<Emphasis Type="Italic">Petasiger islandicus</Emphasis> n. sp. (Digenea: Echinostomatidae) in the horned grebe <Emphasis Type="Italic">Podiceps auritus</Emphasis> (L.) (Aves: Podicipedidae) from Iceland

Petasiger islandicus n. sp. is described and figured from a demographically isolated population of the horned grebe Podiceps auritus auritus (L.) in Lake Myvatn (Iceland). This new species belongs to the group of species with 19 collar spines which possess a large elongate-oval cirrus-sac, well-developed pars prostatica and massive bulb-like cirrus. Within this group, P. islandicus appears most similar to P. oschmarini Kostadinova & Gibson, 1998, a form with similar body dimensions described from the same host, but differs in having a larger head collar, collar spines, oral sucker, pharynx, testes and sucker-width ratio, and a smaller cirrus-sac, cirrus and eggs. Two Nearctic species resemble P. islandicus in general morphology but differ as follows: P. pseudoneocomense Bravo-Hollis, 1969 has a larger body and collar width, notably shorter collar spines, smaller testes and sucker-width ratio, and a shorter but much wider cirrus-sac which is also smaller relative to the ventral sucker and almost entirely anterior to it; and P. caribbensis Nassi, 1980 has a smaller body, shorter collar spines and a seminal vesicle which is small in relation to the cirrus-sac, vitelline fields reaching anteriorly to the level of the genital pore and the intestinal bifurcation is located more anteriorly.     

A revision of Petasiger Dietz, 1909 (Digenea: Echinostomatidae) and a key to its species

Petasiger Dietz, 1909 is revised, and a key to and lists of the records and hosts of the 18 recognised species are presented. The recognised species are: P. exaeretus Dietz, 1909, P. australis Johnston & Angel, 1941, P. combesi Zamparo, Overstreet & Brooks, 2005, P. floridus Premvati, 1968, P. grandivesicularis Ishii, 1935, P. islandicus Kostadinova & Skirnisson, 2007, P. johnstoni n. sp., P. megacanthus (Kotlán, 1922), P. minutissimus Gogate, 1934, P. neocomense Fuhrmann, 1927, P. nitidus Linton, 1928, P. novemdecim Lutz, 1928, P. oschmarini Kostadinova & Gibson, 1998, P. phalacrocoracis (Yamaguti, 1939), P. pseudoneocomense Bravo-Hollis, 1969, P. pungens (Linstow, 1894), P. soochowensis Ku, Chiu, Li & Zhu, 1977 and P. variospinosus (Odhner, 1910). Seven of these species are redescribed on the basis of type and newly collected material. P. laricola Ku, Chiu, Li & Zhu, 1977, Echinochasmus fotedari Chishti & Mir, 1989 and P. neocomense of Cankovi?, Kazi? & Milka (1983) are considered synonyms of P. pungens; P. longicirratus Ku, 1938, P. skrjabini Bashkirova, 1941 and P. nitidus of Chen et al. (1985) synonyms of P. neocomense; P. caribbensis Nassi, 1980 a synonym of P. novemdecim; and P. tientsinensis Ku, Chiu, Li & Zhu, 1977 a synonym of P. exaeretus. P. johnstoni n. sp. is described from Tachybaptus ruficollis novaehollandiae in Australia. It is readily distinguished from the most closely-related P. grandivesicularis Ishii, 1935 and P. australis Johnston & Angel, 1941 by the smaller size of the body and angle collar spines and differences in most other metrical characters. Species attributed to Petasiger which are here considered species inquirendae are: P. antigonus Nigam, 1944 sp. inq., P. chandleri Abdel-Malek, 1952 sp. inq., P. jubilarum Elperina in Skrjabin, Petrov & Bashkirova, 1947 sp. inq., P. nicolli Pande, 1939 sp. inq. and P. spasskyi Oshmarin in Skrjabin, Petrov & Bashkirova, 1947 sp. inq.; and Echinoparyphium inopinatum (Baer, 1959) n. comb. is a species previously attributed to Petasiger.     

