Species of Dactylogyridae (Platyhelminthes: Monogenoidea) infecting marine fishes of Moreton Bay, Queensland, Australia, with proposals of Pleuronectitrema n. gen. and Ecnomotrema n. gen. and descriptions of 13 new species.

Twenty-nine dactylogyrid species were reported from teleosts collected during a survey of the parasites of fishes of Moreton Bay, Queensland, Australia, in 2016. Two new genera, Ecnomotrema n. gen. and Pleuronectitrema n. gen., were proposed, and 13 new species were illustrated and described: Atherinicus difficilis n. sp., Diversohamulus similis n. sp., and Ecnomotrema cetiosum n. sp. from Atherinomorus vaigiensis; Haliotrema apiculum n. sp. from Pempheris schwenkii; Haliotrema tugulduriforme n. sp. from Scarus ghobban; Lethrinitrema australiense n. sp., and Lethrinitrema lituus n. sp. from Lethrinus nebulosus; Tetrancistrum siganioides n. sp. from Siganus fuscescens; Ligophorus bostrychus n. sp. from Planiliza subviridis; Neohaliotrema gemmula n. sp. from Abudefduf vaigiensis; Neohaliotrema moretonense n. sp. from Ab. vaigiensis and Ab. bengalensis; and Pleuronectitrema spirula n. sp. from Pseudorhombus arsius (all from Moreton Bay); Pleuronectitrema kuwaitense Kritsky & Sey n. sp. was described from specimens collected from P. arsius in Kuwait during 1996. Ten new host records were recorded: Chauhanellus duriensis Lim, 1994 and Hamatopeduncularia thalassini Bychowsky & Nagibina, 1969 from Pararius proximus; Diplectanotrema sp. 1 and sp. 2 from Sillago maculata and Goniistius vestitus, respectively; Diversohamulus tricuspidatus Bychowsky & Nagibina, 1969 from At. vaigiensis; Hal. cf. dempsteri (Mizelle & Price, 1964) Young, 1968 from Prionurus microlepidotus; Hal. spirale Yamaguti, 1968 from Upeneus tragula; Ligophorus kaohsianghsieni (Gussev, 1962) Gussev, 1985 from Planiliza subviridis; and Neohaliotrema malayense Lim & Gibson, 2010 from Ab. bengalensis and Ab. whitleyi. Twenty-five new faunal records for Moreton Bay were recorded, including the new species listed above and C. duriensis, Diplectanotrema sp. 1 and sp. 2, Diversohamulus tricuspidatus Bychowsky & Nagibina, 1969, Glyphidohaptor phractophallus Kritsky, Galli, & Yang, 2007, Hal. cf. dempsteri, Hal. johnstoni Bychowsky & Nagibina, 1970, Hal. spirale, Yamaguti, 1968 Hamatopeduncularia thalassini Bychowsky & Nagibina, 1969, Lethrinitrema nebulosum Sun, Li, & Yang, 2014, Ligophorus kaohsianghsieni (Gussev, 1962) Gussev, 1985, Ligophorus parvicopulatrix Soo & Lim, 2012, and Neohaliotrema malayense Lim & Gibson, 2010. Three new combinations were proposed: Hal. spariense Roubal, 1981 as Euryhaliotrema spariense (Roubal, 1981) n. comb.; and Hal. arsiosa Venkatanarasaiah, 1984 and Hal. youngi Venkatanarasaiah, 1984 as Pleuronectitrema arsiosa (Venkatanarasaiah, 1984) n. comb. and Pleuronectitrema youngi (Venkatanarasaiah, 1984) n. comb., respectively; Haliotrema sp. of Zhang is transferred to Pleuronectitrema as Pleuronectitrema sp. Hal. ctenochaeti Yamaguti, 1968 was replaced with Hal. asymphylum n. nom. to remove it from homonymy with Hal. ctenochaeti Young, 1968. Pseudohaliotrematoides zancli Yamaguti, 1968 was transferred to Haliotrema as Haliotrema hawaiiense n. nom. Hal. zancli Yamaguti, 1968 was considered a junior subjective synonym of Hal. dempsteri.

