scholarly journals Morphological changes during the post-embryonic ontogeny of mesothelan spiders and aspects of character evolution in early spiders

Author(s):  
Thomas Huber ◽  
Carolin Haug

AbstractMost morphological studies focus on adult specimens, or if developmental studies are pursued, especially in Euarthropoda, they focus on embryonic development. Araneae (spiders) is one of these groups, in consequence with understudied post-embryonic development. Here we present aspects of the post-embryonic stages of different species of Mesothelae, sister group to the remaining spiders (when fossil species are not taken into account). We used different imaging methods and measured different external morphological structures to detect possible ontogenetic changes. One structure exhibiting post-embryonic changes is the chelicera. Here the significant change occurs between the last immature stage and the adult, yet only in males. For the spinnerets, we could not detect ontogenetic changes, but instead a high variability in length and width, probably due to their lack of pivot joints between the elements. The strongest morphological change during ontogeny occurred on the sternum, which begins with a rather roundish shape in the first stage and changes to being fairly elongate in shape in the last immature stages and the adult. This specific sternum shape only occurs in adults of mesothelan spiders, while opisthothelan spiders have a broader sternum also in the adult. We discuss our results in an evolutionary context, also taking into account recent finds of fossil spiders.

Zootaxa ◽  
2021 ◽  
Vol 4992 (1) ◽  
pp. 1-89
Author(s):  
ADRIAN ARDILA-CAMACHO ◽  
CALEB CALIFRE MARTINS ◽  
ULRIKE ASPÖCK ◽  
ATILANO CONTRERAS-RAMOS

Adult external morphology of the extant raptorial Mantispoidea (Insecta: Neuroptera: Mantispidae and Rhachiberothidae) is compared emphasizing the morphology of the subfamily Symphrasinae as a key group to understand the phylogenetic relationships among the members of the superfamily. Plega dactylota Rehn, 1939 is thoroughly characterized in order to exemplify the morphology of the Symphrasinae. Additionally, following a review of the literature and examination of comparative material of Dilaridae, Berothidae, Rhachiberothidae and all Mantispidae subfamilies, a new interpretation of the components of the raptorial apparatus (i.e., head, prothorax, grasping forelegs, as well as integumentary specializations) is presented. Also, wing venation for these groups is reinterpreted, and new homology hypotheses for wing venation are proposed based on tracheation and comparative analyses. Given the high morphological divergence on the genital sclerites within the Mantispoidea, plus the confusing previous usage of neutral terminology and terms referring to appendages across taxonomic and morphological studies, we attempt to standardize, simplify, and situate terminology in an evolutionary context under the “gonocoxite concept” (multi-coxopod hypothesis). The remarkable morphological similarity of the genital sclerites of Symphrasinae and Rhachiberothidae (sensu U. Aspöck & Mansell 1994) with the Nallachinae (Dilaridae) was taken as a starting point to understand the morphology of other Mantispidae subfamilies. Based on these morphological comparisons, we provide a revised phylogenetic analysis of Mantispoidea. This new phylogenetic analysis supports a sister group relationship between the family Rhachiberothidae, comprising Rhachiberothinae and Symphrasinae, and the family Mantispidae, including the subfamily Mantispinae and its sister taxa Drepanicinae and Calomantispinae, which may represent a single subfamily. Based on these analyses, raptorial condition probably evolved a single time in these insects and subsequently became diversified in the two sister clades of the raptorial Mantispoidea.  


2017 ◽  
Vol 57 (25) ◽  
pp. 321
Author(s):  
André Henrique de Oliveira ◽  
Luciane Cristina de Oliveira Lisboa ◽  
José Eduardo Serrão ◽  
José Cola Zanuncio ◽  
Edmilson Amaral de Souza

Exocrine glands play important role in social organization of insects, such as caste and inter-caste differentiation. Due their functional and structural plasticity, morphological studies on such glands contribute to better understanding the biology of social bees. Therefore, the aim of the study was to characterize the sequence of the post-embryonic development of intramandibular glands of Friesella schrottkyi (Friese, 1900) (Hymenoptera: Apidae) workers using histological and histochemical analyses. The mandibles of pupae at different developmental stages and newly emerged adults were analyzed. The intramandibular glands of F. schrottkyi presented two types: class I glands, in the mandible epidermis and class III glands, inside the mandible cavity that open onto external surface. The intramandibular glands of F. schrottkyi developed during the transition from the prepupae to the white-eyed pupae, as shown by the morphological changes. Black-eyed pupae of F. schrottkyi presented fully developed intramandibular glands.


