If kept under favorable conditions, 90 to 95 

 percent of fertilized eggs will develop to 

 shelled veliger stage, often called the "straight- 

 hinge" stage. The smallest normal straight- 

 hinge larvae nneasure about 68^ long by 55// 



wide (or deep). At about 72° F. the larvae will 

 attain 75 by 67 /i within 48 hours (fig. 7). At 

 this stage some larvae already begin to take 

 in food composed of microscopic water or- 

 ganisms, principally plants. 



9 



A 



72x61 



B 



75x67 



c 



85x80 



F 

 125x133 



G 



160x170 



I 



204x210 



CRASSOSTREA VIRGINICA 

 XII2 



Figure 7. Photomicrographs showing several stages of development of oyster larvae from 



straight-hinge to metamorphosis. The figures below each larva give its length and width in 

 microns. (A micron (</) is 0.001 mm.) Magnification is about 112 times. 



13 



