Other Contributions: Halogen Staining Techniques for Demonstrating Cuticular Details in Nematodes

Abstract

Halogen-silver staining techniques were used to clarify cuticular details in nematode specimens for light microscopy. Nematodes were killed in formaldehyde solutions (0.01-0.1 %, v/v) then fixed in paraformaldehyde or strong (10 % v/v) formaldehyde solution and then rinsed in demineralized water. This was followed by immersion in 1 ml of 0.01 N iodine solution. Times of immersion were 1 min for Hoplolaimus galeatus; 5 min for Belonolaimus gracilis, Pelodera chitwoodi, and Tylenchorhynchus claytoni; and 10 min for Helicotylenchus dihystera. After iodination, specimens were rinsed with demineralized water for 2-30 sec. After rinsing, nematodes were immersed in 0.2 N AgNO for 3-4 min; specimens were then mounted in water and observed. The iodination technique enhanced observation of lateral fields, striae, and cephalic structures for most nematodes. However, for H. galeatus use of a bromination method was superior to the iodine technique. The bromination method consisted of immersion of