Title: Espèces de Dactylogyridae (Platyhelminthes, Monogenoidea) infectant les poissons marins de Moreton Bay, Queensland, Australie, avec la proposition de Pleuronectitrema n. gen. et Ecnomotrema n. gen. et la description de 13 nouvelles espèces. Abstract: Vingt-neuf espèces de Dactylogyridae sont signalées chez des téléostéens collectés lors d'une étude des parasites des poissons de Moreton Bay, Queensland, Australie, en 2016. Deux nouveaux genres, Ecnomotrema n. gen. et Pleuronectitrema n. gen., sont proposés, et 13 nouvelles espèces sont illustrées et décrites : Atherinicus difficilis n. sp., Diversohamulus similis n. sp., et Ecnomotrema cetiosum n. sp. d'Atherinomorus vaigiensis ; Haliotrema apiculum n. sp. de Pempheris schwenkii ; Haliotrema tugulduriforme n. sp. de Scarus ghobban ; Lethrinitrema australiense n. sp. et Lethrinitrema lituus n. sp. de Lethrinus nebulosus, Tetrancistrum siganioides n. sp. de Siganus fuscescens ; Ligophorus bostrychus n. sp. de Planiliza subviridis ; Neohaliotrema gemmula n. sp. d'Abudefduf vaigiensis ; Neohaliotrema moretonense n. sp. d'Ab. vaigiensis et Ab. bengalensis ; et Pleuronectitrema spirula n. sp. de Pseudorhombus arsius (tous de Moreton Bay). Pleuronectitrema hawaiiense Kritsky & Sey n. sp. est décrit à partir de spécimens collectés de P. arsius au Koweït en 1996. Dix nouvelles combinaisons parasites-hôtes sont répertoriées : Chauhanellus duriensis Lim, 1994 et Hamatopeduncularia thalassini Bychowsky & Nagibina, 1969 de Pararius proximus ; Diplectanotrema sp. 1 et sp. 2, respectivement de Sillago maculata et Goniistius vestitus ; Diversohamulus tricuspidatus Bychowsky & Nagibina, 1969 d'At. vaigiensis ; Hal. cf. dempsteri (Mizelle & Price, 1964) Young, 1968 de Prionurus microlepidotus ; Hal. spirale Yamaguti, 1968 d'Upeneus tragula ; Ligophorus kaohsianghsieni (Gussev, 1962) Gussev, 1985 de Planiliza subviridis ; et Neohaliotrema malayense Lim & Gibson, 2010 d'Ab. bengalensis et Ab. whitleyi. Vingt-cinq nouveaux signalements fauniques pour la baie Moreton sont rapportés, y compris les nouvelles espèces énumérées ci-dessus et C. duriensis, Diplectanotrema sp. 1 et sp. 2, Diversohamulus tricuspidatus Bychowsky & Nagibina, 1969, Glyphidohaptor phractophallus Kritsky, Galli et Yang, 2007, Hal. cf. dempsteri, Hal. johnstoni Bychowsky et Nagibina, 1970, Hal. spirale, Hamatopeduncularia thalassini Bychowsky & Nagibina, 1969, Lethrinitrema nebulosum Sun, Li, & Yang, 2014, Ligophorus kaohsianghsieni (Gussev, 1962) Gussev, 1985, Ligophorus parvicopulatrix Soo & Lim, 2012, et Neohaliotrema malayense Lim et Gibson, 2010. Trois nouvelles combinaisons sont proposées : Hal. spariense Roubal, 1981 comme Euryhaliotrema spariense (Roubal, 1981) n. comb. ; Hal. arsiosa Venkatanarasaiah, 1984 et Hal. youngi Venkatanarasaiah, 1984, respectivement comme Pleuronectitrema arsiosa (Venkatanarasaiah, 1984) n. comb. et Pleuronectitrema youngi (Venkatanarasaiah, 1984) n. comb. ; Haliotrema sp. de Zhang est transféré à Pleuronectitrema sous le nom de Pleuronectitrema sp. Hal. ctenochaeti Yamaguti, 1968 est remplacé par Hal. asymphylum n. nom. pour supprimer l'homonymie avec Hal. ctenochaeti Young, 1968. Pseudohaliotrematoides zancli Yamaguti, 1968 est transféré à Haliotrema sous le nom de Haliotrema hawaiiense n. nom. Hal. zancli Yamaguti, 1968 est considéré comme un synonyme subjectif junior de Hal. dempsteri.

KANNAPHALLUS RAPHIDIUM N. SP. (MONOGENOIDEA: MAZOCRAEIDEA: HETERAXINIDAE) PARASITIC ON THE GILL LAMELLAE OF THE GOLDEN TREVALLY GNATHANODON SPECIOSUS (CARANGIFORMES: CARANGIDAE) OCCURRING IN THE COASTAL WATERS OF QUEENSLAND AND WESTERN AUSTRALIA.

An undescribed species of KannaphallusUnnithan, 1957 (Monogenoidea: Heteraxinidae) was collected from the gills of the golden trevally Gnathanodon speciosus (Forsskål) (Carangidae) from Moreton Bay, Queensland, during January 2016 and from Ningaloo Reef, Western Australia, during December 2021 and June 2022. The diagnosis for Kannaphallus was emended and the new species, Kannaphallus raphidium, was described. Kannaphallus virilis of Young, nec Unnithan was placed in synonymy with K. raphidium. The distal components of the male reproductive system and the arrangement of the clamp rows of the haptor occurred as mirror images among specimens of K. raphidium, suggesting that the respective antipodes of K. raphidium may have reproductive implications and function in the site selection of the parasite on the host's gills. A specimen of K. raphidium from Western Australia was sequenced for the cytochrome c oxidase subunit 1 (COI) mtDNA and ITS2 rDNA barcoding markers, and the phylogenetically informative 28S rDNA marker. Maximum likelihood and Bayesian inference analyses based on a partial 28S rDNA alignment, including all comparable heteraxinid sequence data available, resolved the Heteraxininae and Cemocotylinae as reciprocatively paraphyletic and provided evidence that Kannaphallus may be paraphyletic. No taxonomic changes concerning the subfamilies and genera of the Heteraxinidae were proposed. Finally, Kannaphallus univaginalisRamalingam, 1960 and Cemocotylelloides univaginalis (Ramalingam, 1960) Nitta, Kondo, Ohtsuka, Kamarudin, and Ismail, 2022 are considered nomen nuda sensu the International Code of Zoological Nomenclature.

Axinids (Monogenoidea: Mazocraeidea: Microcotylinea) infecting the gill lamellae of some beloniform fishes in the Gulf of Mexico, with descriptions of Axine buccina n. sp. from Hyporhamphus unifasciatus (Ranzani) and Nudaciraxine timucua n. sp. from Strongylura timucu (Walbaum).

