Cardicola opisthorchis n. sp. (Trematoda: Aporocotylidae) from the Pacific bluefin tuna, Thunnus orientalis (Temminck & Schlegel, 1844), cultured in Japan

A new aporocotylid blood fluke is described, based on specimens from the ventricle of the Pacific bluefin tuna, Thunnus orientalis (Temminck et Schlegel), cultured in Wakayama and Nagasaki Prefectures, Japan. The new species is morphologically similar to the members of the genus Cardicola Short, 1953, but shows distinct differences in the body form, location of the testis and the orientation of the ootype. The body of the new species is long and slender, whereas other Cardicola species are small and generally lanceolate. The testis is mostly located posterior to the caeca and anterior to the ovary, occupying 31–45% of body length, in contrast to the known Cardicola species, whose testis is typically intercaecal. The ootype is oriented anteriorly, while in most congeners, it is directed posteriorly or horizontally. Phylogenetic analyses of this aporocotylid, together with Cardicola orientalis Ogawa, Tanaka, Sugihara et Takami, 2010 from the same host, were conducted based on DNA sequences of the ITS2 rDNA and the 28S region of ribosomal RNA. The analyses revealed that the new blood fluke belongs to the genus Cardicola despite the marked morphological differences. Thus, this aporocotylid is named Cardicola opisthorchis n. sp. and the generic diagnosis is emended in this paper. In addition, 100% identity among the ITS2 sequences from the present species, Cardicola sp. from T. orientalis in Mexico and Cardicola sp. from the northern bluefin tuna, Thunnus thynnus (Linnaeus) in Spain suggests that C. opisthorchis n. sp. has a broad geographical distribution and that it infects both the Pacific and northern bluefin tuna.     

Cardicola aurata sp. n. (Digenea: Sanguinicolidae) from Mediterranean Sparus aurata L. (Teleostei: Sparidae) and its unexpected phylogenetic relationship with Paradeontacylix McIntosh, 1934

A new sanguinicolid trematode, Cardicola aurata sp. n., is described from gilthead seabream Sparus aurata L., from off the Spanish Mediterranean coast. The morphology of C. aurata sp. n. generally agrees with the diagnosis of the genus, however, in contrast to all other reported Cardicola spp. the male pore is located sub-medially at the posterior end of the body instead of sinistrally before the posterior end of the body. Based on a comparison of the morphology as well as partial 28S and ITS2 rDNA sequence data from the present species with that from closely related species, it was decided to emend the diagnosis of Cardicola rather than create a new genus, as the aberrant position of the male pore is likely to be an autapomorphy. The phylogenetic analyses revealed a close relationship between Cardicola and Paradeontacylix, two genera with considerable morphological differences; C. aurata sp. n. occupies a position intermediate to these genera. Thus, a morphological comparison of Cardicola, Paradeontacylix and Braya, a genus which is morphologically similar to Cardicola but clusters basal to the Cardicola/Paradeontacylix clade, was conducted. The results of this comparison showed that despite large differences with regard to body shape, the organisation of the internal organs is very similar in species of Cardicola and Paradeontacylix. The synopsis of morphological data and molecular phylogeny allows for interpretations regarding the importance of different morphological features for the phylogenetic inference of the Sanguinicolidae.     

<Emphasis Type="Italic">Sanguinicola maritimus</Emphasis> n. sp. (Digenea: Sanguinicolidae) from Labridae (Teleostei: Perciformes) of southern Australian waters

A new species of Sanguinicola Plehn, 1905 is described from the marine teleosts Notolabrus parilus (Richardson) and N. tetricus (Richardson) (Perciformes: Labridae) from Western Australian and Tasmanian waters. This host distribution is strikingly anomalous; however, the present material fulfils the morphological criteria of Sanguinicola. S. maritimus n. sp. differs from previously described species in having the combination of a body 1,432–1,701 μm long, the oesophagus 18.3–21.7% of the body length, the testis occupying 42.8–52.3% of the body length, an oviducal seminal receptacle and Mehlis’ gland present, ovoid eggs, and vitelline follicles that extend anteriorly past the nerve commissure, laterally past the lateral nerve chords and posteriorly to the anterior margin of the cirrus-sac. S. maritimus also lacks a protrusible anterior proboscis. It also differs in the combination of host and geographical location, being the first Sanguinicola species from a marine teleost and the first from Australian waters.     

