Ontogenetic shifts in natural diet, chelae, and mandible of an omnivorous freshwater crab (Aegla uruguayana): linking morphology and function

Author(s):  
Maria Florencia Viozzi ◽  
Juan Manuel Cabrera ◽  
Federico Giri ◽  
Debora de Azevedo Carvalho ◽  
Verónica Williner

We analyze whether ontogenetic diet change in Aegla uruguayana (Schmitt, 1942) is related to the morphological changes in chelae and mandibles. We use a combination of scanning electron microscope observation (SEM), dietary composition analysis (stomach observation, trophic niche amplitude, trophic overlap, and feeding strategy), and geometric morphometric tools (discriminant analysis and two-block partial least squares analysis). The two structures analyzed by SEM show differences between juvenile and adult specimens, both in their cuticle and morphology specializations. In juveniles, the absence of the lobular tooth is the notable feature. However, in adult sizes it is marked development. Both groups have simple setae with infracuticular articulation and denticles with different arrangements between groups. In the incisive mandible process, the teeth and spines present sharper points in juveniles and considerable wear in adults. Aegla uruguayana presented two trophic strategies: a profile of more predatory traits when younger and mostly detritivorous when adults. The analysis of geometric morphometry substantiates the patterns observed in SEM and stomach contents analysis. The morphology of smaller specimens is associated with the consumption of animal items (ephemeropterans larvae and cladocerans), while in those of larger sizes; it is related to the consumption of plant remains.

1972 ◽  
Vol 43 (6) ◽  
pp. 731-742 ◽  
Author(s):  
M. H. Gleeson ◽  
J. Cullen ◽  
R. H. Dowling

1. To study further the influence of luminal nutrition on small bowel structure and function, segments of rat jejunum and ileum were completely excluded from intestinal continuity by Thiry-Vella by-pass operations. The effect of partial deprivation of luminal nutrition was also studied in jejunal segments that had been surgically transposed to a distal position in the intestinal tract. 2. Macroscopically, by-passed jejunum and ileum both became narrowed and atrophic, whereas the intestine in continuity showed hypertrophic changes similar to those seen after intestinal resection. 3. In by-passed intestine the pattern of villi changed from mucosal ridges to ‘fingers’ and ‘leaves’. Although villous height and total mucosal thickness were both reduced, light microscopy showed that even 6 months after exclusion from intestinal continuity villous morphology was still retained. 4. Epithelial-cell migration rate and turnover time were diminished in both jejunum and ileum after by-pass. In intestine in continuity the migration rate was increased, but the turnover time remained the same as in controls. 5. In by-passed jejunum, in vivo glucose absorption diminished progressively with time, but did not change in excluded ileal segments. 6. After ileo-jejunal transposition, the jejunum showed no major morphological changes, but glucose absorption became significantly depressed. 7. These results further support the concept that intraluminal nutrition exerts a major influence on cell turnover, villous morphology and absorptive function in the small intestine.


Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 285
Author(s):  
Enrico Lunghi ◽  
Fabio Cianferoni ◽  
Stefano Merilli ◽  
Yahui Zhao ◽  
Raoul Manenti ◽  
...  

Speleomantes are the only plethodontid salamanders present in Europe. Multiple studies have been performed to investigate the trophic niche of the eight Speleomantes species, but none of these studies included hybrid populations. For the first time, we studied the trophic niche of five Speleomantes hybrid populations. Each population was surveyed twice in 2020, and stomach flushing was performed on each captured salamander; stomach flushing is a harmless technique that allows stomach contents to be inspected. We also assessed the potential divergence in size and body condition between natural and introduced hybrids, and their parental species. Previously collected data on Speleomantes were included to increase the robustness of these analyses. In only 33 out of 134 sampled hybrid Speleomantes we recognized 81 items belonging to 11 prey categories. The frequency of empty stomachs was higher in females and individuals from natural hybrid populations, whereas the largest number of prey was consumed by males. We compared the total length and body condition of 685 adult salamanders belonging to three types of hybrids and three parental (sub)species. Three group of salamanders (one hybrid and two parental species) showed significantly larger size, whereas no difference in body condition was observed. This study provided novel ecological information on Speleomantes hybrid populations. We also provided insights into the potential divergence between hybrids and parental species in terms of size and body condition. We discuss our findings, and formulate several hypotheses that should be tested in the future.


