Acanthorhachis, a new genus of shark from the Carboniferous (Westphalian) of Yorkshire, England

2013 ◽  
Vol 151 (3) ◽  
pp. 517-533 ◽  
Author(s):  
DAVID M. MARTILL ◽  
PETER J. A. DEL STROTHER ◽  
FLORENCE GALLIEN
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Type Species ◽  
New Genus ◽  
Histological Analysis ◽  
Continuous Variation ◽  
The Family ◽  
The Status ◽  
Permian Extinction ◽  
Scanning Electron

AbstractAn association of diverse hollow spines and dermal denticles (ichthyoliths) from the Carboniferous (Westphalian) of Todmorden, Yorkshire, England are attributed to a new genus of enigmatic shark that may lie close to Listracanthus Newberry & Worthen, 1870. Scanning electron microscopy shows that denticle morphology is highly variable, but forms a morphocline including elongate multi-spined elements as well as robust dome-like stellate denticles and recurved spinose elements. Histological analysis suggests an absence of enameloid. Continuous variation of form between elongate multi-cusped spines to boss-like circular denticles shows that all previously described Palaeozoic species of Listracanthus are probably junior synonyms of the type species L. hystrix Newberry & Worthen, 1870. The status of Listracanthus as a surviving ‘Lilliputian’ taxon after the Permian extinction is questioned. Although the new specimen has affinities with Listracanthus, significant differences in the form of the posterior spines on elongate denticles warrants its placement in the new genus Acanthorhachis gen. nov. The family Listracanthidae is erected to accommodate Listracanthus and Acanthorhachis.

Structure of the cephalic end of two little-known oxyuroid genera, Travnema Pereira, 1938 and Cosmoxynemoides Travassos, 1949, parasites of fishes, as revealed by SEM

1994 ◽  
Vol 68 (4) ◽  
pp. 319-322 ◽  
Author(s):  
F. Moravec ◽  
A. Kohn ◽  
B.M.M. Fernandes
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Type Species ◽  
Freshwater Fishes ◽  
The Other ◽  
New Host ◽  
The Family ◽  
Cephalic Extremity ◽  
New Host Records ◽  
Scanning Electron

AbstractThe cephalic end of the type species of pharyngodonid genera Travnema and Cosmoxynemoides, T. travnema Pereira, 1938 and C. aguirrei Travassos, 1949, parasites of Brazilian freshwater fishes, was studied by scanning electron microscopy. The mouth aperture of Travnema was found to be circular, surrounded by four cephalic papillae and two lateral amphids and the cuticle of the cephalic end had a conspicuous dense sculpture. On the other hand, the mouth aperture of Cosmoxynemoides was triangular, surrounded by three lip-like elevations covering the whole surface of the relatively flat cephalic extremity, each with two inner lobes separated one from another by a short groove; the lip-like elevations bore four medium-sized, kidney-shaped cephalic papillae and two minute amphids (two papillae on the dorsal elevation and one papilla and one amphid on each of two ventrolateral elevations); the cuticle of the cephalic end was smooth. Both species were noted for the absence of oral lamellae and the presence of lateral alae. Both genera are listed in the family Pharyngodonidae but Travnema (and also Hakynema), due to its morphological peculiarities, is considered to represent a distinct subfamily Travnematinae within the Pharyngodonidae. The finding of both T. travnema and C. aguirrei in the characid fish Astyanax bimaculatus lacustris represents new host records.

Re-investigation of Polyoeca dichotoma and Acanthoeca spectabilis (Acanthoecidae: Choanoflagellida)

1984 ◽  
Vol 64 (4) ◽  
pp. 819-827 ◽  
Author(s):  
Shigemitsu Hara ◽  
Eiji Takahashif
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Type Species ◽  
New Genus ◽  
Three Dimensional ◽  
Electron Microscopical ◽  
Scanning Electron

Light and electron microscopical reinvestigation of Polyoeca dichotoma Kent revealed that Acanthoecopsis spiculifera Norris, the type species of the genus, is a synonym for Polyoeca dichotoma. Since this step invalidates the use of the name Acanthoecopsis, a new genus Acanthocorbis was established for the three species formerly included in Acanthoecopsis.The three dimensional arrangement of costal strips forming the loricae of Polyoeca dichotoma and Acanthoeca spectabilis Ellis were examined by scanning electron microscopy. The arrangement of costal strips were similar in both species. The longitudinal costal strips and those forming the spines were arranged outside the supplementary costae and those of the transverse bonds.

