<Emphasis Type="Italic">Lamproglena hepseti</Emphasis> n. sp. (Copepoda: Lernaeidae), a gill parasite of the African pike <Emphasis Type="Italic">Hepsetus odoe</Emphasis> (Bloch) from the Okavango River and Delta,Botswana

During surveys of the biodiversity of fish parasites in the Okavango River and Delta, Botswana, specimens of Lamproglena von Nordmann, 1832 were found associated with the African pike Hepsetus odoe (Bloch). This Lamproglena species distinctly differs from all known species based on morphological features, in particular the cephalothorax and the maxilliped; it is described as L. hepseti n. sp. and is specific to its host, the African pike.     

Integrative taxonomy of Peniculus,Metapeniculus, and Trifur (Siphonostomatoida: Pennellidae), copepod parasites of marine fishes from Chile: species delimitation analyses using DNA barcoding and morphological evidence

Pennellidae is a family of copepod parasites of widely distributed marine fishes. The pennellid species are usually morphologically differentiated by cephalothorax, neck, trunk, and abdomen shape. These characters, however, show high polymorphism and therefore using only this type of data, delimitation at species level of this genus is difficult. In this study, we explored the genetic distances calculated from sequences of a DNA barcoding marker (COI mt) (678 base pairs). We also explored the genetic distances of 25 Peniculus specimens associated within nine marine fish species, four Metapeniculus specimens associated within one marine fish species, and four Trifur specimens associated within one marine fish species. All specimens were collected in Antofagasta Bay, Chile and were calculated from sequences of a DNA barcoding marker (COI mt) (678 base pairs). The genetic distance among the Peniculus specimens was 0.95% from the different host species, the Metapeniculus specimens distance was 0.44% and the Trifur specimens was 2.25%. Genetic difference between Peniculus and Metapeniculus was 17.86% and Peniculus differ from T. tortuosus by 18.16%. We analysed the barcoding gene fragment using Bayesian Inference (BI) for phylogenetic reconstruction using three outgroups. Based on the phylogenetic analysis an ultrametric tree was built and a general mixed Yule-coalescent (bGMYC) model was conducted for species delimitation. Morphometrics analyses were made with Bayesian statistics. Mean and credibility limit (95%) for each parameter was calculated. Results show that based on morphology the individuals collected can be assigned to P. cf. fistula von Nordmann, 1832, Metapeniculus antofagastensis Castro-Romero & Baeza-Kuroki, 1985, and Trifur cf. tortuosus Wilson, 1917. High morphological polymorphism was observed for the lineage of Peniculus associated to several host species of marine fishes. Similar results were obtained for Trifur cf. tortuosus parasites on Chilean marine fishes.     

<Emphasis Type="Italic">Gyrodactylus thlapi</Emphasis>n. sp. (Monogenea) from <Emphasis Type="Italic">Pseudocrenilabrus philander philander</Emphasis> (Weber) (Cichlidae) in the Okavango Delta,Botswana

A new species of Gyrodactylus von Nordmann, 1832 and the first monogenean reported from Botswana is described from the cichlid Pseudocrenilabrus philander philander,bringing the number of gyrodactylids described from the African Continent to 18. Gyrodactylus thlapi n. sp. can be readily discriminated from the other described species almost exclusively by the shape of its hamuli, which have short roots and large, elongate ventral bar attachment points with the dorsal bar attachment point, demarcating the junction between the hamulus shaft and the root, positioned at the anterior terminus of the attachment plane. The marginal hooks of G. thlapi n. sp., which most closely resemble those of G. groschafti Ergens, 1973, are compared and discussed.     

Morphology and molecules reveal the alien <Emphasis Type="Italic">Posthodiplostomum centrarchi</Emphasis> Hoffman, 1958 as the third species of <Emphasis Type="Italic">Posthodiplostomum</Emphasis> Dubois, 1936 (Digenea: Diplostomidae) in Europe

