Monogenea of fishes from the lagoon flats of Palmyra Atoll in the Central Pacific Author Vidal-Martinez, Victor Manuel Author Soler-Jimenez, Lilia Catherinne Author Aguirre-Macedo, Ma. Leopoldina Author Mclaughlin, John Author Jaramillo, Alejandra G. Author Shaw 2, Jenny C. Author James, Anna Author Hechinger, Ryan F. Author Kuris, Armand M. Author Lafferty, Kevin D. text ZooKeys 2017 713 1 23 http://dx.doi.org/10.3897/zookeys.713.14732 journal article http://dx.doi.org/10.3897/zookeys.713.14732 1313-2970-713-1 D70E71F8669C4557B266D4FF8359A511 Benedenia hawaiiensis Yamaguti, 1968 Type host. Priacanthus cruentatus ( Lacepede ) ( Priacanthidae ) Other host and localities. Benedenia hawaiiensis has been reported from more than 24 species of fishes from off Hawai'i ( Whittington et al. 2001 ). From Sargocentron spiniferum ( Forsskal ) ( Holocentridae ) in the South China Sea (as Benedenia sargocentron ) ( Zhang et al. 2001 ). Current host. Acanthurus xanthopterus ( Acanthuridae ), Chaetodon auriga , Chaetodon lunula ( Chaetodontidae ), Mulloidichthys flavolineatus ( Lacepede ) ( Mullidae ), Pseudobalistes flavimarginatus ( Rueppell ) and Rhinecanthus aculeatus (Linnaeus) ( Balistidae ). Site infection. Gills. Prevalence and mean intensity. Acanthurus xanthopterus 5 and 2 (n = 20); Chaetodon auriga 7,7 and 1 (n = 13); Chaetodon lunula 14,3 and 1 +/- 0 (n = 14); Mulloidichthys flavolineatus 7,7 and 2 +/- 0,6 (n = 52); Pseudobalistes flavimarginatus 25 and 1 (n = 4) and Rhinecanthus aculeatus 16,7 and 3 +/- 2 (n = 18). Specimens deposited. CHCM No. 551 (paratypes) (1 slide, 1 specimen). Remarks. Benedenia hawaiiensis was originally described by Yamaguti (1968) from the gills and fins of Priacanthus cruentatus off Hawai'i . Zhang et al. (2001) described Benedenia sargocentron on Sargocentron spiniferum from the South China Sea. However, Deveney and Whittington (2010) determined that B. sargocentron was a junior synonym of B. hawaiiensis , and proposed keeping B. hawaiiensis as the valid name. Benedenia hawaiiensis is characterized by having an opisthaptor which is usually a little longer than wide, provided with a marginal membrane and is notched opposite the marginal hooklets; with 14 marginal hooklets; two between the posterior anchors. The marginal valve is clearly indented at each hooklet and also at the position where the posterior anchor meets the haptor edge. The marginal valve is conspicuous and has one lobe between each of the hooklets around the circumference of the haptor with the anterior lobes being larger and wider. The proximal ends of the anterior anchors overlap the proximal ends of the accessory sclerites, and the distal portion of the anterior anchors overlap the posterior anchors for two-thirds of their lengths. The accessory sclerites are alate and raise the ventral haptoral tissues through which they protrude. The MCO is muscular, well-equipped with circular and longitudinal muscle fibres and lies in a cavity or canal with poorly developed muscle walls. The most prominent feature of the MCO of B. hawaiiensis is that it tapers to form a narrow distal tip. The presence of B. hawaiiensis on the gills of R. aculeatus at Palmyra Atoll represents both a new host and a new geographical record for this species.