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Two orthothecid hyoliths, Gracilitheca astronauta n. sp. and Nephrotheca sophia n. sp. are described from the “middle” Cambrian Buchava Formation of the Skryje-Tý?ovice Basin in the Czech Republic. The new forms are based on about thirty well-preserved external and internal moulds of both conchs and opercula. Gracilitheca astronauta n. sp. is classified under the family Gracilithecidae Sysoev, 1972 and may be distinguished by clearly triangular cross-section of the conch, whereas Nephrotheca sophia n. sp. is characterized by transversally elongated cardinal processes reaching the lateral opercular margin and is combined with the family Orthothecidae Sysoev, 1958 emended Malinky, 2009. Several specimens of G. astronauta show operculum preserved inside of the conch. Stratigraphic ranges and geographic distributions within the Skryje-Tý?ovice Basin are established for both taxa.  相似文献   

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Nine siderite concretions from the Middle Pennsylvanian, Francis Creek Shale (Carbondale Formation, Desmoinesian Series, West‐phalian C‐D), in the Mazon Creek area, Will‐Kankakee Counties, Illinois, U.S.A. preserve clusters of impressions of small eggs. Differential staining of the matrix suggests that the eggs were originally spawn within gelatinous strings containing 1 or 2 rows of eggs. Unfortunately, these egg impressions lack the diagnostic features needed to identify the zoological taxon (taxa) from which they originated.  相似文献   

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During a survey for grasshopper pathogens in Argentina in 2005-2006, individual Covasacris pallidinota from halophylous grasslands in Laprida, Buenos Aires province were found to be infected with a microsporidium. Infection was restricted to the salivary gland epithelial cells. The microsporidium produced ovocylindrical spores averaging 2.6 ± 0.28 × 1.4 ± 0.12 μm (range 2.2-3.4 × 1.1-1.7 μm), which resembled in size and shape the spores of Liebermannia patagonica and L. dichroplusae, two recently described species that also parasitize Argentine grasshoppers. The life cycle of the microsporidium included the formation of polynucleate, diplokaryotic, moniliform, merogonial plasmodia wrapped in flattened cisterns of the host endoplasmic reticulum (ER). Plasmodia divided to produce diplokaryotic cells. The latter underwent elongation, dissociation of diplokarya counterparts, vacuolization, dismantling of the host ER envelope, and deposition of electron-dense material outside the plasma membrane. The resultant binucleate sporogonial plasmodia divided into two uninucleate sporoblasts, which eventually transformed into spores. Uninucleate spores contained a lamellar polaroplast, embraced by an elongated polar sac, anchoring disc, 3-5 polar filament coils, and a cluster of anastomizing tubules (sporoblast trans-Golgi, posterosome) at the posterior end. Sequence similarity of the SSU rDNA of the newly discovered microsporidium (Genbank accession no. EU709818) to L. patagonica and L. dichroplusae was 99% and 97%, respectively, suggesting that the three species belong to one genus. All three species fell into one clade in SSU rDNA-based phylogenetic trees produced by neighbor joining, maximum parsimony, and maximum likelihood analyses with 100% statistical support. We assign the name Liebermannia covasacrae to this microsporidium. It can be easily differentiated from both congeners by host species, tissue tropism, type of sporogony, and several features of morphology. Comparison of the three Liebermannia spp. demonstrates that the nuclear phase (dikaryotic versus monokaryotic spores) and type of sporogony (polysporous versus disporous) may vary in closely related species.  相似文献   

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In the framework of the palaeogeographical reconstruction of the Western Taurus during Jurassic, the study of northern and eastern boundary of the Taurids started. Detailed facies analysis evidenced the position of the Barla Dag ramp between two elevated areas: the southern rimmed shelf extension of the platform system and the northern neritic-beach-land plain. In the basal biostratigraphical and ecological characteristics of the Balcikhisar volcano-sedimentary sequence, correlated with the Fele outcrop, one genus and three new species of foraminifers have been found: Sievoides kocyigiti n. gen., n. sp. and Mesoendothyra altineriana n. sp. from neritic environment, and Kurnubia feleensis n. sp. from rimmed shelf lagoon. Both carbonate sedimentary deposits are intercalated with spilitic-basalt pillow lava flows. The age of the new three species is Kimmeridgian, controlled by some foraminifer golden hooks.  相似文献   

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The first unequivocal fossil echiuran, Coprinoscolex ellogimus gen. et sp.n., is described from the Middle Pennsylvanian Francis Creek Shale of the Mazon Creek area of northeastern Illinois. Specimens are whole-body impressions within siderite concretions. They show anterior proboscides, cigar-shaped trunks, convoluted alimentary canals, and cylindrical pellets. Lack of setae suggests classification in the Family Bonelliidae. Coprinoscolex was most likely a marine deposit-feeder, either crawling over the sediment surface or burrowing to shallow depths while ingesting sediment. While this occurrence does not confirm or deny an annelidan ancestry for the Echiura, it indicates that by the Pennsylvanian, echiurans were unsegmented and essentially modern in form.  相似文献   

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Two sporozoan parasites, Gregarina hylobii and Ophryocystis hylobii n. sp., parasitizing the adults of natural populations of Hylobius abietis are described. The gregarine G. hylobii, a parasite of the gut of H. abietis, has been reexamined and its complete life cycle, including the solitary gamonts, gametocysts, and sporoducts is described. The life cycle of the neogregarine O. hylobii infecting the Malpighian tubules of host animals examined at light and electron microscope levels is discussed. Some data on the prevalence of infections and host-parasite relationships are also discussed.  相似文献   