Metacercariae of two species of Posthodiplostomum Dubois, 1936 (Digenea: Diplostomidae) were subjected to morphological and molecular studies: P. brevicaudatum (von Nordmann, 1832) from Gasterosteus aculeatus (L.) (Gasterosteiformes: Gasterosteidae), Bulgaria (morphology, cox1 and ITS1-5.8S-ITS2) and Perca fluviatilis L. (Perciformes: Percidae), Czech Republic (morphology, cox1, ITS1-5.8S-ITS2 and 28S); and P. centrarchi Hoffman, 1958 from Lepomis gibbosus (L.) (Perciformes: Centrarchidae), Bulgaria (morphology, cox1 and ITS1-5.8S-ITS2) and Slovakia (cox1 and ITS1-5.8S-ITS2). In addition, cercariae of P. cuticola (von Nordmann, 1832) from Planorbis planorbis (L.) (Mollusca: Planorbidae), Lithuania (morphology and cox1) and metacercariae of Ornithodiplostomum scardinii (Schulman in Dubinin, 1952) from Scardinius erythrophthalmus (L.) (Cypriniformes: Cyprinidae), Czech Republic, were examined (morphology, cox1, ITS1-5.8S-ITS2 and 28S). These represent the first molecular data for species of Posthodiplostomum and Ornithodiplostomum Dubois, 1936 from the Palaearctic. Phylogenetic analyses based on cox1 and ITS1-5.8S-ITS2, using O. scardinii as the outgroup and including the three newly-sequenced Posthodiplostomum spp. from Europe and eight published unidentified (presumably species-level) lineages of Posthodiplostomum from Canada confirmed the distinct status of the three European species (contrary to the generally accepted opinion that only P. brevicaudatum and P. cuticola occur in the Palaearctic). The subspecies Posthodiplostomum minimum centrarchi Hoffmann, 1958, originally described from North America, is elevated to the species level as Posthodiplostomum centrarchi Hoffman, 1958. The undescribed “Posthodiplostomum sp. 3” of Locke et al. (2010) from centrarchid fishes in Canada has identical sequences with the European isolates of P. centrarchi and is recognised as belonging to the same species. The latter parasite, occurring in the alien pumpkinseed sunfish Lepomis gibbosus in Europe, is also supposed to be alien for this continent. It is speculated that it colonised Europe long ago and is currently widespread (recorded in Bulgaria, Slovakia and Spain); based on the cox1 sequence of an adult digenean isolate from the Ebro Delta, Spain, only the grey heron (Ardea cinerea L.) (Ciconiiformes: Ardeidae) is known to be its definitive host in Europe.     

A new genus and two new species of Pennellidae (Copepoda: Siphonostomatoida) and an analysis of evolution within the family

Summary A new pennellid genus,Exopenna, is established on the basis of two specimens of a new species,E. crimmeni, recovered from a deep-sea cod,Antimora, caught in the North East Atlantic. It is ectoparasitic and is diagnosed by the combination of a straight body, tightly coiled egg sacs and flattened, plate-like antennary processes. Another new species,Peniculus elongatus, is described from Australian waters and new records ofP. fistula andLernaeenicus ramosus further increase the known pennellid fauna of that region. A preliminary analysis of the phylogenetic relationships of the pennellid genera is undertaken and a partially resolved cladogram produced which identifies the main generic groupings. ac]19850522     

Three new species of Hatschekia Poche, 1902 (Copepoda: Siphonostomatoida: Hatschekiidae) parasitic on boxfishes (Pisces: Tetraodontiformes: Aracanidae and Ostraciidae) in Japanese waters

Three new species of Hatschekia Poche, 1902 are described from the gill filaments of three species of boxfishes captured off southern Japan: H. pseudostracii n. sp. on Kentrocapros aculeatus (Houttuyn) (Aracanidae); H. bibullae n. sp. on Lactoria diaphana (Bloch & Schneider) (Ostraciidae); and H. kuroshioensis n. sp. on Tetrosomus concatenates (Bloch) (Ostraciidae). Of the 93 currently valid species in the genus, these new species differ from the 87 species which lack four stout processes on the posterior margin of the intercoxal sclerites of legs 1 and 2. Those processes are present on the remaining six species and the three new species. Of these nine species, H. pseudostracii n. sp. is distinguished by having a T-shaped chitinous frame on the cephalothorax, the leg 1 exopod twice as long as the endopod and a small parabasal papilla. H. bibullae n. sp. can be differentiated by a combination of morphological features as follows: a well-developed, thumb-shaped parabasal papilla, the leg 1 exopod twice as long as the endopod and a trunk lacking posterior lobes. H. kuroshioensis n. sp. can be recognised by bearing a T-shaped chitinous frame on the cephalothorax, the leg 1 exopod is three times as long as the endopod and the trunk lacks posterior lobes.     

