New genus and species of Aporocotylidae (Digenea) from a basal actinopterygian, the American paddlefish, Polyodon spathula, (Acipenseriformes: Polyodontidae) from the Mississippi Delta

Acipensericola petersoni n. gen., n. sp. (Digenea: Aporocotylidae) infects the heart of the American paddlefish Polyodon spathula (Walbaum, 1792) in the Mississippi Delta. It has robust, spike-like body spines arranged in ventrolateral transverse rows; a bowl-shaped anterior sucker centered on the mouth and having minute spines on the inner anteroventral surface only; a pharynx; an inverse U-shaped ceca extending to near the posterior body end; intercecal testes comprising a pre-ovarian testicular column plus a single testis posteriorly; an extensively lobed ovary located medially and immediately posterior to the testicular column; a spherical ootype that is intercecal and post-ovarian; a Laurer's canal; and a common genital pore. The new species is the first-named aporocotylid collected from a basal actinopterygian. It resembles the chondrichthyan aporocotylids Chimaerohemecus trondheimensis, Orchispirium heterovitellatum, and Hyperandrotrema cetorhini in having an inverse U-shaped ceca, but it is morphologically most similar to the anguilliform aporocotylid Paracardicoloides yamagutii in having that feature plus a comparable anterior sucker, a single testis posteriorly, an intertesticular ovary, and a common genital pore. Sequence data for the complete small subunit ribosomal DNA (18S) do not refute its membership within Aporocotylidae nor its affinity to 1 of those aforementioned aporocotylids: A. petersoni was basal to the few teleost aporocotylids analyzed, and C. trondheimensis was the only taxon basal to A. petersoni. We regard the specimens of Spirorchis sp. previously reported from the shortnose sturgeon Acipenser brevirostrum Lesueur, 1818 as congeneric with the new species.     

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.     

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.     

New genus with two new species of capsalid monogeneans from dasyatids in the Gulf of California

We propose Listrocephalos n. gen. (Monogenea: Capsalidae: Entobdellinae) for 2 new capsalid species that infect the skin of 2 species of diamond stingrays (Dasyatidae) in the Gulf of California. We also provide additional observations on 2 previously described capsalid species, which infect the external body surface of stingrays and are currently in Entobdella Blainville in Lamarck, 1818, and transfer them to the proposed new genus. The members of this genus, Listrocephalos corona (Hargis, 1955) n. comb. (type species), Listrocephalos guberleti (Caballero and Bravo-Hollis, 1962) n. comb., Listrocephalos kearni n. sp., and Listrocephalos whittingtoni n. sp., differ from other entobdellines by the combination of having an anterolateral adhesive pad comprising 2 ventral columns of raised ovoid structures, I pair of glands that flank the preoral depression, a discoid and aseptate haptor that lacks a marginal valve but has clover-shaped papillae dispersed radially over its entire ventral surface, minute and nonoverlapping median haptoral sclerites, a bizarre chamber yielding a duct that opens on the surface of the penis, separate genital pores, and a gland of Goto located between the testes and ovary. Listrocephalos kearni n. sp. infects Dasyatis brevis and is most easily distinguished from its congeners by the combination of lacking penis tubules and having a convoluted proximal portion of the vas deferens that occupies the space between the ootype and ovary. Listrocephalos whittingtoni n. sp. infects Dasyatis longa and is most easily distinguished from its congeners by the combination of having penis tubules and a vaginal pore that is located posterior to the level of the uterus. We report specimens of L. corona from the ventral body surface of Dasyatis say from a new locality, Mississippi Sound, as well as specimens of L. guberleti from the skin of 2 new hosts, Urobatis maculatus and Urobatis concentricus, and a new locality, Elkhorn Slough, California. We provide a diagnostic key and a table of records for Listrocephalos spp.     

