Drilling position of the ear affects growth and ž / mortality of scallop Patinopecten yessoensis, Jay in ear-hanging culture

We evaluated the effect of where the hole is drilled in the shell when using the ear-hanging or Nimai-ake method in scallop aquaculture. We examined its influence on growth and mortality during 8-month growth trials on the scallop Patinopecten yessoensis at Shikabe, Japan. Our Ž . observations showed: 1 no differences in growth and mortality between drilling the hole in the Ž . posterior compared to the anterior ear; 2 that drilling at positions next to the ligament causes Ž . increased mortality; 3 that the lowest increase in shell height and total weight is obtained when Ž . the hole is drilled next to the ligament on the anterior ear; and 4 that growth is greatest when the Ž . hole is drilled near the corners of the ears either on the anterior or posterior ears . q 2001 Elsevier Science B.V. All rights reserved.