The Pacific Notocotylus atlanticus (Digenea: Notocotylidae)

Recently two unidentified Notocotylus species have been recovered from a mallard in Hokkaido, Japan. Preliminary data indicated that one of them may belong to N. atlanticus—a species found in Europe and on the Atlantic coast of North America. Now we have sequenced partial cox1 for several European N. atlanticus isolates and performed a barcode gap analysis. It has shown the conspecificity of European and Japanese worms, bringing up discussion on distribution, transmission and host specificity in this species.     

Notocotylus primulus n. sp. (Trematoda: Notocotylidae) from the crested duck Lophonetta specularioides (Aves,Anatidae) from Patagonian coast,southwestern Atlantic Ocean

Species in the genus Notocotylus (Trematoda, Notocotylidae) are cosmopolitan parasites of mainly aquatic birds and, to a lesser extent, mammals. In this paper we describe Notocotylus primulus n. sp. parasitizing the Crested Duck, Lophonetta specularioides, from the Patagonian coast, southwestern Atlantic Ocean, based on morphological and molecular data. The new species could be distinguished from its congeners by the combination of several features; among them, the position of the genital pore that is prebifurcal and located close to the posterior margin of the oral sucker, a greater number of both ventral papillae and uterine loops, and a large cirrus sac. Molecular results of the ITS2 sequence support the location of this new species in the genus Notocotylus due to a close relationship with Notocotylus malhamensis (the lower genetic distance of the ITS2 sequences).     

Brachylaima phaedusae n. sp. (Trematoda: Brachylaimidae) from door snails in Japan

The metacercarial infections of door snails (Gastropoda: Clausiliidae) with unknown species of the genus Brachylaima (Trematoda: Brachylaimidae) have recently been reported in eastern Honshu and Kyushu, Japan. A large scale snail survey was carried out to clarify their taxonomic status. From the period of 2015 to 2020, a total of 1239 land snails (768 door snails and 471 others) were collected from 32 localities in Honshu, Shikoku, and Kyushu. The resulting trematode isolates were identified as Brachylaima sp. by mitochondrial DNA barcoding. The sporocysts were found only a few from Megalophaedusa sublunellata (Clausiliidae), Tauphaedusa subaculus (Clausiliidae), and Aegista trochula (Camaenidae), while the metacercariae were frequently detected from 14 species of Clausiliidae and 2 species of other families. Although Brachylaima sp. showed a broad range of intermediate hosts, door snails seem to be very important to drive the life cycle. The gravid adults of Brachylaima sp. was experimentally raised from metacercariae using immunosuppressed mice. Morphological, phylogenetical, and ecological considerations prompted us to propose Brachylaima phaedusae n. sp. for this unknown species. The definitive hosts of the new species are completely unknown. The wide geographic distribution and high genetic diversity of the new species suggest a possibility that the definitive host is ground-foraging birds, which prefer door snails.     

Catatropis hatcheri n. sp. (Digenea: Notocotylidae) from Heleobia hatcheri (Prosobranchia: Hydrobiidae) and notes on its life-cycle in Patagonia, Argentina

A new species of Catatropis Oghner, 1905 from a freshwater Neotropical prosobranch snail, Heleobia hatcheri (Hydrobiidae), is described. Naturally infected snails were collected from Nahuel Huapí Lake in Andean Patagonia. The characteristics of the larval stages are also presented. Experimental adults were recovered from the distal region of the intestinal caeca of chicks and ducklings and natural adults from a wild duck Anas platyrhynchos. Adults of Catatropis hatcheri n. sp. can be distinguished from all other species of the genus in having 10-12 (11) ventral glands in each lateral row, the cirrus-sac extending back to between the first third and the middle of the body, the metraterm shorter than the cirrus-sac, a previtelline field of 1,258-1,544 (1,396), vitelline follicles reach back to the anterior border of the testes with some follicles extending slightly lateral to them, only external testicular margin lobed and genital pore in median line just posterior to the intestinal bifurcation. In addition, the eggs have one filament on each pole, the rediae contain one or two mature cercariae, and the cercariae are tri-oculate, with a long tail and encyst in the environment.     

