■' 



200jjm 



/ 



FIGURE 2. — Bluefin tuna otolith etched with EDTA which shows distinctive major increments. A short etching 



time gave good resolution to the outermost increments. 



FIGURE 3. — Protein ridges of microincrements from a bluefin tuna. Strands of protein can be seen to interconnect 



the ridges. 



436 