Three Echinostome Species from Wild Birds in the Republic of Korea

Three echinostome species, i.e., Patagifer bilobus, Petasiger neocomense, and Saakotrema metatestis, are newly recorded in the trematode fauna of the Republic of Korea. They were recovered from 3 species of migratory birds (Platalea minor, Podiceps cristatus, and Egretta garzetta), which were donated by the Wildlife Center of Chungbuk (WCC) and the Conservation Genome Resource Bank for Korean Wildlife (CGRB). Only 1 P. bilobus specimen was recovered from the intestine of a black-faced spoonbill (P. minor), and characterized by the bilobed head crown with a deep dorsal incision and 54 collar spines. Twenty P. neocomense were recovered from the intestine of a great crested grebe (P. cristatus), and they had a well-developed head crown with 19 spines and 2 testes obliquely located at the posterior middle of the body. Total 70 S. metatestis were collected from the bursa of Fabricius of 1 little egret (E. garzetta). It is characterized by stout tegumental spines covered in the entire leaf-shaped body, posterior extension of the uterus, presence of the uroproct and a well-developed head crown with 12 pairs of collar spines on each side. By the present study, these 3 echinostome species are newly added to the trematode fauna in Korea.     

The life-cycle of Petasiger islandicus Kostadinova & Skirnisson, 2007 (Digenea: Echinostomatidae) elucidated with the aid of molecular data

The small planorbid snail Gyraulus cf. laevis (Alder) from Lake Myvatn in Iceland was found to emit large-tailed cercariae with 19 collar spines, and three-spined sticklebacks Gasterosteus aculeatus L. were infected with metacercariae of a species of Petasiger Dietz, 1909. Comparative sequence analysis using ND1 mitochondrial DNA sequences revealed that the rediae and cercariae are conspecific with P. islandicus Kostadinova & Skirnisson, 2007, recently described from an isolated population of the horned grebe Podiceps auritus (L.) at the lake. The redia, cercaria and metacercaria are described and compared with related forms.     

Experimental data on the life-cycle of Petasiger grandivesicularis Ishii, 1935 (Trematoda: Echinostomatidae)

Larval stages of an echinostome were found in Planorbis planorbis in a brackish water lake on the Black Sea coast of Bulgaria. The cercaria is a large-tailed form with 19 collar spines. The life-cycle was completed in the laboratory using aquarium-reared fishes (Lebistes reticulatus, Puntius tetrazona tetrazona, P. pentazona pentazona, P. nigrofasciatus, Carassius auratus auratus and Xiphophorus helleri) as second intermediate hosts and canaries as definitive hosts. The redia, cercaria, metacercaria and experimentally reared adults are described. The species is determined as Petasiger grandivesicularis Ishii, 1935, and its cercaria is compared in detail with those of related forms. A key to the known large-tailed echinostome cercariae from the Palaearctic Region is presented.     

A revision of Patagifer Dietz, 1909 (Digenea: Echinostomatidae) and a key to its species