Benedenia rohdei n. sp. (Monogenea: Capsalidae) from the gills of Lutjanus carponotatus (Perciformes: Lutjanidae) from the Great Barrier Reef,Queensland, Australia,with a description of the oncomiracidium

A benedeniine monogenean, Benedenia rohdei n. sp., is reported from the gills of the stripey Lutjanus carponotatus (Richardson, 1842) (Lutjanidae) from Heron Island and Lizard Island, Queensland, Australia. The oncomiracidium of the new species is also illustrated. B. rohdei n. sp. differs from all known species of the genus in the possession of a sclerite at the tip of the penis. Examination of type-specimens of B. jaliscana Bravo-Hollis, 1952 has shown that the three penis ‘hooks’ described by Bravo-Hollis are unsclerotised conical papillae.     

A re-evaluation of diversity of the Aporocotylidae Odhner, 1912 in <Emphasis Type="Italic">Siganus fuscescens</Emphasis> (Houttuyn) (Perciformes: Siganidae) and associated species

The aporocotylid fauna of the mottled spinefoot, Siganus fuscescens (Houttuyn), from Moreton Bay, Queensland, Australia, was characterised using a combined morphological and molecular approach. Four aporocotylid species were identified, three belonging to the genus Ankistromeces Nolan & Cribb, 2006 and one to Cardicola Short, 1953. Specimens of Cardicola matched an undescribed species from the same host and locality; this species is described as Cardicola mogilae n. sp. Phylogenetic analyses of ITS2 and 28S data showed that C. mogilae n. sp. forms a strongly supported clade with other Cardicola species from siganid fishes. We record Ankistromeces olsoni Nolan & Cribb, 2006 in Moreton Bay for the first time, redescribe A. dunwichensis Nolan & Cribb, 2006 on the basis of new specimens and sequence data and re-report Ankistromeces sp. X from Moreton Bay based on molecular data. We review the status of the ten putative species of aporocotylids reported from siganids. Small variation in ITS2 rDNA sequences, in association with different geographic localities, was previously used to separate Cardicola lafii Nolan & Cribb, 2006 from C. parilus Nolan & Cribb, 2006, C. bartolii Nolan & Cribb, 2006 from C. watsonensis Nolan & Cribb, 2006, C. tantabiddii Nolan & Cribb, 2006 from Cardicola sp. 2, Ankistromeces sp. Y from A. olsoni and Ankistromeces sp. X from Ankistromeces sp. Z. These five combinations are reinterpreted as each representing a single species; Cardicola lafii is recognised as the senior synonym of C. parilus and C. bartolii as the senior synonym of C. watsonensis. This study thus suggests that six, rather than ten, species should be recognised as infecting S. fuscescens. This richness remains greater than is known for any other fish species and siganids are, so far, unique among fishes in harbouring two strongly radiated lineages of aporocotylids.     

Review of the genus Eutetrarhynchus Pintner, 1913 (Trypanorhyncha: Eutetrarhynchidae), with the description of Eutetrarhynchus beveridgei n. sp.

The genus Eutetrarhynchus Pintner, 1913 is revised. Eutetrarhynchus beveridgei n. sp. is described from the spiral intestine of the dwarf whipray, Himantura walga (Müller & Henle) (Myliobatiformes: Dasyatidae), from the South China Sea off the Malaysian part of Borneo. The new species is characterised by a slender, elongate scolex, two oval bothria, muscular bulbs, retractor muscles inserting at the base of the bulbs, and the presence of gland-cells and prebulbar organs. The tentacular armature is typical heteroacanthous with heteromorphous hooks. Eutetrarhynchus beveridgei n. sp. is allocated to the genus due to its distinct segment morphology featuring two internal seminal vesicles and scattered testes occupying the complete intervascular space. It differs from congeners in its relatively small size, much smaller scolex regions and in the presence of a basal armature with a distinct basal swelling. Eutetrarhynchus cortezensis Friggens & Duszynski, 2005 is transferred to Dollfusiella Campbell & Beveridge, 1994, as D. cortezensis n. comb., on the basis of its segment morphology, with testes in a linear arrangement and the absence of internal seminal vesicles. A new generic diagnosis and a key for the identification of species of Eutetrarhynchus is provided.     