A new genus and some cryptic species of Arctic and boreal calloporid cheilostome bryozoans

2006 ◽  
Vol 86 (5) ◽  
pp. 1035-1046 ◽  
Author(s):  
Piotr Kuklinski ◽  
Paul D. Taylor
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
Type Species ◽  
New Genus ◽  
East Greenland ◽  
North East ◽  
Three New Species ◽  
Cheilostome Bryozoans ◽  
Scanning Electron

Study of type and other material using scanning electron microscopy has permitted the recognition of three new species and one new genus of Arctic and boreal calloporid anascans. Originally described from the Gulf of St Lawrence, Callopora whiteavesi is reassigned to Flustrellaria, a calloporid genus not previously reported extant. Material from north-east Greenland misidentified as C. whiteavesi is described as C. weslawski sp. nov. The new genus Septentriopora is introduced for calloporids lacking pore chambers, with a distolateral pair of small interzooidal avicularia that face proximally or proximolaterally, and a reduced ovicell. The type species of Septentriopora, Tegella nigrans, has frequently been misidentified. Many of the supposed records of this species belong to two other species, described here as Septentriopora karasi sp. nov. and S. denisenkoae sp. nov. The apparent ovicell in S. karasi is particularly unusual, being vestigial and kenozooid-like in morphology.

scholarly journals Illustrated description and notes on biology of Dicranocephalus lateralis (Signoret) (Coreoidea: Stenocephalidae) from Maharashtra State, India

2017 ◽  
Vol 9 (10) ◽  
pp. 10792
Author(s):  
Balasaheb V. Sarode ◽  
Nikhil U. Joshi ◽  
Swapnil S. Boyane ◽  
Subodh S. Gaikwad ◽  
Pratik P. Pansare ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Life Cycle ◽  
Scent Gland ◽  
Male And Female ◽  
General Morphology ◽  
Metathoracic Scent Gland ◽  
The Family ◽  
The Status ◽  
Scanning Electron

Dicranocephalus lateralis (Signoret), 1879, a bug from the family Stenocephalidae, is briefly redescribed with colour and scanning electron microscopy (SEM) illustrations of general morphology, including details of male and female genitalia, metathoracic scent gland (MTG), exoskeletal male abdominal glands, eggs and nymphal stages.  The status of other species of this genus in India is also discussed.  This will be the first well-illustrated account of the morphology and life cycle of this bug from India.

Ascospore sculpturing and generic concepts in the Testudinaceae (syn. Zopfiaceae)

1979 ◽  
Vol 57 (2) ◽  
pp. 91-99 ◽  
Author(s):  
D. L. Hawksworth
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Combination ◽  
The Family ◽  
First Time ◽  
Scanning Electron

Generic concepts in the Testudinaceae (Ascomycotina, Loculoascomycetes) are reviewed with particular emphasis on the sculpturing of the ascospores which has been examined by scanning electron microscopy (SEM) for the first time. A key to the nine genera accepted in the family is provided of which two are described as new: Ulospora for U. bilgramii comb.nov. (= Zopfia bilgramii D. Hawksw. et al.), the ascospores of which have three to six deep fissures in each cell, and Zopfiofoveola for Z. punctata comb.nov. (= Zopfia punctata D. Hawksw. & C. Booth), with distinctly and regularly foveolate ascospores. One further new combination is made: Rechingeriella boudieri comb.nov. (= Zopfia boudieri Arnaud). The positions of three additional genera referred to the family by earlier authors but which are excluded from it here are also briefly discussed.

New perspectives on Nephridiacanthus major (Acanthocephala: Oligacanthorhynchidae) collected from hedgehogs in Iran

2020 ◽  
Vol 94 ◽  
Author(s):  
O.M. Amin ◽  
M. Sharifdini ◽  
R.A. Heckmann ◽  
M. Zarean
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phylogenetic Analysis ◽  
Chemical Analysis ◽  
Central Asia ◽  
Molecular Profile ◽  
X Ray ◽  
The Family ◽  
First Time ◽  
Scanning Electron

We describe morphological features not previously reported for this old acanthocephalan Nephridiacanthus major (Bremser, 1811 in Westrumb, 1821) Golvan, 1962 first described over 200 years ago. Our specimens were collected from long-eared hedgehog Hemiechinus auritus (Gmelin, 1770) (Erinaceidae) in Iran. We compare the morphometrics of our material with others previously reported from the same host in Iran, Russia, central Asia and Europe. Our specimens had markedly smaller proboscides, proboscis hooks and lemnisci than those reported from Russia and central Asia, but comparable measurements of other structures with specimens previously described from other collections. We document our new observations with scanning electron microscopy features not previously demonstrable by other observers and provide a chemical analysis of proboscis hooks using energy-dispersive X-ray analysis for the first time. The molecular profile of this acanthocephalan, based on 18S rDNA and cox1 genes, was generated for the first time. The phylogenetic analysis showed that N. major is placed in a clade of the family Oligacanthorhynchidae, well separated from the families Moniliformidae and Gigantorhynchidae.