Patagifer Dietz, 1909 is revised and a key to the species is presented. P. oweni n. sp. is described from Threskiornis molucca (Cuvier) in the Western Province of Papua New Guinea and distinguished from the related P. chandrapuri Srivastava, 1952 by: the shape of the pair of large angle spines (cudgel-shaped vs sub-rectangular); pointed (vs rod-shaped) marginal spines; a smaller body and internal organs; more anteriorly located testes; and larger eggs. The new species differs from P. brygooi Richard, 1964 in its larger body, head collar, suckers, pharynx and eggs, longer oesophagus and testes, the latter being also more elongate and more anteriorly located, and a different number of collar spines (61-62 vs 59). P. bilobus (Rudolphi, 1819) (the type-species), P. parvispinosus Yamaguti, 1933, P. chandrapuri and P. vioscai Lumsden, 1962 are redescribed on the basis of museum and newly collected material. The variations in the number and size of the collar spines and other metrical characters of P. bilobus are studied in two different host species from Europe, Plegadis falcinellus and Platalea leucorodia. Other species considered valid are: Patagifer consimilis Dietz, 1909, P. acuminatus Johnston, 1917, P. fraternus Johnston, 1917, P. wesleyi Verma, 1936, P. brygooi and P. toki Onda, Imai & Ishii, 1983. P. plegadisi Sakla, Monib & Mandour, 1988 and P. simarai Nigam, 1944 are considered synonyms of P. bilobus, and P. sarai Saksena, 1957 is placed in synonymy with P. chandrapuri. Forms considered dubious are: P. bilobus of Machida et al. (Jpn J Parasitol 15:339, 1966) and Machida (Bull Natl Sci Mus Tokyo 11:157-160, 1968), P. simerai [sic] of Mehra (The fauna of India and adjacent countries. Platyhelminthes, 1980), P. skrjabini Hilmy, 1949 sp. inq. and P. srivastavai Peter, 1954 sp. inq. Lists of the records and hosts of the 11 valid species are included.     

A new pronocephalid, Pleurogonius tortugueroi n. sp. (Digenea), from the intestine of green sea turtles (Chelonia mydas) in Costa Rica

A new species of trematode, Pleurogonius tortugueroi n. sp. (Digenea: Pronocephalidae) is described from the lower intestine of green sea turtles (Chelonia mydas) from Tortuguero National Park, Costa Rica. The new species differs from all other species of Pleurogonius by having a short oesophagus and oval testes close to lateral posterior limit of the body. It differs from all other species, except P. malaclemys Hunter 1961, by having an ovary between the testes; moreover the latter species is a parasite of freshwater turtles. All others members of the genus have a long oesophagus, testes placed to some distance from the posterior end, and the ovary is pretesticular. The new species appears most closely related to P. linearis Looss, 1901 but differs from it by having a different body shape, lappets of the head collar close at the cecal bifurcation level, a longer vitellarian field, different testis shape and position, ovary intertesticular, and different egg size.     

Morphology and life history of Petasiger variospinosus (trematoda: echinostomatidae) in the Free State, South Africa

Specimens of the freshwater snail Bulinus tropicus (Krauss, 1848) collected in the Free State, South Africa shed cercariae with an oral collar bearing 27 spines. Tadpoles of the African clawed toad Xenopus laevis laevis Daudin, 1802 collected from the same waters harbored metacercariae with a similar collar of spines. Adults were obtained after feeding infected tadpoles to laboratory-reared reed cormorants, Phalacrocorax africanus (Gmelin, 1789). The parasite was identified as Petasiger variospinosus (Odhner, 1910), the life cycle was experimentally completed, and stages described by the use of light and scanning electron microscopy.     

A new species of Petasiger (Digenea: Echinostomiformes: Echinostomatidae) in the brown pelican, Pelecanus occidentalis, (Aves: Pelecaniformes: Pelecanidae), from the Area de Conservación Guanacaste, Costa Rica

A new species of Petasiger inhabits Pelecanus occidentalis, from the Area de Conservación Guanacaste, Costa Rica. The new species most closely resembles Petasiger novemdecim Lutz 1929 and Petasiger caribbensis Nassi, 1980 by having 19 circumoral spines and vitelline follicles confluent between the ventral sucker and gonads. The new species differs from both of these species by having a cirrus sac that is anteroposteriorly elongate and that reaches posteriorly to the midventral sucker, an ovary and Mehlis' gland that overlap the anterior testis dorsally, a uterus that lies dorsal to the ventral sucker, and a dextromedial genital pore. In P. novemdecim and P. caribbensis the cirrus sac is round and does not extend posteriorly to the anterior margin of the ventral sucker, both the ovary and Mehlis' gland are anterior to the anterior testis, the uterus runs lateral to and not dorsal to the ventral sucker, and the genital pore opens medially and sinistromedially, respectively.     