Longidorus grandis n. sp. and L. paralongicaudatus n. sp. (Nematoda: Longidoridae), Two Parthenogenetic Species from Arkansas

Two new parthenogenetic species of Longidorus were found in Arkansas. Longidorus grandis n. sp. is characterized by its body (5.80-8.24 mm), slightly offset head, head width 20-27 µm, odontostyle 86-100 µm, guide ring 26-35 µm posterior to the anterior end, short conoid to mammiliform tail. Longidorus grandis n. sp. is similar to L. vineacola Sturhan &Weischer, 1964; L. lusitanicus Macara, 1985; L. edmundsi Hunt &Siddiqi, 1977; L. kuiperi Brinkman, Loof &Barbez, 1987; L. balticus Brzeski, Peneva &Brown, 2000; L. closelongatus Stoyanov, 1964; and L. seinhorsti Peneva, Loof &Brown, 1998. Longidorus paralongicaudatus n. sp. is characterized by its body length (2.60-5.00 µm), anteriorly flattened and offset head region 13-18 µm wide, odontostyle length 92-127 µm, guide ring 21-30 µm posterior to the anterior end, tail elongate-conical, and c'' = 1.2-2.6. Longidorus paralongicaudatus n. sp. most closely resembles L. longicaudatus Siddiqi, 1962; L. socialis Singh &Khan, 1996; L. juvenilis Dalmasso, 1969; and L. curvatus Khan, 1986.     

Steinernema brazilense n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode from Mato Grosso, Brazil

A new entomopathogenic nematode, Steinernema brazilense n. sp., was isolated from a single soil sample collected from a natural forest in Mato Grosso do Sul state, Brazil. S. brazilense n. sp. is characterized morphologically by features of infective juveniles (IJ), males and females. For the IJ, body length averaging 1157 (1023-1284) μm, distance from anterior end to excretory pore 95 (87-102) μm, from anterior end to end of esophagus 148 (139-153) μm, tail length 85 (80-104) μm, D% and E% values 63 (58-70) and 106 (95-118.0), respectively. Lateral field pattern variable; the formula for the arrangement of ridges from head to tail is: 2, 4, 6, 8, 6, 2. For the male, the diagnostic characters include spicule averaging 83 (75-89) μm; D% about 65; the ratio SW% about 192. The length of spicule head is greater than width. Lateral field with one narrow ridge. First generation females are characterized by the presence of a ventral postanal swelling. S. brazilense n. sp. is morphologically close to Steinernema diaprepesi. It can be differentiated from S.diaprepesi by its longer IJ body length (1157 vs 1002 μm), longer distance from anterior end to excretory pore (110 vs 75 μm), a longer tail length (103 vs 83 μm); males of the new species with longer spicule (83 vs 79 μm). The new species can be distinguished further from other members of Steinernema glaseri group by characteristics of rDNA of ITS and D2D3 regions.     

New collections of blood flukes (Aporocotylidae) from fishes of the tropical Indo-west Pacific,including a new genus,two new species and molecular evidence that Elaphrobates chaetodontis (Yamaguti, 1970) is widespread in the region

We report new collections of the Aporocotylidae from Australia, French Polynesia, and Japan. A new species of Cardicola Short, 1953 is described from Scomberomorus commerson (Lacépède) (Scombridae), off Lizard Island. Cardicola nolani n. sp. can be distinguished from its congeners based on the position of the oötype, the position of the male genital pore, and the absence of an oral sucker. A new species is described from Abalistes stellatus (Anonymous) (Balistidae), also from off Lizard Island. Phylogenetically the new species forms a strongly-supported clade with Cardicola yuelao Yong, Cutmore & Cribb, 2018, which also infects balistids. These two species are distinct from all other aporocotylids in the combination of exceptionally short anterior and long posterior caeca, a lanceolate body, a single testis, an entirely post-ovarian uterus and the position of the oötype; a new genus, Balistidicola, is proposed for them. Balistidicola corneri n. sp. and B. yuelao (Yong, Cutmore & Cribb, 2018) n. comb. are essentially morphologically cryptic, only distinguishable by the form of the spination (B. corneri has five spines per row and B. yuelao has six). Elaphrobates chaetodontis (Yamaguti, 1970) is reported from 21 species of butterflyfishes (Chaetodontidae) from nine locations in tropical Indo-west Pacific; cox1 sequence data demonstrate extensive geographical structuring in this species. Braya jexi Nolan & Cribb, 2006, Elaphrobates milleri (Nolan & Cribb, 2006), and P. corventum Overstreet & Køie, 1989 are each re-reported from their type-hosts, and Pearsonellum pygmaeus Nolan & Cribb, 2004 and Balistidicola yuelao are each reported from a new host.     

