For histopathology, samples were generally fixed in 5% paraformaldehyde for 11 to 18 d. Whole specimens were de -calci fied in a formic acid−sodium citrate mixture
over night after fixation (Luna 1968). Fixed samples
were rinsed with tap water, dehydrated with a
graded ethanol series, embedded in paraffin, and
sectioned at a thickness of 4 µm with a rotary microtome (Leica).