Insights into the development of Notocotylus attenuatus (Digenea: Notocotylidae) in Lymnaea stagnalis: from mother sporocyst to cercariae

Notocotylus attenuatus (Digenea: Notocotylidae) is a monostome fluke parasitizing the intestinal caeca of waterfowl that uses an injection apparatus to infect its intermediate snail host. Morphology of the invading larva (a sporocyst), and the intramolluscan larval development of this fluke have not been characterized extensively. In this study, experimental infections of Lymnaea stagnalis using N. attenuatus eggs resulted in the development of sporocysts containing one germ ball or mother redia between 12 and 21 days post exposure (p.e.) within the hepatopancreas. Independent mother rediae and developing daughter rediae were present between day 25 and day 42 p.e. Cercariae, within the body of rediae, were detected 42 days p.e. The development of daughter rediae and cercariae started posteriorly in the body of parent redia and these larvae migrated anteriorly during development towards the birth pore. A cercaria was also observed emerging from the birth pore and released cercariae maturated further within the snail hepatopancreas prior to leaving the snail. The intramolluscan development was completed 45 days p.e. when the first fully formed cercariae were shed into the outer environment. These data detail the fascinating post-embryonic development of N. attenuatus and highlight the intricate nature of larval transitions within its snail host.     

Catatropis hatcheri n. sp. (Digenea: Notocotylidae) from Heleobia hatcheri (Prosobranchia: Hydrobiidae) and notes on its life-cycle in Patagonia, Argentina

A new species of Catatropis Oghner, 1905 from a freshwater Neotropical prosobranch snail, Heleobia hatcheri (Hydrobiidae), is described. Naturally infected snails were collected from Nahuel Huapí Lake in Andean Patagonia. The characteristics of the larval stages are also presented. Experimental adults were recovered from the distal region of the intestinal caeca of chicks and ducklings and natural adults from a wild duck Anas platyrhynchos. Adults of Catatropis hatcheri n. sp. can be distinguished from all other species of the genus in having 10–12 (11) ventral glands in each lateral row, the cirrus-sac extending back to between the first third and the middle of the body, the metraterm shorter than the cirrus-sac, a previtelline field of 1,258–1,544 (1,396), vitelline follicles reach back to the anterior border of the testes with some follicles extending slightly lateral to them, only external testicular margin lobed and genital pore in median line just posterior to the intestinal bifurcation. In addition, the eggs have one filament on each pole, the rediae contain one or two mature cercariae, and the cercariae are tri-oculate, with a long tail and encyst in the environment.     

Catatropis chilinae n. sp. (Digenea: Notocotylidae) from Chilina dombeiana (Gastropoda: Pulmonata) and notes on its life-cycle in Patagonia,Argentina

A new species of Catatropis from a freshwater pulmonate snail of the family Chilinidae, which is endemic to South America, is described. Naturally infected Chilina dombeiana were collected from several localities in Andean Patagonia. The characteristics of the larval stages are presented. Experimentally reared adults, located in the distal portion of the intestinal caeca, were recovered from chickens and ducks. Adults of Catatropis chilinae n. sp. can be distinguished from all other species in having 9-11 (10) ventral glands, a cirrus-sac extending between the first third and the middle of the body, a metraterm slightly shorter or equal to the cirrus-sac, vitelline follicles reaching forward to the middle of the body, lobed testes, and a genital pore closely posterior to the caecal bifurcation. Eggs bear polar filaments only at the anopercular end. Rediae have only one or two cercariae. Shed cercariae are trioculate with a long tail and encyst in the environment, and metacercariae become infective 72 hours after encystment. This species is widely distributed between 40°10 S and 43°09 S and it is the first Catatropis species recorded for the Chilinidae and for Argentina.     

