Zhuji

In Zhuji and surrounding areas, pearl farms, or pearl paddies, are scattered among other agricultural enterprises along the highways and in urban backyards, pools of brown muddy water, 1-1.5 meters deep, marked by float lines fes­tooned with green plastic soda bottles or irregular chunks of Styrofoam. Larger farms have all their necessary buildings perched along the paddy dikes, including the farmer's homes, thatch-roofed nucleation sheds, and hatcheries.

Chinese pearl mussels are hatchery-raised. Parent pearl mussels, three to five years in age, are chosen for the quality of their shells and their healthy appearance. Spawning occurs naturally, with sperm being released into the water column and collected by the siphoning female pearl mussels. Fertilized eggs develop in the female's gills until ready for release as glochidia larvae. At this time, the pearl farmer stimulates release of the larvae by moving the gravid females to a small pool containing appropriate host fish. Glochidia remain attached to the fins or gills of the fish for six to twelve days, when they fall off as juvenile clams about 1/4 millimeter in length. Juveniles are transferred to grow-out ponds, thinned regularly to maintain ample space for growth, for about twenty days in the hatchery, followed by about eight months in shallow paddies. Throughout this process, the nurturing ponds are provided with flowing water enriched with "lime milk" or "bean-paste milk, and underlain by a base of "nutritious earth"-a mixture of pine tree soil and chicken or pig manure."'

An eight-month-old Chinese pearl mussel, of only 5-7 centimeters in length, is ready for nucle­ation. The grafters are all Chinese, mostly young women. Tissue squares are coated with yellow antibiotic, and are inserted on the inside surface of the mantle with tools resembling dental picks. After nucleation in the spring, the pearl mussels are cul­tured for two to three years for pearls under 7 millimeters, or twice as long for pearls over 7 millimeters. Grow-out first occurs in crowded shallow bam­boo baskets, and later in net bags of a few large clams, each suspended from the float lines. Duck dung, liquefied bean curd, and lime are added to the water as "supernutrition" for the growing pearl mussels.  Entire crops can be sold and moved to another pearl farm between nucleation and harvest.