2015 ◽  
pp. 29-33
Author(s):  
Zsuzsanna Csóri ◽  
András Gáspárdy ◽  
András Jávor

This work seeks to explore the morphological changes of the Hungarian (Hortobágy) Zackel sheep's skull, which occurred in the past 50–70 years. In this study, we compared individuals skull forms by geometric morphometric methods. The origin of the breed is not known, we do not know when entering the Carpathian Basin. Therefore, the comparison involved the only known early archaeological findings. We have shown that there is no difference between each period colour variations, but over time change has occurred in the skull formation of the breed.


2013 ◽  
Author(s):  
Jonathan P. Tennant ◽  
Norman MacLeod

Snout shape is a prominent aspect of herbivore feeding ecology, controlling both forage selectivity and intake rate. Many previous investigations have suggested that ruminant feeding classes can be discriminated via snout shape, with grazing and browsing species attributed ‘blunt’ and ‘pointed’ snouts respectively, with an intermediate sub-grouping. This aspect of functional ecology is analysed for the first time using a statistically rigorous geometry-based framework to compare the two-dimensional profiles of the premaxilla in ventral aspect for a large sample of ruminant species. Our results suggest that, when a sample of browsing and grazing ruminants are classified ecologically based on a range of independent indicators of their feeding strategy, they cannot be fully discriminated on the basis of their premaxilla profile shape. Instead, our sample forms a shape variation continuum with overlap between groupings, but with a 78 percent chance of successful categorisation. Moreover, previously used terminology such as ‘pointed’ and ‘blunt’ are largely inadequate for delimiting snout shape varieties, insofar as these terms lack the descriptive power to define the morphological disparity demonstrated. These results suggest that previous attempts to use snout shape as a proxy for feeding style in ruminants may have been biased due to under-sampling of this highly diverse group and to lack of geometric rigour in the assessment of shape data. Alternatively, conflicting or inadequate evidence in defining ‘browsers’ and ‘grazers’ could have caused incorrect assignment to ecological groups, distorting our analyses. The relation between snout shape and body mass are also documented.


2014 ◽  
Vol 94 (7) ◽  
pp. 1509-1516 ◽  
Author(s):  
Hasna Kadri ◽  
Sondes Marouani ◽  
Mohamed Nejmeddine Bradai ◽  
Abderrahmen Bouaïn

Food and feeding strategy of the thornback ray, Raja clavata, were studied from stomach contents analysis of specimens caught monthly in the Gulf of Gabes. The data were analysed according to sex, size and season. At total of 1280 stomachs was examined, from specimens ranging from 14 to 110 cm total length (TL), of which 1076 (83.98%) contained food. Thornback ray feed mainly on teleosts, crustaceans and cephalopods, whereas gastropods and polychaetes are occasionally consumed. Significant differences were found between the diets of males and females; however, ontogenetic changes were also detected, with crustaceans constituting the greatest proportion of the diet of smaller rays. Both teleosts and cephalopods increased in importance with growth of the skates. Prey diversity increased with size; large and mobile prey species were more commonly found in the diet of larger skates. Diet composition showed seasonal variations. Quantitative analyses and graphical methods indicate that the thornback ray is a generalist feeder.


2003 ◽  
Vol 284 (4) ◽  
pp. C1048-C1053 ◽  
Author(s):  
Eisuke F. Sato ◽  
Masahiro Higashino ◽  
Kazuo Ikeda ◽  
Ryotaro Wake ◽  
Mitsuyoshi Matsuo ◽  
...  

