Two new species of Clestobothrium (Cestoda: Bothriocephalidea), parasites of Merluccius australis and m. hubbsi (Gadiformes: Merlucciidae) from the Patagonian shelf of Argentina, with comments on Clestobothrium crassiceps (Rudolphi, 1819)

Abstract: Two new species of bothriocephalidean cestodes, Clestobothrium splendidum sp. n. from Merluccius australis (Hutton) and Clestobothrium cristinae sp. n. from Merluccius hubbsi Marini from the Patagonian shelf of Argentina, are described. Clestobothrium splendidum can be typified by the following characteristics: a medium-sized strobila composed of410-528 proglottides that are much wider than long; 49-90 testes per mature proglottis, partially surrounding the ovary posteriorly; a transversely elongated genital pore situated anterior to spurious articulations; presence of a genital atrium; a globular cirrus-sac occupying 4-6% of mature proglottis width; a vagina with sphincter and three pairs of osmoregulatory canals on each side of the proglottis. Clestobothrium cristinae is characterised by its small size; 71-219 proglottides; 39-64 testes per mature proglottis, usually surrounding completely the ovary posteriorly; a rounded genital pore situated at the same level of spurious articulations; an oval cirrus-sac occupying 8-16% of mature proglottis width; and three pairs of osmoregulatory canals on each side of the proglottis. Clestobothrium cristinae shares with C. splendidum the type and distribution of microtriches, except for the central surface delimited by two lips. Additionally, type and voucher materials of Clestobothrium crassiceps (Rudolphi, 1819) from Merluccius merluccius were studied. A key to species is provided.     

Ailinella mirabilis gen. n., sp. n. (eucestoda: pseudophyllidea) from Galaxias maculatus (Pisces: Galaxiidae) in the Andean-Patagonian region of Argentina

Ailinella gen. n. (Pseudophyllidea: Triaenophoridae) is proposed to accommodate Ailinella mirabilis sp. n. from Galaxias maculatus (Jenyns, 1842), a freshwater fish inhabiting the Andean lakes in Argentinean Patagonia. Ailinella belongs to the Triaenophoridae because it has a marginal genital pore, a follicular vitelline gland, and a ventral uterine pore. The new genus can be distinguished from other triaenophorids by the following combination of characters: a small body size, a low number of proglottides, which are longer than wide, a truncated pyramidal to globular scolex, a rectangular apical disc, presence of the neck, lack of internal longitudinal musculature separating the cortex from the medulla, testes distributed in one central field surrounding the ovary laterally and posteriorly, the vagina predominantly anterior to the cirrus sac, vitelline follicles circum-medullary, the genital pores post-equatorial, a saccate uterus, and operculate eggs. Blade-like spiniform microtriches were present on all tegument surfaces, and tumuli on all surfaces of the scolex and the anterior surface of the neck. Microtriches were characterized according to their size and density, and tumuli according to their size, inter-tumulus distance and density. Ailinella mirabilis is the first cestode described from G. maculatus and the second triaenophorid species recorded from a South American freshwater fish.     

Revision and phylogeny of rhamnocercinae monaco, Wood et Mizelle, 1954 (Monogenoidea: Diplectanidae)

Species of Rhamnocercinae Monaco, Wood et Mizelle, 1954 are gill parasites of sciaenid fishes (Perciformes). Seven are marine species (three in the western Atlantic and four in oriental Pacific) and one is a neotropical freshwater species (Rio Doce Basin, Brazil). While the status of the subfamily may be questioned, this assemblage of species is apparently supported by several shared apomorphic and plesiomorphic characters, such as: (1) peduncular spines with anterior and posterior roots; (2) haptor laterally expanded, armed with anchors (two pairs); bars (one ventral, two dorsal); 14 hooks and haptoral accessory spines; and (3) double (nested) tubes of the male copulatory organ (MCO), directed posteriorly with the genital pore lying posterior to the MCO. The phylogenetic hypothesis for the eight known species of this clade is: (Spinomatrix penteormos (Rhamnocercoides stichospinus, Rhamnocercoides menticirrhi) Rhamnocercus oliveri (Rhamnocercus rhamnocercus (Rhamnocercus stelliferi, Rhamnocercus bairdiella, Rhamnocercus margaritae)). This hypothesis indicates that Spinomatrix penteormos represents the sister group of all remaining rhamnocercines. The resulting phylogenetic sister-group relationships support the transfer of Rhamnocercus stichospinus Seamster et Wood, 1956 to Rhamnocercoides Luque et Iannacone, 1991 as Rhamnocercoides stichospinus (Seamster et Wood, 1956) n. comb.     