Jurassic conchostracans from Carapace Nunatak, southern Victoria Land, Antarctica

1994 ◽  
Vol 6 (1) ◽  
pp. 105-113 ◽  
Author(s):  
Shen Yanbin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Middle Jurassic ◽  
New Genus ◽  
New Genus And Species ◽  
Victoria Land ◽  
Number Of Individuals ◽  
Scanning Electron

Fossiliferous horizons of the Ferrar Group at Carapace Nunatak of southern Victoria Land have yielded the richest and most diverse freshwater Jurassic biota hitherto recorded from Antarctica. Fossil conchostracans are the most important in terms of number of individuals and distributional area. Scanning electron microscopy is used to establish a new genus and species (Carapacestheria balli), and Cyzicus (Lioestheria) disgregaris Tasch is attributed to Carapacestheria disgregaris (Tasch) emend. The conchostracan fauna of the Ferrar Group, characterized by Carapacestheria, is probably of early Middle Jurassic age.

scholarly journals Fine Structure of Maxillary Palps in Adults of Hermetia illucens (Diptera: Stratiomyidae)

2020 ◽  
Author(s):  
M Pezzi ◽  
C Scapoli ◽  
M Bharti ◽  
M J Faucheux ◽  
M Chicca ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sexual Dimorphism ◽  
Hermetia Illucens ◽  
The Family ◽  
Sensory Structures ◽  
First Time ◽  
Maxillary Palps ◽  
Scanning Electron

Abstract A relevant species in waste management but also in forensic, medical, and veterinary sciences is the black soldier fly, Hermetia illucens (Linnaeus; Diptera: Stratiomyidae). An ultrastructural study by scanning electron microscopy (SEM) was conducted for the first time on maxillary palps of both sexes, describing in detail the morphology and distribution of sensilla and microtrichia. The maxillary palps, composed of two segments, show sexual dimorphism in length and shape. In both sexes, the first segment is covered only by microtrichia, but the second one is divided into two parts: the proximal one, covered only by microtrichia, and the distal one containing both microtrichia and sensory structures. These structures include two types of sensory pits and one of chaetic sensilla. Due to sexual dimorphism in palp size, females have a higher number of sensory pits. The sexual dimorphism of palps and the presence and role of sensilla in H. illucens was discussed in comparison to other species of the family Stratiomyidae and of other Diptera. This study may represent a base for further investigations on mouthpart structures of this species, involved in key physiological activities, such as feeding, mating and oviposition.

scholarly journals On cestode and digenean parasites of Clarias gariepinus (Burchell, 1822) from the Rietvlei Dam, South Africa

2006 ◽  
Vol 73 (2) ◽  
Author(s):  
M. Barson ◽  
A. Avenant-Oldewage
Keyword(s):  
Electron Microscopy ◽  
South Africa ◽  
Scanning Electron Microscopy ◽  
New Record ◽  
Histological Analysis ◽  
Clarias Gariepinus ◽  
Host Fish ◽  
Mean Intensity ◽  
Anterior Intestine ◽  
Scanning Electron

Sharptooth catfish, Clarias gariepinus, from the Rietvlei Dam near Pretoria, South Africa were examined for internal platyhelminth parasites. Two adult cestodes, Polyonchobothrium clarias (stomach) (prev alence 71 %, mean intensity = 5, n = 7) and Proteocephalus glanduliger (anterior intestine) (prevalence 14 %, mean intensity = 2, n = 7), were found in the gut while metacercariae of one larval digenean, Ornithodiplostomum sp. (prevalence 14 %, mean intensity = 140, n = 7), were found encysted in the muscles. The morphology of these species, based on light and scanning electron microscopy as well as histological analysis, and how they differ from previously described specimens, are discussed. Ornithodiplostomum is a new record in southern Africa. Infection levels of the host fish were mild compared to records from previous surveys.

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