Five species of Axinidae (Monogenoidea: Mazocraeidae) were recovered from the gill lamellae of four of six species of needlefishes and halfbeaks examined from the Gulf of Mexico off Florida: Axine buccina n. sp. from a common halfbeak Hyporhamphus unifasciatus (Ranzani); Nudaciraxine gracilis (Linton, 1940) Price, 1962 (minimum prevalence 60%) from the Atlantic needlefish Strongylura marina (Walbaum); Nudaciraxine timucua n. sp. (36%) from the timucu Strongylura timucu (Walbaum); and Axinoides raphidoma Hargis, 1956 (29%) and Chlamydaxine truncata (Hargis, 1956) Unnithan, 1957 (29%) both from the houndfish Tylosurus crocodilus (Péron & LeSueur). The American halfbeak Hyporhamphus meeki Banford & Collette (24 specimens examined) and the redfin needlefish Strongylura notata (Poey) (94 specimens) were uninfected with axinids. The two new axinid species were figured and described. The current status of the Axinidae was explored, which suggested that an objective evaluation of its position within the Monogenoidea is needed.

Bychowskicotylids (Monogenoidea: Gastrocotylinea) infecting the gills of the sweetlips Diagramma labiosum Macleay (Haemulidae) in Moreton Bay, Queensland, Australia, with the proposal of Lebedevia n. gen. and description of Lebedevia lebedevi n. sp.

Two species of Bychowskicotylidae (Monogenoidea: Gastrocotylinea) were collected from the gills of the sweetlips Diagramma labiosum Macleay (Haemulidae) obtained from Moreton Bay, Queensland, Australia, during January 2016. Lebedevia n. gen. is proposed for bychowskicotylids having 1) a bilaterally symmetrical haptor with four pairs of gastrocotylid-like clamps and lacking an armed lappet (anchors and hooks absent); 2) longitudinal sclerotized internal ridges lining the vas deferens, 3) an unarmed male copulatory organ, and 4) four interconnected vesicles located posterior to the genital atrium and lying on the body midline dorsal to the uterus and ventral to the vas deferens. Lebedevia lebedevi n. sp., the type and only species of the genus, is described, and Tonkinopsis transfretanus Lebedev, 1972 is recorded for the first time in Moreton Bay. Yamaguticotyla Price, 1959 (Bychowskicotylidae) is considered nomen nudum, and the authorship of the genus is corrected to Yamaguticotyla Yamaguti, 1963.

The nomenclatural status of Heteraxinoides Yamaguti, 1943, Heteraxinoides Yamaguti, 1963, Allopseudaxine Yamaguti, 1943, Axine tripathii Price, 1962, and Axine tripathii Yamaguti, 1963, with the proposal of Neoheteraxinoides nom. nov. (Monogenoidea: Microcotylinea).

An analysis of the nomenclature of Heteraxinoides Yamaguti, 1943, Heteraxinoides Yamaguti, 1963, Allopseudaxine Yamaguti, 1943, Axine tripathii Price, 1962, and Axine tripathii Yamaguti, 1963 was conducted, which resulted in the proposal of the following: 1) the subgenus Heteraxinoides Yamaguti, 1943 is a nomen nudum; 2) Heteraxinoides Price, 1962 and Heteraxinoides inada (Ishii & Sawada, 1938) Price, 1962 represent the correct authorships for the respective taxa; 3) Heteraxinoides Yamaguti, 1963 and Heteraxinoides Yamaguti sensu Price are junior homonyms of Heteraxinoides Price, 1962; 4) Heteraxinoides Price, 1962 is a junior subjective synonym of Axine Abildgaard, 1794; 5) Heteraxinidae Price, 1962 is a junior objective synonym of Heteraxinidae Unnithan, 1957; 6) Allopseudaxine Yamaguti, 1943 is valid and available sensu the International Code of Zoological Nomenclature; and 7) the homonyms Axine tripathii Price, 1962 and Axine tripathii Yamaguti, 1963 are objective junior synonyms of Axine hemirhamphae Tripathi, 1959. Neoheteraxinoides nom. nov. is proposed to replace the junior homonym Heteraxinoides Yamaguti, 1963, and the following new combinations are advanced: Neoheteraxinoides argiropsi (Mamaev, 1977) comb. n., N. atlanticus (Gayevskaya & Kovaljova, 1979) comb. n., N. caprodontis (Yamaguti, 1968) comb. n., N. chinensis (Yamaguti, 1937) comb. n., N. hargisi (Price, 1962) comb. n., N. novaezealandiae (Dillon & Hargis, 1965) comb. n., N. oligoplitis (Meserve, 1938) comb. n., N. pseudosciaenai (Gupta & Khullar, 1968) comb. n., N. regis (Dillon & Hargis, 1965) comb. n., N. scorpis (Sanders, 1944) comb. n., N. triangularis (Goto, 1894) comb. n. (type species), N. xanthophilis (Hargis, 1956) comb. n., N. xanthophiloides (Price, 1962) comb. n., and N. zhukovi (Caballero & Bravo Hollis, 1963) comb. n.

Euryhaliotrema dolichodrilus n. sp. and Euryhaliotrema mimulus n. sp. (Monogenoidea: Dactylogyridae) infecting the gill lamellae of porgies, Calamus spp. (Perciformes: Sparidae) from the Gulf of Mexico off Florida, U.S.A.

