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1.
Five species of the loricate genus Lagenophrys were found on freshwater hosts and are described for the first time. Lagenophrys dennisi n. sp., L. incompta n. sp., and L. oregonensis n. sp. are ectosymbionts of astacid crayfish. Lagenophrys foxi n. sp and L. missouriensis n. sp. are ectosymbionts of gammarid amphipods. All five species appear to occur only m North America. Protargol preparations of the five species reveal that the peristomial myoneme is much broader and more extensive in telotrochs and metamorphosing individuals than in adults. Darkly staining bands appearing to be somatic myonemes were also seen underneath the surface of the body and in the center of the body of telotrochs and metamorphosing individuals. The telotroch of Lagenophrys is so different from the adult that it constitutes a true larval form rather than a simple dispersal stage. Structural parallels between the telotroch of Lagenophrys and mobiline peritrichs suggest the hypothesis that mobilines evolved from the telotroch of a sessiline pentrich which had first evolved into a true larval form.  相似文献   

2.
Lagenophrys novazealandae n. sp. occurs on the gills of Paranephrops zealandicus, a parastacid crayfish from New Zealand. The new species has the hemispheroidal lorica most common among members of its genus and is distinguished by its possession of large tubercles on the thickened edge of the anterior lip of the lorica aperture, a deep cleft in the left side of the lip's edge, and a ovoid to reniform macronucleus located in the right-hand part of the body. It is probable that an as yet unnamed species of Lagenophrys known to occur on another species of Paranephrops in New Zealand is distinct from L. novazealandae but phylogenetically related to it. Lagenophrys petila n. sp. occurs on setae of Parastacoides tasmanicus, a parastacid from Tasmania. The new species has an ovoid lorica tapering to a slender pseudostalk at the posterior end, a type of lorica possessed by only two other members of its genus that also attach to their host's setae. It is distinguished from the other ovoid species by the proportions of the lorica, the extreme shortness of the lips of the lorica aperture, and an ovoid macronucleus located in the right, anterior part of the body. Clefts in the lips of L. novazealandae and other members of Lagenophrys may function as points of flexure to allow the lips to bend in ways that accommodate interspecific differences in the size of the epistomial disk and its operation during suspension feeding.  相似文献   

3.
One species of Lagenophrys and two species of Operculigera are described for the first time. Lagenophrys machaerigera n. sp. was discovered on the freshwater crab Gecarcinautes goudoti and varies between two extreme forms in the structure of its lorica aperture. Operculigera carcini n. sp. was also found on G. goudoti and exhibits several characteristics that set it apart from other members of its genus. Some of these characteristics also suggest a phylogenetic link between O. carcini and the genus Lagenophrys. Operculigera madagascarensis n. sp. was discovered on the parastacid crayfish Astacoides granulimanus. The occurrence of O. madagascarensis on a Madagascan parastacid and other species of Operculigera on Chilean parastacids suggests that parastacids are the oldest hosts of the genus Operculigera. Continental drift is the most likely mechanism by which species of Operculigera and parastacids could have been dispersed to distant parts of the southern hemisphere. The absence of Operculigera on Australian parastacids may be due to its replacement by the genus Setonophrys on those hosts.  相似文献   

4.
Three species of chromadorids two of which are new to science are described from bottom samples of Lake Tana, L. Ziway and River Abbay, Ethiopia. Achromadora inflata n. sp. and Ethmolaimus zullinii n. sp. are characterized by a uniquely inflated and offset anterior end. The latter is an exception in its genus also by its possession of a well developed dorsal tooth and inconspicuous ventrosublateral denticles. Prodesmodora nurta Zullini, 1988 is reported here for the first time out of its type locality and is described in detail. SEM pictures of Ethmolaimus zullinii n. sp. and Prodesmodora nurta, and complete setae maps of the three species are also presented.Abbreviations used ABE = anterior body end - ABW = anal body width - Amph = amphid - Amph W = amphidial fovea width - CBW = corresponding body width - CSL = cephalic setae length - Ddent = dorsal denticle - GL = gonad length - L = length - LM = light microscope - LRW = lip region width - MBW = maximum body width - n = number of specimens - NR = nerve ring from the anterior end - PBE = posterior body end - Ph L = pharyngeal length (neck length) - PrL = prerectal length - RL = rectal length - SEM = scanning electron microscope - V-A = distance from vulva to anus - Vdent = ventral denticle - W = width  相似文献   