Heterodera raskii n. sp. (Heteroderidae: Tylenchina), a Cyst Nematode on Grass, from Hyderabad,India

Heterodera raskii n. sp. is described and illustrated from specimens collected from roots of bulb grass, Cyperus bulbosus, in Hyderabad, India. The new species belongs to the ''goettingiana'' group and differs from closely related H. cyperi by the elongate ovoid shaped cysts and females, greater fenestral length, width, vulval slit, and absence of egg sac. The stylet knob shape was round in second-stage juveniles and posteriorly sloping in females and males of H. raskii n. sp., while it was anteriorly directed in second-stage juveniles and spherical in females and males of H. cyperi.     

Morphological and Molecular Characterization of Longidorus americanum n. sp. (Nematoda: Longidoridae), a Needle Nematode Parasitizing Pine in Georgia

We describe and illustrate a new needle nematode, Longidorus americanum n. sp., associated with patches of severely stunted and chlorotic loblolly pine, (Pinus taeda L.) seedlings in seedbeds at the Flint River Nursery (Byromville, GA). It is characterized by having females with a body length of 5.4-9.0 mm; lip region slightly swollen, anteriorly flattened, giving the anterior end a truncate appearance; long odontostyle (124-165 µm); vulva at 44%-52% of body length; and tail conoid, bluntly rounded to almost hemispherical. Males are rare but present, and in general shorter than females. The new species is morphologically similar to L. biformis, L. paravineacola, L. saginus, and L. tarjani but differs from these species either by the body, odontostyle and total stylet length, or by head and tail shape. Sequence data from the D2-D3 region of the 28S rDNA distinguishes this new species from other Longidorus species. Phylogenetic relationships of Longidorus americanum n. sp. with other longidorids based on analysis of this DNA fragment are presented. Additional information regarding the distribution of this species within the region is required.     

Helicotylenchus oleae n. sp. and H. neopaxilli n. sp. (Hoplolaimidae), Two New Spiral Nematodes Parasitic on Olive Trees in Italy

Helicotylenchus oleae n. sp. and H. neopaxilli n. sp., from olive roots and soil in Italy, are described and illustrated. Helicotylenchus oleae can be distinguished from the related species H. canadensis and H. tunisiensis especially by the smaller styler, its distinctive tail shape, and a tail longer than one anal body width. Helicotylenchus neopaxilli differs from the close species H. paxilli by having a conical, anteriorly truncated labial region, shorter stylet, and phasmids always anterior to level of anus. Also illustrated and discussed are histopathological changes within feeder roots of olive caused by the feeding activity of the semi-endoparasitic H. oleae.     

<Emphasis Type="Italic">Capillaria appendigera</Emphasis> n. sp. (Nematoda: Capillariidae) from the goldbanded jobfish <Emphasis Type="Italic">Pristipomoides multidens</Emphasis> (Day) (Lutjanidae) and new records of other intestinal capillariids from marine perciform fishes off Australia