2012 ◽  
Vol 33 (2) ◽  
pp. 239-250 ◽  
Author(s):  
Javier Goldberg ◽  
Florencia Vera Candioti ◽  
Mauricio Sebastián Akmentins

Within Anura, direct development involves ontogenetic changes of the biphasic ancestral pattern. The recent partitioning of the genus Eleutherodactylus, along with the proposition of the unranked taxon Terrarana, has renewed an interest to the morphological and ecological diversity among direct-developing frogs. The morphological changes during embryonic development of Oreobates barituensis is similar to those of other Neotropical direct-developing species, including the reduction or absence of several larval and embryonic characters (e.g., external gills and adhesive glands), heterochronic changes (e.g., early developing limbs and late persistence of ciliated epidermal cells), and the appearance of new structures (e.g., egg tooth). The tail achieves an extraordinary peramorphic development (encloses the entire embryo), and the location of its expanded part is interpreted as a heterotopic change resulting in a novel trait. An enveloping tail with apparently non-heterotopic fins, combined with the absence of gills, has been only reported for a species of the related genus Craugastor, and these morphologies suggest an informative perspective for the study of evolution of direct development in terraranans.


Author(s):  
Semeleva E.V. ◽  
Blinova E.V. ◽  
Zaborovsky A.V. ◽  
Vasilkina O.V. ◽  
Shukurov A.S.

In this work, we studied the pharmacological activity of zinc and magnesium salts of 2-aminoethanesulfonic acid in white non-linear male rats with amyotrophic lateral sclerosis, which was modeled by neurotoxicantsimplication into the pelvic part of spinal cord. After the reproduction of the pathology in animals, the indices of motor activity were recorded in the Rotarod test, and morphological studies of spinal cord sections stained according to Nisl in the Belshovsky modification were carried out. It was shown that the magnesium salt of 2-aminoethanesulfonic acid (compound LHT-317) to a greater extent reduces the development of motor disorders in experimental animals compared with the control group on the 4th day of observation. The course of intravenous administration of the studied compounds of 2-aminoethanesulfonic acid did not inhibit morphological changes in the spinal cord that develop in degenerative-dystrophic pathology of the central nervous system: connections. Moreover, if, against the background of treatment with zinc salt, the total area of motor zones in animals of the experimental group exceeded that of control rats, then the number of motoneurons did not differ from the control.


2020 ◽  
Vol 99 (9) ◽  
pp. 1001-1006
Author(s):  
Elvira F. Repina ◽  
Denis O. Karimov ◽  
Samat S. Baygildin ◽  
Gulnara V. Timasheva ◽  
Nadezhda Yu. Khusnutdinova ◽  
...  

Introduction. Among noninfectious diseases, one of the leading places belongs to pathologies caused by the action of industrial toxicants. In this regard, the search for drugs for the prevention and treatment of various intoxications is one of the priority tasks of public health. Treatment of intoxication with drugs with antioxidant and antihypoxic activity is more effective. The aim of this study was to investigate morphological changes in parenchymal organs (liver, kidneys, and pancreas) under acute exposure to high doses of carbon tetrachloride and to evaluate the effectiveness of their correction with a new composition of oxymethyluracil with ascorbic acid. Material and methods. The composition of 5-hydroxy-6-methyluracil with ascorbic acid was first synthesized at the Ufa Institute of Chemistry, Ufa Federal Research Center, RAS. The preventive effect of the new drug was studied in comparison with “Heptor” on the carbon tetrachloride-induced liver injury model. Morphological studies of the liver, pancreas, and kidneys of laboratory animals were carried out. Results. Studies have shown the prophylactic administration of new composition of 5-hydroxy-6-methyluracil with ascorbic acid to have a protective effect on the structure of parenchymal organs in acute carbon tetrachloride intoxication, comparable to the drug “Heptor” (possibly superior). However, reparative properties were observed only in the drug “Heptor”. Conclusion. Comparative estimation of morphological changes in parenchymal organs under acute exposure to high doses of carbon tetrachloride indicates the protective effect of prophylactic administration of the composition of 5-hydroxy-6-methyluracil with ascorbic acid, comparable to the drug “Heptor” (possibly superior).


