Microfiber reinforcement of an arthropod cuticle

1973 ◽  
Vol 144 (3) ◽  
pp. 409-433 ◽  
Author(s):  
Friedrich G. Barth
Keyword(s):  
Arthropod Cuticle ◽  
Microfiber Reinforcement

The Cuticle of Peripatopsis Moseleyi

1964 ◽  
Vol s3-105 (71) ◽  
pp. 281-299
Author(s):  
ELAINE A. ROBSON
Keyword(s):  
Body Wall ◽  
Light And Electron Microscopy ◽  
Thick Layer ◽  
The Body ◽  
Muscle Fibres ◽  
Terrestrial Arthropods ◽  
Dermal Glands ◽  
Arthropod Cuticle ◽  
Primitive Condition ◽  
Pore Canals

The integument of Peripatopsis moseleyi has been examined by light and electron microscopy with particular reference to the structure and formation of the cuticle. The evidence supports the idea that Peripatus is a true arthropod but not that it has direct affinities with the annelids. The characteristics of arthropod cuticle are present in their simplest form and pore canals and dermal glands are lacking. The cuticle is 1 or 2 µ, thick except in the hardened claws and spines. Above the procuticle (chitinprotein) is a thin 4-layered epicuticle. It is possible that the innermost of the 4 layers (prosclerotin) may correspond to cuticulin of other arthropods. In the claws and spines tanning in this layer extends to the procuticle. Hydrofuge properties of the cuticle probably depend on the outer layers of epicuticle, and it is suggested that the lamina concerned might consist of oriented lipid associated with lipoprotein (Dr. J. W. L. Beament). Wax and cement are absent. Non-wettability of the cuticle is probably ensured by the contours of micropapillae which cover the surface. Similar structures arise in Collembola and other terrestrial arthropods by convergence. The formation of new cuticle before ecdysis is described. After the epicuticular layers are complete, the bulk of the procuticle is laid down in a manner probably common to all arthropods. Secreted materials originate in small vesicles derived from rough endoplasmic reticulum and from scattered Golgi regions. The latter contribute to larger vacuoles which rise to the surface of the cell and liberate material in a fluid state. This later consolidates to form procuticle. Vesicles may also open to the surface directly, and ribosomes probably occur free in the cytoplasm. At this stage the cell surface is reticulate, especially under micropapillae. The ordinary epidermis has only one kind of cell, attached to the cuticle by tonofibrils disposed like the ribs of a shuttlecock, and to the fibrous sheaths of underlying muscle-fibres by special fibres of connective tissue. These features and the presence of numerous sensory papillae are associated with the characteristic mobility of the body wall. The appearance of epidermal pigment granules, mitochondria, the nuclear membrane, and a centriole are noted. No other cells immediately concerned in the formation of cuticle have been found. By contrast myriapods, which do not have wax either, possess dermal glands secreting far more lipid than is found in the Onychophora. The wax layer found in insects and some arachnids constitutes an advance of high selective value which emphasizes the primitive condition of the Onychophora. It is noted that the thick layer of collagen separating the haemocoel from the epidermis probably restricts the transfer of materials. It is suggested that since some features of cuticular structure and formation appear to be common to all arthropods, it is possible that some of the endocrine mechanisms associated with ecdysis may also be similar throughout the phylum.

Adsorbed layers: the stimulus to settlement in barnacles

1963 ◽  
Vol 158 (972) ◽  
pp. 364-387 ◽  
Keyword(s):  
Laboratory Experiments ◽  
Water Soluble ◽  
Soluble Protein Fraction ◽  
Molecular Configuration ◽  
Chemical Sense ◽  
Insoluble Material ◽  
Water Soluble Protein ◽  
Adsorbed Layers ◽  
Arthropod Cuticle ◽  
Balanus Balanoides

The factor responsible for inducing settlement in cyprids of Balanus balanoides (L.) can be fractionated by ammonium sulphate, and gives positive reactions to a series of tests identifying it with arthropodin, the water soluble protein fraction of arthropod cuticle. Solutions of the settling factor have little effect on the behaviour of cyprids exploring a surface, and do not promote settlement. Slate surfaces previously soaked in a dilute seawater extract of the settling factor can be distinguished by cyprids from freshly cleaned slates, even when cyprids and both surfaces are freshly immersed in the same extract that was previously used to soak the first set of slates. It is argued from this that the cyprids must respond to a specific molecular configuration manifested by the protein only when physically or chemically bound to a surface. Since in nature cyprids respond to a surface consisting of protein tanned by the natural polyphenols of the epicuticle (sclerotin), we consider that in our laboratory experiments with adsorbed layers of soluble arthropodin they respond to the same molecular configuration at the surface. Such recognition of specific molecular groupings of an insoluble material involves a truly contact chemical sense, which we have called a ‘tactile chemical sense’. This facility may exist in other animals. The settlement behaviour of barnacle cyprids is analyzed in terms of instinctive behaviour.