A new species of Cardicola Short, 1953 (Digenea: Sanguinicolidae) parasitizing the Brazilian flathead, Percophis brasiliensis Quoy et Gaimard 1824, from the coasts of Mar del Plata, Argentina

Cardicola ambrosioi n. sp. (Digenea: Sanguinicolidae) is found in the blood vessels of liver and gills of the Brazilian flathead, Percophis brasiliensis Quoy and Gaimard, 1824 (Pisces: Percophidae), from Mar del Plata, Argentina. Among the 13 known species within Cardicola Short, 1953, the new species closely resembles Cardicola coridodacis Manter, 1954, from which it is distinguished by having a relatively shorter oesophagus, the vitellaria extending anteriorly to the nerve commissure, rather than to the end of anterior caeca, the female pore located closer to male pore, the latter situated medially instead of laterally and by possessing a larger Mehlis gland and a smaller seminal vesicle.     

Littorellicola billhawkinsi n. gen., n. sp. (Digenea: Aporocotylidae) from the myocardial lacunae of Florida pompano, Trachinotus carolinus (Carangidae) in the Gulf of Mexico; with a comment on the interrelationships and functional morphology of intertrabecular aporocotylids

Littorellicola billhawkinsi n. gen., n. sp. infects the myocardial lacunae of the ventricle and atrium of Florida pompano, Trachinotus carolinus in the northern Gulf of Mexico. It differs from other aporocotylid genera by the combination of having a body 10–30× longer than wide, a posterolateral body protuberance, lateral spine rows, an aspinous anterior sucker comprising a slightly muscular rim circumscribing the mouth, asymmetrical posterior ceca 14–20× length of the anterior ceca and lacking diverticula or secondary rami, tens of testes distributing in a cobblestone-like field anterior and posterior to the distal ends of the posterior ceca, an oviducal seminal receptacle comprising the distal portion of the oviduct, and a post-cecal ovary plus by lacking rosethorn-shaped spines, a pharynx, and a Laurer's canal. The new species appears host specific to Florida pompano because no conspecific infection was detected in 134 carangids of 8 species in 4 genera captured nearby the type locality. Psettarium sebastodorum Holmes, 1971 is transferred to the new genus, as Littorellicola sebastodorum (Holmes, 1971) n. comb., because it and the new species differ from species of Psettarium by the combination of having multiple testes plus 8 other features detailed herein. This report brings the number of nominal Gulf of Mexico aporocotylids to 12 species of 8 genera, represents only the second record of an aporocotylid from a carangid there, and supports the notion that elongated, “thread-like” aporocotylids with lateral spine rows are seemingly well-adapted for infecting myocardial lacunae or embedding in the myocardium of their definitive fish hosts.     

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.     

A new enteric nematode of Camallanus (Nematoda: Camallanidae) from Jiyu Island of Amoy (Taiwan Strait)

A new enteric nematode, Camallanus jiyuensis n. sp., is described from the intestine of the shokihaze goby, Tridentiger barbatus (Günther, 1861), collected from the beach of Jiyu Island, Amoy, southeast of China. The new species differs from its congeners mainly in the following combination of characters. The body is rather small in size, with 2 squarish, chitinized thickenings on the anterior border of the buccal capsule. The prongs of the trident are unequal. The nerve ring is near the posterior end of tridents. Cervical papillae are located in the middle of muscular esophagus. The excretory pore is located in the posterior third of muscular esophagus. Twelve pairs of pedunculate caudal papillae are present, of which 7 pairs are preanal and 5 are postanal. Spicules are similar, but subequal in length; the right and the left account for 9.8% and 8.9% of body length, respectively. The vulva does not protrude conspicuously from body surface and is located postequatorially.     

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.     

