File 2830/1914 Pt 2 'Persian Gulf: Pearl Fisheries. Investigation into Alleged Depletion of Pearl Banks. Germans and the Industry. Concessions, etc.' [‎250v] (513/578)

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An Enemy not identified.
TVipva ia onp pnemv of the pearl oyster which I believe has not been in any way identified as
yet. This fish or whatever it iB, has the instinct to make a round hole on the shell o£ the oyster just
above the muscle by which it closes its shell, and thus has the ouster at its mer y-
TheXers suppose it to be the trigger fish, but, according to Mr Thomas, the trigger fish cou^
not make such a hoffin a mature oyster. I have seen hundreds of shells of oysters bored or b.tten
through in this way.*
Sea Snakes.
Sea snakes, of ^*0^ thec 0 ^® ®®^ e ^^®P® c ^os^on the^pearl^banks^some^of^omjraratwe^^large
oTthtaexeeTthatmieof tarEuropei a wonderful story of having seen the sea snakes
dbtinff fhei P r tonaues into the oysters as he drifted over the bank, and on two occasions said he actually
lw the snakes eatinv the oysters. He also said he saw the trigger fish making the round holes above
referred to on the shell of the oyster. These and some other wonderful stones had to be swallowed
" rth a The*native^!dea is that snakes prey on the oysters. If the European diver is to be believed, he
actually saw the snakes eating the oysters as reported by him on two occasions, and saw them darting
their tongues into the oysters when lying with the valves open. There is no mention made of snakes
in Mr Thomas’s report. There are several varieties on the Ceylon banks, and they are seen on he
surface in numbers in March. Some of them are of large size and have powerful jaws and teeth.
Some are very venomous.t
Shellfish.
There are I believe many enemies of the oyster in the shape of comparatively small shellfish,
which I believe prey on them, though perhaps not to any serious extent. , „
The divers often bring up oyster shells perfectly bright with the hinges unbroken and small
pieces of flesh adhering to the shell. Some animal had no doubt preyed on them. The native idea
is that this was done by snakes.J , T ,, . , n . x-u ^ i.
I believe from the experience Captain Donnan and I had on the bank during the fishery in
1874, that the oysters had been preyed on by small shellfish, of which there are plenty on the banks.
During the fishery of 1874 the late Mr. Nevill accompanied Sir William Gregory on his visit
to the banks as Conchologist. He remained behind in Silavatturai. He was there a week, but for
some reason never went again to the bank. He gave Captain Donnan some fish-traps, which he asked
Captain Donnan to sink on the bank at night, so that he might take them up in the morning and see
what was in them. He always found fish in them, and a large number of small shells, which
had completely eaten the flesh of some of the fish, leaving the skeletons perfectly clean. Two or
three of such shells inserting themselves into an oyster as it lies with its shell open would soon eat
away the flesh without in any way injuring the shell. It may be said that the oyster is too sensitive,
and would close its shell before its enemy gets in. I have had experience, however, that this is not
always the case. At the fishery of 1888 in the kottu two young musk rats were caught by the neck
and killed by the oysters closing on them when they had thrust their heads in. In 1891 a sparrow
was caught in the same way. This and the oyster I have now preserved in arrack in my collection.
I had the rats and oysters also, but they have been removed by some one. One of the shells I have
referred to is not larger than the head of the rat or the head and beak of the sparrow, and once in its
shell would protect it, whilst it would in a short time disable the oyster and eat it.
Skates—(TrygonWarnak); Tamil “ Valuvadi tirukkai.”
Skates are a very formidable enemy of the pearl oyster.§ See Mr. Thomas’s Account of the
Skates.)
There are several species of skates, small and large. The skate seen by Mr. Ihomas at
Tuticorin was the Trygon warnak.
I have not come across any mention of the skate as doing any damage till the fishery of 18bo
(of which hereafter).
Some species grow to an enormous size, and when their size, weight, crushing power, and
mode of feeding, as described by Mr. Thomas are considered, it can easily be understood what
destruction, such as occurred in 1864, would take place on a bank if 50 or 100 of such creatures come
on it.
Some time after the destruction of the oysters in 1864, which was attributed to the skates by the
native divers, it was reported to me that two large skates had been caught by the fishermen of Van-
kalai near Mannar.ll I did not receive the information until after they had been cut up and disposed
of, and therefore could not make a personal inspection of them. They were described to me as 13 and
14 feet across and 3 feet deep in the deepest part. I mentioned this in one of my reports, and it was
thought that I had been deceived by the person who gave me the information, who it was thought
might have gradually increased the size of the animals as he decreased his distance to Mannar.^
Mr. Ford, however, of Kalpitiya, who was to ha^e been Magistrate at the fishery of 1864, came
to Mannar on his way to Jaffna in a ballam from Kalpitiya some time after and called on me. He
said he had been sceptical as to the size of the skates as given by me, but was quite satisfied after
what he saw from the ballam, a large skate having leaped out of the water close to the ballam, fully
the size I had given of those caught at Vankalai. I did not, however, know then that skates leaped
out of the water. I subsequently saw a large one about half the size floating on the sea close to the
inspection vessel at the inspection of 1868, when rowing about with Captain Leighton to watch the
divers. The alarm was given of “ shark” and the divers stopped work. It disappeared just as we
reached the ship. However, the late Mr. Marcus Crawford, Assistant Agent of Mannar, set tli°
matter of size at rest. He gave me a sketch and measurement of a large skate caught near the south
bar of Mannar (see annexed sketch). This creature measured across 14 feet.
* See Appendix 5, A and R.
t See Appendix B 1 and B 2.
J See Appendix 5, A.
§ Appendix 1,0 3.
See Appendix 5, A and B.
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