Brachylaima lignieuhadrae n. sp. (Trematoda: Brachylaimidae) from land snails of the genus Euhadra in Japan

Land snails of the genus Euhadra (Gastropoda: Bradybaenidae) are indigenous to the Japanese Archipelago. The larvae of an unknown species, tentatively named as Brachylaima sp. B (Trematoda: Brachylaimidae), have been found from Euhadra brandtii sapporo in Hokkaido, the northernmost island of Japan. In this study, a large-scale snail survey covering a wide area of Japan was conducted to confirm the larval parasite from members of Euhadra and related genera. Sporocysts with cercariae were found only from Eu. brandtii sapporo in Hokkaido and Euhadra callizona in central Honshu at low prevalence (1.0–9.6%). The metacercariae were detected widely from 6 species of Euhadra and the related genera at high prevalence (7.1–100%). A molecular identification by DNA barcoding demonstrated almost all of the larvae to be Brachylaima sp. B. Adult worms experimentally raised from the metacercariae were morphologically most similar to Brachylaima ezohelicis in Hokkaido, but could be differentiated by the microstructure of the tegumental surface. We propose Brachylaima lignieuhadrae n. sp. for the unknown species, based on the morphology, DNA profile, host specificity, and geographic distribution. Phylogeography of the new species suggests a possibility that migratory birds serve as the definitive hosts.     

Sargassum boreale sp. nov. (Fucales, Phaeophyceae) from Hokkaido, Japan

A new species, Sargassum boreale Yoshida et Horiguchi is described. It belongs to the subgenus Bactrophycus section Teretia, with cylindrical receptacles and is distinct from Sargassum confusum C. Agardh, S. pallidum (Turner) C. Agardh and Sargassum microceratium (Turner) C. Agardh in having a rather elongated stem with smooth surface and distantly issuing main branches, with narrow leaves. The distinction between S. boreale and these species is also revealed by a difference in internal transcribed spacer 2 (ITS‐2) sequences. In addition to the base substitutions, the existence of a large gap in S. boreale distinguishes this species from others. Sargassum boreale is distributed around Hokkaido and Saghalien to 50°N latitude. A key to the species of section Teretia is provided.     

<Emphasis Type="Italic">Notocotylus biomphalariae</Emphasis> n. sp. (Digenea: Notocotylidae)from <Emphasis Type="Italic">Biomphalaria peregrina</Emphasis> (Gastropoda: Pulmonata) in Patagonia,Argentina

A new species of Notocotylus was found parasiting a freshwater pulmonate snail, Biomphalaria peregrina. Naturally infected snails were collected from two temporary ponds in the Nahuel Huapí National Park in Patagonia. The characteristics of the larval stages are presented. Experimental adults were recovered from the intestinal caeca of ducks and chicks. Adults of Notocotylus biomphalariae n. sp. exhibit an aspinose tegument, two lateral rows of 11 ventral glands and a median row of four, a uterus with 12–16 coils of which 2–4 are previtelline, a metraterm equivalent in size to 65–68% of the cirrus-sac length, a previtelline field which extends to the middle of the body, a lobed testis and a genital pore closely posterior to the intestinal bifurcation. The rediae have one to three cercariae. The cercariae, when shed, are trioculate and have a long tail; they encyst in the environment and become infective 12 days after encystment.     

New species and new genus of Pseudohaploporinae (Digenea): Pseudohaploporus pusitestis sp. n. and Parahaploporus elegantus n. g., sp. n. (Digenea: Pseudohaploporinae) from Vietnamese mullet fish

