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Based on light and scanning electron microscopical studies, a new nematode parasite, Pseudodelphis eleginopsis n. sp. (Dracunculoidea: Guyanemidae), is described from tissues behind the gills of the Patagonian blennie Eleginops maclovinus (Cuvier) (Perciformes: Eleginopsidae) off the Atlantic coast (San Matías and San José Gulfs) of Patagonia, Argentina. The new species is mainly characterised by the length of the body (males 10–13 mm, larvigerous females 31–59 mm), the number (14) and arrangement of cephalic papillae, the absence of a buccal capsule, the muscular to glandular oesophagus length ratio (1:3–4) of larvigerous females, the length of the spicules (48–63 µm) and the number (7 pairs) and arrangement of the caudal papillae in the male. Pseudodelphis eleginopsis n. sp. is the first species of this genus described from a marine fish in the Atlantic Ocean and the first known dracunculoid parasitising the fish host belonging to the family Eleginopsidae. As revealed by the examination of very young females of the new species, the female genital tract of Pseudodelphis spp. is monodelphic. The genus Syngnathinema Moravec, Spangenberg & Frasca, 2001 is considered a junior synonym of Pseudodelphis Adamson & Roth, 1990 and, consequently, S. californiense and S. chitwoodi are transferred to Pseudodelphis as P. californiensis (Moravec, Spangenberg & Frasca, 2001) n. comb. and P. chitwoodi (Moravec & Kuchta, 2013) n. comb., respectively. Two dracunculoid species, Pseudodelphis limnicola Brugni & Viozzi, 2006 and the previously established Philonema percichthydis Moravec, Urawa & Coria, 1997, both described from the same freshwater host species, Percichthys trucha (Valenciennes), in the same region (Patagonia), are considered to be identical; therefore, the valid name of this species is Pseudodelphis percichthydis n. comb. and P. limnicola becomes its junior synonym. A key to the species of Pseudodelphis is provided.  相似文献   

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The bacterial species of the genus Xenorhabdus in the family Enterobacteriaceae have a mutualistic association with steinernematid entomopathogenic nematodes (EPNs), which have been used as biological control agents against soil insect pests. In this study we present the genetic and phenotypic characterizations of the Xenorhabdus species isolated from steinernematid nematodes in Japan. The 18 Japanese Xenorhabdus isolates were classified into five bacterial species based on 16S ribosomal RNA (16S rRNA) gene sequences: Xenorhabdus bovienii, Xenorhabdus hominickii, Xenorhabdus indica, Xenorhabdus ishibashii, and Xenorhabdus japonica. There was no genetic variation between the 16S RNA sequences among the three X. ishibashii isolates, 0–0.1% variation among the five X. hominickii isolates, and 0–0.5% among the eight X. bovienii isolates. Phenotypic characterization demonstrated that representative isolates of the five bacterial species shared common characteristics of the genus Xenorhabdus, and only X. hominickii isolates produced indole. Symbiotic association and co-speciation of Xenorhabdus bacteria with Steinernema nematodes from Japan are discussed.  相似文献   

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The aporocotylid fauna of the mottled spinefoot, Siganus fuscescens (Houttuyn), from Moreton Bay, Queensland, Australia, was characterised using a combined morphological and molecular approach. Four aporocotylid species were identified, three belonging to the genus Ankistromeces Nolan & Cribb, 2006 and one to Cardicola Short, 1953. Specimens of Cardicola matched an undescribed species from the same host and locality; this species is described as Cardicola mogilae n. sp. Phylogenetic analyses of ITS2 and 28S data showed that C. mogilae n. sp. forms a strongly supported clade with other Cardicola species from siganid fishes. We record Ankistromeces olsoni Nolan & Cribb, 2006 in Moreton Bay for the first time, redescribe A. dunwichensis Nolan & Cribb, 2006 on the basis of new specimens and sequence data and re-report Ankistromeces sp. X from Moreton Bay based on molecular data. We review the status of the ten putative species of aporocotylids reported from siganids. Small variation in ITS2 rDNA sequences, in association with different geographic localities, was previously used to separate Cardicola lafii Nolan & Cribb, 2006 from C. parilus Nolan & Cribb, 2006, C. bartolii Nolan & Cribb, 2006 from C. watsonensis Nolan & Cribb, 2006, C. tantabiddii Nolan & Cribb, 2006 from Cardicola sp. 2, Ankistromeces sp. Y from A. olsoni and Ankistromeces sp. X from Ankistromeces sp. Z. These five combinations are reinterpreted as each representing a single species; Cardicola lafii is recognised as the senior synonym of C. parilus and C. bartolii as the senior synonym of C. watsonensis. This study thus suggests that six, rather than ten, species should be recognised as infecting S. fuscescens. This richness remains greater than is known for any other fish species and siganids are, so far, unique among fishes in harbouring two strongly radiated lineages of aporocotylids.  相似文献   

