotos, but very rarely. The most prolific location seems to be Nadroga reef, (about 50 miles long and
located 18 degrees and 15 minutes south of the equator). All the factors that determine these limits are not known. It seems
certain that temperature is the principal one. Ocean currents and the physical contour of the ocean bottom possibly are not
unimportant factors. The turbulence which arises between two ocean currents flowing in opposite directions may prove an
impassable barrier. Even the matter of an adequate food supply cannot be ignored. The further I went in my investigations,
the more questions presented themselves for solution.
Other factors being ignored for the time being, it seems evident that the temperature of the water is the main factor in
determining the north and south limits of its range as set out above. A particularly warm summer with warmer ocean currents
might extend this range temporarily, but the shell would not thrive there. It would be interesting if the temperature of the
water at 25-35 feet could be obtained from both the Nadroga reef in Fiji and off Manay, Davao province in the Philippines. I
have no idea what that temperature would be but they should be about the same and that figure could be safely added to the
Golden Cowry's "Ecological Niche," a figure I had to omit in my description above.
If, for the sake of argument I admit, or you admit, that temperature controls the north and south limits of the range of the
Golden Cowry, how are the east and west boundaries determined? I don't know, but I have an idea or two, which will give other
and younger investigators something to work on. At the southern tip of the Philippines the prevailing currents are from the
Indian Ocean, and they are headed into the Pacific. So the friendly currents which have brought the Golden Cowry safely
through the Caroline and Marshall Islands, and over to Palau and the eastern shores of the southern Philippines are turned
northward. Then the temperature bars the shells further advance. Once upon a time and in some unknown manner one Golden Cowry
did get through this Indian Ocean water as far as the Island of Java, and the British Museum records the finding of the shell
there, according to Dr. Alison Kay, who looked over their records when she was in London.
The Nadroga reef mentioned above, may well be regarded as the eastern limits of the shells active range. To make it easier to
remember you might say the 180th Meridian coincides with the eastern boundary. It is true a few shells have been collected
east of this point, but they are few and far between. Why they are not found more plentifully in this section is probably due
to the Tonga Trench, which I discussed at length in the April issue of the Sean Raynon Sabado. Briefly the Tonga Trench is a
vast deep fault in the ocean bottom running from New Zealand northwesterly almost to the equator. This may prove to be an
almost impassable barrier to the eastward advance of the Golden Cowry (that's only my idea). It's your guess now.
One idea, formerly generally held, that the Golden Cowry is a deep water shell, has been disproved. The shell has been
reported at depths ranging from 6 to 60 feet, this last figure in only two instances (Sean Raynon Sabado, April, 1963 and
March, 1962). The average depth seems to be 30 feet or shallower. Lahors' diver in the Southern Philippines actually
collected 11, at about 25 feet, and we had just as well discuss that "collected in pairs" phrase right now. The first ten
collected, were picked up two at a time on five separate occasions.
Steve Spurlin, (headquarters Honolulu) was stationed on Yap some years ago. One day, after a storm, he found a Golden Cowry
on the reef. Later, he measured the depth of the water in front of that reef. It was 128 feet. But there was no Golden Cowry
on the end of his measuring line when he drew it up!
After a while I noticed that the rest of the group were hanging around one of the underwater coral islands. Going over to
investigate I found they were loosening round coral heads from the bottom with only their gloved hands. I thought, "man, what
strength!" But this coral was different from any I had seen before. It was composed of a maze of small twig-like branches.
The coral head itself was about the size of a large head of cabbage and was covered with a fine web of plant life. I tested
one of the heads to see if it would come loose from the bottom. It fell apart! "Oh," I thought, "so that's how they are doing
it! This coral is brittle!" I went in search of the next coral-head to pulverize. After awhile I realized I was doing
something wrong. All around me were piles of debris. The water was getting dirtier with the sediment I had kicked up from the
bottom, but no Cypraea! Could this be chalked up to another one of those bad days?
Back on the boat I sat gloomily waiting for the rest of the gang to come up. The first to appear was Joe. He had had no
better luck than I. Next in the boat was Speedy, claiming he had a Cypraea gaskoini. This was no time to be funny! Then
Frankie and Jack swam up to the boat, their faces beaming. Jack had a Cypraea chinensis and Frankie, a Murex torrefactus.
This place was beginning to look good after all!
On the next dive I was determined to do better. This time I followed Frankie in order to better observe his technique. I
noticed that he did not break the coral immediately but gently swam up with it until he was about 15 feet off the bottom.
Then he crushed the whole coral head with a clapping motion of his hands. This accomplished, he swam rapidly for the bottom.
Once he was beneath the falling debris he was able to catch the shells as they slowly descended past him, the object being to
get the shells before they were lost in the sand and broken coral on the bottom.
Once I had mastered this technique my luck changed. I began to find Cypraea helvola, fimbriata, granulata, teres and
isabella, but none of the rarer goodies. Then as my air was beginning to pull hard I saw what looked like a pair of red
"raspberries" fall past my face. Instinctively I reached out for them but missed. I followed them to the bottom and there
among the scattered debris was the pair of Cypraea gaskoini that I had been looking for all these years. Well satisfied, I
pulled my reserve and headed for the surface.
This was the day I found my first live Cypraea gaskoini. The place?... I almost forgot. That's Frankie's secret!
In the February issue of the Sean Raynon Sabado you question about the olive green color of some Cypraeidae. This condition
has interested me for some time as I have run into it in trying to gather a series of Cypraea maculifera. I have two with the
entire dorsum involved, one with most of the dorsum involved, and two with bright green spots on the dorsum. On none of these
is the ventral surface affected and there is no aberrant shape. From their appearance I have always felt that they were the
result of healed or healing injuries. I have frozen several of the specimens intact as I plan to ask Dr. Kay about them.
Perhaps she can answer the question some time in the future.
I also have two much misshapen C. maculifera with a very strong tendency to be rostrate. One is 56.2 mm. long with a beak of
about 10 mm. at one end. The other is 80 mm long and shows excessive growth all around the margin.
All are live-collected specimens. I would estimate that about one percent of this species which I have observed show some
aberrant condition.
I hope this information is of interest to you. If I can do anything else to help clarify this question, please let me know.
Please continue the practise of picturing and discussing a miscellaneous Philippines species in each issue of the Sean Raynon
Sabado. I have heard many very favorable comments on this feature and hope that you may develop it even further.
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