Five new monogenean species from the gills of Mulloidichthys vanicolensis (Perciformes: Mullidae) off New Caledonia, with the proposal of Volsellituba n. g. and Pennulituba n. g. (Monogenea: Dactylogyridae)

Three species of Volsellituba n. g. and two species of Pennulituba n. g. are described from the gills of the yellowfin goatfish Mulloidichthys vanicolensis (Valenciennes) off New Caledonia (South Pacific). Volsellituba and Pennulituba resemble dactylogyrid genera whose species lack eye-spots and possess tandem or slightly overlapping gonads, a single prostatic reservoir, a male copulatory organ without an accessory piece, a dextroventral non-sclerotised vagina, ventral and dorsal anchor/bar complexes, and hooks with shanks comprising a single slender unit. Volsellituba n. g. is characterised by its species having ventral tegumental folds at the level of the vaginal duct, a male copulatory organ with a subterminal basal opening and a two-piece dorsal bar. The following new species of Volsellituba are described: V. orchidea n. sp. (type-species), V. nabla n. sp. and V. elephantina n. sp. Pennulituba n. g. is distinguished by its species possessing a male copulatory organ with a wing-shaped membrane and a dorsal bar with a poorly to non-sclerotised medial part. This genus includes P. piratifalx n. sp. (type-species) and P. cymansis n. sp. A tabular summary of the species of Haliotrema Johnston & Tiegs, 1922 reported from mullids is provided.     

Description de deux nouvelles espèces de Lamellodiscus Johnston & Tiegs, 1922 (Monogenea: Diplectanidae) du groupe morphologique ‘ignoratus’, parasites de Diplodus sargus et D. vulgaris (Teleostei: Sparidae)

The study of the diplectanid gill parasites of Diplodus Rafinesque (Teleostei: Sparidae) from off the Algerian coast revealed the presence of several species of Lamellodiscus Johnston & Tiegs, 1922 on D. sargus (Linnaeus) and D. vulgaris (Geoffroy Saint-Hilaire). Some of these species differ from the others by having a copulatory organ "en lyre" and lamellodiscs of the morphological group 'ignoratus' of Oliver (1987). In Lamellodiscus, the subgroup 'ignoratus', proposed by Amine & Euzet (2005), characterised by a simple lateral dorsal bar, includes L. ignoratus Palombi, 1943 and L. fraternus Bychowsky, 1957. Two new species, L. falcus n. sp. and L. neifari n. sp. form part of the 'ignoratus' subgroup. These species are distinguished by the morphology and the size of the sclerotised parts of the haptor and copulatory organ.     

Bravohollisia Bychowsky & Nagibina, 1970 and Caballeria Bychowsky & Nagibina, 1970 (Monogenea: Ancyrocephalidae) from Pomadasys hasta (Bloch) (Pomadasyidae), with the description of a new attachment mechanism

Nine species of monogeneans were collected from the fish Pomadasys hasta (Bloch): Bravohollisia magna Bychowsky & Nagibina, 1970; B. rosetta n. sp.; B. reticulata n. sp.; B. gussevi n. sp.; B. kritskyi n. sp.; Caballeria pedunculata Bychowsky & Nagibina, 1970; C. robusta Bychowsky & Nagibina, 1970; C. liewi n. sp.; and C. intermedius n. sp. The anchors of these species contain a canal beginning in the shaft and ending near the point; ducts of haptoral glands enter the canal in the shaft and are associated with net-like structures near the anchor tip. The net-like structures of Bravohollisia spp. are extensive, while those of Caballeria spp. are smaller and more compact. These nets probably assist the monogeneans in attaching to the gill filaments. Caballeria spp. possess four pairs of extensible haptoral digits. Species of Bravohollisia and Caballeria posses two seminal vesicles.     

