Trichodina truttae Mueller, 1937 (Ciliophora: Peritrichida), a common pathogenic ectoparasite of cultured juvenile salmonid fishes in British Columbia: redescription and examination by scanning electron microscopy

1984 ◽  
Vol 62 (9) ◽  
pp. 1842-1848 ◽  
Author(s):  
J. R. Arthur ◽  
L. Margolis
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
British Columbia ◽  
Pacific Salmon ◽  
Salmo Gairdneri ◽  
Diagnostic Features ◽  
Detailed Surface ◽  
Juvenile Pacific Salmon ◽  
Oral Surface ◽  
Scanning Electron

The trichodinid ciliate Trichodina truttae Mueller, 1937 is redescribed from silver-impregnated specimens collected from the skin of cultured juvenile Pacific salmon (Oncorhynchus spp.) and steelhead trout (Salmo gairdneri) from British Columbia, and its detailed surface topography was examined by scanning electron microscopy (SEM). Diagnostic features evident by light microscopy are the large size (body diameter 114–179 μm), high denticle number (28–30), and high number (about 20) of radial pins per denticle. Especially noteworthy characters revealed by SEM that may be important for species identification are the presence of radial ridges on the oral surface and two markedly different lengths of cilia within the adoral ciliary spiral. This is the first verified report of T. truttae from Canada.

Phyllodistomum umblae (Fabricius) (Digenea, Gorgoderidae) from British Columbia salmonids: a description based on light and scanning electron microscopy

1987 ◽  
Vol 65 (7) ◽  
pp. 1703-1712 ◽  
Author(s):  
T. A. Bakke ◽  
R. E. Bailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
British Columbia ◽  
Electron Microscope ◽  
Salmo Salar ◽  
Electron Microscope Study ◽  
Salvelinus Fontinalis ◽  
Salmo Gairdneri ◽  
Scanning Electron Microscope Study ◽  
Scanning Electron

Specimens of Phyllodistomum umblae (Fabricius, 1780) from Oncorhynchus nerka (Walbaum) from the Nautley River, British Columbia, and Salmo gairdneri Richardson from the Stuart River, British Columbia, are described and figured using light microscopy and scanning electron microscopy. Particular emphasis is placed on describing the numbers, types, and arrangement of papillae as seen with scanning electron microscopy. No significant differences were observed between the present Canadian material from O. nerka and S. gairdneri and specimens of P. umblae described from Norway, Sweden, and the U.S.S.R. Thus, P. umblae has a holarctic distribution in salmonids. Phyllodistomum limnosa Sandeman and Pippy, 1967, described from Salmo salar L. and Salvelinus fontinalis (Mitchill) from Newfoundland, is regarded as a synonym of P. umblae. Phyllodistomum lachancei Choquztte, 1947, described from S. fontinalis in Quebec, probably is also a synonym of P. umblae, but a more detailed scanning electron microscope study of the papillae in P. lachancei is required for confirmation.

To morphology, ecology and distribution of rare species Sellaphora hustedtii (Krasske) Lange-Bertalot et Werum (Bacillariophyta) from waterbodies of the Gydan Peninsula

2014 ◽  
Vol 48 ◽  
pp. 57-65 ◽  
Author(s):  
S. I. Genkal ◽  
M. I. Jarushina
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
River Basin ◽  
Rare Species ◽  
Western Siberia ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Diagnostic Features ◽  
Scanning Electron Microscopy Study ◽  
Scanning Electron

A rare species Sellaphora hustedtii, which is also new for the flora of Russia, has been found in waterbodies of the Messoyakha River basin (south-western part of the Gydan Peninsula, Western Siberia). The scanning electron microscopy study revealed variability of the main quantitative and qualitative diagnostic features of the species (length and width of the valve, number of striae and areolae in 10 μm, shape of the valve and structure of the raphe). New data on the ecology and distribution of the species allowed us to specify its diagnosis.

scholarly journals A reexamination of Yuknessia from the Cambrian of British Columbia and Utah

