Redescription of Promecostethus unifalculatus, the only known harvestman from Crozet Islands (Opiliones: Triaenonychidae)

Zootaxa ◽  
2020 ◽  
Vol 4861 (1) ◽  
pp. 120-130
Author(s):  
WILLIANS PORTO ◽  
ABEL PÉREZ-GONZÁLEZ

Promecostethus unifalculatus Enderlein, 1909, is the only representative of the order Opiliones from the Crozet Islands. The species belongs to the family Triaenonychidae and is biogeographically interesting because it is a candidate for transoceanic dispersal, a very rare event in this ancient family. Despite this significance, P. unifalculatus is taxonomically still poorly known, and a redescription of this species using modern taxonomic standards is urgently needed. Here we redescribe the species, offer the first description and illustrations of the male genitalia and provide a full exomorphological survey of the species using scanning electron microscopy. Furthermore, we provide an emended diagnosis for the genus Promecostethus and discuss its relationship with some morphologically similar genera. 

1979 ◽  
Vol 57 (2) ◽  
pp. 91-99 ◽  
Author(s):  
D. L. Hawksworth

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.


2020 ◽  
Vol 94 ◽  
Author(s):  
O.M. Amin ◽  
M. Sharifdini ◽  
R.A. Heckmann ◽  
M. Zarean

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.


Author(s):  
M Pezzi ◽  
C Scapoli ◽  
M Bharti ◽  
M J Faucheux ◽  
M Chicca ◽  
...  

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.


Zootaxa ◽  
2019 ◽  
Vol 4619 (3) ◽  
pp. 401-430 ◽  
Author(s):  
NESTOR FERNANDEZ ◽  
PIETER THERON ◽  
SERGIO LEIVA ◽  
ANINE JORDAAN

Diplobodes africanus Mahunka, 1987, is redescribed by using Scanning Electron Microscopy (SEM) in order to complement optical microscopy. Diplobodes thailande sp. nov. from Thailand is described. For both species we include inclined views, to permit detailed analysis of ventral regions and to aid understanding of the complex relationships between elevated and depressed zones. Diplobodes thailande sp. nov. presents previously undescribed structures on legs III, which are involved in the leg folding process. Rwandabodes kayoveae gen. nov., sp. nov. presents a series of particular characteristics, such as: elevated interlamellar process on prodorsum, composed of a triangular structure, externally delimited by a low lamellar furrow; in setae inserted on elevated interlamellar process; large free lamellar tip; notogaster lacking ridges; anterior genital furrow extends into an oblique lateral depression; depressed area anterior to anal zone; both zones clearly delimited. These characteristics permit easy differentiation from related genera. 


1971 ◽  
Vol 49 (8) ◽  
pp. 1259-1261 ◽  
Author(s):  
Larry F. Grand ◽  
Royall T. Moore

Basidiospores of 13 North American species of Strobilomycetaceae were examined by scanning electron microscopy. Similarities and differences of surface features among species are discussed in relation to their possible role in the taxonomy of the family.


1994 ◽  
Vol 68 (4) ◽  
pp. 319-322 ◽  
Author(s):  
F. Moravec ◽  
A. Kohn ◽  
B.M.M. Fernandes

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.


2000 ◽  
Vol 6 (3) ◽  
pp. 202-210
Author(s):  
Kevin T. Reynolds

Abstract At the species level, bryozoans (class Phylactolaemata) in the family Plumatellidae are difficult to organize taxonomically. Of principal concern is the absence of consistent distinguishing features due mainly to plasticity of the group, a common problem with soft-bodied invertebrates. Yet, within the last three decades, analysis of distinctive chitinous statoblasts—using scanning electron microscopy—has resolved certain taxonomic questions. I examined statoblasts from 30 similar collections, the majority from the midwestern United States, and identified four distinct subgroups. Also, nine new statoblast surface features were identified: fold, polar grooves, bead, cave, demarcation, parasutural zone, ridge, sutural band, and sutural knob. The surface features of floating statoblasts (floatoblasts) provide useful data for species identification. Most consistently useful in plumatellids is a suture which varies from one species to the next. Mound-like tubercles and net-like ridges are next in the extent of variability. Finally, folds and polar grooves are present but vary even within floatoblasts from the same colony. Analysis of the suture in Plumatella fungosa, over a 5-day germination period, reveals all features at the site remain intact regardless of the initial age of the floatoblast. Only the suture line itself splits lengthwise to permit emergence of the new animal.


1991 ◽  
Vol 39 (2) ◽  
pp. 119 ◽  
Author(s):  
JJ Bruhl

Morphology at different developmental stages was investigated by dissection and by scanning electron microscopy (SEM) in five sedges: Eleocharis (three species) and Schoenoplectus (both Cyperoideae, Scirpeae), and Lepidosperma (Caricoideae, Schoeneae). In each case all the perianth segments (scales or bristles) were positioned outside the staminal primordia or stamens, consistent with classical interpretations of flowers. Putative exceptions and previous alternative interpretations of floral morphology in the Cyperaceae are discussed. SEM developmental studies of Hypolytreae (e.g. Scirpodendron) are needed for further clarification of interpretative floral/inflorescence morphology in the family.


1995 ◽  
Vol 69 (4) ◽  
pp. 670-685 ◽  
Author(s):  
D. I. Mackinnon ◽  
T. N. Smirnova

Four species of megathyrid brachiopods from the Lower Cretaceous (Berriasian) of Crimea, Ukraine, and one species of megathyrid from the lower Upper Cretaceous (Cenomanian) of England are reinvestigated using scanning electron microscopy. The species are variously assigned to one existing genus, Praeargyrotheca Smirnova (P. hexaplicata (Smirnova) and P. megatrema (J. de C. Sowerby)) and two new genera, Krimargyrotheca (K. concinna (Smirnova) and K. balkii n. gen. and n. sp.) and Evargyrotheca (E. alta (Smirnova)). Taxa are distinguished principally on differences in shell shape, plication, and, in particular, surface microornament. The shell microstructure of all five species is investigated with particular emphasis on endopunctation and microornament. Dental plates are present briefly early in ontogeny. Based on the possession of transient dental plates, a septalium, and conspicuous microornament, Praeargyrotheca is removed from the family Megathyrididae and assigned, along with the two new genera, to a new family Praeargyrothecidae. Scanning electron microscopy study of loop development in both fossil and Recent terebratelloids and megathyrids supports a recent immunological study of living taxa from both groups that suggests that the two groups are not as closely linked phylogenetically as previously maintained. The family Megathyrididae is thus removed from the superfamily Terebratelloidea and assigned, along with the new family Praeargyrothecidae, to a new superfamily Megathyridoidea.


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