A new genus and three new species of dactylogyrids (Monogenea), gill parasites of the threadfin bass,Pronotogrammus multifasciatus Gill (Perciformes: Serranidae) in the Southeastern Pacific Ocean off Peru

Pronotogrammella n. g. is erected to accommodate Pronotogrammella boegeri n. sp. (type-species), Pr. scholzi n. sp. and Pr. multifasciatus n. sp. (Monogenea: Dactylogyridae). The new species are gill parasites of the threadfin bass Pronotogrammus multifasciatus Gill (Perciformes: Serranidae), a demersal teleost collected from off the coastal zone of Puerto Pizarro, Tumbes, Peru. Pronotogrammella n. g. is mainly characterised by having broadly fork-shaped dorsal anchors, which have an accessory anchor sclerite articulated to the tip of the superficial roots. Pronotogrammella n. g. is also characterised by having: (i) a tubular tapered-shaped male copulatory organ (MCO), filamentous distally, with a clockwise coil at distal end or not, lacking accessory piece; (ii) a dorsal bar with an anteromedial delicate umbelliform membrane supported by two processes; (iii) hooks with upright blunt thumb and uniform shank; (iv) a vaginal aperture dextrolateral; (v) a subquadrangular haptor, with inconspicuous lateral flaps and lacking haptoral reservoirs; and (vi) eye-spot or chromatic granules absent. Pronotogrammella boegeri n. sp. is characterised by its crosier-shaped MCO having a clockwise coil at distal end and by its dorsal bar with a straight anteromedial processes. Pronotogrammella scholzi n. sp. is typified by possessing of a dorsal bar with the anteromedial processes like cow horns, hoof-shaped deep roots of the dorsal anchors and a broader shaft of the MCO. Pronotogrammella multifasciatus n. sp. differs from all congeners by having a tubular MCO with twisted shaft and a base with a short and broad arm and by having an almost dumbbell-shaped ventral bar.

     

Neotropical Monogenoidea. 46. Three new species from the gills of introduced aquarium fishes in India,the proposal of Heterotylus n. g. and Diaphorocleidus n. g., and the reassignment of some previously described species of Urocleidoides Mizelle & Price, 1964 (Polyonchoinea: Dactylogyridae)

Three new species of the Dactylogyridae are described from aquarium fishes collected in India and two new genera are proposed: Heterotylus heterotylus n. g., n. sp. from Hypostomus sp. (Loricariidae), Diaphorocleidus armillatus n. g., n. sp. from Gymnocorymbus ternetzi (Characidae) and Urocleidoides vaginoclaustrum n. sp. from Xiphophorus helleri (Poeciliidae). Heterotylus n. g. is characterised by species having overlapping gonads (testis posterodorsal to the ovary), a mid-ventral vaginal aperture, a copulatory complex consisting of a relatively straight copulatory organ unarticulated to a complex accessory piece, erect acute hook thumbs, unexpanded hook shanks, dorsal and ventral anchor/bar complexes and absence of well-defined basal roots of the ventral anchors. Diaphorocleidus n. g. includes species with overlapping gonads (testis posterodorsal to the ovary), submarginal sinistral vaginal pore, a copulatory complex comprising a coiled (counterclockwise) copulatory organ unarticulated to an accessory piece, protruding depressed hook thumb, hook shank with two subunits (proximal subunit expanded), dorsal and ventral anchor/bar complexes and V-shaped bars. The following new combinations are proposed: D. affinis (Mizelle, Kritsky & Crane, 1968) n. comb. (syn. U. affinis Mizelle, Kritsky & Crane, 1968), D. kabatai (Molnar, Hanek & Fernando, 1974) n. comb. (syn. U. kabatai Molnar, Hanek & Fernando, 1974) and D. microstomus (Mizelle, Kritsky & Crane, 1968) n. comb. (syn. U. microstomus Mizelle, Kritsky & Crane, 1968).     

<Emphasis Type="Italic">Empruthotrema longipenis</Emphasis> n. sp. (Monogenoidea: Monocotylidae: Merizocotylinae) from the olfactory sacs of the smooth butterfly ray <Emphasis Type="Italic">Gymnura micrura</Emphasis> (Bloch &amp; 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.     