2015 ◽  
Vol 89 (1) ◽  
pp. 82-95 ◽  
Author(s):  
Steven T. LoDuca ◽  
Jean-Bernard Caron ◽  
James D. Schiffbauer ◽  
Shuhai Xiao ◽  
Anthony Kramer
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
British Columbia ◽  
National Park ◽  
Red Alga ◽  
Fine Scale ◽  
Burgess Shale ◽  
Phylogenetic Affinity ◽  
New Material ◽  
Scanning Electron

AbstractTo investigate the phylogenetic affinity of Yuknessia simplex Walcott, 1919, scanning electron microscopy was applied to the Burgess Shale (Cambrian Series 3, Stage 5) type material and to new material from the Trilobite Beds (Yoho National Park) and specimens from the Cambrian of Utah. On the basis of fine-scale details observed using this approach, including banding structure interpreted as fusellae, Yuknessia Walcott, 1919 is transferred from the algae, where it resided for nearly a century, to the extant taxon Pterobranchia (Phylum Hemichordata). Considered as such, Yuknessia specimens from the Trilobite Beds and Spence Formation (Utah) are amongst the oldest known colonial pterobranchs. Two morphs regarded herein as two different species are recognized from the Trilobite Beds based on tubarium morphology. Yuknessia simplex has slender erect tubes whereas Yuknessia stephenensis n. sp., which is also known in Utah, has more robust erect tubes. The two paratypes of Y. simplex designated by Walcott (1919) are formally removed from Yuknessia and are reinterpreted respectively as an indeterminate alga and Dalyia racemata Walcott, 1919, a putative red alga.

Comparative morphology of myrmecophilous immature stages of European Microdon species (Diptera: Syrphidae): updated identification key and new diagnostic characters

Zootaxa ◽  
2020 ◽  
Vol 4789 (2) ◽  
pp. 348-370 ◽  
Author(s):  
GIULIA SCARPARO ◽  
ROBERT WOLTON ◽  
MARCO MOLFINI ◽  
LUIGI CAO PINNA ◽  
ANDREA DI GIULIO
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sibling Species ◽  
Comparative Morphology ◽  
Immature Stages ◽  
Outward Appearance ◽  
Diagnostic Features ◽  
Diagnostic Characters ◽  
Ant Nests ◽  
Scanning Electron

Hoverflies (Diptera: Syrphidae) of the genus Microdon Meigen have larvae that live in ant nests where they are predatory on ant larvae. Reflecting the exceptional challenges of this very specialized lifestyle, Microdon eggs, larvae and puparia are highly distinctive in their morphology. Detailed descriptions of these immature stages is, however, lacking for all but a very few species, and much of this has been limited through the sole use of light microscopes. Here, using Scanning Electron Microscopy (SEM), we present detailed, comparative descriptions of the immature stages of three European Microdon species: M. analis, M. devius and M. myrmicae. Given that many adult Microdon species are very similar to each other in their outward appearance, we demonstrate that the morphology of their immature stages can improve our understanding of the phylogeny of the genus. We also discuss how particular adaptations of the immature morphology may allow their myrmecophilous life within ant nests. In this paper new diagnostic features are also presented to distinguish M. myrmicae from its sibling species M. mutabilis—the two are morphologically indistinguishable as adults. 

Isoetes × marensis, a new interspecific hybrid from western Canada

1995 ◽  
Vol 73 (9) ◽  
pp. 1345-1353 ◽  
Author(s):  
Donald M. Britton ◽  
Daniel F. Brunton
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
British Columbia ◽  
Key Words ◽  
North American ◽  
Interspecific Hybrid ◽  
Western Canada ◽  
Hybrid Plants ◽  
Surface Ornamentation ◽  
Scanning Electron

A new interspecific hybrid in Isoetes, I. maritima Underw. × I. howellii Engelm., is delineated and described from the Shuswap Highlands region of British Columbia by means of cytology and scanning electron microscopy of spores. Isoetes × marensis D.M. Britton and D.F. Brunton, hyb.nov. is the name proposed for this taxon. It is triploid (3x; 2n = 33) and is believed to produce only sterile and (or) aborted spores. Hybrid plants have polymorphic spores that demonstrate size and surface ornamentation features intermediate between those of the putative parents. Three populations were examined, each growing with both of the putative parents in silt and sand among granite cobble over clay along an emergent lakeshore. Isoetes × marensis is the first described North American hybrid involving an amphibious Isoetes. It is expected to be a rare taxon owing to the restricted sympatric area of the putative parents and their tendency to occupy different habitats. Key words: Isoetes, Isoetes howellii, Isoetes maritima, hybrid, British Columbia.

