Influence of temperature on larval ontogenesis of Geophagus brasiliensis (Quoy & Gaimard, 1824) (Pisces: Cichlidae)

Zygote ◽  
2021 ◽  
pp. 1-6
Author(s):  
Marcelo Duarte Ventura Melo ◽  
Alessandro Loureiro Paschoalini ◽  
Nilo Bazzoli

Summary Studies on the larval development of fish are essential for conservation and improvements in cultivation techniques. Geophagus brasiliensis popularly known as Cará has potential as a fish of interest in ornamental aquaculture. Wild adults of G. brasiliensis were kept in an aquarium for spontaneous reproduction. Newly hatched larvae were transferred to 5-litre aquaria at 22, 26 and 30°C until total yolk sac resorption. Histological slides were used for biometric analysis and monitoring of larval ontogenesis at different temperatures. Histologically, from the first to the fourth days it was possible to identify myomeres, optic vesicle, yolk syncytial layer, brain, heart and differentiation of the eye layers. From the fourth to the seventh days, it was possible to identify mandibular and gill cartilages, swim bladder, liver, prismatic epithelium with striated border in intestine and renal epithelium. All biometric measurements increased over the days, except height and length of the yolk sac, which gradually decreased until the complete resorption of the yolk sac that occurred on the fifth day at a temperature of 30°C, the sixth day at 26°C and the seventh day at 22°C. Morphological events at 30°C such as the reabsorption of the yolk sac, the appearance of cartilage in the branchial arches and differentiation of the layers of the eyes occurred faster compared with the other temperatures tested. Opening of the mouth and digestive tract occurred at a similar time on the fourth day in all temperatures.

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3013
Author(s):  
Leszek Czechowski

The paper deals with an examination of the behaviour of glued Ti-Al column under compression at elevated temperature. The tests of compressed columns with initial load were performed at different temperatures to obtain their characteristics and the load-carrying capacity. The deformations of columns during tests were registered by employing non-contact Digital Image Correlation Aramis® System. The numerical computations based on finite element method by using two different discrete models were carried out to validate the empirical results. To solve the problems, true stress-logarithmic strain curves of one-directional tensile tests dependent on temperature both for considered metals and glue were implemented to software. Numerical estimations based on Green–Lagrange equations for large deflections and strains were conducted. The paper reveals the influence of temperature on the behaviour of compressed C-profile Ti-Al columns. It was verified how the load-carrying capacity of glued bi-metal column decreases with an increase in the temperature increment. The achieved maximum loads at temperature 200 °C dropped by 2.5 times related to maximum loads at ambient temperature.


Development ◽  
1992 ◽  
Vol 115 (1) ◽  
pp. 289-303 ◽  
Author(s):  
A. Orr-Urtreger ◽  
M.T. Bedford ◽  
M.S. Do ◽  
L. Eisenbach ◽  
P. Lonai

The alpha receptor of PDGF (Pdgfra) is expressed in primitive endoderm and mesoderm derivatives throughout embryogenesis. In the early primitive streak stage the gene is transcribed in the visceral and parietal endoderm. Later it is expressed in the presomitic mesoderm, yolk sac and amnion. During somitogenesis its transcription localizes to the heart and the somites. Subsequently, it is transcribed in the dermatome, the sclerotome, the developing limb and in various mesenchymal tissues of visceral organs. Its wild-type expression pattern correlates well with the phenotype of homozygous mutant Patch (Ph) embryos, where the Pdgfra gene is deleted. The Ph phenotype is first detectable at the primitive streak stage with convoluted and hypertrophic visceral yolk sac, deformed neural plate and disorganized or missing mesoderm. Most Ph/Ph embryos die before the 11th day of gestation. Those that survive till early organogenesis are very small, have hypertrophic yolk sacs, small and undifferentiated somites, convoluted neural tubes, large heart and pericardium, rudimentary limb buds and branchial arches. Our observations together suggest that the alpha PDGF receptor may be required for the normal development of visceral endoderm and mesoderm derivatives.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2507
Author(s):  
Jinxian Zhai ◽  
Hanpeng Zhao ◽  
Xiaoyan Guo ◽  
Xiaodong Li ◽  
Tinglu Song