1992 ◽  
Vol 6 ◽  
pp. 107-107
Author(s):  
Timothy J. Gaudin ◽  
William D. Turnbull

The mammalian order Xenarthra (including the living Neotropical armadillos, anteaters, and tree sloths) has figured importantly in recent hypotheses of interordinal relationships among eutherian mammals. It has been suggested that the group shares a common ancestry both with the extant Old World order Pholidota (i.e. the pangolins or scaly-anteaters) and the extinct North American group Palaeanodonta. Furthermore, these three groups have been linked together into a monophyletic Cohort Edentata, which has been hypothesized to represent the sister-group to all other eutherians. This placement of edentates relative to the remainder of Eutheria has been supported in part by a purported difference in the morphology of the stapes in the two groups- edentates possessing a primitive, imperforate/columelliform morphology, other placentals a derived, perforate/stirrup-shaped morphology.A recent study of stapedial morphology among mammals by Novacek and Wyss (1986) suggests that within the Xenarthra itself a perforate stapes is found among armadillos, but that the pilosa in particular (the clade including anteaters and sloths) and the order as a whole are characterized primitively by an imperforate stapes. Our studies of the xenarthran ear region (Patterson et al., in press) have uncovered new ontogenetic and paleontological evidence which contradict the findings of Novacek and Wyss. Among adults of the two extant tree sloth genera, the stapes lacks a stapedial foramen. However, in both genera, this adult imperforate morphology is derived from a perforated juvenile stapes. Novacek and Wyss ignored fossil species in their consideration of the xenarthran stapes. It has long been known that extinct ground sloths of the family Mylodontidae possessed a large stapedial foramen. Unfortunately, until now no stapes were known from the remaining ground sloth families, the Megatheriidae and the Megalonychidae. We have uncovered a complete left stapes of an early Miocene megatheriid ground sloth Eucholoeops ingens. This stapes possesses a well-developed stapedial foramen. We believe that this new paleontological evidence, combined with our information on the ontogeny of the stapes in the living genera, clearly indicates that a perforate stapes is primitive for sloths. Moreover, when we plot distributions of stapedial morphologies of both living and fossil edentates onto a phylogeny of the Edentata, we can demonstrate that the a large stapedial foramen is primitive for the Xenarthra as a whole, and probably for the entire Cohort Edentata. Such a distribution makes it unlikely that stapedial morphology can be used to separate edentates from other eutherian mammals.


2013 ◽  
Vol 31 ◽  
pp. 49-54 ◽  
Author(s):  
Md Moniruzzaman Sarker ◽  
Sirajul Islam ◽  
Tsuyoshi Uehara

The complete embryonic development of the mangrove sesarmid crab Neosarmatium indicum (A. Milne Edwards, 1868) was described based on internal and external morphological changes in live fertilized eggs reared in the laboratory. Several pairs of N. indicum were collected from the Nuha River mangrove swamp of the southern Okinawa Island, Japan, which is consisted mainly with the mangrove Kandelia candel, and densely populated by the genus Perisesarma and Neosarmatium indicum . The fertilized eggs were macrolecithal, centrolecithal and spherical in shape, filled with uniform dark olive colour, without evidence of any development. The diameter of fertilized egg was 0.36 mm, which increased to 0.47 mm before hatching. Embryo development from fertilized eggs to hatching (first zoea stage) lasted average of 16 days at 25°C and salinity at 80‰. Sixteen stages of embryonic development were categorized by following continuous observation using an optical DIC microscope equipped with digital camera, video camera and printer. After 24 hours of incubation, fertilized eggs became 32-celled stage of development. Before hatching, many chromatophores (mostly black) were evident in the abdominal segments and the telson of embryos. At the end of 16 days incubation, the zoea larvae were successfully hatched out, which were reared in the laboratory conditions for further development.DOI: http://dx.doi.org/10.3329/ujzru.v31i0.15400Univ. j. zool. Rajshahi Univ. Vol. 31, 2012 pp. 49-54


2015 ◽  
Vol 2 (6) ◽  
pp. 150114 ◽  
Author(s):  
Jason Hodin ◽  
Matthew C. Ferner ◽  
Gabriel Ng ◽  
Christopher J. Lowe ◽  
Brian Gaylord

Complex life cycles have evolved independently numerous times in marine animals as well as in disparate algae. Such life histories typically involve a dispersive immature stage followed by settlement and metamorphosis to an adult stage on the sea floor. One commonality among animals exhibiting transitions of this type is that their larvae pass through a ‘precompetent’ period in which they do not respond to localized settlement cues, before entering a ‘competent’ period, during which cues can induce settlement. Despite the widespread existence of these two phases, relatively little is known about how larvae transition between them. Moreover, recent studies have blurred the distinction between the phases by demonstrating that fluid turbulence can spark precocious activation of competence. Here, we further investigate this phenomenon by exploring how larval interactions with turbulence change across ontogeny, focusing on offspring of the sand dollar Dendraster excentricus (Eschscholtz). Our data indicate that larvae exhibit increased responsiveness to turbulence as they get older. We also demonstrate a likely cost to precocious competence: the resulting juveniles are smaller. Based upon these findings, we outline a new, testable conception of competence that has the potential to reshape our understanding of larval dispersal and connectivity among marine populations.