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Cardinal fish are commercially valuable species. In the Colombian Caribbean Sea E. occidentalis and E. pandionis occurred in 37and 35% of tows during a research trawl survey (>200 m), respectively and the biology of these vulnerable species is unknown. The aim of this work is to describe the spatial distribution patterns of biomass, size structure and morphometric relationships of E. occidentalis and E. pandionis in deep waters of the Colombian Caribbean Sea. The samples were collected by trawling in depths between 200 and 550 m. No statistical differences were found in size by sexes in both species. In female and male E. occidentalis the growth was isometric, while in female and male E. pandionis it was positive allometric. E. occidentalis occurred mainly in the northern zone of Colombian Caribbean Sea, with highest aggregations off Santa Marta and Riohacha. E. pandionis was distributed in the northern area between Santa Marta and Riohacha and in the southern area between Cartagena and Morrosquillo Gulf. However, before the exploitation of these species is considered, further research is required to determine basic life history traits, such as growth, reproduction, recruitment, and mortality.  相似文献   

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Deladenus (=?Beddingia) siricidicola (Tylenchida: Neotylenchidae) is the most effective biocontrol agent used against the invasive wood wasp, Sirex noctilio (Fabricius) (Hymenoptera: Siricidae). The nematodes feed and reproduce on the wood-inhabiting fungus, Amylostereum areolatum (Chaillet ex Fr.) Boidin (Russulales: Amylostereaceae) and parasitise larvae of S. noctilio. In the nematode biocontrol program, the nematodes are inoculated into herbicide-weakened ‘trap trees’. Recent declines in nematode parasitism of S. noctilio in Australia have coincided with an increased incidence of an exotic bark beetle, Ips grandicollis (Eichhoff) (Coleoptera: Curculionidae), attacking trap trees and vectoring a wood-inhabiting fungus, Ophiostoma ips (Rumbold) Nannfelt (Ophiostomatales: Ophiostomataceae), which may inhibit migration of the nematode within the tree to the detriment of S. noctilio biocontrol. Several in vitro and in vivo experiments were conducted to investigate the effect of fungal interactions on the ability of D. siricidicola to locate and reproduce on A. areolatum. Deladenus siricidicola showed preference to A. areolatum in the presence and absence of O. ips, but the presence of O. ips negatively affected the choice response and the number of eggs laid by the nematodes. Deladenus siricidicola was unable to survive and reproduce on O. ips. Results give a clearer understanding of the choice response of D. siricidicola in I. grandicollis infested trees, explaining the disruptive impact of bark beetles on biocontrol of S. noctilio, an effect that could extend from Australia to other important pine growing countries.  相似文献   

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A new opecoelid trematode is reported from fishes of the Lethrinidae, Lutjanidae and Nemipteridae off Lizard Island on the northern Great Barrier Reef, Australia. The new species keys to Neolebouria Gibson, 1976 and shows strong similarity to several species of that genus, but is not consistent with the type-species, N. georgiensis Gibson, 1976, or others known from temperate/polar and/or deep-sea fishes. The new species is also phylogenetically distant from N. lanceolata (Price, 1934) Reimer, 1987, the only representative of the genus for which molecular data are available. A new genus, Trilobovarium n. g., is proposed for the new species, T. parvvatis n. sp. Eight morphologically similar species, previously recognised as belonging to Neolebouria, from shallow-water, mostly tropical/subtropical fishes, are transferred to Trilobovarium: T. diacopae (Nagaty & Abdel Aal, 1962) n. comb.; T. ira (Yamaguti, 1940) n. comb.; T. khalili (Ramadan, 1983) n. comb.; T. krusadaiense (Gupta, 1956) n. comb.; T. lineatum (Aken’Ova & Cribb, 2001) n. comb.; T. moretonense (Aken’Ova & Cribb, 2001) n. comb.; T. palauense (Machida, 2014) n. comb.; and T. truncatum (Linton, 1940) n. comb. Paramanteriella Li, Qiu & Zhang, 1988 is resurrected for five species of Neolebouria with a post-bifurcal genital pore: P. cantherini Li, Qiu & Zhang, 1988; P. capoori (Jaiswal, Upadhyay, Malhotra, Dronen & Malhotra, 2014) n. comb.; P. confusa (Overstreet, 1969) n. comb.; P. leiperi (Gupta, 1956) n. comb.; and P. pallenisca (Shipley & Hornell, 1905) n. comb. Neolebouria georgenascimentoi Bray, 2002, a species with an exceptionally long cirrus-sac, is transferred to Bentholebouria Andres, Pulis & Overstreet, 2004 as B. georgenascimentoi (Bray, 2002) n. comb., and N. maorum (Allison, 1966) Gibson 1976, an unusual species known from cephalopods, is designated a species incertae sedis. Eleven species are retained in a revised concept of Neolebouria.  相似文献   