Two Species of Stephanostomum Looss, 1899 (Digenea: Acanthocolpidae) from Marine Fishes off Namibia,Including S. Beukelaardori n. sp.

Stephanostomum kovalevae Parukhin, 1968 from the intestine of Lophius vomerinus off Swakopmund, Namibia, is redescribed. It is characterised by its large number (c. 73-88) of circum-oral spines, its relatively very long hindbody and the vitellarium reaching close to or just overlapping the ventral sucker. S. beukelaardori n. sp., from the intestine of Zenopsis conchifera off Walvis Bay, Namibia, is described. It belongs to the group of species where the vitellarium reaches the ventral sucker, and which has c. 32-38 circum-oral spines. It is closest to S. casum (Linton, 1910), but differs in lacking the lining of prominent spines in the ejaculatory duct, probably in egg-size and in both forebody and hindbody lengths.     

Himasthla escamosa n. sp. (Digenea: Echinostomatidae) from the kelp gull, Larus dominicanus (Charadriiformes: Laridae), on the Patagonian coast, Argentina

In this article, we describe a new species of Himasthla Dietz, 1909 (Digenea: Echinostomatidae) from Larus dominicanus Lichtenstein (Aves: Laridae) in northern Patagonia, Argentina. We also describe the hosts, localities, and key diagnostic features and the measurements of the so far 25 described species. Of these species. Himasthla militaris, H. leptosoma, H. elongata, H. secunda, H. megacotyla, H. multilecithosa, H. piscicola, H. compacta, H. schachtachtinskoi, H. littorinae, H. continua, H. avosettae, and H. interrupta are similar to H. escamosa n. sp. in having 29 head collar spines. Himasthla leptosoma, H. piscicola, H. multilecithosa, H. interrupta, H. continua, and H. militaris can be differentiated from the new species mainly by the extension of the vitellaria. Himasthla avosettae, H. megacotyla, H. elongata, H. compacta, and H. littorinae have a different size or arrangement (or both) of head collar spines compared with H. escamosa. Himasthla secunda can be distinguished from H. escamosa n. sp. in having a larger body, testes, and ovary and a different position of the ovary. The comparison with H. schachtachtinskoi could not be done because the bibliography was not available. This is the first record of the genus in Argentina and from L. dominicanus.     

Rhopalotrema (Digenea: Didymozoidae), a new genus from Australian platycephalid fishes

Rhopalotrema n. g. is erected to accommodate two new species of didymozoid collected from platycephalid fishes from South-east Queensland, Australia and is assigned to the subfamily Didymozoinae. Rhopalotrema elusiva n. sp. is described from the fins of Platycephalus fuscus and R. pterygionastes n. sp. is described from the fins of P. indicus. The new genus is similar to Neometadidymozoon, but is distinguished from it by the structure of the testes, which are convoluted and extend from near the anterior end of the hindbody to a point only a short distance into the forebody. The two new species are distinguished from each other by their size and the size and shape of the oral sucker and pharynx.     

A description of Cinclotaenia georgievi n. sp. (Cestoda: Dilepididae), a tapeworm from the dipper Cinclus cinclus (L.) (Passeriformes: Cinclidae)

Cinclotaenia sp., described originally by Georgiev & Genov (1985) from the dipper Cinclus cinclus (L.) in Bulgaria, has recently been identified from the same host in the Carpathian Mountains in the Slovak Republic. This tapeworm is considered to be a new species, which is named C. georgievi n. sp. It is characterised by: a scolex armed with 23-27 (predominantly 24-26) hooks in two rows; hooks 30.5-36 microm long, with a blade 10-13.5 microm long and resembling in shape the diorchoid hooks of hymenolepidids; irregularly alternating genital pores with simple genital atria; a slightly conical cirrus armed by small spines of up to 3 microm in length; 24-51 testes posterior to a bi-alate, branched ovary; a gravid uterus filled with egg packets; and eggs with filaments. C. georgievi n. sp. differs from the closely-related C. tarnogradskii (Dinnik, 1927) in the slightly higher number of rostellar hooks, which have longer blades, and a larger cirrus.     