5.
Lagenophrys singularis is removed from Lagenophrys and designated the type species of Paralagenophrys n. g. Compared to members of Lagenophrys, the oral area of P. singularis is radically distorted. Paralagenophrys apparently also lacks second-type division, a special phase of sexual reproduction characteristic of Lagenophrys and associated with its adaptation to symbiotic life on crustaceans. Members of Lagenophrys are obligate ectocommensals of crustaceans. In contrast, P. singularis (Kellicott, 1887) n. comb. occurs most often on the leaves of aquatic vascular plants.  相似文献   

6.
N. I. Zaslavskaya 《Hydrobiologia》1995,309(1-3):123-128
Eight species of the genus Littorina were hitherto recognised in the north-western region of the Pacific Ocean: L. sitkana, L. brevicula, L. mandshurica, L. squalida, L. aleutica, L. naticoides, L. kasatka and L. subrotundata. Using allozyme electrophoresis it has been demonstrated that, in the Kurile Islands, three of these species (L. sitkana, L. subrotundata and L. kasatka) co-occur, together with a fourth, still undescribed species (L. sp.). These four species were compared at 16 loci coding for 13 enzymes. All species were easily distinguished by diagnostic enzyme markers. The mean genetic distances and ranges between species pairs are: L. sitkana and L. sp. D = 0.622 (0.561–0.741), L. sitkana and L. subrotundata D=0.981 (0.821–1.110), L. subrotundata and L. sp. D=0.975 (0.955–0.995). The genetic distance between L. kasatka and each of the other three species was greater than 1 (range 1.123–2.087). These data suggest that L. sitkana, L. subrotundata and L. sp could be members of a species complex; according to current classifications these three belong to the subgenus Neritrema. However, the genetic distance between L. kasatka and L. sitkana is much greater than between L. sitkana and other Neritrema species, and thus supports the classification of L. kasatka in the subgenus Littorina.  相似文献   

7.
Summary The asexual geckoLepidodactylus lugubris, its sexual congenerL. sp. (Takapoto) and hybrids between the two species inhabit the atoll of Takapoto, providing a natural experiment for studying co-existence and interactions between asexual and sexual populations. The range of the sexual species is confined to one section of the lagoon beach and the trees and buildings which abut it, whereas the asexual is distributed across the whole atoll and occupies many habitats. Behavioural experiments revealed no asymmetry in levels of aggression between the two species, suggesting that the confinement ofL. sp. (Takapoto) to the lagoon beach is not due to agonistic interactions. Ecological differences among the constituent clones of the asexual species exist but cannot completely account for the broader habitat use of the asexual. Within a single habitat, one clone ofL. lugubris consumes a wider range of prey items than its sexual relative. Other studies have found that the asexuals are extremely heterozygous relative to the sexuals; we hypothesize that their broad ecological tolerance may be attributable to heterosis. The co-existence of the sexual and parthenogenetic lizards on this small island seems to be stable and may be facilitated by the specialization of the sexual taxon to beach habitats.  相似文献   

8.
SYNOPSIS. Four new species of Henneguya (myxosporidan) are described from Ictalurus punctatus Rafinesque (channel catfish). They are as follows: Henneguya postexilis sp. n. and Henneguya longicauda sp. n. from the gills; Henneguya adiposa sp. n. from the adipose fin; and Henneguya diversis sp. n. from the liver, kidney, connective tissue of muscles and fins, and tumor-like external growths. Henneguya pellis sp. n. is described from the dermis of Ictalurus furcatus (LeSueur) (blue catfish). The development stages of all described species are discussed. Henneguya exilis Kudo was found on the gills of one I. punctatus; notes on its spore characteristics are presented.  相似文献   