Morphological Changes in Gill Epithelia of Heat-Stressed Rainbow Trout, Salmo gairdneri: Evidence in Support of a Temperature-Induced Surface Area Change Hypothesis

1981 ◽  
Vol 38 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Dan Jacobs ◽  
Edward F. Esmond ◽  
Edward L. Melisky ◽  
Charles H. Hocutt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Rainbow Trout ◽  
Morphological Changes ◽  
Salmo Gairdneri ◽  
Mucus Production ◽  
Secondary Lamellae ◽  
Gill Structure ◽  
Surface Area Change ◽  
Scanning Electron

Surface morphology of the gill structure of hatchery-reared rainbow trout (Salmo gairdneri) exposed to heat shock was examined by scanning electron microscopy. Changes were greatest in fish previously acclimated to 6 °C and exposed to 24 or 30 °C water for 3–5 d. Gill epithelia of heat-stressed fish showed a reduction and loss of the microridge patterns. The surface of the efferent arterial sides of the primary lamellae became irregular and rugose, and fusion of the secondary lamellae occurred at higher temperatures. The morphological changes along with an increase in mucus production may be a major factor in causing hypoxia in heat-stressed fish.Key words: gill epithelium, rainbow trout, primary lamellae, secondary lamellae, temperature, heat stress, scanning electron microscopy

scholarly journals Variation in seed morphology in the genus Erica L. (Ericaceae)

2009 ◽  
Vol 16 (1) ◽  
pp. 1-106 ◽  
Author(s):  
Piotr Szkudlarz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cape Floristic Region ◽  
Seed Morphology ◽  
Key To Species ◽  
Tropical Africa ◽  
Seed Shape ◽  
Diagnostic Features ◽  
Seed Characteristics ◽  
Scanning Electron

Variation in seed morphology in the genusEricaL. (Ericaceae)Seed morphology was studied in 136 species ofErica, including 123 from South Africa (Cape Floristic Region), 5 from tropical Africa, and 8 from Europe. Seed anatomy was studied in 13 selected species by light and scanning electron microscopy. Seed morphology of each species was described and documented by SEM micrographs. Ten major diagnostic features were selected, concerning seed shape, primary sculpture, and fine relief. On the basis of these features, the species were divided into 14 groups. Within them, 40 morphologically homogeneous subgroups were distinguished, which could possibly be used in future revisions of the genus. A key to species identification has been developed on the basis of seed characteristics. A very close similarity was observed between seeds of someEricaspecies from distant parts of the distribution range of this genus.

Morphological features of the eggs of Pentatomidae (Hemiptera: Heteroptera)

Zootaxa ◽  
2009 ◽  
Vol 1984 (1) ◽  
pp. 1-30 ◽  
Author(s):  
VIVIANA C. MATESCO ◽  
BRENDA B. R. J. FÜRSTENAU ◽  
JORGE L.C. BERNARDES ◽  
CRISTIANO F. SCHWERTNER ◽  
JOCÉLIA GRAZIA
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Morphological Features ◽  
External Morphology ◽  
Diagnostic Features ◽  
Genus Level ◽  
Type C ◽  
Average Size ◽  
Chorion Type ◽  
Scanning Electron