南海轮盘虫属(单殖吸虫, 分室科) 一新种及一新记录种

记述采自中国南海日本红娘鱼（Lepidotrigla japonica）鳃上的单殖吸虫1新种:红娘鱼轮盘虫（Trochopus lepidotrigla sp.nov.）,以及绿鳍鱼（Chelidonichthys kumu）鳃上的1中国新记录种:戈尔韦轮盘虫（Trochopus gaillimhe Little,1929）。新种红娘鱼轮盘虫以其后吸器上3对锚钩特殊的形态大小而区别于该属的近似种。所有标本均保存于华南师范大学生命科学学院鱼类寄生虫学研究室。     

Blood flukes (Digenea: Aporocotylidae) of stingrays (Myliobatiformes: Dasyatidae): Orchispirium heterovitellatum from Himantura imbricata in the Bay of Bengal and a new genus and species of Aporocotylidae from Dasyatis sabina in the northern Gulf of Mexico

We redescribe Orchispirium heterovitellatum based on the holotype and 3 original voucher specimens collected from the mesenteric blood vessels of scaly whiprays Himantura imbricata (Bloch and Schneider, 1801) (as Dasyatis imbricatus) captured in the western Bay of Bengal off Waltair, India. We emend the diagnosis of Orchispirium to include anterior sucker present, testis looping, cirrus sac enveloping large internal seminal vesicle, oviducal seminal receptacle present, and metraterm short and thin-walled. We describe Myliobaticola richardheardi n. gen., n. sp. based on live observations, light microscopy, and scanning electron microscopy of adult specimens collected from between the cardiac trabeculae of Atlantic stingrays Dasyatis sabina (Lesueur, 1824) captured in Mississippi Sound (type locality), Mississippi, and Apalachicola Bay, Florida. The new species has a minute, aspinous body lacking lateral tubercles; an aspinous and eversible anterior sucker lacking a peduncle; a posterior esophageal swelling; an inverse U-shaped intestine; smooth ceca terminating in the anterior body half; a looping testis lacking lobes; a cirrus sac enveloping a large internal seminal vesicle; a medial and primarily post-testicular ovary; an oviducal seminal receptacle; a postgonadal uterus flanking the internal seminal vesicle; a short and thin-walled metraterm; and a common genital pore. It lacks a pharynx and Laurer's canal. No other named aporocotylids infect a member of cohort Batoidea or have the combination of an aspinous body, an aspinous anterior sucker, a posterior esophageal swelling, an inverse U-shaped intestine, a looping testis, a cirrus sac enveloping a large internal seminal vesicle, and a common genital pore; these observations indicate that O. heterovitellatum and M. richardheardi are closely related. The discovery of a second species representing a second genus of Aporocotylidae in diamond stingrays (Dasyatidae) suggests that Batoidea is an undersampled host group for aporocotylid infections.     

中国广西盲鳅一新种——环江高原鳅(英文)

2007年4月,在广西壮族自治区环江县川山镇乐衣村附近一洞穴采集到一批盲鳅类标本。经鉴定,为高原鳅属(Triplophysa)鱼类一新种,被命名为环江高原鳅(Triplophysa huangjiangensis)。该新种以以下组合特征与高原鳅属的其他已知种类相区别:无眼;通体无鳞;尾鳍分叉;尾柄上、下叶具发达的软鳍褶;背鳍后缘平截;背鳍起点距尾鳍基的距离短于距吻端的距离;背鳍分枝鳍条数为8~9;胸鳍分枝鳍条数为10~11;腹鳍分枝鳍条数为6~7;臀鳍分枝鳍条数为6;尾鳍分枝数为13~14;胸鳍长为胸鳍起点至腹鳍起点间距的52.3%~70.7%;腹鳍起点位于背鳍起点之前下方;外侧吻须最长,为侧面头长的47.0%~73.8%;前鼻孔位于一短管中,末端延长呈须状;鳔后室发达,末端可伸达腹鳍起点。     

Cardicola beveridgei n. sp. (Digenea: Aporocotylidae) from the mangrove jack,Lutjanus argentimaculatus (Perciformes: Lutjanidae), and C. bullardi n. sp. from the Australian spotted mackerel,Scomberomorus munroi (Perciformes: Scombridae), from the northern Great Barrier Reef

