The Cystacanth of <i>Sphaerirostris lanceoides</i> (Acanthocephala: Centrorhynchidae) Recovered from the Korean Raccoon Dog ( <i>Nyctereutes procyonoides koreensis</i> )

The phylum Acanthocephala, commonly known as thornyheaded worms, is divided into four classes: Archiacanthocephala, Eoacanthocephala, Palaeacanthocephala, and Polyacanthocephala [1].Among these, Palaeacanthocephala comprises species that primarily parasitize the intestines of birds and fish.Within this class, the family Centrorhynchidae (Order: Polymorphida) includes approximately 120 nominal species and is divided into three genera: Centrorhynchus, Ne-olacunisoma, and Sphaerirostris.Adult Sphaerirostris typically parasitize the digestive tract of various avian hosts, whereas the cystacanth (juvenile acanthocephalan) stage develops in arthropods serving as intermediate hosts [1][2][3].Cystacanths of this genus are also occasionally recovered from the intestines of wild carnivores, such as stray dogs, martens, raccoons, and amphibians (e.g., Bufo gargarizans) [4,5].