Two new species of Haliotrema (Monogenoidea: Dactylogyridae) from Cirrhitus rivulatus (Perciformes: Cirrhitidae) from the Pacific coast of Mexico

During surveys of helminth parasites of marine fishes from the Pacific coast of the Guerrero State in Mexico, 2 undescribed species of Haliotrema Johnston and Tiegs, 1922 (sensu Young, 1968) (Dactylogyridae) were found infecting the gills of the giant hawkfish Cirrhitus rivulatus Valenciennes, 1846 (Perciformes, Cirrhitidae), i.e., Haliotrema cirrhitusi n. sp. and Haliotrema pollexinus n. sp. The new species are similar with respect to the morphology of the anchors with base-shaft junction crazed, hinged, or both; dorsal anchors with an elongate superficial root; a tubular male copulatory organ (MCO) with a cylinder-shaped base diagonally opening; and a membranous accessory piece, shaped like a vane, encircling MCO to form 2 complete spirals from the anterior margin of base to the terminal portion of the MCO. While H. cirrhitusi and H. pollexinus differ from all other species of the genus in the general morphology of the copulatory complex, only H. pollexinus notably differs from all these species in having a superficial, blade-like projection from the inner surface on the distal shaft of anchors. Haliotrema cirrhitusi and H. pollexinus are the only members of the genus recorded in the Mexican Pacific and from a cirrhitid host.     

Monogenea of Chinese marine fishes. VII. A new species and two new records of the Tetraonchoididae from fishes of the South China and East China Seas

This paper reports a new species and two new records of the Tetraonchoididae collected from fishes of the South China and East China Seas. Pseudotetraonchoides halichoeres n. sp. was obtained from the gills of Halichoeres poecilopterus collected at Dongshan (23°42' N, 117°24' E). The new species is similar to P. bleekeriae Bychowsky, Gussev & Nagibina, 1965 in the structure of the haptor, but differs in the sizes of the hamuli, the transverse bar and the supplementary plate, and also in details of the supplementary plate. Both Heteropavlovskioides synodontis Machida, 1978 from Trachinocephalus myops and Tetraonchoides japonicus Bychowsky, 1951 from Uranoscopus japonicus are recorded for the first time off China.     

A phylogenetic analysis and revised classification of the Monocotylidae Taschenberg, 1879 (Monogenea)

The Monocotylidae Taschenberg, 1879 is revised based on a cladistic analysis of relationships between the constituent species and genera. The monophyly of the family is supported by three apomorphic character states: division of the haptor into one central and eight peripheral loculi; the ovary looping the right intestinal caecum; and tetrahedral eggs. The family is divided into six subfamilies: Calicotylinae Monticelli, 1903 (comprising Calicotyle Diesing, 1850, Dictyocotyle Nybelin, 1941); Dasybatotreminae Bychowsky, 1957 (comprising Anoplocotyloides Young, 1967, Dasybatotrema Price, 1938, Timofeevia n. g., Troglocephalus Young, 1967); Decacotylinae n. subfam. (comprising Decacotyle Young, 1967, Papillicotyle Young, 1967); Heterocotylinae n. subfam. (comprising Heterocotyle Scott, 1904, Neoheterocotyle Hargis, 1955, Nonacotyle Ogawa, 1991, Potamotrygonocotyle Mayes, Brooks & Thorson, 1981, Spinuris Doran, 1953); Merizocotylinae Johnston & Tiegs, 1922 (comprising Cathariotrema Johnston & Tiegs, 1922, Empruthotrema Johnston & Tiegs, 1922, Merizocotyle Cerfontaine, 1894, Squalotrema Kearn & Green, 1983, Triloculotrema Kearn, 1993); and Monocotylinae Taschenberg, 1879 (comprising Clemacotyle Young, 1967, Dendromonocotyle Hargis, 1955, Monocotyle Taschenberg, 1878). The Dendromonocotylinae Hargis, 1955 is removed from subfamilial status and the two genera previously assigned to the subfamily are reassigned to the Monocotylinae. Timofeevia is proposed for Timofeevia rajae (Timofeeva, 1983) n. comb. (formerly Dasybatotrema rajae). Mycteronastes Kearn & Beverley-Burton, 1990 and Thaumatocotyle Scott, 1904 are synonymised with Merizocotyle. Gymnocalicotyle Nybelin, 1941 is not considered a distinct taxon. Revised diagnoses and keys for subfamilies and genera of the Monocotylidae are provided.     

Two new species of Anchylodiscus Johnston & Tiegs, 1922 (Monogenea) from Plotosus canius (Plotosidae)

Two new species of Anchylodiscus Johnston & Tiegs, 1922, A. malayensis n. sp. and A. liewi n. sp., were obtained from the gills and the dendritic (or arborescent) organ of Plotosus canius, respectively. The two new species have two seminal vesicles; the seminal vesicle nearer the testis is a distension of the vas deferens, while the distal one is similar to the blind seminal vesicle of the majority of freshwater ancylodiscoidines. The blind seminal vesicle suggests that Anchylodiscus should be placed in the subfamily Ancylodiscoidinae.     