Two new species of Euryhaliotrema Kritsky & Boeger, 2002 (Monogenoidea: Dactylogyridae) were described from the gill lamellae of porgies, Calamus spp. (Perciformes, Sparidae), collected from the Gulf of Mexico off Florida: Euryhaliotrema dolichodrilus n. sp. from littlehead porgy Calamus proridens Jordan & Gilbert (type host), knobbed porgy Calamus nodosus Randall and Caldwell, grass porgy Calamus arctifrons Good & Bean, sheepshead porgy Calamus penna (Valenciennes), and jolthead porgy Calamus bajonado (Bloch & Schneider); and Euryhaliotrema mimulus n. sp. from jolthead porgy. The two new species along with Euryhaliotrema amydrum Kritsky & Bakenhaster, 2011, Euryhaliotrema carbuncularium Kritsky & Bakenhaster, 2011, Euryhaliotrema carbunculus (Hargis, 1955) Kritsky & Boeger, 2002, Euryhaliotrema luisae Cruces, Chero & Luque, 2018, Euryhaliotrema magnopharyngis Cruces, Chero & Luque, 2018, and Euryhaliotrema spirulum Kritsky & Bakenhaster, 2011 appeared to form a subgroup of species that developed secondarily within Euryhaliotrema.

ON THAUMATOCOTYLE SCOTT, 1904 (MONOGENOIDEA: MONOCOTYLIDAE) AND THAUMATOCOTYLE PSEUDODASYBATIS HARGIS, 1955 WITH DESCRIPTIONS OF ITS PUTATIVE SIBLING SPECIES THAUMATOCOTYLE ADELPHA N. SP. AND THAUMATOCOTYLE CASIGNETA N. SP. PARASITIZING THE OLFACTORY ORGANS OF PELAGIC EAGLE RAYS (MYLIOBATIFORMES: AETOBATIDAE) IN THE PACIFIC OCEAN.

An emended diagnosis of ThaumatocotyleScott, 1904 (Monogenoidea: Monocotylidae) and a list of its species are provided. Merizocotyle urolophiChisholm and Whittington, 1999, Merizocotyle macrostrobusChisholm and Whittington, 2012, Merizocotyle papillaeChisholm and Whittington, 2012, and Merizocotyle rhadinopeosChisholm and Whittington, 2012 are transferred to Thaumatocotyle as new combinations. Thaumatocotyle pseudodasybatisHargis, 1955 is redescribed and is currently restricted to Thaumatocotyle-like helminths parasitizing the olfactory organs of the white-spotted eagle ray Aetobatus narinari (Euphrasen, 1790) (Myliobatiformes: Aetobatidae) in the western Atlantic Ocean. Two new species are described that infect the olfactory organs of pelagic eagle rays: Thaumatocotyle adelpha n. sp. from the ocellated eagle ray Aetobatus ocellatus (Kuhl, 1823) in the central and western Pacific Ocean and Thaumatocotyle casigneta n. sp. from the Pacific eagle ray Aetobatus laticeps Gill, 1865 from the eastern Pacific Ocean off the western coast of Mexico. Based on comparative morphology, T. pseudodasybatis, T. adelpha, and T. casigneta appear to form a subgroup of species that developed secondarily within the genus.

Monocotylids (Monogenoidea) infecting elasmobranchs in Moreton Bay, Queensland, Australia, with descriptions of Calicotyle cutmorei n. sp. (Calicotylinae) and Dendromonocotyle raiae n. sp. (Monocotylinae).

Eighteen monocotylid species were collected from elasmobranchs during surveys of the parasites of fishes of Moreton Bay, Queensland, Australia. Two new species, Calicotyle cutmorei n. sp. (Calicotylinae) from Carcharhinus sorrah (Valenciennes) (Carcharhiniformes) and Dendromonocotyle raiae n. sp. (Monocotylinae) from Hemitrygon fluviorum (Ogilby) and Neotrygon trigonoides (Castelnau) (both Myliobatiformes) are described and illustrated. Six new faunal records for Moreton Bay are reported: Thaumatocotyle australensis Beverley-Burton & Williams, 1989 (Merizocotylinae) from Maculabatis toshi (Whitley) (Myliobatiformes); Monocotyle corali Chisholm, 1998 (Monocotylinae) from Pastinachus ater (Macleay) (Myliobatiformes); Neoheterocotyle rhynchobatis (Tripathi, 1959) Chisholm, 1994 (Heterocotylinae) from Glaucostegus typus (Anonymous [Bennett]) and Aptychotrema rostrata (Shaw) (both Rhinopristiformes); and Decacotyle elpora Marie & Justine, 2005 (Decacotylinae), Dendromonocotyle torosa Chisholm & Whittington, 2004 (Monocotylinae), and Clemacotyle australis Young, 1967 (Monocotylinae) from Aetobatus ocellatus (Kuhl) (Myliobatiformes). Maculabatis toshi is a new host record for T. australensis, and A. rostrata is a new host record for N. rhynchobatis. Ten species previously recorded from Moreton Bay were collected: Monocotyle caseyae Chisholm & Whittington, 2005 (Monocotylinae) and Heterocotyle whittingtoni Chisholm & Kritsky, 2020 (Heterocotylinae) from M. toshi; Monocotyle sp. A of Chisholm (1998a) (Monocotylinae) from H. fluviorum; Dendromonocotyle kuhlii Young, 1967 and Monocotyle kuhlii Young, 1967 (both Monocotylinae) from N. trigonoides; Thaumatocotyle cf. pseudodasybatis Hargis, 1955 (Merizocotylinae), Empruthotrema kearni Whittington, 1990 (Merizocotylinae) and Decacotyle octona Young, 1967 (Decacotylinae) from A. ocellatus; and Mycteronastes icopae (Beverley-Burton & Williams, 1989) Kearn & Beverley-Burton, 1990 (Merizocotylinae) and Troglocephalus rhinobatidis Young, 1967 (Dasybatotreminae) from G. typus.