Cardicola Short, 1953 is a genus of the Aporocotylidae Odhner, 1912 (Digenea), with 25 currently recognised species described from 32 species of Perciformes and Mugiliformes fishes around the world, including eight species from the Great Barrier Reef. Here, we describe two new species from this region, namely Cardicola beveridgei n. sp. from the ventricle and atrium of the mangrove jack, Lutjanus argentimaculatus (Forsskål) (Perciformes: Lutjanidae), and Cardicola bullardi n. sp. from the ventricle of the Australian spotted mackerel, Scomberomorus munroi Collette & Russo (Perciformes: Scombridae), from off Lizard Island, Queensland, Australia. These two new species are most easily distinguished from the 25 current members of Cardicola in having the combination of i) a spinous oral sucker, ii) an anteriorly intercaecal ovary, iii) a uterus that extends anteriorly from the oötype, iv) the number of spines per ventrolateral transverse row, and in v) body size and the length/width ratio, vi) the oesophagus and caecal length(s) relative to body total length, vii) the length of the posterior caeca relative to the anterior pair, viii) the testis length/width ratio and its total size relative to that of the body, ix) the postovarian field as a percentage of body length, and x) egg size. In addition, C. beveridgei n. sp. is further differentiated by possessing a female genital pore that opens anterodextral to the male pore while C. bullardi n. sp. differs further in possessing a testis that is almost entirely intercaecal and does not extend anteriorly to the level of the intestinal bifurcation. Employing genetic analysis of ITS2 rDNA sequence data, representing these species and a further 13 recognised and three putative species of Cardicola, we were able to unequivocally confirm these specimens as distinct (9–22% different over 420 nucleotide positions). Distance analysis of ITS2 showed that i) species of Cardicola from the Siganidae formed a monophyletic clade, to the exclusion of other Cardicola species reported from the Scombridae, Sparidae, Lutjanidae and Chaetodontidae, ii) a general phylogenetic isolation exists between the species of Cardicola reported from scombrid fishes, and iii) C. beveridgei n. sp. and Cardicola milleri Nolan & Cribb, 2006 from lutjanids and Cardicola chaetodontis Yamaguti, 1970 from chaetodontids are phylogenetically close, despite the evolutionary remoteness between the host groups and their highly disparate biology. Given the likelihood of many additional species being attributed to Cardicola, we predict that continued molecular analyses will indicate that this genus will prove to incorporate a series of radiations in association with particular fish taxa as well as evidence of host-switching. (Nucleotide sequences reported in this paper are available in the GenBank database under accession no. KF752497).     

A new genus and species of Brachycoeliidae (Digenea) from Chiropterotriton sp. (Caudata: Plethodontidae) in Mexico and its phylogenetic position within the Plagiorchiida based on partial sequences of the 28S ribosomal RNA gene