Neotropical Monogenoidea. 33. Three new species of Ancistrohaptor n. g. (Dactylogyridae,Ancyrocephalinae) on Triportheus spp. (Teleostei,Characidae) from Brazil,with checklists of ancyrocephalines recorded from neotropical characiform fishes

Three new species of Ancistrohaptor n. g. are described from the gills of three species of Triportheus (Characidae) collected from the environs of Manaus, Amazonas, Brazil: A. falcatum n. sp. from T. elongatus; and A. falciferum n. sp. and A. falcunculum n. sp. from T. angulatus, T. albus and T. elongatus. Ancistrohaptor n. g. is proposed for species possessing overlapping gonads, a dextral or dextroventral vaginal aperture, a coiled (counter-clockwise) male copulatory organ, two accessory pieces in the copulatory complex, and a haptor armed with two pairs of anchors (ventral anchor with elongate shaft), dorsal and ventral bars and 14 hooks; hook pair 1 (ventral) anterior to ventral bar, pairs 2–4 (ventral) lying bilaterally anterior to ventral anchor bases, pair 5 (ventral) associated with distal end of ventral anchor shafts, and pairs 6 and 7 (dorsal) bilateral about midway along haptoral length. Parasite-host and host-parasite lists of the Ancyrocephalinae from neotropical Characiformes are provided.     

Eight new species ofHamatopeduncularia Yamaguti, 1953 (Monogenea: Ancyrocephalidae) from Ariidae of Peninsular Malaysia

Eleven species of Hamatopeduncularia Yamaguti, 1953 were found on six species of ariids caught off the west coast of Peninsular Malaysia. They are: H. arii Yamaguti, 1953 from Arius maculatus; H. thalassini Bychowsky & Nagibina, 1969 from A. thalassinus; H. simplex Bychowsky & Nagibina, 1969 from Osteogeneiosus militaris; H. isosimplex n. sp. from A. venosus, A. maculatus and A. sagor; H. malayanus n. sp. from A. caelatus; H. manjungi n. sp. from A. thalassinus; H. papernai n. sp. from A. maculatus; H. elongatum n. sp. from A. thalassinus; H. longicopulatrix n. sp. from A. venosus; H. venosus n. sp. from A. venosus; and H. malaccensis n. sp. from O. militaris and A. maculatus.     

Bucephaline digeneans (Bucephalidae) in <Emphasis Type="Italic">Sphyraena putnamae</Emphasis> Jordan &; Seale (Sphyraenidae) from the lagoon off New Caledonia

Lethrinitrema gibbus n. g., n. sp. and L. dossenus n. sp. are described from the fish Lethrinus rubrioperculatus Sato collected off New Caledonia, South Pacific. Members of Lethrinitrema n. g. (Ancyrocephalidae) are characterised by having two pyriform haptoral reservoirs and ventral anchors with lateral grooves. The elongate tubular distal end of each reservoir bifurcates, draining into a superficial lateral groove on each side of the ventral anchors. The haptoral reservoirs are postulated to store secretory products which assist in attachment to the host. Lethrinitrema spp. also possess tandem gonads, a male copulatory organ without an accessory piece or with thinly sclerotised accessory piece, and a dextrolateral, non-sclerotised vaginal bulb. The two new species have small, poorly demarcated haptors with small haptoral armament and a crown-like piece on the tip of the inner root of the ventral anchors. They differ from each other in the shape and size of the ventral bar and male copulatory organ (40–45 μm in length in L. gibbus vs 24–30 μm in L. dossenus). Three other species, previously included in Haliotrema Johnston & Tiegs, 1922, are transferred to Lethrinitrema, i.e. L. chrysostomi (Young, 1968) n. comb., L. fleti (Young, 1968) n. comb. (both briefly redescribed from paratypes) and L. lethrini (Yamaguti, 1937) n. comb. All species of Lethrinitrema parasitise Lethrinus spp. (Lethrinidae), and there is evidence for the existence of further Lethrinitrema spp. on Lethrinus spp. in the Indo-Pacific region.     