Cucullanus oceaniensis sp. n. (Nematoda: Cucullanidae) from Pacific eels (Anguilla spp.)

A new species of parasitic nematode, Cucullanus oceaniensis sp. n., is described from the intestine of the giant mottled eel Anguilla marmorata (type host) from Futuna Island (Wallis and Futuna Islands, Polynesia) and from A. marmorata and Anguilla sp. (cf. obscura) from Fiji Islands (Melanesia, South Pacific). The main distinguishing characteristics are the length of spicules (668-1,020 microm), situation of deirids (slightly anterior to the oesophago-intestinal junction) and the excretory pore (some distance posterior to the end of oesophagus), and the arrangement of caudal papillae in the male. It is the third known species of Cucullanus from Oceania and the first one reported from freshwater eels in the region of South Pacific. Cucullanus faliexae Morand et Rigby, 1998 is considered a junior synonym of Cucullanus australiensis Baylis, 1927.     

Redescription of Proteocephalus bagri and p. Rhamdiae (Cestoda: Proteocephalidae), parasites of Rhamdia quelen (Siluriformes: Pimelodidae) from South America, with comments on morphological variation

The pimelodid fish Rhamdia quelen (Quoy et Gaimard, 1824) in South America harbours two species of proteocephalid cestodes, Proteocephalus bagri Holcman-Spector et Ma?é-Garzón, 1988 and P. rhamdiae Holcman-Spector et Ma?é-Garzón, 1988. These species are redescribed based on a detailed morphological study, supported by multivariate analysis (principal component analysis). Features distinguishing these species are: (1) the shape of proglottides, (2) the mean number of testes, (3) the topography of vitelline follicles, (4) the thickness of internal longitudinal musculature, (5) the mean number of uterine branches, (6) the ratio of cirrus pouch length to proglottis width, (7) the shape of ovary in mature and gravid proglottides and (8) the genital pore position in mature proglottides. The specific status of P. bagri and P. rhamdiae is confirmed and neotypes of both species are designated.     

Two new species of Rhabdochona (Nematoda: Rhabdochonidae) from freshwater fishes in Thailand

Two new species ofrhabdochonid nematodes are described from the intestine of freshwater fishes in Chiang Mai Province, northern Thailand: Rhabdochona (Rhabdochona) pseudomysti sp. n. from the catfish Pseudomystus siamensis (Regan) (Bagridae, Siluriformes) in the Fang Brook, a tributary of the Kok River (the Mekong River basin), Fang District and Rhabdochona (Globochona) thaiensis sp. n. from the cyprinid Mystacoleucus marginatus (Valenciennes) (Cyprinidae, Cypriniformes) in the Ping River (the Chao Phraya River basin), Muang District. Rhabdochona pseudomysti is mainly characterized by simple, leaf-like oval deirids (a unique feature among Rhabdochona spp.), a prostom with 14 anterior teeth, the presence of basal prostomal teeth, the length ratio of the muscular and glandular portions of oesophagus (1:2.1-2.6), an unusually long left spicule (1.10-1.22 mm), length ratio of spicules (1:11.5-14.7), arrangement of genital papillae, and conspicuously elevated vulval lips. Rhabdochona thaiensis differs from other representatives of the subgenus Globochona Moravec, 1972 possessing caudal projections on the tail tip in that it has only 2 claw-shaped projections located ventrally on the tail tip of both males and females; the species is mainly characterized by the presence of distinct pseudolabia, 8 anterior prostomal teeth, absence of basal teeth, bifurcated deirids, length ratio of the muscular and glandular portions of oesophagus (1:11.3-11.9), conspicuously short (135-141 microm) left spicule, arrangement of genital papillae, and somewhat elevated vulval lips. Fully developed eggs of R. pseudomysti and R. thaiensis remain unknown. These are the first nominal species of Rhabdochona reported from Thailand.     

