Koronacantha mexicana n. gen., n. sp. (Acanthocephala: Illiosentidae) from marine fishes in Chamela Bay, Jalisco, Mexico.

A new species and genus of Acanthocephala is described based on specimens found in the intestine of Anisotremus interruptus (Gill, 1862), Haemulon sexfasciatum Gill, 1863, Haemulon scudderi Gill, 1863, Pomadasys leuciscus (Günther, 1864), and Eugerres sp. Jordan and Evermann, 1927, from the marine waters of Chamela Bay, Jalisco, México. Koronacantha mexicana n. sp. is characterized by having an elongate proboscis with a heavy cuticle, cuticular body spines, and 8 cement glands, indicating that it should be assigned to the Illiosentidae Golvan, 1960. The genus Koronacantha n. gen. can be distinguished from other members of the family by the possession of (1) a row of heavy, strongly recurved proboscis hooks in the shape of an inverted apostrophe with roots that are simple but exaggerated in size and a small hook blade, occurring just anterior to a posteriormost comblike group of 4 or 5 small, close-set hooks, (2) cerebral ganglion near middle of proboscis receptacle, and (3) paired sensory papillae at mid-neck.