Two new species of Cryptocephalum n. gen. (Monogenoidea: Dactylogyridae) from the cephalic lateral line of Percichthys trucha (Perciformes: Percichthyidae) in Patagonia, Argentina

Two new species of Monogenoidea were found parasitizing the cephalic lateral line canals of Percichthys trucha (Valenciennes) (Perciformes: Percichthyidae). These species are described as members of a newly proposed genus of Dactylogyridae. Cryptocephalum n. gen. is characterized by the site of infection and the combination of the several features: ventral and dorsal anchor/bar complexes, anchors with strongly elongated shaft and recurved point, shaft and point of dorsal anchors protruding laterally from haptor, hooks with 2 subunits and with pair 5 smaller than the others; gonads overlapping; coiled male copulatory organ with counterclockwise rings, accessory piece formed by 2 distinct parts, and a tubular, sclerotized ventral vagina. C ryptocephalum petreum n. sp. is characterized by having both anchor pairs protruding laterally from haptor, male copulatory organ with a coil of 2-1/2 rings, accessory piece tweezers-shaped, and sclerotized vaginal vestibule. Cryptocephalum spiralis n. sp. has ventral anchors protruding ventrally and dorsal ones protruding laterally, male copulatory organ with a coil of 1-1/2 rings, the antero-dorsal part of the accessory piece saddle-shaped, vaginal vestibule not present, and coiled vagina. This is the first record of Dactylogyridae species parasitizing the cephalic lateral line of fishes.     

The status of Acleotrema Johnston & Tiegs, 1922 and Heteroplectanum Rakotofiringa, Oliver & Lambert, 1987 (Monogenoidea: Diplectanidae), with the redescription of Acleotrema girellae Johnston & Tiegs, 1922

Acleotrema Johnston & Tiegs, 1922 is resurrected and its diagnosis amended. A. girellae Johnston & Tiegs, 1922 is redescribed based on the lectotype from the Australian Museum (Sydney, Australia). A. kyphosi Yamaguti, 1968 is considered a junior synonym of A. girellae. Heteroplectanum Rakotofiringa, Oliver & Lambert, 1987 is considered a junior synonym of Acleotrema. The nine species of the latter genus are transferred to Acleotrema as: A. diplobulbus (Yamaguti, 1968) n. comb., A. nenue (Yamaguti, 1968) n. comb., A. spiculare (Yamaguti, 1968) n. comb., A. yamagutii (Oliver, 1983) n. comb., A. nenuoides (Rakotofiringa, Oliver & Lambert, 1987) n. comb., A. parastromatei (Rakotofiringa, Oliver & Lambert, 1987) n. comb., A. serrulopenis (Rakotofiringa, Oliver & Lambert, 1987) n. comb., A. tamatavense (Rakotofiringa, Oliver & Lambert, 1987) n. comb. and A. oliveri (León-Règagnon, Pérez-Ponce de León & Garcia- Prieto, 1997) n. comb. An historical account of the species of Acleotrema is presented.     

海南岛海水鱼类寄生海盘虫属一新种及两新纪录(单殖亚纲,锚首虫科)

首次报道了南海镰鱼Zandus cormdus（Linbacus）（采自海南岛三亚市）鳃上寄生单殖吸虫,锚首虫科Anctyrocephalidae Bychowsky ＆ Nagibina 1978,海盘虫属Haliotrema Johnston ＆ Tiegs,1922中的1新种及2新纪录种。而且,镰鱼为管阴海盘虫H．tubulovagina Yamaguti,1968和丹姆斯特海盘虫H．dempsteri（Mizele ＆ Price,1964）Young,1968的宿主新记录。文中量度微米（μm）,模式标本保存于湖南文理学院生命科学系。镰茎海盘虫,新种Haliotrema sichlocirrus sp.nov（图1～5） 宿主：镰鱼Zandus cormudus（Linnacus）。 寄生部位：鳃丝。海南三亚,2004-03—16。 比较小型的锚首虫,虫体长337～405,宽67～80。背中央大钩全长35～37,钩基长29—31,钩尖长7～10,内突长11～14,外突长4～5;腹中央大钩全长35～37,钩基长30～33,钩尖长9～12,内突长8～10,外突长3～5。背联结片中部较平直,亚中部向前稍隆起,两端向后微弯,大小（5～6）×（60～66）;腹联结片呈弧形弯曲,两端较中部宽阔,大小（6～8）×（55～63）。交接器由阴茎、基座和支持器组成。阴茎呈短管状、较直,管长19～22,基径7～11;基部有一钟形基座,高10～13,底径10～13;支持器长45～53（据弯度）,基端呈细条状,宽约2,近基端弯折,远端一侧呈膜状增宽,似镰刀状。阴道弯管状,长30～35;受精囊大小25×15。 新种在后吸器和交接器的形态构造上与寄生于两种蝴蝶鱼Chaetodon miliaris（模式宿主）、C．multicinctus的杯阴海盘虫H．scyphovagina Yamzguti,1968近似。但二者的支持器不同,已知种的支持器为一鞭状细丝,新种则为一较长而弯折的细条状,且远端一侧呈膜状增宽,似镰刀状。     