Sympatric species of Deretrema Linton, 1910: D. combesae n. sp. and D. combesorum n. sp. (Digenea: Zoogonidae) from the manybar goatfish Parupeneus multifasciatus (Quoy & Gaimard, 1824) (Perciformes: Mullidae) from New Caledonia

Two sympatric species of Deretrema, D. combesae n. sp. and D. combesorum n. sp. are described from the manybar goatfish Parupeneus multifasciatus from off New Caledonia, South Pacific. D. combesae n. sp. does not fit any of the described Deretrema subgenera. The combination of the characters, tegumental spines, caeca reaching past the testes, the vitellarium reaching into the hindbody, much of the uterus at the level of and anterior to the gonads, a long oesophagus, testes in the hindbody and the pre-testicular ovary are not found in any of the described subgenera. D. combesorum n. sp. fits into the subgenus Deretrema (Deretrema), but differs from the described species in the sucker-ratio, eggs size, elongate shape and contiguous testes. The sympatry of these dissimilar species of Deretrema casts doubt on the value of the subgenera in Deretrema.     

Mactra veneriformis, an intertidal clam, as a new second intermediate host for Acanthoparyphium marilae (Digenea: Echinostomatidae)

Metacercariae of Acanthoparyphium marilae Yamaguti, 1934 (Digenea: Echinostomatidae) were discovered in an intertidal clam, Mactra veneriformis, in a southwestern coastal area of the Republic of Korea. A total of 128 metacercariae were detected from 10 clams examined. They were round, 320 microm in average diameter, with 23 collar spines. They were fed experimentally to chicks, and 10 days later adult flukes were obtained. The adults were morphologically characterized by the head collar with a single row of 23 dorsally uninterrupted spines, without special end group spines, a round ventral sucker, 2 round and tandem testes, and vitellaria extending at lateral fields from the posterior extremity not beyond the middle level of the posterior testis. The most characteristic feature of this species was the limited distribution of vitellaria, which differs from Acanthoparyphium tyosenense Yamaguti, 1939, the metacercariae of which are encysted in the same mollusk species. This is the first report in which the metacercariae of this species were detected, and the intertidal bivalve, M. veneriformis, has been identified as a second intermediate host for A. marilae.     

Molecular characterisation of four echinostomes (Digenea: Echinostomatidae) from birds in New Zealand,with descriptions of <Emphasis Type="Italic">Echinostoma novaezealandense</Emphasis> n. sp. and <Emphasis Type="Italic">Echinoparyphium poulini</Emphasis> n. sp.

Morphological and molecular characterisation of echinostome specimens (Digenea: Echinostomatidae) recovered in one Anas platyrhynchos L. and one Cygnus atratus (Latham) (Anseriformes: Anatidae) from New Zealand revealed the presence of two known species, Echinostoma miyagawai Ishii, 1932 and Echinoparyphium ellisi (Johnston & Simpson, 1944) and two species new to science. Comparative morphological and phylogenetic analyses supported the distinct species status of Echinostoma novaezealandense n. sp. ex Branta canadensis (L.), A. platyrhynchos and C. atratus, and Echinoparyphium poulini n. sp. ex C. atratus. Echinostoma novaezealandense n. sp., a species of the “revolutum” species complex characterised by the possession of a head collar armed with 37 spines, keyed down to E. revolutum but was distinguished from the latter in having a much narrower body with almost parallel margins, longer oesophagus, wider cirrus-sac, larger seminal vesicle, much smaller ventral sucker, ovary, Mehlis’ gland and testes, more anteriorly located ovary and testes, and distinctly smaller eggs (81–87 × 42–53 vs 106–136 × 55–70 µm). This new species appears similar to Echinostoma acuticauda Nicoll, 1914 described in Australia but differs in having a longer forebody, more posteriorly located ovary and testes, and much smaller eggs (81–87 × 42–53 vs 112–126 × 63–75 µm). Echinoparyphium poulini n. sp. is differentiated from the four species of Echinoparyphium possessing 37 collar spines considered valid as follows: from E. chinensis Ku, Li & Chu, 1964 in having a much smaller body, four (vs five) angle spines and simple seminal vesicle (vs bipartite); from E. schulzi Matevosyan, 1951 in having a less robust body at a comparable body length, much smaller ventral sucker, ovary and testes, and longer but narrower eggs (87–109 × 50–59 vs 70–85 × 60–84 µm); and from the two smaller forms, E. serratum Howell, 1968 and E. aconiatum Dietz, 1909, in a number of additional metrical features correlated with body size and especially in the possession of much larger collar spines. Partial fragments of the mitochondrial nad1 and 28S rRNA genes were amplified for representative isolates of the four species and analysed together with sequences for Echinostoma spp. and Echinoparyphium spp. available on GenBank. Phylogenetic analyses based on the mitochondrial nad1 gene revealed congruence between the molecular data and species identification/delineation based on morphology; this was corroborated by the 28S rDNA sequence data.     

