Neohexostoma, Price, 1961

Zhu, Pei-Wei, Li, You-Zhi, Liu, Lin, Ding, Xue-Juan & Yuan, Kai, 2020, Neohexostoma gymnosardae n. sp. (Monogenea, Hexostomatidae), a gill parasite of Gymnosarda unicolor (Valenciennes) (Teleostei, Scombridae) in the South China Sea, Parasite (Paris, France) 27 (71), pp. 1-9 : 7

Key to species of Neohexostoma (modified from Millemann [ 21] and Zambrano [ 35]):

1. Non-existent separation between the termination of testes and the anterior of haptor........ ... ... ... ... ... ... .... .........2 Remarkable separation between the termination of testes and the anterior of haptor.. .... ..... ... ... ... ... ... .... ......3 2. Clamps similar in size.. ... ... ... ... .... .... N. kawakawa Clamps decreasing backwards in size.. ... .... N. mochimae 3. A strong constriction before haptor.. ... ... ... ... ... .... 4 No constriction before haptor.. ... ... ... ... ... ... .... ......5 4. Haptor with a split in its posterior margin.. ... ... ... ... ... ... .... .... .... ...... ... .... . N. gymnosardae Haptor with a short lappet.. ... ... ... ... ... .... N. thunninae 5. Most posterior pair of clamps approximately one-half the size of anterior pairs.. ... ... ... ... .... .... N. extensicaudum Most posterior pair of clamps slightly smaller than anterior three pairs ..... ... ... ... ... ... ... ... ... ... ... ... ... .... ......6 6. Eggs with two short polar filaments.. .... . N. robustum Eggs with two long polar filaments.. ... ... ... ... ... .... ...7 7. Lateral sclerites of clamps straight.. ... ... .... . N. pricei Lateral sclerites of clamps double-pronged.. ... ... ... ... .... ..... ... ... ... ... ... .... ............ N. euthynni