Two new species of Pseudohaploporinae, Pseudohaploporus pusitestis sp. n. and Parahaploporus elegantus n. g., sp. n., are described from intestines of the Vietnamese mullet fish Moolgarda seheli and Osteomugil cunnesius, respectively. Pseudohaploporus pusitestis sp. n. differs from two known Pseudohaploporus species, P. vietnamensis and P. planiliza, by the absence of a diverticulate hermaphroditic duct and muscular sphincters at the proximal end of the hermaphroditic sac. Metrically, P. pusitestis sp. n. is close to P. vietnamensis and differs from this species and from P. planilizum by lower maximum sizes of most parameters. Parahaploporus elegantus n. g., sp. differs from representatives of Pseudohaploporus by the presence of a single testis and the armament of hermaphroditic duct and is morphologically close to trematodes of the genus Haploporus. However, P. elegantus n. g differs from all known Haploporus species from mugilids of the Indo-West Pacific by the structure of the armament of the hermaphroditic duct and also by size of body, organs and eggs. The validity of designating two new species and a new genus of trematodes is supported by ITS and 28S rDNA sequence data. Phylogenetic reconstructions showed that the new trematodes belong to the Pseudohaploporinae, which formed a well-supported cluster within the monophyletic Haploporidae.     

Macvicaria taksengi n. sp. (Digenea: Opecoelidae) in marine teleosts from Pinang,Malaysia

Summary A new species, Macvicaria taksengi (Opecoelidae: Plagioporinae), is described from the fishes Otolithes ruber and Sillago sihama from Pinang, Malaysia. It differs from most other members of the genus in the position of the ovary relative to the testes and the anterior position of the genital pore. A brief discussion on the Indo-West Pacific forms of the genus Macvicaria and related genera includes references to several new combinations: M. [Lebouria] isaitschikowi (Layman, 1930), M. [Plagioporus] sillagonis (Yamaguti, 1938), M. [Plagioporus] chrysophrys (Nagaty & Abdel Aal, 1969) and M. [Plagioporus (Plagioporus)] longisaccus (Fischthal & Kuntz, 1964).     

Ogmogaster heptalineatus n.sp. (Trematoda: Notocotylidae) from the Chilean sea lion Otaria flavescens

Summary Ogmogaster heptalineatus n.sp. is described from the Chilean sea lion Otaria flavescens. Distinct characteristics of the species are: presence of 7 longitudinal ridges on the ventral surface, cirrus armed with scales, testes and ovary deeply lobed and eggs circular with short polar filaments. This is the first report of the genus Ogmogaster from South America and the first report of Otaria flavescens as a host for this genus. ac]19820320     

Strzeleckia major n. g., n. sp. and S. minor n. sp. (Digenea: Hasstilesiidae) from Antechinus swainsonii (Marsupialia: Dasyuridae) in Australia

Strzeleckia major n. g., n. sp. and S. minor n. sp. are described from the dusky antechinus Antechinus swainsonii (Marsupialia: Dasyuridae) from the Kosciusko National Park in southern New South Wales, Australia. The two species were found together in the same individual host animals but occupy different sites in the intestine. The new genus is placed within the Hasstilesiidae, where it differs from the only other genus, Hasstilesia, by being more elongate and in having larger suckers, tandem testes, the ovary between rather than opposite the testes, and in having the caeca not reaching the posterior end of the body. It is suggested that the life-cycles of these species are similar to those of other hasstilesiids. Pupillid snails may act as sole intermediate hosts.     

Haematoloechus danbrooksi n. sp. (Digenea: Plagiorchioidea) from Rana vaillanti from Los Tuxtlas,Veracruz, Mexico

Haematoloechus danbrooksi n. sp. from the lungs of Rana vaillanti in Veracruz state, Mexico, was found. The new species is most similar morphologically to H. medioplexus, H. parviplexus, and H. meridionalis in having a ventral sucker less than half the diameter of the oral sucker. It differs from these species by the extension of the vitellaria, which are shorter in the new species, and in the shape of the tegumental spines, which are blunt in the new species. It differs from all other known species of Haematoloechus in the distribution of the uterine loops that are arranged diagonally and that present several short, extracecal. longitudinal loops in the postacetabular region. The new species shows 1.2% sequence divergence in partial 28S sequence with respect to H. medioplexus, 1.1% with H. parviplexus. and 2.5% with H. meridionalis, sequence divergences complementing the morphological differences.