Polymorphonuclear leukocytes (PMN) play crucial roles in protecting hosts against invading microbes and in the pathogenesis of inflammatory tissue injury. Although PMN migrate into mucosal layers of digestive and respiratory tracts, only limited information is available of their fate and function in situ. We previously reported that, unlike circulating PMN (CPMN), PMN in the oral cavity spontaneously generate superoxide radical and nitric oxide (NO) in the absence of any stimuli. When cultured for 12 h under physiological conditions, oral PMN (OPMN) showed morphological changes that are characteristic of those of apoptosis. Upon agarose gel electrophoresis, nuclear DNA samples isolated from OPMN revealed ladder-like profiles characteristic of nucleosomal fragmentation.l-cysteine, reduced glutathione (GSH), and herbimycin A, a protein tyrosine kinase inhibitor, suppressed the activation of caspase-3 and apoptosis of OPMN. Neither thiourea, superoxide dismutase (SOD), nor catalase inhibited the activation of caspase-3 and apoptosis. Moreover, N-acetyl-Asp-Glu-Val-Asp-aldehyde (Ac-DEVD-CHO), inhibitor for caspase-3, inhibited the fragmentation of DNA. These results suggested that oxidative stress and/or tyrosine-kinase-dependent pathway(s) activated caspase-3 in OPMN, thereby inducing their apoptosis.


2019 ◽  
Vol 14 (7) ◽  
pp. 1934578X1986066 ◽  
Author(s):  
K. J. Senthil Kumar ◽  
Yu-Hsin Hsieh ◽  
Ting-Yu Lin ◽  
Shih-Chang Chien ◽  
Jiunn-Wang Liao ◽  
...  

Indigenous cinnamon ( Cinnamomum osmophloeum Kaneh) is a native tree species in Taiwan and has been reported to have various bioactivities including insecticidal, larvicidal, and antimicrobial effects. The chemical finger print of C. osmophloeum is similar to that of commercial cinnamon species with lower coumarin content. The present study was aimed to investigate the antidyslipidemia effects of indigenous cinnamon ( Cinnamomum osmophloeum Kaneh) leaf powder (CoLP) on hypercholesterolemia hamsters. Hyperlipidemia was induced by high-cholesterol (HChol) diet for 4 weeks. Two percent and 5% CoLP, and gemfibrozil (positive control; 0.25%) were administered for 10 weeks following HChol diet. Control groups were fed with normal diet (ND) or ND+5% CoLP. Behavioral, physiological, and serum biochemical parameters were determined. We found that oral administration of CoLP for 10 weeks significantly reduced the HChol-induced increase of total cholesterol (TC), triglyceride, and low-density lipoprotein levels in plasma of hamsters. In addition, HChol-induced elevation of serum glutamic oxaloacetic transaminase and glutamic pyruvic transaminase levels was significantly reversed by CoLP in a dose-dependent manner, whereas blood urea nitrogen and creatinine levels were unaffected. Further standard diagnostic tests support that consumption of CoLP did not show any behavioral and morphological changes in hamsters. Furthermore, chemical composition analysis revealed that two new flavanol glycosides, kaempferol-3- O-α-l-rhamnopyranosyl-(1→2)-α-l-arabinofuranosyl-7- O-α-l-rhamnopyranoside (4) and kaempferol-3- O-β -d-apiofuranosyl-(1→2)-α-l-arabinofuranoside (5) along with 4 known flavonoid glycosides were identified in leaves of C. osmophloeum. Taken together, these results concluded that CoLP possessed strong antidyslipidemic effects. Therefore, C. osmophloeum leaves could be a safe food supplement for treating hypercholesterolemia.