Heterocotyle whittingtoni n. sp. (Monogenea: Monocotylidae) from the gills of the black-spotted whipray, Maculabatis toshi (Whitley) (Myliobatiformes: Dasyatidae), collected in coastal waters of Queensland, Australia.

Heterocotyle whittingtoni n. sp. (Monogenea: Monocotylidae) is described from the gills of the black-spotted whipray Maculabatis toshi (Whitley) (Dasyatidae) collected from Moreton Bay near Dunwich and Peel Island, and from the eastern Gulf of Carpentaria off Weipa, Queensland, Australia. Heterocotyle whittingtoni n. sp. has a single sinuous ridge surmounting the haptoral septa and the male copulatory organ lacks an accessory piece. The new species can be distinguished from the two other Heterocotyle species that have this combination of characters by the distal portion of the male copulatory organ which is slightly flared with uniquely thickened walls and by the morphology of the testis. The identity of the host of H. whittingtoni n. sp. is discussed. We confirm that the host of the monocotylids Dendromonocotyle lasti Chisholm & Whittington, 2005 and Monocotyle caseyae Chisholm & Whittington, 2005 originally identified as "Himantura sp." was M. toshi.

Neotropical Monogenoidea. 63. Atopogyrodactylus praecipuus gen. et sp. n. (Gyrodactylidae), an oviparous gyrodactylid from the external surface of a bristlenose catfish Ancistrus sp. (Siluriformes: Loricariidae) from the Rondônian Amazon, Brazil.

Atopogyrodactylus n. gen. (Gyrodactylidae) is proposed for Atopogyrodactylus praecipuus n. sp. (type species by monotypy), a protandrous and oviparous gyrodactylid from the external surfaces of an unidentified bristlenose catfish Ancistrus sp. (Siluriformes: Loricariidae) from the head waters of the Rio Candeias in the State of Rondônia, Brazil. The new genus contains species morphologically similar to those of Nothogyrodactylus Kritsky Boeger, 1991 as shown by members of both genera having accessory copulatory sclerites associated with the male copulatory organ (MCO). Atopogyrodactylus differs from Nothogyrodactylus by its species lacking haptoral bars and having a sclerotized haptoral plate overlying the ventral anchors. The new species most closely resembles Nothogyrodactylus amazonicus Kritsky Boeger, 1991 by possessing a flared proximal filament on the egg and a single morphologically similar accessory copulatory sclerite associated with an allantoid MCO.

Correction to: Species of Monogenoidea infecting the gill lamellae of the common silver-biddy Gerres oyena (Forsskål) and the common silver belly Gerres subfasciatus Cuvier (Perciformes: Gerreidae) in Moreton Bay, Queensland, Australia.

During registration of specimens of Protogyrodactylus scalmophorus and Protogyrodactylus ichthyocercus for the Queensland Museum, it was noticed that the collection sites of the holotypes of the two species provided on the slide labels did not correspond to the published type-localities. While both species were collected from two localities within Moreton Bay as recorded in the paper, the type-locality for each is here corrected to that reported as the "Other locality" in the respective taxonomic summaries.

Gymnurahemecus bulbosus gen. et sp. nov. (Digenea: Aporocotylidae) infecting smooth butterfly rays, Gymnura micrura (Myliobatiformes: Gymnuridae) in the northern Gulf of Mexico, with a taxonomic key and further evidence for monophyly of chondrichthyan blood flukes.

Gymnurahemecus bulbosus gen. et sp. nov. infects the heart of smooth butterfly rays, Gymnura micrura in the Gulf of Mexico. Gymnurahemecus differs from all other accepted aporocotylid genera by having one column of C-shaped lateral tegumental spines, a medial oesophageal bulb anterior to a diverticulate region of the oesophagus, inverse U-shaped intestinal caeca, a non-looped testis, an oviducal ampulla, a Laurer's canal, and a post-caecal common genital pore. The new species, the shark blood flukes (Selachohemecus spp. and Hyperandrotrema spp.), and the chimaera blood fluke Chimaerohemecus trondheimensis are unique by having C-shaped lateral tegumental spines. Selachohemecus spp. and the new species have a single column of lateral tegumental spines, whereas Hyperandrotrema spp. and C. trondheimensis have 2-7 columns of lateral tegumental spines. The new species differs from Selachohemecus spp. most notably by having an inverse U-shaped intestine. The other ray blood flukes (Orchispirium heterovitellatum, Myliobaticola richardheardi, and Ogawaia glaucostegi) differ from the new species by lacking lateral tegumental spines, a medial oesophageal bulb, and a Laurer's canal and by having a looped testis. Phylogenetic analysis using large subunit ribosomal DNA (28S) indicated that the new species is sister to the clade that includes the other sequenced adult blood fluke (O. glaucostegi), which infects a ray in Australia. These results agree with and extend previous morphology- and nucleotide-based phylogenetic assertions that the blood flukes of early-branching jawed craniates (Chondrichthyes) are monophyletic and phylogenetically separated from the blood flukes of later-branching ray-finned fishes (Actinopterygii: Euteleostei).

