Koronacantha pectinaria n. comb. (Acanthocephala: Illiosentidae) from Microlepidotus brevipinnis (Haemulidae) and redescription of Tegorhynchus brevis.

Tegorhynchus pectinarius Van Cleave, 1940, is redescribed on the basis of male and female specimens in Microlepidotus brevipinnis from the marine waters of Costa Rica and México. The elongate proboscis with a heavy cuticular coating, cuticular body spines, 8 cement glands, and the heavy, strongly recurved hooks in the shape of an inverted apostrophe with roots that are simple but exaggerated in size with a small hook blade indicate that T. pectinarius should be assigned to Koronacantha Monks and Pérez-Ponce de León, 1996. Koronacantha pectinaria n. comb. can be distinguished from Koronacantha mexicana in having strongly recurved hooks only on the dorsal side of the proboscis, a conspicuous patch devoid of normally developed hooks located just anterior to the recurved hooks, trunk spines extending from the anterior end of the trunk posteriorly over 85% of the trunk, lacking genital spines in both sexes, and by the basal comblike group of small close-set hooks made up of 5 to 7 hooks. In K. mexicana, the recurved hooks occur as a complete ring, no patchlike area devoid of hooks exists, trunk spines begin at posterior end of receptacle and extend posteriorly over rest of trunk, genital spines are present in both sexes, and the basal comblike group of small close-set hooks consists of 4 or 5 hooks. Tegorhynchus brevis Van Cleave, 1921, is redescribed based on the original specimens, and Tegorhynchus, Koronacantha, and Illiosentis are considered diagnostically distinct.