Eggs of 14 species within two subfamilies (Edessinae and Pentatominae, tribes Carpocorini, Nezarini, Pentatomini, Procleticini, and one unplaced species) of neotropical pentatomids were studied with scanning electron microscopy, and their external morphology was characterized in detail (chorion surface, operculum, and aero-micropylar processes). Eggs of these species have similar characteristics to those already described for other pentatomids. Most of them are barrelshaped, except in Edessa meditabunda (with spherical eggs) and Odmalea basalis (whose eggs have flattened lateral faces). A “T”-shaped ruptor ovis is present in all studied species; eclosion line at the operculum rim may be visible or not. Average size of eggs (length x width) ranges from 0.9 ± 0.12 x 0.9 ± 0.05 mm (Euschistus picticornis) to 2.1 ± 0.12 x 1.7 ± 0.10 mm (Chinavia erythrocnemis); the number of the aero-micropylar processes ranges from 10 (C. musiva) to 86 (C. obstinata). Chorion surface has a variable aspect: eggs of Euschistus spp., Loxa deducta, and Pallantia macunaima have the spinose chorion type; C. erythrocnemis, C. longicorialis, C. obstinata, C. pengue, and Grazia tincta have a reticulate chorion; C. musiva, O. basalis, and E. meditabunda have a granulated chorion; and Thyanta humilis has a salebrose chorion type. All the species with described eggs in the Edessinae share the same diagnostic features. In Pentatominae, we did not identify shared characters among the species at subfamily or tribe level. Chorion sculpture pattern and aero-micropylar processes shape, as well as number, are diagnostic features at genus level; however, a few species could be identified in the egg stage.

A review of freshwater species of Diphyllobothrium with redescriptions and the distribution of D. dendriticum (Nitzsch, 1824) and D. ditremum (Creplin, 1825) from North America

1987 ◽  
Vol 65 (9) ◽  
pp. 2216-2228 ◽  
Author(s):  
Karin Andersen ◽  
Hilda Lei Ching ◽  
Rolf Vik
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
British Columbia ◽  
North America ◽  
Freshwater Species ◽  
Histological Techniques ◽  
Diphyllobothrium Dendriticum ◽  
Fish Samples ◽  
Diphyllobothrium Latum ◽  
Scanning Electron

Plerocercoids of Diphyllobothrium were studied from fish samples representing eight species of salmonids from British Columbia, Wyoming, Quebec, and Maine. Adults were studied mainly from experimental infections of golden hamsters, Mesocricetus auratus (Waterhouse). Using scanning electron microscopy and histological techniques, the plerocercoids and adults were identified as Diphyllobothrium dendriticum or Diphyllobothrium ditremum. Morphological comparisons were made with European specimens of these two species and those of Diphyllobothrium latum (Linnaeus, 1758). Among the nine freshwater species reviewed, Diphyllobothrium cordiceps (Leidy, 1872), Diphyllobothrium sebago (Ward, 1910), and Diphyllobothrium ursi Rausch, 1954, are considered synonyms of Diphyllobothrium dendriticum.

Light and scanning electron microscopic studies on Trichodina labrisomi n.sp. from Labrisomas nuchipinnis (Osteichthyes: Labrisomidae) from Mangrove Lake, Bermuda

1993 ◽  
Vol 71 (9) ◽  
pp. 1855-1860
Author(s):  
Thomas G. Rand
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Body Shape ◽  
The Body ◽  
Electron Microscopic ◽  
Scanning Electron Microscopic ◽  
Microscopic Studies ◽  
Oral Surface ◽  
Scanning Electron

Trichodina labrisomi n.sp. from the gills of the hairy blenny, Labrisomas nuchipinnis (Quoy and Gaimard), in Mangrove Lake, Bermuda, is described using light microscopy and scanning electron microscopy (SEM). Light microscopy reveals that the dimensions and morphology of T. labrisomi are similar to those given for only 13 previously described species of Trichodina (T. acuta Lom, 1961; T. baicalensis Dogiel, 1957; T. cottomephori Stein, 1979; T. dalli Zhukov, 1964; Trichodina domerguei domerguei Lom and Shtein 1966; T. elegans Stein, 1979; T. fultoni Davis, 1947; T. jadranica Haider, 1964; T. jadranica noblei Lom, 1970; T. partidisci Haider, 1964; T. reticulata Hirschmann et Partsch, 1955; T. tenuidens Faure-Fremiet, 1943; and T. tenuiformis Stein, 1979). However, compared with these similar forms, T. labrisomi n.sp. is distinguished by the dimensions of its body and denticulate ring and (or) the appearance of its silver-impregnated adhesive disc and denticles. Features of T. labrisomi examined by SEM include the body shape, pellicle, aboral pellicular pores, border membrane, aboral ciliary complex, and adoral ciliature, which are described and compared with those of other trichodinids studied using SEM. SEM also revealed that bacilli were distributed circumequatorially over the oral surface of T. labrisomi.

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