Euryhaliotrema spp. (Monogenoidea: Dactylogyridae) Parasitic on the Gill Lamellae of Perciform Fishes in Moreton Bay, Queensland, Australia, with the Description of Euryhaliotrema solenophallus sp. nov. from the Silver Moony Monodactylus argenteus (Linnaeus) (Monodactylidae).

BACKGROUND: The present paper represented the third installment on the monogenoidean parasites collected during a workshop exploring the diversity of the parasites of fishes in Moreton Bay, Queensland, Australia. Previous reports on monogenoids collected during the workshop included species parasitizing beloniform and gerreid fishes. PURPOSE: During January 2016, the author, having responsibility for the identification and description of monogenoids, participated in a workshop supported by an Australian Biological Resources Study Grant to Drs. Thomas Cribb and Scott Cutmore, University of Queensland, to explore the diversity of parasites infecting the fishes of Moreton Bay, Queensland, Australia. METHODS: Approximately 100 species of marine fishes were necropsied for parasites. Standard procedures for collecting, mounting, drawing, and measuring of monogenoids were employed. RESULTS: A new species of Euryhaliotrema was collected and described from the silver moony Monodactylus argenteus (Monodactylidae) and the first recording of Euryhaliotrema spirotubiforum on the dory snapper Lutjanus fulviflamma and Russell's snapper Lutjanus russellii (both Lutjanidae) in Moreton Bay was reported. CONCLUSION: The results suggested that the diversity of dactylogyrids off eastern Australia is under estimated in the literature.

Species of Monogenoidea infecting the gill lamellae of the common silver-biddy Gerres oyena (Forsskål) and the common silver belly Gerres subfasciatus Cuvier (Perciformes: Gerreidae) in Moreton Bay, Queensland, Australia.

As part of a survey of the parasites infecting the fishes of Moreton Bay, Queensland, Australia, the gill lamellae of two species, the common silver-biddy Gerres oyena (Forsskål) and the common silver belly Gerres subfasciatus Cuvier (both Gerreidae), were found infected with monogenoids as follows: Metahaliotrema filamentosum Venkatanarasaiah, 1981 (Dactylogyridae) was redescribed from G. oyena and recorded from G. subfasciatus (both new host records); Metahaliotrema imparilis n. sp., Protogyrodactylus monacanthus n. sp., Protogyrodactylus vulgaris n. sp. (all Dactylogyridae), Gyrodactylus xynus n. sp. (Gyrodactylidae), and Polylabris gerres (Sanders, 1944) Mamaev & Parukin, 1976 (Microcotylidae) were reported from G. subfasciatus; and Protogyrodactylus scalmophorus n. sp., Protogyrodactylus ichthyocercus n. sp., and Protogyrodactylus similis n. sp. were recorded from G. oyena. The new species are described, and the finding of M. filamentosum and P. gerres from Moreton Bay represent new geographic records. Haliotrema digyroides Zhang, 2001 and Haliotrema subancistroides Zhang, 2001 are transferred to Metahaliotrema Yamaguti, 1953 as Metahaliotrema digyroides (Zhang, 2001) n. comb. and Metahaliotrema subancistroides (Zhang, 2001) n. comb., respectively.

Dactylogyrids (Monogenoidea) infecting the gill lamellae of some beloniform fishes from Moreton Bay, Queensland, Australia, with a redescription of Hareocephalus thaisae Young, 1969 and descriptions of six new species of Hemirhamphiculus Bychowsky & Nagibina, 1969.

Three species of beloniform fishes were found infected with species of Monogenoidea Bychowsky, 1937 during a survey of the diversity of parasites infecting the fishes of Moreton Bay, Queensland, Australia. The diagnoses of Hareocephalus Young, 1969 and Hemirhamphiculus Bychowsky & Nagibina, 1969 (both Polyonchoinea Bychowsky, 1937: Dactylogyridae Bychowsky, 1933) were emended. Hareocephalus thiasae Young, 1969, type-species of the genus, was recorded and redescribed from the gill lamellae of the stout longtom Tylosurus gavialoides (Castelnau) (Belonidae), and six new species of Hemirhamphiculus were described from the gill lamellae of three host species: Hemirhamphiculus exserocephalus n. sp. from T. gavialoides; Hemirhamphiculus choanophallus n. sp. and Hemirhamphiculus flagrum n. sp. from the river garfish Hyporhamphus regularis (Günther) (Hemiramphidae); and Hemirhamphiculus perexiguus n. sp., Hemirhamphiculus krabsi n. sp., and Hemirhamphiculus imcomptus n. sp. from the southeastern snub-nose garfish Arrhamphus sclerolepis krefftii (Steindachner) (Hemiramphidae). An unidentified species of the Suborder Microcotylinea Lebedev, 1972 (Heteronchoinea Boeger & Kritsky, 2001) was found infecting single specimens of each of H. regularis and A. sclerolepis krefftii. Parahemirhamphiculus Bychowsky & Nagibina, 1969 is placed in junior subjective synonymy with Hemirhamphiculus, and its three species, Parahemirhamphiculus pinguis Bychowsky & Nagibina, 1969, Parahemirhamphiculus brevilamellatus Zhang, 2001, and Parahemirhamphiculus longilamellatus An & Zhang, 1988 are transferred to Hemirhamphiculus.