9.
Two new capsalid species, Pseudallobenedenia arabica n. sp. from the gills of Pristipomoides filamentosus (Lutjanidae) from the Arabian Sea and Lagenivaginopseudobenedenia tinrowi n. sp. from the gills of Etelis carbunculus (Lutjanidae) from the eastern Pacific Ocean are described and illustrated. P. arabica differs from the most similar species, P. opakapaka Yamaguti, 1966, in the greater width of the body, its larger haptor and anterior adhesive discs, the form and sizes of the testes and ovary, and differences in host and locality. L. tinrowi differs from its congener, L. etelis Yamaguti, 1966, in the larger size of the body and its organs, the absence of eye-spots and Goto's glands, and differences in the arrangement of the genital organs. All of the species in these two genera differ from other capsalids by the presence of a voluminous uterus and an extremely long penis forming a loop. All species in these two genera are parasites of fishes of the family Lutjanidae and are reported from Indo-Pacific subtropical areas.  相似文献   

10.
Sea bass,Lateolabrax japonicus, from the Ariake Sea, characterized by black dots on the lateral body region as in the Chinese sea bass,L. sp., were examined and compared morphologically and genetically withL. japonicus andL. sp. Some meristic characters of the Ariake form tended to fall midway between values for the two former species. Genetic features, evaluated by isozyme analyses, indicated that the Ariake form as represented a simple Mendelian population, there being no significant differences from a Hardy-Weinberg equilibrium according to chi-square tests. Although some extreme differences in allelic frequencies were found at some loci betweenL. japonicus andL. sp., the Ariake form possessed many heterozygotes at thePROT-1 * locus, in addition to allelic frequencies at some loci conforming to those ofL. sp. Average allele numbers per locus, rate of polymorphic loci and average heterozygosity of the Ariake form were higher than for eitherL. japonicus orL. sp., indicating high genetic variation in the former. The results suggested that the Ariake population is genetically independent of other populations ofL. japonicus, but might be genetically influenced byL. sp.  相似文献   

11.
Leptographium species have predominantly been described from North America, Canada and Europe. These fungi generally occur on conifers and many cause blue-stain of lumber. MostLeptographium species are also associated with insects and in particular, bark beetles (Coleoptera: Scolytidae). Recently, an unknown species ofLeptographium was isolated from pine infested with anIps sp. in Indonesia. In addition, two unknown species have been collected from red spruce (Picea rubra) and balsam fir (Abies balsamea) roots from high elevation sites in Eastern North America. The latter isolates are unusual in that they are associated with the feeding wounds made by the conifer swift mothKorscheltellus gracilus (Lepidoptera: Hepialidae), which is a habitat unique for species ofLeptographium. Comparison with knownLeptographium species has revealed that the isolates from Indonesia and those from Eastern North America represent three previously undescribed taxa. They are, therefore, described in this study asL. pineti sp. nov,L. abieticolens sp. nov. andL. peucophilum sp. nov.  相似文献   

12.
Linuparus White, 1847 comprises three extant species, Linuparus trigonus (Von Siebold, 1824), L. sordidusBruce, 1965, and L. somniosusBerry and George, 1972, as well as 32 fossil species. Most fossil records are from North America and Europe, but the extant species are all confined to the Indo-West Pacific. Different colour forms in L. trigonus and L. sordidus have been noted, with Northern Hemisphere specimens generally darker in colour for both species. The phylogenetic relationships of the extant Linuparus species, including the colour forms, were investigated using mitochondrial 12S rRNA and COI gene sequence analysis. We found no genetic evidence to differentiate the colour morphs of L. sordidus, but the two colour forms of L. trigonus were clearly distinct at the species level. This is supported morphologically by a consistent difference in the shape of the thoracic sternum between the two forms. The paler coloured Southern Hemisphere form is described as a new species, L. meridionalis. Phylogenetic analysis shows that L. trigonus and L. meridionalis sp. nov. are derived sister taxa, while L. somniosus is basal within the genus. Thus the present results support the previous hypothesis that Linuparus was originated in shallow water.  相似文献   