Coprolites and ostracods from the Dinantian of Foulden, Berwickshire, Scotland

1985 ◽  
Vol 76 (1) ◽  
pp. 49-51 ◽  
Author(s):  
John E. Pollard
Keyword(s):  
Vertical Distribution ◽  
Brackish Water ◽  
Fish Scales ◽  
Lower Carboniferous ◽  
Arthropod Cuticle ◽  
The Vertical Distribution

ABSTRACTCoprolites of four distinct shapes, cylindrical, discoidal, beaded and irregular masses, are described from 11 horizons within Bed 16 of the Foulden sequence. These coprolites are composed of either phosphatic or claystone material, although they have not been analysed mineralogically or chemically. Their producers appear to have been fish, probably both nektonic predators and nekto-benthonic scavengers or detritus feeders.Ostracods are poorly preserved and of two broad types, thick shelled paraparchitids including Shemonaella scotoburdigalensis and thin shelled podocopids, possibly species of Carbonita or Cavellina. This ostracod assemblage represents a conservative ‘carbonaceous fades’ fauna which occurs widely in plant-rich sediments in lower Carboniferous (Courceyan) sequences of northern England and southern Scotland. Other microfauna includes spirorbid worm tubes, fish scales, arthropod cuticle fragments, spat of myalinid bivalves, plant fragments and spores. No significant changes in the vertical distribution of the microfauna could be detected.The microfauna indicates a general fresh to brackish water lacustrine or lagoonal environment possibly with access to quasi-marine conditions.

scholarly journals The multi-layered protective cuticle of Collembola: a chemical analysis

2014 ◽  
Vol 11 (99) ◽  
pp. 20140619 ◽  
Author(s):  
Julia Nickerl ◽  
Mikhail Tsurkan ◽  
René Hensel ◽  
Christoph Neinhuis ◽  
Carsten Werner
Keyword(s):  
Electron Microscopy ◽  
Chemical Composition ◽  
Chemical Analysis ◽  
Decisive Role ◽  
Arthropod Cuticle ◽  
Characteristic Layers ◽  
Protein Rich ◽  
Base Structure ◽  
Soil Habitat

Collembola, also known as springtails, are soil-dwelling arthropods that typically respire through the cuticle. To avoid suffocating in wet conditions, Collembola have evolved a complex, hierarchically nanostructured, cuticle surface that repels water with remarkable efficiency. In order to gain a more profound understanding of the cuticle characteristics, the chemical composition and architecture of the cuticle of Tetrodontophora bielanensis was studied. A stepwise removal of the different cuticle layers enabled controlled access to each layer that could be analysed separately by chemical spectrometry methods and electron microscopy. We found a cuticle composition that consisted of three characteristic layers, namely, a chitin-rich lamellar base structure overlaid by protein-rich nanostructures, and a lipid-rich envelope. The specific functions, composition and biological characteristics of each cuticle layer are discussed with respect to adaptations of Collembola to their soil habitat. It was found that the non-wetting characteristics base on a rather typical arthropod cuticle surface chemistry which confirms the decisive role of the cuticle topography.

Spore assemblages from the Lower Devonian ‘Lower Old Red Sandstone’ deposits of the Rhynie outlier, Scotland

2006 ◽  
Vol 97 (2) ◽  
pp. 167-211 ◽  
Author(s):  
Charles H. Wellman
Keyword(s):  
Lower Devonian ◽  
Geological Structure ◽  
Thermal Maturity ◽  
Red Sandstone ◽  
Good Surface ◽  
New Information ◽  
History Of ◽  
Arthropod Cuticle ◽  
Age Range ◽  
First Time

ABSTRACTSince the late 1980s an extensive programme of trenching/borehole drilling has been undertaken in order to study the Lower Devonian ‘Lower Old Red Sandstone’ deposits of the Rhynie outlier in the Grampian Highlands of Scotland. The boreholes have provided new information on the stratigraphical succession and geological structure of the Rhynie outlier, both of which were hitherto poorly understood due to the paucity of good surface exposure and the complex geological relationships of the deposits. One hundred and eighteen palynological samples were collected, representing much of the stratigraphical sequence of the inlier, of which 106 were productive. Productive samples yield assemblages of well preserved palynomorphs, dominated by spores and phytodebris, but also containing arthropod cuticle and rare freshwater algal remains. The spore assemblages are systematically described and two new genera and six new species proposed. They are similar throughout the sequence and the spores belong to the polygonalis–emsiensis Spore Assemblage Biozone of Richardson & McGregor (1986) and the PoW Oppel Zone (possibly Su Interval Zone) of Streel et al. (1987), indicating an early (but not earliest) Pragian–?earliest Emsian age range, that may possibly be restricted to latest Pragian–?earliest Emsian. The palynomorph assemblages contain only terrestrial forms, supporting sedimentological interpretation of the deposits as ‘Lower Old Red Sandstone’ fluviatile and lacustrine deposits, with occasional extrusive volcanics and volcaniclastic sediments intercalated. The palynomorphs are of variable thermal maturity (within and between samples), probably reflecting differential heating associated with the complex volcanic/hydrothermal system. The new palynological data provide, for the first time, a reliable biostratigraphical age for the deposits, and suggest that they accumulated relatively rapidly. Spore biostratigraphy and thermal maturity studies facilitate correlation of the tectonically complex deposits, and shed light on other aspects of the geological history of the outlier. The palynomorph assemblages also aid interpretation of the biota of the Rhynie basin, including the exceptionally preserved biotas of the Rhynie and Windyfield cherts.

Influence of cellulose microfiber reinforcement for polyvinyl alcohol on the layer growth of plasma-deposited a-C:H

2020 ◽  
Vol 109 ◽  
pp. 108065
Author(s):  
Torben Schlebrowski ◽  
Zineb Kassab ◽  
Mounir El Achaby ◽  
Stefan Wehner ◽  
Christian B. Fischer
Keyword(s):  
Polyvinyl Alcohol ◽  
Layer Growth ◽  
Microfiber Reinforcement
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