Empruthotrema longipenis n. sp. (Monogenoidea: Monocotylidae: Merizocotylinae) from the olfactory sacs of the smooth butterfly ray Gymnura micrura (Bloch & Schneider) (Myliobatiformes: Gymnuridae) in the Gulf of Mexico.

A new species of Empruthotrema Johnston & Tiegs, 1922 is described based on specimens collected from the olfactory sacs of smooth butterfly rays Gymnura micrura (Bloch & Schneider) captured in Mobile Bay (northcentral Gulf of Mexico), Alabama, USA. Empruthotrema longipenis n. sp. is most similar to the type-species Empruthotrema raiae (MacCallum, 1916) Johnston & Tiegs, 1922 by having 12 marginal and two interhamular loculi with members of haptoral hook pair 1 located midway along the periphery of each interhamular loculus and those of hook pair 2 located at the marginal termini of the bilateral septa flanking the interhamular loculi. Empruthotrema longipenis n. sp. differs from E. raiae by having a much longer male copulatory organ and from its remaining congeners by the sinistral and extracecal ejaculatory bulb flanking the pharynx, the number of interhamular and marginal septa, and the distribution of hook pairs 1 and 2 along the haptoral margin. This is the first report of a monocotylid from the smooth butterfly ray and from Mobile Bay. The diversity of haptoral morphotypes among the currently accepted species of Empruthotrema is detailed and discussed in the context of monophyly of the genus.

Resurrection of Mycteronastes (Monogenoidea: Monocotylidae), with Description of Mycteronastes caalusi n. sp. from Olfactory Sacs of the Smalltooth Sawfish, Pristis pectinata (Pristiformes: Pristidae), in the Gulf of Mexico off Florida.

Mycteronastes Kearn and Beverley-Burton, 1990 (Monogenoidea: Monocotylidae: Merizocotylinae) was resurrected from subjective synonymy with Merizocotyle Cerfontaine, 1894 , and its diagnosis was emended to include monocotylids with a haptor lacking a central loculus and having 5 peripheral (2 bilateral pairs and an unpaired anteromedial loculus), 1 interhamular, and 17 marginal loculi. The 3 species of Mycteronastes accepted herein are parasitic within the olfactory sacs of rays and sawfishes: Mycteronastes icopae ( Beverley-Burton and Williams, 1989 ) Kearn and Beverley-Burton, 1990 (type species) from the giant shovelnose ray, Glaucostegus typus (Anonymous (Bennett)) (Glaucostegidae), in the southwestern Pacific Ocean; Mycteronastes undulatae Kearn and Beverley-Burton, 1990 from the undulate ray, Raja undulata Lacepède (Rajidae), in the northeastern Atlantic Ocean; and Mycteronastes caalusi n. sp. from the smalltooth sawfish, Pristis pectinata Latham (Pristidae), in the Gulf of Mexico. Mycteronastes caalusi is most easily differentiated from its congeners by the combination of having 2 median cephalic papillae, an oval haptor that is wider than the body proper and lacks a deeply scalloped margin, a comparatively large anteromedial peripheral loculus, an unsclerotized male copulatory organ that is wholly anterior to the vaginal pores, a relatively small distal portion of the uterus (ootype chamber) that is mostly anterior to the vaginae, and a delicate uterus. The present study is the first report of a monocotylid from the olfactory sacs of P. pectinata and the first record of a species of Mycteronastes from the Gulf of Mexico. Notes on the taxonomy and systematics of some species assigned to Calicotyle Diesing, 1850 (Monocotylidae: Calicotylinae) are included.

Revision of Metahaliotrema Yamaguti, 1953 (Monogenoidea: Dactylogyridae), with new and previously described species from the spotted scat Scatophagus argus (Linnaeus) (Perciformes: Scatophagidae) in Vietnam.

An emended diagnosis of Metahaliotrema Yamaguti, 1953 (Monogenoidea: Dactylogyridae) is provided based on specimens of six species collected from the spotted scat Scatophagus argus (Linnaeus) (Scatophagidae) in Vietnam: M. scatophagi Yamaguti, 1953 (type-species); M. cf. yamagutii Mizelle & Price, 1964; M. mizellei Venkatanarasaiah, 1981; M. kulkarnii Venkatanarasaiah, 1981; M. ypsilocleithrum n. sp.; and M. similis n. sp. Methaliotrema filamentosum Venkatanarasaiah, 1981 from the whipfin silver-biddy Gerres filamentosus Cuvier (Gerreidae) is included as the only other valid member of the genus. Metahaliotrema arii Yamaguti, 1953 from an ariid catfish is considered incertae sedis within the Dactylogyridae; and Metahaliotrema srivastavai Singh & Agarwal, 1994 from a bagrid catfish is transferred to Chauhanellus Bychowsky & Nagibina, 1969 as Chauhanellus srivastavai (Singh & Agarwal, 1994) n. comb. Metahaliotrema geminatohamula Pan, Ding & Zhang, 1995 from spotted scat in China is determined to be a junior subjective synonym of M. scatophagi. The two new species and M. scatophagi, M. mizellei, and M. kulkarnii are described or redescribed based on specimens from Vietnam.

Pseudorhabdosynochus species (Monogenoidea, Diplectanidae) parasitizing groupers (Serranidae, Epinephelinae, Epinephelini) in the western Atlantic Ocean and adjacent waters, with descriptions of 13 new species.