Two new species of Ergasilidae (Copepoda: Poecilostomatoida) parasitic on Mugil cephalus L. from southern Africa

Two new species of Ergasilidae are described from southern Africa; a representative of the genus Dermoergasilus Ho et Do, 1982 on the gill rackers and one of Ergasilus von Nordmann, 1932 on the gill filaments of the striped mullet, Mugil cephalus L.The striped mullet, Mugil cephalus Linnaeus, has a wide geographical distribution and is parasitized by more than 40 different species of parasitic copepods (Ho & Do, 1982). It acts as host for seven species of Ergasilidae, i.e. Diergasilus kasahari Do, 1981, Dermoergasilus amplectens (Dogiel et Akhmerov, 1952), Ergasilus seiboldi von Nordmann, 1832, Nipergasilus bora (Yamaguti, 1939) and Ergasilus lizae Kroyer, 1963, Ergasilus mugilis Vogt, 1879 and Ergasilus cyanopictus Carvalho, 1962.Ergasilids have been reported from mullets on the African continent, i.e. E. lizae from Tunisia (Raibaut, Ben-Hassine & Prunes, 1975) and Ghana (Paperna, 1969). The present study has shown that two new species of Ergasilidae occur on the southern periphery of the continent, which are described below.Type specimens were deposited in the collection of the Dept. of Zoology, Rand Afrikaans University.     

A new species of parasitic copepod of the genus <Emphasis Type="Italic">Hatschekia</Emphasis> Poche, 1902 (Siphonostomatoida: Hatschekiidae) from filefishes (Pisces: Tetraodontiformes: Monacanthidae) from off Okinawa,Japan

Hatschekia khahajya n. sp. is described from the gill filaments of two monacanthid fishes, Cantherhines dumerilii (Hollard) and Amanses scopes (Cuvier), caught off Okinawa, Japan. The new species can be distinguished from its congeners by the possession of the following combination of characters: cephalothorax length/trunk length ratio greater than 0.40; cephalothorax with a pair of lateral bars on the chitinous ring and a posterior pair of surface ridges; trunk with a bifurcate chitinous frame extending over its anterior third and with well-developed posterior lobes that extend beyond the abdomen; and four processes plus two spinular rows on the distal margin of the intercoxal sclerite of legs 1 and 2.     

Two new species of <Emphasis Type="Italic">Sagum</Emphasis> Wilson, 1913 (Copepoda: Siphonostomatoida: Lernanthropidae) parasitic on reef fishes off the Ryukyu Islands

Two new species of parasitic copepods, Sagum gurukun n. sp. and S. bitaro n. sp. (Siphonostomatoida: Lernanthropidae), are described based on specimens collected from the gill filaments of the double-lined fusilier Pterocaesio digramma (Bleeker) (Actinopterygii: Perciformes: Caesionidae) and the five-lined snapper Lutjanus quinquelineatus (Bloch) (Actinopterygii: Perciformes: Lutjanidae), respectively, caught off Iriomote-jima Island, the Ryukyu Islands, East China Sea, Japan. The findings bring the number of species of Sagum to 14. The two new species are similar in the morphology of the head and the legs 3 and 4 to the three congeners, S. folium Ho, Liu & Liu, 2011, S. paracaesionis Izawa, 2014 and S. vietnamiensis Kazachenko, Kovaleva, Nguyen & Ngo, 2017. Sagum gurukun n. sp. is differentiated from the three congeners by the proportions of the caudal rami, the absence of leg 5, and the shape of the legs 1 and 2. Sagum bitaro n. sp. differs from the three congeners and S. gurukun n. sp. by the presence of the conical leg 5 armed with an apical seta. A key to the species of the genus Sagum, based on the available information on female morphology in previous publications and the present study, is provided. To date, a total of 19 species of lernanthropid copepods considered valid are known in Japanese waters.     

A new species of Philometra (Nematoda: Philometridae) from the sand perch Diplectrum formosum (Serranidae) off Florida, northern Gulf of Mexico

A new nematode species, Philometra diplectri n. sp. (Philometridae), is described from male and female specimens found in unidentified tissues of head and anterior trunk (males) and subcutaneously in the mouth and under the operculum (females) of sand perch, Diplectrum formosum (Linnaeus) (Serranidae, Perciformes), from the northern Gulf of Mexico off Florida (Florida Middle Grounds). Based on light and scanning electron microscopy examination, the new species differs from other congeners parasitizing the subcutaneous tissues, fins, tissues of the buccal cavity, and gill covers or gill arches of marine and brackish-water fishes, mainly in having 8 conspicuously large cephalic papillae of the external circle, the absence of caudal projections, and the shape and small size of the anterior inflation of the esophagus in gravid females, and in possessing 5 pairs of caudal papillae and spicules 66-78 μm long in males. Philometra diplectri is the first known species of this genus whose gravid females are parasitic in the head tissues of serranid fishes.     