A new species of Taeniacanthus (Copepoda: Taeniacanthidae) parasitic on two pufferfish species, Marilyna meraukensis and M. darwinii (Teleostei: Tetraodontidae), from Australia

A new species of Taeniacanthidae (Copepoda, Cyclopoida), Taeniacanthus kiemae sp. n., is described based on adult female and male specimens collected from the branchial cavity wall of Marilyna meraukensis (de Beaufort) and M. darwinii (Castelnau) (Teleostei, Tetraodontidae) caught in Australian waters. The new species differs from its congeners by having the following combination of characters in the adult female: (1) maxilla armed with a stout terminal process and two small elements; (2) multiple rows of spinules on the large pectinate process of the antenna; (3) an extremely long and thin maxilliped claw; (4) second exopodal segment of leg 1 with eight setae; (5) third exopodal segment of leg 3 with three spines and four setae; (6) third exopodal segment of leg 4 with three spines and two setae; and (7) each spine on the free exopodal segment of leg 5 with a subterminal flagellum. Taeniacanthus kiemae is the second copepod species reported from M. meraukensis and M. darwinii and the first taeniacanthid species reported from pufferfishes in Australia.     

Psettarium anthicum sp. n. (Digenea: Sanguinicolidae) from the heart of cobia Rachycentron canadum (Rachycentridae) in the northern Gulf of Mexico

Psettarium anthicum sp. n. (Digenea: Sanguinicolidae) infects the myocardium and atrial wall of the cobia Rachycentron canadum (Linnaeus, 1766) (Rachycentridae) in the northern Gulf of Mexico off Mississippi, USA. It is the first member of Psettarium Goto et Ozaki, 1930 reported from other than the Indian Ocean or Pacific Ocean and the second species of the genus reported from cobia. It differs from its congeners by the combination of having posterior caeca with lateral projections appearing as thorns in lateral view and the male pore anterior to the o?type. The species of Psettarium, P. japonicum (Goto et Ozaki, 1929) (type species), P. tropicum Manter, 1940, P. sebastodorum Holmes, 1971, P. rachycentri (Lebedev et Parukhin, 1972) comb. n. (syn. Psettarioides rachycentri Lebedev et Parukhin, 1972) and P. anthicum sp. n., differ from other sanguinicolids by the combination of having an elongate body with a sinistral posterolateral protuberance, minute, straight tegumental body spines in ventrolateral transverse rows, posterior caeca greater than seven time the anterior caeca length, the o6type near the posterior end of the body, a uterus primarily between the ovary and o?type and an oviduct and vitelline duct extending posteriad primarily between the uterus and dextral body margin. We emend Psettarium and provide a diagnostic key to the species. Psettarioides is regarded as a junior synonym of Psettarium because herein we return its type species, P. tropicum, to Psettarium. Regarding the three other sanguinicolids formerly of Psettarioides, we suspect that P. pseudupenei Lebedev et Parukhin, 1972 belongs to Psettarium but include it only tentatively pending an examination of type or other material; we tentatively place P. kurochkini Parukhin, 1976 in Cardicola Short, 1952; and we designate P. grandis (Lebedev et Mamaev, 1968) as incertae sedis pending examination of type or other appropriate material.     

葡萄根围二种剑线虫(矛线目:长针线虫科)的鉴定

 从我国湖南、山东和河北三省的一些葡萄园中发现了二种习居于葡萄根围的剑线虫,分别为美洲剑线虫(Xiphinema americanum Cobb,1913)和湖南剑线虫新种(X.huna-niense n.sp.)。湖南剑线虫新种的主要鉴别特征是阴门极靠身体前部(V=24-27),阴道向后斜,与身体横径成明显的角度(8-21℃);仅一个后生殖枝,旁边分支形成二个卵巢;尾部末端中间指状突起很长(20-22μm);幼虫尾部比成虫尾部细长,末端指状突起也较长;各虫龄的c'值与虫龄大小成反比;没有发现雄虫。湖南剑线虫与巴西利亚剑线虫(X.brasilienseLordello,1951)和太平洋剑线虫(X.radicicola Goodey,1936)最接近,但存在明显的区分特征。     

