Most adult linguatulids are elongate, worm-like, cylindrical, and tongue-shaped. Some adult species have body annulations or rings. The anterior extremity of linguatulids is characterized by a mouth, four hooks, and broad tongue-shape (Figures 2 and 4). The posterior extremity is often narrow and cylindrical (Sambon, 1922; John and Petri, 2006).
Linguatula serrata females are 80-130 mm long; 8-10 mm wide anteriorly, 2 mm posteriorly. Males are 18-20 mm long; 3-4 mm wide anteriorly, 0.5 mm posteriorly (Figure 2). Eggs are 90 by 70 microns. Color is yellowish and nymphal forms have a single row of minute spines (Sambon, 1922).