Figure 1

Morphological differentiation of Baylisascaris procyonis (A, D) from B. columnaris (B, E and C, F). A - C: Unstained cross section of lateral cuticle through anterior end of adult female worms (about 10 centimetres in length), 6 millimetres behind mouthparts and rotated 90° in plane. Cross section in lateral view showing outer cuticle lining (ol), inner cuticle lining (il), hypodermis (h) and cervical support in hyaline layer (arrow). Sometimes, cervical supports of the deeper layer are visible, though not in focus (arrowhead). A: Female B. procyonis (isolate Bp9), wide arch-like cervical support B: Female B. columnaris (K19), narrow A-like support C: Female B. columnaris (K10), narrow A-like support. D - F: Posterior end of males showing pre-cloacal papillae (p), pericloacal roughened areas (R) with rounded posterior margin in figure E, bare pre-cloacal rim (b), extruded spicules (S, not in focus in D), post- cloacal papillae (short arrow), terminal part of tail knob (D) or spike (G; E and F out of focus) shaped (long arrow). D: Ventrolateral view of B. procyonis (Bp19), precloacal roughened patch 42 μm and postcloacal patch 72 μm in width. E: Lateral view of B. columnaris (K23), F: Lateral view of B. columnaris (K22). G: Lateral view of posterior end of male B. columnaris (P27), showing spike shaped posterior end of the tail (arrow) and pericloacal roughened patches in close up; precloacal patch (right) 63 μm and postcloacal patch (left) 79 μm in width. Scale bars in μm. See Table 3 for molecular classification of isolate numbers.