Revision of Dioncopseudobenedenia Yamaguti, 1965 including the description of D. ancoralis sp. n. (Monogenea: Capsalidae) from Pacific acanthuroid teleosts

Dioncopseudobenedenia Yamaguti, 1965 (Monogenea: Capsalidae) is redefined. Dioncopseudobenedenia kala Yamaguti, 1965 (type species) is redescribed from type material from Hawaii and from new specimens from Heron Island, Queensland, Australia and New Caledonia. We made detailed observations on D. macracantha Yamaguti, 1968 from type material from Hawaii, and from new material from Heron Island and New Caledonia. Dioncopseudobenedenia ancoralis sp. n. is described from the gill chamber of Siganus lineatus (Valenciennes) from Green Island and Heron Island, Australia and from New Caledonia. This study confirms that only one pair of large central sclerites is present on the haptor in Dioncopseudobenedenia species. The male copulatory organ in species of Dioncopseudobenedenia is a penis contained in a fluid-filled space (= penis canal) with weakly muscular walls. Dioncopseudobenedenia kala and D. ancoralis bear a sclerite at the tip of the penis. In D. macracantha, the structure of the penis, which has no terminal sclerite, indicates it may combine the functions of a penis and a cirrus. Dioncopseudobenedenia is compared with Calicobenedenia Kritsky et Fennessy, 1999, the other capsalid genus with a single pair of large sclerites on the haptor. The large haptoral sclerites in species of Dioncopseudobenedenia resemble accessory sclerites, whereas those of C. polyprioni Kritsky et Fennessy, 1999 resemble hamuli. Observations of oncomiracidia confirmed that the large haptoral sclerites in D. kala are accessory sclerites. Haptoral morphology suggests that different Dioncopseudobenedenia spp. employ different means of attachment. Mating behaviour was observed twice between two different pairs of D. kala specimens from Heron Island. Two preserved specimens from Nouméa, New Caledonia had structures near the dorsal vaginal pore that we interpret as spermatophores. This is the first report of spermatophores in a capsalid inhabiting the gill chamber. The geographic distribution of Dioncopseudobenedenia spp. is discussed.     

滑刃线虫属一新种——西洋参叶线虫

 1990~1991年在吉林左家中国农科院特产研究所试验地的西洋参叶片上发现多角形褐色病斑,由一种滑刃线虫为害引起。其种的鉴别特征为:口针较短(7.5~10.0 μm),唇区基部缢缩,排泄孔的位置位于神经环和贲门之间,尾尖突为星状,雄虫的交合刺具较明显的顶尖和喙突,与滑刃线虫属内的其它种不同。经鉴定为滑刃线虫一新种,定名为西洋参叶线虫Aphelenchoides panaxofolia.     

Two new species of Myliocotyle (Monogenea: Monocotylidae) from the gills of Aetomylaeus maculatus and A. nichofii (Elasmobranchii: Myliobatidae) from Sarawak, Borneo, Malaysia

Myliocotyle borneoensis sp. n. and M. multicrista sp. n. (Monocotylidae: Heterocotylinae) are described from the gills of the mottled eagle ray, Aetomylaeus maculatus (Gray), and the banded eagle ray A. nichofii (Bloch et Schneider) (Myliobatidae), respectively, collected from the northern coast of Malaysian Borneo. These are the first monogeneans to be described on elasmobranchs from Borneo. The formerly monotypic Myliocotyle (for M. pteromylaei) was distinguished from other monocotylids by the distribution and morphology of the eight sclerotised dorsal haptoral accessory structures and the morphology of the male copulatory organ. However, we have determined that M. pteromylaei has ten structures on the dorsal surface of the haptor. Myliocotyle borneoensis is distinguished from M. pteromylaei by the morphology of the male copulatory organ and its accessory piece. Myliocotyle multicrista has 12 sclerotised dorsal haptoral accessory structures and a male copulatory organ with two accessory pieces. Additional sclerotised ridges across the ventral surfaces of each loculus (except the posterior-most pair) are also present in M. multicrista. The diagnosis for Myliocotyle is revised given our discovery of additional dorsal haptoral accessory structures in the type species and to accommodate other new characters of the two new species. Anterior secretions of Myliocotyle are discussed.     