2019 ◽  
Vol 98 (9) ◽  
pp. 1004-1010
Author(s):  
E. F. Repina ◽  
D. O. Karimov ◽  
G. V. Timasheva ◽  
N. Yu. Khusnutdinova ◽  
A. R. Gimadieva ◽  
...  

Introduction. The high frequency of chemical poisoning is accompanied by an increase in the absolute number of cases of chemical damage to the liver. There is growing evidence that acute chemical poisoning in Russia is among the leading non-infectious diseases leading to premature death of male and female working-age people. It seems relevant to search for new pharmacological agents with low toxicity and high hepatoprotective activity, which increase the body’s stability under the influence of adverse environmental factors. The use of metabolic action drugs combining antioxidant and antihypoxic activity as hepatoprotectors is promising. The purpose of this study is an experimental evaluation of the hepatoprotective activity of a new composition of oxymethyluracil with succinic and fumaric acids. Material and methods. The composition of 5-hydroxy-6-methyluracil with succinic and fumaric acids was first synthesized at the Ufa Institute of Chemistry. Using the model of acute liver toxic damage with carbon tetrachloride in laboratory animals, the prophylactic effect of a new drug was studied in comparison with heptor (ademetionine). Biochemical and morphological studies of laboratory animals’ biomaterial were conducted. Results. The analysis showed that when using the studied drugs, biochemical parameters were close to the level of control animals. Morphological changes in the liver were less pronounced in the group of animals treated with the new composition, compared with changes in the structure of the liver of animals treated with heptorator (ademetionin). Conclusion. The new composition of 5-hydroxy-6-methyluracil with succinic and fumaric acids has a protective effect on the liver of laboratory animals with the acute toxic effects of carbon tetrachloride, comparable, and in some cases, exceeding the preventive effect of heptoperam (ademetionine).


Author(s):  
O. V. Pelypenko

Every fifth inhabitant of the earth has been diagnosed with osteoarthritis of various etiologies. Morphological studies of arthritis provide a theoretical basis for creating optimal treatments for this pathology. Given the polyetiological nature of the disease, the choice of the optimal experimental model, which would be as close as possible to the real conditions of inflammatory process reproduction, is the topical issue. The purpose of the study was to confirm the pathological reaction of the joint tissues of laboratory animals in response to intraperitoneal administration of ƛ-carrageenan. The study was performed on 50 white Wistar rats males aged 12 weeks, weighing 130-150 g. The animals were euthanized by an overdose of anaesthesia according to the terms of the study (1 - 30 days). Fragments of the distal metaepiphyses of the femur and proximal metaepiphyses of the tibia were used for histological examination. Staining of sections obtained on the microtome was performed with haematoxylin, eosin, and Van Gieson`s stain. From the first day of the experimental study, a corresponding reaction of the joint tissues was being observed. Particularly pronounced were the changes in the synovial membrane in the form of oedema of the villi accompanied by an increased filling of blood vessels with foci of thrombosis. Gradually, up to 5 days in the synovial membrane, proliferative changes took place with a clear definition of the multilineage of the integumentary layer, vascular reaction with a tendency to thrombosis, in some places necrosis of synoviocytes was observed, but relative integrity of the morphological structure was still provided by protective barriers of bone and cartilage. On the 7th day pronounced resorption of both bone and cartilage tissue occurred, tissue structure became disorganized and functional layer became thin, accompanied by massive intracellular lysis. The process of synoviocytes necrobiosis with fatty degeneration spread. The histological picture of 10 days is characterized by generalized destruction of bone beams; the destroyed cartilage was replaced by granulation tissue with the presence of cavities. Massive foci of lymphocytic infiltration were observed in the synovial membrane. On the 14th day, a fragmentation of cartilage happened, most of the bone beams (trabeculae) were destroyed. After 3 weeks the morphological picture of cartilage tissue was determined by the appearance in the lacunae of viable cells, the number of which was close to normal. Bone beams were restored, although they remained thin. In a synovial membrane, the hyperplasia of apical departments of villi, leukocytes infiltration, disorganization of connective tissue, and separate vascular disturbances remained. 30 days of the experiment were characterized by a relative recovery of structural relationships to normal. The obtained data confirm the feasibility of using carrageenan in experimental studies of osteoarthritis.


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