13.
李玉  陈双林  李惠中 《菌物学报》1993,12(Z1):107-112
本文补报了中国团毛菌科四个种,弱小团网菌Arcyria exigua sp. nov.和聚生团网菌Arcyria aggregata sp. nov.为新种,瑞士团网菌Arcyria helvetica和纹丝半网菌Hemitrichia intorta为中国新记录种。文中对二新种进行了描述,附有形态特征电镜扫描照片,并讨论了与相似种间的区别。新种的模式标本保存在中国科学院微生物研究所真菌标本室。  相似文献   

14.
Three species of the genus Trichodina are reported from the gills of marine fishes in south-eastern Tasmania, Australia. Two of these species are new: T. australis n. sp. from five atherinid fish species, Atherinosoma microstoma, Leptatherina presbyteroides, Kestratherina brevirostris, K. esox and K. hepsetoides; and T. nesogobii n. sp. from Nesogobius sp. 1. One previously reported species, T. jadranica Raabe, 1958, was also found on Nesogobius sp. 1.  相似文献   

15.
Two fungal pathogens of the mantis shrimp (Oratosquilla oratoria) in Yamaguchi and Aichi Prefectures, Japan are described as the new species Plectosporium oratosquillae and Acremonium sp. (a member of the Emericellopsis marine clade). Both fungi infect the gills of the mantis shrimp, which become brown or black due to melanization. The former species is characterized by its slow growth on artificial seawater yeast extract peptone glucose (PYGS) agar, pale yellow to pale orange or grayish yellow colonies, short cylindrical solitary phialides with a wavy tip, and one-celled ellipsoidal conidia. Although lacking the two-celled conidia demonstrated by the type species Plectosporium tabacinum, the taxonomic placement of the new species was confirmed by DNA sequence analysis of the internal transcribed spacer (ITS) region of ribosomal DNA (ITS1, 5.8S rDNA and ITS2). Acremonium sp., the other causal pathogen, differs from P. oratosquillae by its fast growth on PYGS agar, pale orange to salmon-colored colonies, long, slender conidiophores consisting of solitary phialides with tips lacking an undulate outline, and typically cylindrical conidia. Analysis of ITS and β-tubulin gene sequences placed this fungus within the phylogenetically distinct Emericellopsis (anam. Acremonium) marine clade. Various physiological characteristics of both pathogens were also investigated. This is the first report of a fungal infection found on the mantis shrimp in Japan.  相似文献   

16.
To more confidently assess phylogenetic relationships among astome ciliates, we obtained small subunit (SSU) rRNA sequences from nine species distributed in six genera and three families: Almophrya bivacuolata, Eudrilophrya complanata, Metaracoelophrya sp. 1, Metaracoelophrya sp. 2, Metaracoelophrya intermedia, Metaradiophrya sp., Njinella prolifera, Paraclausilocola constricta n. gen., n. sp., and Paraclausilocola elongata n. sp. The two new species in the proposed new clausilocolid genus Paraclausilocola n. gen. are astomes with no attachment apparatus, two files of contractile vacuoles, and an arc-like anterior suture that has differentiations of thigmotactic ciliature on the anterior ends of the left kineties of the upper surface. Phylogenetic analyses were undertaken using neighbor-joining, Bayesian inference, maximum likelihood, and maximum parsimony. The nine species of astomes formed a strongly supported clade, showing the subclass Astomatia to be monophyletic and a weakly supported sister clade to the scuticociliates. There were two strongly supported clades within the astomes. However, genera assigned to the same family were found in different clades, and genera assigned to the same order were found in both clades. Thus, astome taxa appear to be paraphyletic when morphology is used to assign species to genera.  相似文献   