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Two new gregarines in the recently erected genus Psychodiella (formerly Ascogregarina), Psychodiella sergenti n. sp. and Psychodiella tobbi n. sp., are described based on morphology and life cycle observations conducted on larvae and adults of their natural hosts, the sand flies Phlebotomus sergenti and Phlebotomus tobbi, respectively. The phylogenetic analyses inferred from small subunit ribosomal DNA (SSU rDNA) sequences indicate the monophyly of newly described species with Psychodiella chagasi. Ps. sergenti n. sp. and Ps. tobbi n. sp. significantly differ from each other in the life cycle and in the size of life stages. The sexual development of Ps. sergenti n. sp. (syzygy, formation of gametocysts and oocysts) takes place exclusively in blood-fed Ph. sergenti females, while the sexual development of Ps. tobbi n. sp. takes place also in males and unfed females of Ph. tobbi. The susceptibility of Phlebotomus perniciosus, Phlebotomus papatasi, Ph. sergenti, Ph. tobbi, and Phlebotomus arabicus to both gregarines was examined by exposing 1st instar larvae to parasite oocysts. High host specificity was observed, as both gregarines were able to fully develop and complete regularly the life cycle only in their natural hosts. Both gregarines are considered as serious pathogens in laboratory-reared colonies of Old World sand flies.  相似文献   

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A new species of Alcataenia is described from razorbills Alca torda Linnaeus from the southern region of the North Sea in the coastal waters of Belgium. It differs from known species of the genus in having 18–20 rostellar hooks measuring 63–74 m in length. Other attributes include a cirrus-sac 145–228 m in length, 36–49 testes and a vitelline gland measuring 114–202 × 59–112 m. This is the first species of Alcataenia described from razorbills and appears to be the only member of the genus which is endemic to the North Atlantic basin.  相似文献   

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A new genus and species of monogenean belonging to Hexabothriidae, Hypanocotyle bullardi n. gen. n. sp., is described based on specimens collected from the gill filaments of the diamond stingray, Hypanus dipterurus (Jordan et Gilbert) (Myliobatiformes: Dasyatidae), a demersal chondrichthyan collected off the coast of Callao, Peru. Hypanocotyle n. gen. has the following combination of diagnostic features that differentiate it from other hexabothriid genera: haptor symmetrical; vasa efferentia having proximal (narrow, with thin glandular wall) and distal (expanded, interlaced, with thick glandular wall) portions, joining medially to form vas deferens; vas deferens having proximal (expanded, sinuous, with thick glandular wall) and distal (narrow, strongly sinuous, with thin glandular wall) portions; male copulatory organ unarmed, proximal portion slightly sinuous and tube-like, distal portion funnel-shaped; prostatic glands present, distributed around of the MCO; seminal receptacle present; ootype lacking longitudinal rows of large cells (no oötype côtelé); vaginae parallel, with well-differentiated proximal (glandular, narrow, tube-like, slightly sinuous) and distal (musculoglandular, convoluted) portions; gland cells surrounding the vaginal duct along the entire length of distal portion, densely clustered in middle portion; uterine eggs with 2 elongate filaments. Phylogenetic reconstructions by maximum-likelihood method, based on newly obtained partial 18S and 28S sequences, shows that H. bullardi n. gen. is included within the family Hexabothriidae, order Diclybothriidea. This is the second hexabothriid genus recorded from a diamond stingray (Dasyatidae), and the fourth hexabothriid species recorded from Peru. A key to hexabothriid genera is provided.  相似文献   

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A new species of Tantulocarida, Microdajus tchesunovi sp. n., was found on tanaid host, Typhlotanais sp. of the family Nototanaidae, collected from silty sediment in the Kandalaksha Bay in the White Sea. Several tantulus larvae, developing males at different stages of metamorphosis, and early stages of parthenogenetic females were found attached to different sites of their hosts. Ultrastructure of the new species was studied with SEM. Microdajus tchesunovi sp. n. can be easily distinguished from other species of the genus Microdajus Greve by the presence of a pair of longitudinal dorsal lamellae at the anterior end of the cephalon. It is also characterized by the presence of an endopod seta on the sixth thoracopod and the absence of thoracopodal endites. A morphological comparison of species of the family Microdajidae is presented in tabular form.  相似文献   

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During a trans-Saharan expedition in 1980 a number of samples were collected from stagnant and running fresh and slightly saline water bodies. One of them, collected from the Oued En-Namous in a small oasis yielded several interesting nematodes, among which was a newHalalaimus species described herein asHalalaimus algeriensis n. sp. It comes close toH. minusculus Tchesunov, 1978, but differs in tailshape, absence of males and habitat. It also resembles the marine speciesH. gracilis de Man, 1888, but differs in the relative length of the anterior setae, the absence of a lateral field and absence of males. The new species can be differentiated fromH. stammeri Schneider, 1940, the only fresh water species found hitherto, by its shorter body, more anterior and wider fovea, and the length and position of the anterior setae. The various juvenile stages can be separated on the basis of body length, foveal length and genital primordium.  相似文献   

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The author described two new species of Nematoda-Rhabditidae collected from the auditory meatus of catle with ear infection: Rhabditis (Rhabditis) freitasi sp.n. from Formosa county in the state of Goiás and Rhabditis (Rhabditis) costai sp.n. from Sert?ozinho county in the state of S?o Paulo.  相似文献   

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