A morphological type of Sarcocystis cysts found in one of two examined great black-backed gull, Larus marinus (Linnaeus) (Laridae), is considered to represent a new species for which the name Sarcocystis lari sp. n. is proposed and its description is provided. The cysts are ribbon-shaped, very long (the largest fragment found was 6 mm long) and relatively narrow (up to 75 μm). Under a light microscope the cyst wall reaches up to 1 μm and seems to be smooth. Using a computerized image analysis system, knolls, which resemble protrusions on the wall surface, are visible. Lancet-shaped cystozoites measure in average 6.9 × 1.4 μm (range 6.3-7.9 μm × 1.2-1.5 μm) in length. Observed using Transmission electron microscopy (TEM), the cyst wall is wavy and measures up to 1.2 μm in thickness. The parasitophorous vacuolar membrane has regularly arranged small invaginations. Cyst content is divided into large chambers by septa. Sarcocystis lari sp. n. has type-1 tissue cyst wall and is morphologically indistinguishable from other bird Sarcocystis species characterized by the same type of the wall. On the basis of 18S rRNA gene, 28S rRNA gene and ITS-1 region sequences, S. lari is a genetically distinct species, being most closely related to avian Sarcocystis species whose definitive hosts are predatory birds.
Here we present the first evidence of female dimorphism in ectoparasitic quill mites of the family Syringophilidae (Actinotrichida: Prostigmata: Cheyletoidea). Stibarokris phoeniconaias Skoracki et OConnor, 2010 and Ciconichenophilus phoeniconaias Skoracki et OConnor, 2010 so far have been treated as two distinct species cohabiting inside the quills of feathers of the lesser flamingo Phoeniconaias minor (Geoffroy Saint-Hilaire) and the American flamingo Phoenicopterus ruber Linnaeus. Although females of these species differ morphologically by the extent of body sclerotisation, presence/absence of lateral hypostomal teeth, and shape of dorsal setae, their important common features are the lack of leg setae vs II, and both stylophore and peritremes shape. Here, we apply the DNA barcode markers to test whether the differences between S. phoeniconaias and C. phoeniconaias have a genetic basis, indicating that they really are distinct taxa, or whether they just represent two morphs of a single species. All analysed sequences (616 bp for COI and 1 159 bp for 28S rDNA) obtained for specimens representing females of both studied taxa as well as male, tritonymph, protonymph and larva of S. phoeniconaias were identical, which indicates that S. phoeniconaias and C. phoeniconaias are conspecific. The formal taxonomic consequence of our results is denial of the genus status of Ciconichenophilus Skoracki et OConnor, 2010 and species status of C. phoeniconaias, and recommendation that they should be treated as junior synonyms of Stibarokris Kethley, 1970 and S. phoeniconaias, respectively.
Five new species of Acanthobothrium van Beneden, 1850 from the spiral intestine of a specimen of an unusual species of Himantura from the Arafura Sea off northern Australia are described. Acanthobothrium oceanharvestae sp. n. is one of 26 category 1 species (sensu Ghoshroy and Caira 2001) lacking post-ovarian testes; it differs from these in total length, number of proglottids, number of testes, cirrus sac size and details of the terminal genitalia. Acanthobothrium popi sp. n. is unique among category 2 species in its possession of post-ovarian testes. Acanthobothrium rodmani sp. n. is a category 6 species distinct from all congeners in the dense blade-like spinitriches on the distal surfaces of its anterior-most bothridial loculi and conspicuously tapered posterior bothridial margins, which are reflexed anteriorly. Acanthobothrium romanowi sp. n. differs from most other category 1 species in that its genital pore is distinctly posterior. It differs from the remaining category 1 species in size, testis number, cephalic peduncle microthrix form, proglottid shape, and bothridial loculus dimensions. Acanthobothrium zimmeri sp. n. is among the six category 1 species with post-ovarian testes. It differs from these species in total length, ovary shape, number of proglottids and testes and vas deferens extent. This brings the number of Acanthobothrium species with post-ovarian testes to 10, all of which are Indo-Pacific in distribution, and 7 of which parasitize Himantura species. A key to the five new species parasitizing Himantura sp. is provided. Sequence data for the D1-D3 region of 28S rDNA for the five new species and two congeners parasitizing other Himantura species shows no intraspecific variation. Analysis of these and comparable data for two species available in GenBank (Acanthobothrium parviuncinatum and Acanthobothrium sp. 1) showed an interspecific variation of 0.7-11.3% among species pairs. Bayesian, Likelihood and Parsimony phylogenetic analyses of these data for these nine species indicate that the five new species parasitizing Himantura sp. are generally not each others' closest relatives.