17.
During the spring of 1981, trichodinid protozoa were collected from the gills or urinary bladder of the following species of fishes of Rybinsk Reservoir, USSR, located on the upper reaches of the Volga River system: Esox lucius, Rutilus rutilus, Leuciscus idus, Blicca bjoerkna, Abramis ballerus, Pelecus cultratus, Lota lota, and Perca fluviatilis. A total of 13 species of Trichodinidae was recovered from Rybinsk fishes, among which are three new species of the genus Trichodina: T. izyumovae n. sp. from the gills of L. idus, T. borokensis n. sp. from the gills of P. cultratus, and T. kupermani n. sp. from the gills of A. ballerus. Other species of trichodinids reported are T. modesta Lom, 1980; T. nigra Lom, 1969; T. pediculus (O. F. Müller, 1786); T. prowazeki Grupcheva & Lom, 1980; T. rostrata Kulemina, 1968; T. urinaria Dogiel, 1940; T. ophiocephalus Kostenko & Karaev, 1976; Paratrichodina incisa (Lom, 1959); Trichodinella epizootica (Raabe, 1950); and Tripartiella copiosa Lom, 1959. Photomicrographs and morphometric data are presented for each species and aspects of their host and geographic distribution discussed. Trichodina algonquinensis Li & Desser, 1983 is considered a synonym of T. urinaria Dogiel, 1940.  相似文献   

18.
Seawater DMS in a perturbed coastal ecosystem   总被引:1,自引:0,他引:1  
Intra- and interspecific niche overlap for two mayfly species with similar life cycle timing, Rhithrogena semicolorata and Ecdyonurus sp. gr. venosus, were investigated. The nymphs were classified into 5 classes according to size and spatial overlaps are measured along a substratum roughness gradient. Substratum roughness selection was investigated by defining utilisation curves, optimum and tolerance values of the nymphs in relation to larval growth. Differences between species and size classes within each species were observed. Ecdyonurus sp. gr. venosus dominated on rough substrates, whereas R. semicolorata was most abundant on smooth substrates. An intermediate value of total interspecific substratum roughness overlap (0.49) was found. Higher intraspecific than interspecific overlap values suggested a spatial niche segregation between the two species. The results suggested that the spatial niches measured, were closer to the `fundamental niches' than could be expected if competition was acting on the two studied populations.  相似文献   

19.
Three species of Rhabdolaimus de Man, 1880 and two (of which one is new to science) of Udonchus Cobb, 1913 are described from sediment samples of two lakes, two rivers and a hot spring, Ethiopia. Udonchus merhatibebi n.sp. is characterized by a distinctly truncate lip region and small cardia surrounded by gland cells that he on the anterior intestine at 45 °. The presence of twelve rugae in the cheilostome in the genus Udonchus is reported here for the first time. As a result, the family Rhabdolaimidae has been moved from suborder Leptolaimina to the superfamily Microlaimoidea in the suborder Chromadorina. The family Rhabdolaimidae is also subdivided into the subfamilies Rhabdolaiminae Chitwood, 1951 and Undonchinae n. subfam.. Scanning electronmicroscopic pictures of the five species viz. R. aquaticus de Man, 1880, R. cf. minor Cobb, 1914, R. terrestris de Man, 1880, U. merhatibebi n.sp. and U. tenuicaudatus Cobb, 1913 are also given.Abbreviations ABE = anterior body end - ABW = anal body width - Amph = amphid - Amph W = amphidial fovea width - CBW = corresponding body width - GL = gonad length - G1L = anterior gonad length - G2L = posterior gonad length - L = length - LM = light microscope - LRW = lip region width - MBW = maximum body width - n = number of specimens - NR = nerve ring from the anterior end - Ph L = pharyngeal length (neck length) - RL = rectal length - SEM = scanning electron microscope - V-A = distance from vulva to anus - W = width  相似文献   

20.
记述中国滑菌蚊属4新种:浅黄滑菌蚊Leia bubaline sp.nov.,密毛滑菌蚊Leia densisetosa sp.nov.,黑龙江滑菌蚊Leia heilongjiangensis sp.nov.,和粗角滑菌蚊Leia robusticornis sp.nov.。编制了该属中国种类检索表。模式标本保存于浙江农林大学昆虫标本室。  相似文献   

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