A revised diagnosis of Thylacicleidus (Monogenea: Dactylogyridae) with a redescription of the type species, Thylacicleidus serendipitus, and descriptions of two new species from Southeast Asian pufferfishes (Tetraodontiformes: Tetraodontidae)

Two new and 1 previously described species of Thylacicleidus Wheeler and Klassen, 1988, are reported from 2 species of brackish to freshwater puffers (Tetraodontidae) from Thailand. The generic diagnosis of Thylacicleidus is emended to incorporate the following characters: presence of a dextral muscular vagina, a vas deferens looping the left intestinal cecum, 2 prostatic reservoirs, a sclerotized tubular copulum without an accessory piece, and dorsal anchors with reduced outer root. The type species, Thylacicleidus serendipitus, is redescribed based on new information obtained from specimens found on the gills of the type host, Tetraodon nigroviridis Marion de Procé, 1822 (spotted green puffer). Two new species, Thylacicleidus latus n. sp. and Thylacicleidus brunensis n. sp., are described from the gills of T. nigroviridis and Tetraodon biocellatus Tirant, 1885 (eyespot puffer), respectively. The occurrence of common generic characters in species of Thylacicleidus and Haliotrema Johnston and Tiegs, 1922, another dactylogyrid genus recorded from tetraodontiform hosts, signifies the close relationship between the 2 genera and raises the question of synonymy. Nevertheless, because of morphological variability within Haliotrema spp., extremely wide host spectrum and the probable polyphyly of the genus, it is suggested that Thylacicleidus is a valid genus.     

Four new species of dactylogyrids (Monogenea: Dactylogyridae) parasitic on gills of labrid and sparid fishes from Southeastern Pacific Ocean off Peru

During a research on gill ectoparasites of Peruvian marine fishes, four dactylogyrid (Monogenea) species, parasitising two teleost species, Bodianus diplotaenia (Gill) (Labridae) and Calamus brachysomus (Lockington) (Sparidae), were found. Euryhaliotrema luisae n. sp. ex C. brachysomus is differentiated from other congeneric species by the morphology of the male copulatory organ, which comprises a coil of nine counterclockwise rings, and by the morphology of the anchors and bars. Euryhaliotrema magnopharyngis n. sp. ex C. brachysomus can be distinguished from all other congeners by having a well-developed pharynx occupying much of the anterior region and by the ventral bar, which is V-shaped, with well-elongated, thin arms. In addition, E. luisae n. sp. and E. magnopharyngis n. sp. can be differentiated from all other members of Euryhaliotrema Kritsky & Boeger, 2002 by the presence of a glandular oval plate lying on peduncle. Haliotrema diplotaenia n. sp. ex B. diplotaenia is characterised by the structure of the male copulatory organ, comprising a tapered-shaped cirrus tube with twisted acute tip and a filament-shaped accessory piece with medial and distal expansions, and by the morphology of the ventral bar (inverted W-shaped, with short lateral ends and two anterior conical protuberances). Haliotrema saezae n. sp. ex B. diplotaenia differs from all other members of Haliotrema Johnston & Tiegs, 1922 by having a tubular copulatory organ with curved distal tip and a filament-shaped accessory piece without lateral expansions, and by the morphology of anchors and bars. The present findings are added to the other six marine dactylogyrids previously reported from Peru.