Neotropical Monogenoidea. 40. Protorhinoxenus prochilodi gen. n., sp. n. (Monogenoidea: Ancyrocephalinae), parasite of prochilodus lineatus (Characiformes: Prochilodontidae) from south Brazil

The monotypic Protorhinoxenus gen. n. is proposed to accommodate a species with the following characteristics: 1) tubular sclerotised vagina, 2) vaginal pore dextrolateral, 3) ventral and dorsal anchors with undifferentiated elongate shaft and base (representing approximately 2/3 of the length of anchor), and 4) superficial and deep roots of ventral and dorsal anchors lacking. Protorhinoxenus prochilodi sp. n. is described from the gills of Prochilodus lineatus (Valenciennes) of the Represa Capivari-Cachoeira, Municipality of Campina Grande do Sul, metropolitan area of Curitiba, Paraná. Specimens of other probable new species of Protorhinoxenus are reported from Prochilodus lineatus of the Rio Paranapanema, Municipality of Salto Grande, S?o Paulo; Hoplias spp. of the Rio Dois de Fevereiro, Municipality of Antonina, Paraná, and the Rio Piraquara, metropolitan area of Curitiba, Parana; Leporinus elongatus Valenciennes of the Rio Tibagi, Municipality of Jataizinho, Parana; and Schizodon fasciatum Agassiz of the Rio Solim?es, island of Marchantaria, near Manaus, Amazonas. Protorhinoxenus appears to be a sister group of Rhinoxenus Kritsky, Boeger et Thatcher, 1988 based on the following apparent synapomorphies: 1) ventral and dorsal anchors lacking superficial and deep roots, 2) ventral and dorsal anchors with elongate shaft, and 3) male copulatory organ with counterclockwise rings.     

Tapeworms (Cestoda: Proteocephalidea) of firewood catfish Sorubimichthys planiceps (Siluriformes: Pimelodidae) from the Amazon River

A survey of proteocephalidean cestodes found in the firewood catfish Sorubimichthys planiceps (Spix et Agassiz) from the Amazon River is provided. The following taxa parasitic in S. planiceps are redescribed on the basis of their type specimens and material collected recently in the Amazon River, near the type localities in Brazil, and in Iquitos, Peru: Monticellia lenha Woodland, 1933; Nomimoscolex lenha (Woodland, 1933) (syn. Proteocephalus lenha Woodland, 1933); and Monticellia megacephala Woodland, 1934, for which a new genus, Lenhataenia, is proposed, with L. megacephala (Woodland, 1934) comb. n. as its type and only species. The new genus is a member of the Monticelliinae, i.e. has all genital organs in the cortex, and is most similar to Chambriella in possessing biloculate suckers and lacking a metascolex. It differs in the morphology of the cirrus-sac that contains a strongly coiled, thick-walled internal sperm duct (vas deferens) and a muscular cirrus of the appearance typical of most proteocephalideans, whereas that of Chambriella is sigmoid, with voluminous, tightly sinuous thick-walled internal sperm duct. In addition, Lenhataenia possesses a well developed internal musculature, whereas the internal musculature of Chambriella is weakly developed, formed by a low number of muscle fibres. The scolex morphology and distribution of microtriches of Peltidocotyle lenha (Woodland, 1933) (syn. Othinoscolex lenha Woodland, 1933 and Othinoscolex myzofer Woodland, 1933), Chambriella sp. and Choanoscolex sp. are described using scanning electron microscopy. The two latter taxa may be new for science and are reported from S. planiceps for the first time.     

广州毛刺线虫新种的描述

 广州毛刺线虫新种(Trichodorus guangzhouensis n. sp.)采集于广州市白云区的莴苣(Lactuca sativa)根际土壤。其主要鉴别特征是虫体和瘤针较短;雄虫的3个腹中颈乳突位于瘤针后和排泄孔前,交合刺短、无刚毛和条纹,泄殖腔前有3个腹中生殖乳突,精细胞大、有大且呈香肠形的核;雌虫阴门纵裂,阴门骨化结构小、三角形到园三角形、相距较近,阴道长度大于阴门处体宽的1/3,受精囊大、有精子。该新种在多数形态特征测量数据上,以及雄虫的3个腹中颈乳突位置、泄殖腔前腹中生殖乳突数量、精细胞形态,雌虫受精囊和阴门骨化结构形态等特征上,与背弯毛刺线虫(Trichodorus reduncus Siddiqi & Sharma,1995)相近似。但它们在雄虫交合刺和引带形态、第一腹中生殖乳突(SP1)的位置,雌虫阴门形态等特征上存在显著差异。     

