crucian carp and rainbow trout human endoparasites against which the endoparasite control agent of the present invention is effective are roughly classified into protozoa and helminths examples of the protozoa include but are not limited thereto rhizopoda such as entamoeba histolytica mastigophora such as leishmania trypanosoma and trichomonas sporozoea such as plasmodium and toxoplasma and ciliophora such as balantidium coli examples of the helminths include but are not limited thereto nematoda such as ascaris lumbricoides anisakis toxocara canis trichostrongylus spp enterobius vermicularis hookworms for example ancylostoma duodenale necator americanus ancylostoma braziliense etc angiostrongylus spp gnathostoma spp filarial worms filaria wuchereria bancrofti brugia malayi etc onchocerca volvulus dracunculus medinensis trichinella spiralis and strongyloides stercoralis acanthocephala such as macracanthorhynchus hirudinaceus gordiacea such as gordioidea hirudinea such as hirudo nipponia trematoda such as schistosoma japonicum schistosoma mansoni schistosoma haematobium clonorchis sinensis heterophyes heterophyes fasciola spp and paragonimus spp and cestoda such as diphyllobothrium latum sparganum mansoni sparganum proliferum diplogonoporus grandis taeniidae for example taeniarhynchus saginatus taenia solium echinococcus etc hymenolepis spp dipylidium caninum mesocestoides lineatus bertiella spp and nybelinia surmenicola non human mammalian or avian endoparasites against which the endoparasite control agent of the present invention is effective are roughly classified into protozoa and helminths examples of the protozoa include but are not limited thereto apicomplexa such as coccidia for example.