Metabolites ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 339
Author(s):  
Alec Millner ◽  
G. Ekin Atilla-Gokcumen

Lipids are emerging as key players of senescence. Here, we review the exciting new findings on the diverse roles of lipids in cellular senescence, most of which are enabled by the advancements in omics approaches. Senescence is a cellular process in which the cell undergoes growth arrest while retaining metabolic activity. At the organismal level, senescence contributes to organismal aging and has been linked to numerous diseases. Current research has documented that senescent cells exhibit global alterations in lipid composition, leading to extensive morphological changes through membrane remodeling. Moreover, senescent cells adopt a secretory phenotype, releasing various components to their environment that can affect the surrounding tissue and induce an inflammatory response. All of these changes are membrane and, thus, lipid related. Our work, and that of others, has revealed that fatty acids, sphingolipids, and glycerolipids are involved in the initiation and maintenance of senescence and its associated inflammatory components. These studies opened up an exciting frontier to investigate the deeper mechanistic understanding of the regulation and function of these lipids in senescence. In this review, we will provide a comprehensive snapshot of the current state of the field and share our enthusiasm for the prospect of potential lipid-related protein targets for small-molecule therapy in pathologies involving senescence and its related inflammatory phenotypes.


2011 ◽  
Vol 2 (1) ◽  
pp. 12 ◽  
Author(s):  
Ann Brasey ◽  
Raouf Igue ◽  
Loubna Djemame ◽  
Serge Séguin ◽  
Paolo Renzi ◽  
...  

<p>Antisense oligonucleotides (AON) delivered via inhalation are in drug development for respiratory diseases. In rodents and monkeys, repeated exposure to high doses of inhaled phosphorothioate (PS) AON can lead to microscopic changes in the lungs, including accumulation of alveolar macrophages in the lower airway that have a <em>foamy</em> appearance. The functional consequences that result from this morphological change are unclear as there is controversy whether the vacuoles/inclusion bodies reflect normal clearance of the inhaled AON or are early indicators of lung toxicity. The morphological and functional responses of macrophage to PS AON were characterized <em>in vitro</em> using the comparator drug amiodarone, as a known inducer of foamy macrophages. Morphological changes of increased vacuolization with the presence of lamellated structures were observed in macrophages in response to both amiodarone and AON treatment. Functional responses to the drugs clearly differed with amiodarone treatment leading to apoptosis of cells and cell death, release of proinflammatory mediators IL-1RA, MIP-1<em>α </em>and TNF<em>α</em>, decrease in IP-10, a cytokine shown to be involved in protection against pulmonary fibrosis and altered phagocytosis capacity of the cells. In contrast, AON in concentrations up to 30 μM, had no effect on cell viability or apoptosis, had minimal effects on pro-inflammatory cytokines, increased IP-10 levels and did not alter the phagocytic capacity of the cells. Exposure of macrophages to AON<em> in vitro</em>, led to morphological changes of increased vacuolization, but did not lead to functional consequences which were observed with another vacuolization-inducing drug, suggesting that the <em>in vivo </em>phenotypic changes observed following inhalation of AON may be consistent with a clearance mechanism and not an activation or impairment of macrophages.</p>


1999 ◽  
Vol 121 (4) ◽  
pp. 503-513 ◽  
Author(s):  
C. Wang ◽  
X. Cheng ◽  
A. M. Sastry ◽  
S. B. Choi

Experimental findings are presented which demonstrate the coupled transport, mechanical and morphological changes in porous battery materials when they are cycled electrochemically. These materials, comprised of a mixture of powdered nickel and nickel fiber, act as substrates in nickel-metal hydride (NiMH) cells, and function as porous, conductive containment for positive-plate active material. They can offer substantial weight and cost savings over more traditional sintered or foam materials, provided they can be designed to produce good conductivity over many (>500) electrochemical cycles. This study represents an expansion of previous work by the authors, which had established some key differences in the behavior of substrate materials for a small number of cells. Here, these difference are validated with a greater variety and number of electrochemical/material experiments, along with a parallel study on morphological changes. In the second paper in this series (Cheng et al., 1999b), transport and mechanics models are presented to explain the observed differences, using microstructural models based on observations in this study.


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