Seventeen of twenty-three species of groupers collected from the western Atlantic Ocean and adjacent waters were infected with 19 identified species (13 new) of Pseudorhabdosynochus Yamaguti, 1958 (Dactylogyridea, Diplectanidae); specimens of the Spanish flag Gonioplectrus hispanus, coney Cephalopholis fulva, marbled grouper Dermatolepis inermis, mutton hamlet Alphestes afer, and misty grouper Hyporthodus mystacinus were not infected; the yellowmouth grouper Mycteroperca interstitialis and yellowfin grouper Mycteroperca venenosa were infected with unidentified species of Pseudorhabdosynochus; the Atlantic creolefish Paranthias furcifer was infected with an unidentified species of Diplectanidae that could not be accommodated in Pseudorhabdosynochus. The following species of Pseudorhabdosynochus are described or redescribed based entirely or in part on new collections: Pseudorhabdosynochus americanus (Price, 1937) Kritsky & Beverley-Burton, 1986 from Atlantic goliath grouper Epinephelus itajara; Pseudorhabdosynochus yucatanensis Vidal-Martínez, Aguirre-Macedo & Mendoza-Franco, 1997 and Pseudorhabdosynochus justinella n. sp. from red grouper Epinephelus morio; Pseudorhabdosynochus kritskyi Dyer, Williams & Bunkley-Williams, 1995 from gag Mycteroperca microlepis; Pseudorhabdosynochus capurroi Vidal-Martínez & Mendoza-Franco, 1998 from black grouper Mycteroperca bonaci; Pseudorhabdosynochus hyphessometochus n. sp. from Mycteroperca interstitialis; Pseudorhabdosynochus sulamericanus Santos, Buchmann & Gibson, 2000 from snowy grouper Hyporthodus niveatus and Warsaw grouper Hyporthodus nigritus (new host record); Pseudorhabdosynochus firmicoleatus n. sp. from yellowedge grouper Hyporthodus flavolimbatus and snowy grouper H. niveatus; Pseudorhabdosynochus mcmichaeli n. sp., Pseudorhabdosynochus contubernalis n. sp., and Pseudorhabdosynochus vascellum n. sp. from scamp Mycteroperca phenax; Pseudorhabdosynochus meganmarieae n. sp. from graysby Cephalopholis cruentata; Pseudorhabdosynochus beverleyburtonae (Oliver, 1984) Kritsky & Beverley-Burton, 1986 from dusky grouper Mycteroperca marginata; Pseudorhabdosynochus mizellei n. sp. from red hind Epinephelus guttatus; Pseudorhabdosynochus williamsi n. sp. from rock hind Epinephelus adscensionis; Pseudorhabdosynochus bunkleywilliamsae n. sp. from Nassau grouper Epinephelus striatus; Pseudorhabdosynochus mycteropercae n. sp. from tiger grouper Mycteroperca tigris; and Pseudorhabdosynochus tumeovagina n. sp. from speckled hind Epinephelus drummondhayi. Pseudorhabdosynochus woodi n. sp. from red hind Epinephelus guttatus is described based on specimens from the US National Parasite Collection (USNPC). Drawings of the haptoral and copulatory sclerites of the type specimens in the USNPC of Pseudorhabdosynochus monaensis Dyer, Williams & Bunkley-Williams, 1994 from rock hind Epinephelus adscensionis are presented. Finally, a note confirming Pseudorhabdosynochus epinepheli Yamaguti, 1958 rather than its senior synonym Pseudorhabdosynochus epinepheli (Yamaguti, 1938) Kritsky & Beverley-Burton, 1986 as the type species of Pseudorhabdosynochus is provided.

Acanthocercodes n. g. (Monogenoidea: Diplectanidae) for species parasitising threadfins (Perciformes: Polynemidae), with description of Acanthocercodes bullardi n. sp. from the Atlantic threadfin Polydactylus octonemus (Girard) and reassignment of three species of Diplectanum Monticelli, 1903 from the Indo-Pacific Ocean.

Acanthocercodes n. g. (Diplectanidae) is proposed for Acanthocercodes bullardi n. sp. and three previously described species of Diplectanum all parasites of the gill lamellae of threadfins (Perciformes: Polynemidae). The new genus is characterised by species having peduncular spines composed of an anteriorly directed point and a flattened base from which an anterior root arises. Members of the genus lack auxiliary spinous or sucker-like structures in the haptor. Acanthocercodes bullardi n. sp. is described from the Atlantic threadfin, Polydactylus octonemus (Girard), in the Gulf of Mexico off Louisiana, USA. Diplectanum polynemus Tripathi, 1957 is redescribed and transferred to Acanthocercodes as A. polynemus (Tripathi, 1957) n. comb. based on specimens collected from the fourfinger threadfin, Eleutheronema tetradactylum (Shaw), from the mouth of the River Adelaide, Northern Territory, Australia. Diplectanum spinosum (Maillard & Vala, 1980) (=Pseudodiplectanum spinosum Maillard & Vala, 1980) and Diplectanum megacirrus (Maillard & Vala, 1980) (=Pseudodiplectanum megacirrus Maillard & Vala, 1980) from the lesser African threadfin, Galeoides decadactylus (Bloch), are transferred to Acanthocercodes as A. spinosum (Maillard & Vala, 1980) n. comb. and A. megacirrus (Maillard & Vala, 1980) n. comb., respectively.