Here, we present the results of a taxonomic survey of the nematodes parasitizing fishes from the lagoon flats of Palmyra Atoll, Eastern Indo-Pacific. We performed quantitative parasitological surveys of 653 individual fish from each of the 44 species using the intertidal sand flats that border the atoll’s lagoon. We provide morphological descriptions, prevalence, and mean intensities of the recovered seven species of adult nematode (Pulchrascaris chiloscyllii, Capillariidae gen. sp.,Cucullanus bourdini,Cucullanus oceaniensis,Pseudascarophissp., Spinitectus (Paraspinitectus) palmyraensissp. nov.,Philometra pellucida) and three larval stages (Pulchrascarissp.,Hysterothylaciumsp.,Cucullanussp.). We recorded:Pulchrascaris chiloscylliifromCarcharhinus melanopterus; Capillariidae gen. sp. fromChaetodon lunula,Lutjanus fulvus, andEllochelon vaigiensis;Cucullanus bourdinifromArothron hispidus;Cucullanus oceaniensisfromAbudefduf sordidus;Pseudascarophissp. fromChaetodon auriga,Chaetodon lunula, andMulloidichthys flavolineatus; Spinitectus (Paraspinitectus) palmyraensissp. nov.fromAlbula glossodonta;Philometra pellucidafromArothron hispidus; and three larval forms,Pulchrascarissp. fromAcanthurus triostegus,Acanthurus xanthopterus,Rhinecanthus aculeatus,Platybelone argalus,Carangoides ferdau,Carangoides orthogrammus,Caranx ignobilis,Caranx melampygus,Caranx papuensis,Chaetodon auriga,Chanos chanos,Amblygobius phalaena,Asterropteryx semipunctata,Valencienea sexguttata,Kyphosus cinerascens,Lutjanus fulvus,Lutjanus monostigma,Ellochelon vaigiensis,Mulloidichthys flavolineatus,Upeneus taeniopterus,Gymnothorax pictus,Abudefduf septemfasciatus,Abudefduf sordidus, andStegastes nigricans;Hysterothylaciumsp. type MD fromAcanthurus triostegus,Carangoides ferdau,Chaetodon lunula,Chanos chanos,Kyphosus cinerascens,Abudefduf sordidus, andArothron hispidus; andCucullanussp. fromCaranx ignobilis. Spinitectus (Paraspinitectus) palmyraensissp. nov.(Cystidicolidae) is described from the intestine of roundjaw bonefishAlbula glossodonta. All the nematode species reported in this study represent new geographical records. We discuss how our survey findings compare to other areas of the Indo-Pacific, and the way the relatively numerical dominance of trophically transmitted larval stages likely reflect the intact food web of Palmyra Atoll, which includes a large biomass of large-bodied top predator sharks and ray-finned fishes.