Morphological and molecular characterization of three new species of Gyrodactylus (Monogenea: Gyrodactylidae) infecting Sicydium salvini (Teleostei: Gobiidae) in Mexican rivers draining into the Pacific Ocean

The genus Gyrodactylus von Nordmann, 1832 is one of the most diverse within the class Monogenea; it contains mainly parasites of freshwater and marine teleost fishes. Around 40 species of Gyrodactylus have been described from gobiid fishes; mainly in Europe, as only two species are known from the Americas. In this study, we describe three new gyrodactylids from the body surface and fins of the goby Sicydium salvini (Gobiidae, Sycydiinae), which has a wide distribution on the Pacific coast, from Mexico to Panama. We describe Gyrodactylus oaxacae n. sp., G. atoyacensis n. sp. and G. salvini n. sp. collected from rivers draining to the eastern Pacific in the state of Oaxaca, Mexico. Morphologically, G. atoyacensis n. sp. and G. salvini n. sp. are very similar, and both are easily differentiated from G. oaxacae n. sp. Phylogenetic hypotheses based on sequences of the Internal Transcribed Spacers (ITS1–5.8S-ITS2 rDNA) and the D2 + D3 domains of the large ribosomal subunit (28S rDNA) support the erection of the three new taxa; and suggest that G. atoyacensis n. sp. and G. salvini n. sp. are sister species. These gyrodactylids are the first monogeneans described from gobies of the genus Sicydium in Mexico.     

New species of Hatschekia Poche, 1902 (Copepoda: Hatschekiidae) parasitic on marine fishes of Kuwait

Three new species of Hatschekia are described from the gill filaments of fishes taken in the Persian Gulf: H. seyi n. sp. from Heniochus acuminatus (Linnaeus), H. nodosa n. sp. from Lutjanus coccineus (Cuvier) and H. tanysoma n. sp. from L. fulviflamma (Forsskål). H. seyi differs from its congeners in having the cephalothorax longer than the trunk; H. nodosa, in having multiple nodules on the posterolateral margins of the trunk; and H. tanysoma, in having the trunk more than six times the length of cephalothorax and some pinnate setae on legs 1 and 2.     

Identification of Monogenea made easier: a new statistical procedure for an automatic selection of diagnostic linear measurements in closely related species

We introduce a new statistical method to select which morphological characters are most useful to identify monogenean species. The method estimates the average size overlap of candidate diagnostic structures among a set of species to individuate those that mostly differ between the species. To demonstrate our approach, we report a comprehensive analysis conducted on two of the most species‐rich monogenean genera: Dactylogyrus Diesing, 1850 and Gyrodactylus von Nordmann, 1832. We demonstrate that, in contrast to common taxonomic practice, very few but highly diagnostic measurements are necessary to correctly identify a specimen. In particular, we found that most of Dactylogyrus and Gyrodactylus species can be classified on the basis of the width of the supplementary connecting bar and of the length of the hook sickle, respectively.     

A new genus and species of hatschekiid copepod (Siphonostomatoida) from groupers (Actinopterygii: Serranidae) collected off the Ryukyu Archipelago, Japan

A new genus and species of copepod, Mihbaicola sakamakii n. g., n. sp., belonging to the siphonostomatoid family Hatschekiidae, is described based on the females collected from inside the tissue of the branchiostegal membrane in three species of the groupers, Epinephelus fasciatus (Forsskål) (type-host), E. merra Bloch and Cephalopholis leopardus (Lacépède), collected off Okinawa-jima Island and Iriomote-jima Island, Ryukyu Archipelago, North Pacific Ocean. The new genus can be distinguished from other hatschekiid genera by a combination of the following characters in the female: the head is composed of the cephalosome and the pedigerous somite; the cephalothorax is expanded into a pair of posteroventral lobes carrying leg 1; legs 1 and 2 are biramous and composed of the protopod and both rami are 2-segmented; leg 3 is absent; and leg 4 is represented by a rounded lobe with a chitinous pointed apical process.     

Simognathus coreensis, a new halacarid mite (Halacaridae: Acari) from Korea

Simognathus coreensis n. sp. is described on the basis of the specimens collected from Youngdeok, the east coast of South Korea. This is the first record of this genus from Korea. Diagnostic features are as follows: big cornea present on ocular plate, covering major portion of it; lateral claws II–IV with accessory process which contain about 5 minute (meaning `very small') teeth, and lateral claws smooth ventrally; prominent foveae on all telofemora; anterodorsal and posterodorsal plate subequal; lateral side of anterior epimeral plate foveate. This species is similar to S. corneatus Otto and S. exoticus Otto. Dissimilarities are discussed. Abbreviations: AD, anterodorsal plate; AE, anterior epimeral plate; ds, dorsal setae of idiosoma I; GA, genitoanal plate; GO, genital opening; PE, posterior epimeral plate; EP I, epimeral process I; PGS, perigenital setae; P1-P3, first to third palpal segment; SGS, subgenital seta.