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The genus Praepedaliodes Forster, 1964, the only representative of the mega-diverse mostly Andean Pedaliodes complex lineage in the Brazilian Atlantic Forest, is revised. Prior to this study, four species were known, P. phanias (Hewitson, 1862), P. granulata (Butler, 1868), P. amussis (Thieme, 1905) and P. exul (Thieme, 1905). Here, a further six are described, all from SE Brazil, expanding to 10 the number of species in this genus. Lectotypes are designated for P. phanias, P. granulata and P. amussis. The genus is most diverse in the Serra da Mantiqueira (São Paulo, Rio de Janeiro, Minas Gerais) and in the Serra Geral (Paraná, Santa Catarina) with seven species occurring in both ranges. Praepedaliodes phanias is the most widespread species and the only one found in the western part of the Atlantic Forest; only this species and P. duartei Dias, Dolibaina & Pyrcz n. sp. occurring to near sea level. Other species, P. zaccae Dolibaina, Dias & Pyrcz n. sp., P. francinii Freitas & Pyrcz n. sp., P. sequeirae Pyrcz, Dias & Dolbaina n. sp., P. landryi Pyrcz & Freitas n. sp. and P. pawlaki Pyrcz & Boyer n. sp. are strictly montane and the highest species richness is reached at 1400–1800 m. One species, P. sequeirae n. sp., is a narrow endemic found only at timberline in the Agulhas Negras massif above 2300 m. Immature stages are described for two species, P. phanias and P. landryi n. sp. Molecular data (barcode region of cytochrome oxidase, subunit I) and adult morphology, including male and female genitalia, support the genus as monophyletic, belonging to a predominantly Andean clade of the Pedaliodes Butler, 1867 complex. Morphological evidences, in particular female genitalia comparative analysis, indicate the genera Physcopedaliodes Forster, 1964 and Panyapedaliodes Forster, 1964 as possibly the closest relatives to Praepedaliodes. Molecular data are inconclusive in this respect.  相似文献   

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Geometric morphometrics is a quick and reliable approach to differentiate fish stocks based on the variation of otolith shapes. In this study, morphometric analysis of otolith shapes was used to differentiate three species of Scomber. The sagittae morphology of S. scombrus otolith is totally different from that of S. japonicus and S. australasicus. Multivariate analysis consistently showed that S. japonicus was morphologically similar to S. australasicus, whereas a significant difference in otolith shapes was detected between S. scombrus and other two species of Scomber. The rostrum, antirostrum, excisural notch and dorsal-posterior margin of the otolith reflect the main variations between the three species of Scomber. Shape indices and Fourier coefficients were used to discriminate fish species using analysis of variance and Fisher discriminant analysis. The shape indices successfully differentiated 100%, 95.7% and 96.4% of otoliths in S. japonicus, S. australasicus and S. scombrus, respectively, while the Fourier coefficients only discriminated 70.0%, 61.9% and 91.3% of the sagittae in S. japonicus, S. australasicus and S. scombrus. This study indicates that the shape analysis on the sagittae morphometrics of otoliths is a better method to differentiate species of Scomber.  相似文献   

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Staphylococcus aureus produces capsular polysaccharides (CPs) both in vivo and under defined culture conditions being serotypes 5 and 8 the most prevalent. S. aureus isolates that fail to produce CP5 or CP8 are defined as non-typeable (NT). Loss of capsule expression, however, may lead to S. aureus persistence in a chronically infected host. The prevalence of NT strains of S. aureus isolated from bovine mastitis varies according to the geographic origin of the strain. The aims of this work were to detect phenotypically and genotypically the capsular profile of 144 S. aureus isolated from bovine mastitis in Argentina, Chile, and Uruguay and explore the factors that are considered to be associated with capsule expression as presence of IS257, IScap, and agr typing of non-related collection. The detection of the IS257, IScap, cap genes, and agr typing was performed using PCR. The detection and quantification of capsular polysaccharide production were performed by ELISA assays. We found that 96% of the S. aureus isolates investigated carried cap5(8) genes but over 75% of strains do not express capsule in the three countries studied. However, only 6 isolates from Argentina carried the IScap element that totally suppressed the expression of the capsule, suggesting that other factors could influence on CP expression. Moreover, the agrI/NT association was statistically significant suggesting that this profile is a phenomenon observed not only in other parts of the world but also in our region.  相似文献   

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Both sexes of a new species of pandarid copepod are described from sharks of the genus Squalus L. (Squaliformes: Squalidae). Specimens of Pseudopandarus cairae n. sp. were collected from Squalus bucephalus Last, Séret & Pogonoski and S. melanurus Fourmanoir & Rivaton in New Caledonian waters, the first parasitic copepod to be described from either host species. This is the eighth nominal species of Pseudopandarus Kirtisinghe, 1950 and the first to be described from a shark of the order Squaliformes. Pseudopandarus cairae n. sp. is easily distinguished from P. australis Cressey & Simpfendorfer, 1988, P. longus (Gnanamuthu, 1951) Cressey, 1967, and P. pelagicus Rangnekar, 1977 in having the female genital complex concealed beneath an elongate dorsal genital shield with a trilobed posterior margin. It can be distinguished from P. gracilis Kirtisinghe, 1950 and P. scyllii Yamaguti & Yamasu, 1959 by the armature of the leg 4 endopod and by the proportions of the dorsal genital shield. The new species is unique among known species of Pseudopandarus in its possession of only 1 setal element on the distal endopod segment of leg 4. In addition to describing the new species, the host associations of all species of Pseudopandarus are reviewed and observations are made regarding sexual dimorphism and mode of attachment. A key to the species considered valid is provided.  相似文献   

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