46 MADRAS FISHERIES BULLETIN VOL. XI, 



Gulf of Mannar, I believe that in those years when pearl oysters 

 are poor in pearls though abundant numerically, the canning of 

 their flesh would prove a remunerative undertaking. For details 

 of the anatomy, see Herdman and Hornell in Ceylon Pearl Fishery 

 Reports, volume II, page 37. 



Fig. 28. — TiiK Indian Pearl-Ovster. Natural size. 



Its permanent habitat in Indian waters seems to be the shallows 

 of Palk Bay where extensive beds, comparatively thinly populated, 

 exist in several localities. The pearl banks in the Gulf of Mannar, 

 both on the Indian and Ceylon sides, are not continuously occupied 

 by pearl oyster deposits ; their occurrence is irregular and roughly 

 cyclic, short series of productive years alternating with longer 

 series of blank years when the beds are either very poorly stocked 

 or absolutely barren. These banks appear to be repopulated at 

 intervals by spat from the permanent or mother beds in Palk Bay. 

 When this happens, the resultant beds are often exceedingly 

 extensive, aggregating even as much as a hundred square miles in 

 area in some years. The quantity that comes to maturity is com- 

 paratively small, but even then a favourable year may yield 

 anything up to 40 or even 80 millions of oysters during a fishery. 

 To harvest pearls the fishers must wait till the oysters are over three 

 years old, but if they are required for canning purposes they may 

 be fished profitably when two years old. At this age they are very 

 delicate and more tender than when they are a year or more older. 