External morphological differences between Crepidostomum farionis and Crepidostomum metoecus (Trematoda: Allocreadiidae), parasites of salmonids,as revealed by SEM

Scanning electron microscopy examinations of trematode specimens belonging to Crepidostomum farionis (O.F. Muller, 1784) and C. metoecus Braun, 1900, collected from brown trout, Salmo trutta fario L., in the Czech Republic, made it possible to study their surface morphology including details not described previously. The tegument of both species bears numerous characteristic papillae around the oral sucker (in C. metoecus also around the ventral sucker) and the ventral and dorsal surfaces of the forebody, exhibiting a high degree of variability in numbers and arrangement, with tegumental bosses forming lateral fields on the forebody and minute sensory receptors with submerged cilia scattered on the surface of the dorsal part of the oral sucker. In addition to marked differences in the size, shape and position of the oral muscular lobes, both species distinctly differ in the number of genital pores: two separate pores in C. farionis and a single pore in C. metoecus.     

Heliocotyle ewingi sp. n. (Monogenea: Monocotylidae) from the gills of Myliobatis australis (Myliobatididae) from Tasmania, Australia

Heliocotyle ewingi sp. n. (Monogenea: Monocotylidae) is described from the gills of Myliobatis australis Macleay, 1881 (Myliobatididae) collected from Norfolk Bay near Hobart, Tasmania, Australia. Heliocotyle ewingi can be distinguished readily from the only other species in the genus, Heliocotyle kartasi Neifar, Euzet et Ben Hassine, 1999, by the presence of a single pseudoseptum on each of the peripheral loculi except the posteriormost, eyespots and by the morphology of the male copulatory organ which is a short, straight sclerotised tube which lacks a sclerotised accessory piece. The generic diagnosis is revised to accommodate the new species and the anterior glands are discussed.     

Comparative morphology of eggs of the Haplorchiinae (Trematoda: Heterophyidae) and some other medically important heterophyid and opisthorchiid flukes.

The egg morphology of the following medically important small flukes from Southeast Asia and Far East were studied: Opisthorchis viverrini, Clonorchis sinensis (Opisthorchiidae), Haplorchis taichui, H. pumilio, H. yokogawai, Stellantchasmus falcatus and Metagonimus sp. (Heterophydiae). This study revealed a great intraspecific variability and interspecific similarity in size and shape of eggs. The eggs shape does not seem to be suitable for species identification. On the other hand, biometrical analysis of egg size enabled us to divide eggs from the species studied into four distinct groups according to the Faust-Meleney index (FMI) characterizing egg size rather than the length and width of eggs. The surface structures of eggs, delineated by using a scanning electron microscope (SEM), appeared to be a suitable morphological feature for distinguishing some groups of small flukes. Eggs from the Haplorchiinae were typified by the characteristic filamentous mesh structure. The problems of identification of eggs in human stool samples and suitability of using morphological criteria such as shape and size of eggs are discussed herein.     

Taxonomical study into two new species of Philometra (Nematoda: Philometridae) previously identified as Philometra lateolabracis (Yamaguti, 1935)

Males of the nematode Philometra lateolabracis (Yamaguti, 1935), the type species of the genus Philometra Costa, 1845, were discovered for the first time in gonads of its type host, the Japanese seaperch, Lateolabraxjaponicus (Cuvier). Morphological comparisons carried out between the collected male and female P. lateolabracis with the male and female philometrid nematodes previously reported as P. lateolabracis infecting chicken grunt, Parapristipoma trilineatum (Thunberg), and red sea bream, Pagrus major (Temminck et Schlegel), revealed that the latter represent two new species, Philometra isaki sp. n. and Philometra madai sp. n., respectively. Molecular comparison of ITS2 rDNA between P. lateolabracis and P. madai supported the morphological conclusion that the two nematodes obtained from different fish species should be assigned to different species.