Based on light and scanning electron microscopical studies, a new nematode parasite, Capillaria appendigera n. sp. (Capillariidae), is described from the intestine of the goldbanded jobfish Pristipomoides multidens (Day) (Perciformes, Lutjanidae) from the Arafura Sea West, off the northern coast of Australia. The new species, belonging to the subgenus Procapillaria Moravec, 1987, differs from other congeneric species from fishes mainly in the length (0.92–1.13 mm), shape and structure of the spicule, obtuse spines on the spicule sheath and the structure of eggs. It is characterised, in the male, by the presence of two well-developed dorsolateral caudal lobes, a pair of lateral papillae, a heavily sclerotised spicule with many rough transverse grooves covering almost the entice spicule surface (except for spicule ends), a spinose spicule sheath, and in the female, by a subterminal anus, mostly the presence of a large vulval appendage and by eggs (size 54–69 × 27–33 µm) encapsulated by a conspicuous light-coloured superficial layer. Capillaria appendigera n. sp. is the 12th nominal species of capillariids recorded from fishes in Australian waters and the second known capillariid species parasitising fishes of the perciform family Lutjanidae. In addition, four unidentifiable, morphologically different types of capillariid females, probably representing undescribed species, were recorded from the intestines of marine fishes off the northern coast of Australia: Capillariidae gen. sp. 1 and Capillariidae gen. sp. 2 from Lutjanus johnii (Bloch) and L. malabaricus (Bloch & Schneider), respectively (both Lutjanidae), Capillariidae gen. sp. 3 from Protonibea diacanthus (Lacépède) (Sciaenidae) and Capillariidae gen. sp. 4 from Rachycentron canadum (Linnaeus) (Rachycentridae).     

Steinernema biddulphi n. sp., a New Entomopathogenic Nematode (Nematoda: Steinernematidae) from South Africa

A new species of entomopathogenic nematode (EPN), Steinernema biddulphi n. sp., was isolated from a maize field in Senekal, Free State Province of South Africa. Morphological and molecular studies indicated the distinctness of S. biddulphi n. sp. from other Steinernema species. Steinernema biddulphi n. sp. is characterized IJs with average body length of 663 μm (606–778 μm), lateral fields with six ridges in mid-body region forming the formula 2,6,2. Excretory pore located anterior to mid-pharynx (D% = 46). Hyaline layer occupies approximately half of tail length. Male spicules slightly to moderately curved, with a sharp tip and golden brown in color. The first generation of males lacking a mucron on the tail tip while the second generation males with a short filamentous mucron. Genital papillae with 11 pairs and one unpaired preanal papilla. The new species is further characterized by sequences of the internal transcribed spacer (ITS) and partial 28S regions (D2-D3) of the ribosomal DNA (rDNA). Phylogenetic data show that S. biddulphi n. sp. belongs to the “bicornutum” clade within the Steinernematidae family.     

New species of Cardicola (Digenea: Aporocotylidae) from heart of Atlantic croaker, Micropogonias undulatus (Perciformes: Sciaenidae), of the South Atlantic Bight

Cardicola parvus n. sp. (Digenea: Aporocotylidae) infects the heart of Atlantic croaker, Micropogonias undulatus (Linnaeus, 1766) (Perciformes: Sciaenidae), in the South Atlantic Bight off Cow Island (34°38'49″N, 76°33'41″W, type locality) and Figure Eight Island (34°15'48″N, 77°44'27″W), North Carolina, USA, and off Jacksonville Beach (30°08'23″N, 81°20'52″W), Florida, USA. The new species is most easily differentiated from other members of Cardicola Short, 1953 by the combination of having a minute adult body (≤ 1 mm total length) that is 3.1-4.7× longer than wide, widely dispersed ventral tegumental sensory papillae, ~180 tegumental spine rows per side of body, a spheroid anterior sucker that is apparently aspinous, an esophagus that is 38-39% of the body total length, a male genital pore that is anterior to the ootype, a uterus that transitions from ascending to descending portions posterolaterally to the ovary, and a nearly transverse oviducal seminal receptacle. The new species is the second named aporocotylid from a littoral fish of the South Atlantic Bight and the fifth aporocotylid species reported from fishes of the northwestern Atlantic Ocean.     

Heterorhabditis atacamensis n. sp. (Nematoda: Heterorhabditidae), a new entomopathogenic nematode from the Atacama Desert, Chile

