30 



122. The confluence of Kadero and Kuranji creeks offers some poten- 

 tiality of improvement under intelligent treatment, but the only really suitable 

 localities for culture work on an extensive scale are Karachi backwater and the 

 estuary of the Hab river. 



123. The first step in culture will be to ascertain the spawning season. 

 To do this, it will be necessary to examine adult oysters every week or fort- 

 night from May till October ; the progressive development of the milky white 

 reproductive glands enveloping the liver and alimentary canal the fleshly mass 

 lying between the hinge and the adductor muscle must be noted and as 

 soon as the glands begin to swell and the sperm or ova flows out readily from 

 punctures made in the gland upon the application of gentle pressure, a 

 quantity of limed tiles made up into small bundles should be immersed at 

 intervals of ten days at low tide level in the neighbourhood of a quantity of 

 mature oysters. The place I recommend for the experiment is Nawa Nar near 

 the Maurypur Salt Works. Here is a large stretch of firm and stable bottom, 

 plenty of natural cultch and a certain number of mature oysters, I cannot say 

 if there be now a sufficiency of the latter present ; fishing has been actively 

 carried on here of late years and I think it is probable that a supply of old 

 oysters to constitute a breeding stock will have to be provided, preferably from 

 Kutch or Sonmiani, as large sized oysters are still procurable there. If any 

 be procured from Kutch, care should be taken to import them during the cold 

 season and effect their transport rapidly, as I understand there has frequently 

 been great mortality among oysters imported from Kutch owing to head winds 

 entailing a prolonged sea passage. 



124. The place where the breeders are deposited should be fenced in with 

 a palisade of such a description as will demarcate the ground occupied but at 

 the same time offer no considerable resistance to the ebb and flow of the tide. 

 PI. 1, fig. 2 shows a form of palisade in use in France to protect oyster parks 

 from the depredations of fishes. The bundles of limed tiles may be placed 

 either within or without the demarcated area; in France spat collectors 

 are usually outside and placed as far out in the channels as possible. 

 In several experiments made at Ennore near Madras I bound the tiles 

 into bundles consisting of 4 or 5 tiers of two tiles iu each tier, each alter- 

 nate row being laid ac right angles to the one under it. Ordinary semi-cylin- 

 drical country tiles are the most suitable form to employ ; Mangalore tiles are 

 not of a useful shape. All the tiles in the bundles should be arranged concave 

 side downwards as this arrangement contributes distinctly to keep this surface 

 free from sediment ; it also provides shady sheltered nooks for attachment such 

 as oyster spat particularly love. 



125. Were the tiles employed to receive no preliminary treatment this 

 would not militate against a rich spat fall upon their surfaces, but it would 

 have the great disadvantage that the brood oysters obtained could not be 

 removed without usually fatal injury except by breaking the tile into frag- 

 ments. To obviate tbis a process of covering the tile with a thin> friable, and 

 easily detached coating of lime mortar has been devised. The oyster spat 

 therefore adhere not directly to the tile but to this thin coating and when it is 

 desired to remove them, this can be done readily and without damage to either 

 oysters or tiles, by flaking off the lime by a series of short smart blows 

 administered by means of a chisel-shaped knife. 



126. The actual process of liming tiles as practised in France and 

 Holland is described in detail in my report on " The Practice of Oyster 

 Culture at Arcachon and its Lessons for India," forming Bulletin No. V 

 of the Madras Fisheries Bureau. A description, illustrated with a series of 

 photographs and figures, of the large crates in which the French oyster farmers 

 pack their tile collectors is given in the same publication, a copy of which 

 should be given for guidance to the officer to be charged with the operations 

 now recommended. 



127. During the first season's experiments, only small bundles of tiles 

 ueed be used. Each should bear a metal label impressed with a serial number. 