The present study describes the anatomy and surface topography of the metacercaria of Microphallus primas (Jägerskiöld, 1909) infecting the shore crab Carcinus maenas (L.) in Aveiro estuary, northern Portugal. The metacercaria species identification resulted from the combined use of morphological and molecular data, particularly the 28S rDNA gene. The metacercariae encysted preferentially in the host's hepatopancreas and also in the gonads. Isolated cysts were present in two distinct forms, spherical and oval, and were shown to be the identical species by the internal transcribed spacer 1 (ITS1) sequence. Chemically excysted metacercariae were studied by light (LM) and scanning electron microscopy (SEM). Their specific characteristics observed include the particular aspect of the vesiculo-prostatic pouch surrounded by a very thin membrane, the presence of a prominent muscular papilla, and an obvious metraterm. The dorsal and ventral tegumental surfaces of the metacercaria were densely packed with similar squamous spines, which decreased in number and size towards the hindbody. The edges of the posterior and ventral face of the body were coated with numerous microvilli, whose function remains unknown. In order to identify the species of metacercariae, we compared a 28S partial rDNA sequence of the two forms of cysts with the same 28S partial region of M. primas available in GenBank. With this comparison, we determined that the sequences had a 100% similarity and therefore belonged to the same species, i.e., M. primas.
Bentholebouria colubrosa gen. n. et sp. n. (Digenea: Opecoelidae) is described in the wenchman, Pristipomoides aquilonaris (Goode et Bean), from the eastern Gulf of Mexico, and new combinations are proposed: Bentholebouria blatta (Bray et Justine, 2009) comb. n., Bentholebouria longisaccula (Yamaguti, 1970) comb. n., Bentholebouria rooseveltiae (Yamaguti, 1970) comb. n., and Bentholebouria ulaula (Yamaguti, 1970) comb. n. The new genus is morphologically similar to Neolebouria Gibson, 1976, but with a longer cirrus sac, entire testes, a rounded posterior margin with a cleft, and an apparent restriction to the deepwater snappers. Morphologically, the new species is closest to B. blatta from Pristipomoides argyrogrammicus (Valenciennes) off New Caledonia but can be differentiated by the nature of the internal seminal vesicle (2-6 turns or loops rather than constrictions), a longer internal seminal vesicle (occupying about 65% rather than 50% of the cirrus sac), a cirrus sac that extends further into the hindbody (averaging 136% rather than 103% of the distance from the posterior margin of the ventral sucker to the ovary), and a narrower body (27% rather than 35% mean width as % of body length). A Bayesian inference analysis of partial sequence of the 28S rDNA from Neolebouria lanceolata (Price, 1934), Cainocreadium lintoni (Siddiqi et Cable, 1960), Hamacreadium mutabile Linton, 1910, Opecoeloides fimbriatus (Linton, 1910), Podocotyloides brevis Andres et Overstreet, 2013, the new species, and previously published comparable sequences from 10 opecoelid species revealed two clades. One clade includes deep-sea (≥ 200 m) and freshwater fish opecoelids + Opecoeloides Bremser in Rudolphi, 1819, and a second clade included those opecoelids from shallow-water marine, perciform fishes.
The systematic position and phylogenetic relationships of the family Cortrematidae Yamaguti, 1958 have always been controversial. In the present study, the phylogenetic relationships of this family and its constituent genera and families within the superfamily Microphalloidea were evaluated using previously published and newly obtained sequences of 28S rDNA of Cortrema magnicaudata (Bykhovskaya-Pavlovskaya, 1950) (Cortrematidae), Phaneropsolus praomydis Baer, 1971 and Microtrema barusi Sitko, 2013 (Phaneropsolidae). Results clearly demonstrate that the genus Cortrema Tang, 1951 is closest to Gyrabascus Macy 1935, both genera forming one of the clades within the family Pleurogenidae in the superfamily Microphalloidea and sharing several important morphological features. Thus, the family Cortrematidae should be considered among synonyms of the Pleurogenidae. Based on the analysis of morphology, C. corti Tang, 1951, C. testilobata (Bykhovskaya-Pavlovskaya, 1953) and C. niloticus Ashour, Ahmed et Lewis, 1994 are considered junior synonyms of C. magnicaudata. The phylogenetic position of P. praomydis as a family-level branch not showing close relationships with other families of the Microphalloidea, supports the status of the Phaneropsolidae as an independent family. The genus Parabascus Looss, 1907 previously considered within the Phaneropsolidae clearly belongs to the Pleurogenidae. In addition, the molecular phylogeny has demonstrated that the recently described phaneropsolid Microtrema barusi belongs to the microphallid genus Microphallus Ward, 1901. Therefore, Microtrema Sitko, 2013 is considered a junior synonym of Microphallus. Our analysis has also confirmed the status of Collyriclidae as a family within the Microphalloidea. Not yet sequenced representatives of other families within the Microphalloidea (e.g. Anenterotrematidae, Eumegacetidae, Renschtrematidae, Stomylotrematidae, etc.) need to be included in future molecular phylogenetic studies to better unravel the taxonomic structure and content of this diverse digenean superfamily.
Tapeworms of the order Spathebothriidea Wardle et McLeod, 1952 (Cestoda) are reviewed. Molecular data made it possible to assess, for the first time, the phylogenetic relationships of all genera and to confirm the validity of Bothrimonus Duvernoy, 1842, Diplocotyle Krabbe, 1874 and Didymobothrium Nybelin, 1922. A survey of all species considered to be valid is provided together with new data on egg and scolex morphology and surface ultrastructure (i.e. microtriches). The peculiar morphology of the members of this group, which is today represented by five effectively monotypic genera whose host associations and geographical distribution show little commonality, indicate that it is a relictual group that was once diverse and widespread. The order potentially represents the earliest branch of true tapeworms (i.e. Eucestoda) among extant forms.