Microsomacanthus polystictae sp. n. and other cestodes of the family Hymenolepididae (Cyclophyllidea) from Steller's eider Polysticta stelleri from the Chaun lowlands (northwestern Chukotka)

8 species of cestodes belonging to the family Hymenolepididae were recorded from Polysticta stelleri (Pall.) in the Chaun lowland. A new species of hymenolepidids, Microsomacanthus polystictae sp. n., differing from close (by the length of proboscis hooks) species of the genus in the structure and size of the copulatory organ is described. Brief diagnosis of the new species: cestodes small, specimens ending with hermaphrodite proglottids 2.44 to 2.91 mm long. Proboscis hooks 0.038 to 0.042 mm long, blade 0.011 to 0.012 mm long. Strobila of maximum length with 84 proglottids. In young male proglottids the aporal testis half as large as poral and median ones, in well-developed proglottids testes 0.020 to 0.026 X 0.023 to 0.032 mm. Bursa of cirrus 0.150 to 0.190 X 0.020 to 0.028 mm. Cirrus 0.107 mm long, basis 0.008 to 0.011 mm wide, median part 0.012 to 0.014 mm wide, apical part 0.004 mm wide. Cirrus armed with spines 0.003 to 0.004 mm long. Ovary bilobate, yolk gland compact. Spermatheca small, situated medially, in front of poral ovary lobe. Copulative part of vagina sacciform, 0.086 to 0.118 mm long, 0.023 to 0.037 mm maximum width. Distally and proximally vagina with muscular sphincters. Uterus sacciform, with 35 to 40 embryos. There were no mature "eggs" in the material.     

Echinostoma macrorchis in Lao PDR: Metacercariae in Cipangopaludina Snails and Adults from Experimentally Infected Animals

The echinostome metacercariae encysted in Cipangopaludina sp. snails that were purchased from a market in Vientiane Municipality, Lao PDR, were identified as Echinostoma macrorchis (Digenea: Echinostomatidae) through recovery of adult flukes after experimental infection to rats and a cat. The metacercariae were round, 113-128 (121)×113-125 (120) µm, having a thick cyst wall, a head collar armed with collar spines, and excretory granules. The adult flukes recovered from the rats and cat at day 14 and 30 post-infection, respectively, were elongated, ventrally curved, and 3.9-6.3×0.7-1.1 mm in size. The head collar was distinct, bearing 43-45 collar spines with 5 angle spines on each side. Two testes were large (as the name implies), tandem, and slightly constricted at the middle, with irregular margins. Eggs were operculated, ovoid to elliptical, and 88-95×56-60 µm. In scanning electron microscopy, the head collar was prominent, with 43-45 collar spines. Scale-like tegumental spines were densely distributed on the ventral surface between the oral and ventral suckers. Sensory papillae were distributed mainly on the tegument around the 2 suckers. It is confirmed that E. macrorchis is distributed in Lao PDR using Cipangopaludina sp. snails as the second intermediate host.