A new Heterorhabditis species of entomopathogenic nematode was isolated from soil of the Atacama Desert in Chile. The new species is characterized by morphometrics of the infective juvenile (IJ) with length (L)?=?611 (578-666)?μm, head to excretory pore length (EP)?=?115 (101-126)?μm, tail?=?69 (62-79)?μm long, (EP/tail)?×?100 (E%)?=?165 (149-182) and L/maximum body diameter (ratio a)?=?28 (25-31). The male has spicules 45 (40-49)?μm long, gubernaculum 20 (17-22)?μm long and (spicule length/anal body diameter)?×?100 (SW%)?=?205 (179-249). The hermaphroditic adult has shallow cuticular folds immediately anterior and posterior to the vulva, a slight post-anal swelling and a finely rounded tail terminus. Morphologically, H. atacamensis n. sp. resembles H. safricana, H. marelatus, H. downesi and H. amazonensis, but can be distinguished by characters of adult and IJ stages. In particular, for adult males, H. atacamensis n. sp. differs from H. amazonensis by the number and orientation of the genital papillae and from H. downesi by the position of the excretory pore; by the shape of the female tail terminus from H. downesi and by the position of the IJ hemizonid from H. marelatus. Heterorhabditis atacamensis n. sp. is further characterized by internal transcribed spacer (ITS) and D2D3 rDNA sequences, the closest species, H. safricana, being separated by 13?bp across 730?bp of the ITS (incorporating ITS1 (partial sequence), 5.8S (complete sequence), ITS2 (complete sequence)) and 5?bp across 592?bp of the partial 28S (incorporating D2D3) sequence. The morphological and molecular data confirm that H. atacamensis n. sp. is a valid species.     

Hysterothylacium simile n. sp. and H. aduncum (Rudolphi, 1802) (Nematoda: Raphidascarididae) from marine fishes in the Bohai and Yellow Sea, China, with comments on the record of H. paralichthydis (Yamaguti, 1941) from Chinese waters

Hysterothylacium simile n. sp., collected from the Japanese seabass Lateolabrax japonicus (Cuvier) (Perciformes: Lateolabracidae) in the Bohai Sea off China, is described using both light and scanning electron microscopy. The new species differs from its congeners in the presence of narrow lateral alae originating a short distance posterior to the base of the ventrolateral lips, a long intestinal caecum (60.4–79.1% of oesophageal length) and a relatively short ventricular appendix (intestinal caecum to ventricular appendix ratio 1:0.58–0.85), long spicules (2.11–2.99 mm, 4.25–7.83% of body length), the number and arrangement of the caudal papillae (32–36 pairs arranged as follows: 27–31 pairs precloacal, 1 pair paracloacal, and 4–5 pairs postcloacal with the second or third pair double) and the presence of a particular midventral precloacal papilla. Specimens originally identified as Contracaecum paralichthydis Yamaguti, 1941 [now H. paralichthydis (Yamaguti, 1941)] by Xü (1957), collected from the yellow striped flounder Pseudopleuronectes herzensteini (Jordan & Snyder) (Pleuronectiformes: Pleuronectidae) in the Yellow Sea off China, were also re-examined. Their morphology clearly revealed they belong to H. aduncum (Rudolphi, 1802), which is also redescribed based on Xü’s material. In addition, the morphological variation of caudal papillae in H. aduncum from P. herzensteini was compared, using scanning electron microscopy, with specimens collected from another three fish hosts, Lophius litulon (Jordan) (Lophiiformes: Lophiidae), Scomberomorus niphonius (Cuvier) (Perciformes: Scombridae) and Cleisthenes herzensteini (Schmidt) (Pleuronectiformes: Pleuronectidae), from the Yellow Sea off China.     

Microcotyle omanae n. sp. (Monogenea: Microcotylidae), a parasite of Cheimerius nufar (Valenciennes) (Sparidae) from the Arabian Sea

Microcotyle omanae n. sp. (Monogenea: Microcotylidae) is described from the gills of Cheimerius nufar (Valenciennes) (Sparidae) from the Arabian Sea. The new species closely resembles Microcotyle arripis Sandars, 1945, M. helotes Sandars, 1944, M. caudata Goto, 1984 and M. sebastis Goto, 1984, which have also been found in the Indo-Pacific. Microcotyle omanae n. sp. differs from M. arripis, M. helotes and M. caudata by its greater number of testes, from M. arripis, M. helotes by its greater length of the genital atrium, length/width ratio of the genital atrium and length of the eggs, and from M. helotes also in greater width of the clamps, from M. caudata and M. sebastis in its greater number of clamps and additionally from M. sebastis by its smaller genital atrial spines and clamps and by the ratio between length and width of the genital atrium. Moreover, the mature specimens of the new species have greater average body length than all above mentioned species. Correlations between 15 morphometric characters and body length are analysed in the new species, and their significance for species differentiation is discussed.