Parabrachycoelium longicaecum n. gen., n. sp. (Digenea: Brachycoeliidae) is described from the intestine of a plethodontid salamander Chiropterotriton sp. Hosts were collected in bromeliads at the cloud forest of Tlaquilpa, Veracruz, Mexico. Members of the Brachycoeliidae Looss, 1899 (sensu Yamaguti, 1971) are characterized by having a spined tegument; ceca usually short, not passing level of gonads, but longer in some species; gonads posterior to, or in region of, acetabulum, with ovary anterior to testes; a well developed cirrus pouch containing a bipartite seminal vesicle; and uterus occupying entire hind-body posterior to testes. However, this combination of morphological traits prevents the inclusion of the new taxon in any of the genera in that family; a new genus was, therefore, erected to accommodate the new species. The new taxon is readily distinguished from members belonging to Brachycoelium Dujardin, 1845, Mesocoelium Odhner, 1910, and Tremiorchis Mehra and Negi, 1925, by having long ceca extending into the posterior third of the body, slightly surpassing the testes, and vitellaria extending along the body. The new species morphologically resembles Caudouterina rhyacotritoni Martin, 1966, a digenean parasitizing a plethodontid salamander; however, the latter species lacks spines in the tegument and is actually placed within the Allocreadiidae. To demonstrate further the phylogenetic position of the new taxon, we sequenced the D1-D3 regions of 28S rRNA gene and conducted a phylogenetic analysis of available sequences for the order to which brachycoeliids belong (Plagiorchiida). Sequence divergence of the partial 28S rRNA gene confirms its distinction from the aforementioned brachycoeliids, and the phylogenetic position within the Plagiorchiida places the new species as closely related to a clade formed by Brachycoelium + Mesocoelium. Divergence levels and phylogenetic position within the Plagiorchiida verifies the validity of the new genus and its inclusion in Brachycoeliidae.     

A new aporocotylid (Digenea) species from blood vascular system of gag grouper, Mycteroperca microlepis (Perciformes: Serranidae), off Alabama, with an emendation of Pearsonellum Overstreet & Køie, 1989

Pearsonellum lemusi n. sp. (Digenea: Aporocotylidae) infects the blood vascular system of the gag grouper, Mycteroperca microlepis (Perciformes: Serranidae), in the north central Gulf of Mexico, approximately 80 km south of Dauphin Island, Alabama (29°34'09″N, 88°22'16″W). The new species can be most easily differentiated from its only congeners Pearsonellum corventum Overstreet and K?ie, 1989 (type species) and Pearsonellum pygmaeus Nolan and Cribb, 2004 , both of which infect Australian serranids, by the combination of having a large adult body (3,237 × 570 μm), a cecal intersection comprising an elongated medial channel, anterior ceca >10% of total body length, ovary narrower than testis, and pre-ovarian uterus not looping between testis and ovary. The embryonated eggs of the new species infect gill epithelium, are spheroid, and measure 25-30 μm in diameter. Sympatric Gulf of Mexico serranids were negative for aporocotylid infections: coney, Cephalopholis fulva (n = 1); Nassau grouper, Epinephelus striatus (3); red grouper, Epinephelus morio (32); yellowedge grouper, Epinephelus flavolimbatus (1); rock hind, Epinephelus adscensionis (1); red hind, Epinephelus guttatus (2); Warsaw grouper, Epinephelus nigritus (3); graysby, Cephalopholis cruentata (1); black grouper, Mycteroperca bonaci (1), and tattler, Serranus phoebe (2). The new species is the first aporocotylid described from a serranid outside of the southwestern Pacific Ocean. The diagnosis of Pearsonellum Overstreet and K?ie, 1989 is herein emended to include anterior sucker having concentric rows of spines anterior to mouth, pharynx absent, esophagus length <1/2 total body length, vas deferens connecting with cirrus sac anteromedially, ovary occupying posterior 1/4-1/3 of body, primary vitelline duct dextral, and oviducal seminal receptacle extending posteriad in parallel with lateral body margin, not transverse nor constricted anteriorly or posteriorly by sharp bends or kinks.     

Observations on a cucullanid nematode of marine fishes from Taiwan Strait, Dichelyne (Cucullanellus) jialaris n. sp

