Line drawings of males of Cathayacanthus spinitruncatus from Leiognathus equulus in Vietnam. (1) A paratype male; note the very long proboscis receptacle compared to the trunk. The dots are trunk spines. (2) The reproductive system of specimens in Figure 1; note the posterior position of the reproductive system and the two larger anterior cement glands and the cluster of four posterior glands. Trunk spines not shown. (3) The proboscis of a male specimen and a representative sample of enlarged dorsal (right) and ventral (left) hooks numbered from anterior. (4) A trunk spine from the mid-trunk area.