During a helminthological examination of marine fishes from south of the Minnan-Taiwan Bank Fishing Ground, Taiwan Strait, Fujian, China, a new cucullanid nematode, Dichelyne (Cucullanellus) jialaris n. sp., was removed from the intestine of the red seabream, Pagrus major (Temminck & Schlegel, 1834). The new species differs from its congeners mainly in the following characters: body size medium but with relative long spicules of 1.01 mm (0.97-1.06) in length or 20.0% (18.21-21.8%) of the body length; proximal end of spicules somewhat expanded and distal end rounded; gubernaculum I-shaped, slightly narrow in the middle part, both ends rounded; both anterior and posterior cloaca lips round or oval, prominent and unequal in size. The anterior cloaca lip is at least 2 times larger than the posterior one. There is a conspicuous papilliform structure within the central of anterior and posterior cloacal lip. Vulva of female is not prominent, slightly postequatorial; distance from vulva to anterior end of body is 4.3 (3.0-5.5) mm or 58.0% (54.0-62.0%) of the body length. Considering the result of comparing the structure of so-called unpaired median papilla with the 10 pairs of caudal petiolated papillae in the body of the same individual. the papilliform structures are just a backstop for the cloacal lips, this new species represents the first record of a nematode of the Dichelyne, subgenus Cucullanellus in marine fishes of China Sea.     

Sindiplozoon coreius n. sp. (Monogenea: Diplozoidae) from the gills of Coreius guichenoti (Cyprinidae) in China

Sindiplozoon coreius n. sp. is described from the gills of Coreius guichenoti in Sichuan province, China. There is a smooth tegument and a cup-like widened area in the posterior part of the worm body, which are particular features of the genus Sindiplozoon. There are no branched intestinal caeca before the widened area, but some branches reach the fourth clamp in the hind body; there was no cross striation on the anterior arch of the anterior clamp jaw and medial part of the posterior jaw, which are distinguished from the other species in Sindiplozoon. In addition, S. coreius n. sp. shared the highest ITS2 sequence identity (96.0%) with S. ctenopharyngodoni. The established phylogenetic tree showed that the two species of Sindiplozoon formed a sister group. The k2p genetic distance between the new species and other diplozoids was higher than 3.4%, which suggested interspecific differentiation.     

Hemitriakis complicofasciata, a new whitefin topeshark (Carcharhiniformes: Triakidae) from Japan

Hemitriakis complicofasciata sp. nov. is described from 18 specimens from the waters of the Ryukyu Islands, southern Japan. This new species is distinguishable from other congeners by the following characters: higher vertebral counts (46–52 monospondylous vertebrae and 124–131 precaudal total vertebrae), presence of a developed posterior nasal flap, first dorsal fin origin anterior to free rear tips of pectoral fin, shorter snout length (snout tip to oral length less than 1.8 times internarial width), absence of an accessory cartilage at symphysial part of upper jaw, and dark complicated lines and rings on embryos and juveniles.     

A new species of Liniscus (Nematoda: Trichuridae) from Oxymycterus rufus and Akodon azarae (Cricetidae: Sigmodontinae) in Buenos Aires Province, Argentina

Liniscus diazae n. sp. (Nematoda: Trichuridae) is described from the urinary bladder of Oxymycterus rufus and Akodon azarae (Cricetidae: Sigmodontinae) from Buenos Aires Province, Argentina. Liniscus diazae can be differentiated from its congeners by having a much longer spicule and without an elevated vulva. In addition, L. diazae can be distinguished from L. incrassatus and L. himizu by having a longer body length. Males are similar in posterior width to L. papillosus and L. himizu, but thinner than L. incrassatus and L. maseri. This is the second record of a capillarid from mammals in Argentina. An updated list of capillarid species of rodents and insectivores from North America, with their synonyms, hosts, sites of infection, and geographic distribution, is provided.     

A new species of Curimatopsis Steindachner (Characiformes: Curimatidae) from the Rio Nhamundá, Amazon basin

A new species of Curimatopsis is described from the Rio Nhamundá, Amazon basin in northern Brazil. The new species is distinguished from congeners by the presence of a distinctive concentration of dark pigmentation over the entire lower lobe of the caudal fin, reticulate pattern of body pigmentation, lower jaw longer than and overlapping the anterior portion of the upper jaw, crescent‐shaped posterior nostril and by morphometric and meristic data. Comments on the phylogenetic position of the new species within Curimatopsis are also provided.