The relationship between temperature and the mechanical properties of an end cross-linked equal molar random copolyether elastomer of 3,3-bis(azidomethyl)oxetane and tetrahydrofuran (P(BAMO-r-THF)) was investigated. During this investigation, the performances of two P(BAMO-r-THF) elastomers with different thermal histories were compared at different temperatures. The elastomer as prepared at 20 °C (denoted as S0) exhibited semi-crystallization morphology. Wide angle X-ray diffraction analysis indicated that the crystal grains within elastomer S0 result from the crystallization of BAMO micro-blocks embedded in P(BAMO-r-THF) polymeric chains, and the crystallinity is temperature irreversible under static conditions. After undergoing a heating-cooling cycle, this elastomer became an amorphous elastomer (denoted as S1). Regarding mechanical properties, at 20 °C, break strains and stresses of 315 ± 22% and 0.46 ± 0.01 MPa were obtained for elastomer S0; corresponding values of 294 ± 6% and 0.32 ± 0.02 MPa were obtained for elastomer S1. At −40 °C, these strains and stresses simultaneously increased to 1085 ± 21% and 8.90 ± 0.72 MPa (S0) and 1181 ± 25% and 10.23 ± 0.44 MPa (S1), respectively, owing to the strain-induced crystallization of BAMO micro-blocks within the P(BAMO-r-THF) polymeric chains.


Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 80-82
Author(s):  
Raoani Cruz Mendonça ◽  
Sarah Pittigliani Ikebata ◽  
Sérgio Leandro Araújo-Silva ◽  
João Vitor Azevedo Manhães ◽  
Mônica Yumi Tsuzuki

SummaryThe flameback pygmy angelfish Centropyge aurantonotus, highly appreciated and valued by the aquarium market, is heavily harvested and traded. Temperature is one of the abiotic factors that has the most influence on fish development, especially in the early stages of life. For captive production, it is essential to know the appropriate environmental parameters for each species. In this sense, this study aimed to evaluate the influence of temperature on the embryonic development and hatching rates of C. aurantonotus incubated at six different temperatures (20, 22, 24, 26, 28, 30°C). Embryonic development events were very similar in terms of morphological and chronological characteristics compared with other species of the genus Centropyge. Incubation time was inversely proportional to temperature. The treatment at 22°C required twice the time of that required by 30°C treatment for hatching to occur. The best incubation temperature range was 24–28°C. Values below 22°C and at 30°C showed lower hatching rates compared with other treatments. Based on these results, the recommended temperature at which to incubate C. aurantonotus eggs is between 24–28°C.


2011 ◽  
Vol 689 ◽  
pp. 43-48
Author(s):  
Min Jie Liang ◽  
Hai Hong Liao ◽  
Wen Jiang Ding ◽  
Zheng Chen

The influence of temperature on atomic site occupation probability (SOP) in L12--Ni3(Al1-xFex) has been studied using microscopic phase-field simulation for Ni3Al-Fe alloy with the lower Fe content. Microscopic phase-field kinetics model was further extended to study the temporal evolution of atomic site occupation and atomic anti-sites behavior, which was revealed in detail at the different temperatures. The results show that the size, number and the precipitation mechanism of L12phases also present obvious changes with the increase of temperature. The SOP of each atom on its right-sites decreases slowly; while the SOP of Fe atoms are far lower than those of Al atoms. On the other hand, the SOP of each atom on its anti-sites increases gradually. The formation of NiAl(Ni atoms form anti-sites on Al sites) is more easily and the formation of NiAlis more sensitive to temperature than that of FeNi(Fe atoms form anti-sites on Ni sites). Atomic site occupation will not evolve during the early stage of precipitation, which becomes more and more obvious.


2008 ◽  
Vol 575-578 ◽  
pp. 848-853
Author(s):  
Yu Ping Zhu ◽  
Guan Suo Dui

A constitutive model for magnetic shape memory alloys is developed through a combined consideration of micromechanical and thermodynamic theories. Of special concern is the influence of different temperatures on field-induced reorientation strain for a NiMnGa single-crystal specimen. The theoretical results are found to be in general agreement with experimental data. It is shown that the method is accurate and simple.


1858 ◽  
Vol 148 ◽  
pp. 887-894 ◽  

Fraunhofer, in his original measurements of the fixed lines of the spectrum, noted the thermometer, and those who since his time have occupied themselves with the determi­nation of refractive indices, must have frequently noticed that changes of temperature affect the amount of refraction; yet of the many observations now on record, few have affixed to them the temperature at which they were made. Baden Powell has drawn out some refractive indices of the same substance taken at different temperatures, but remarks that the whole subject, both as to the facts of the case and as to their bear­ing on the theoretical formulæ, remains to be investigated. Among his beautiful researches on light, M. Jamin has recently published one or two experiments on refrac­tion, heat, and density; but, with this exception, he has left untouched the great question of the influence of temperature. Some years ago Baden Powell kindly lent his instrument to one of us for the pur­pose of investigating this question. It is described and figured in the Report of the British Association for 1839. It consists essentially of a small telescope moving on a circle graduated so finely, that by means of a vernier and magnifying glass it may be read to 10"; to ensure accuracy, there is a vernier at each end of the moveable arm: in front of the telescope are appliances for fixing any solid prism, or a hollow prism capable of containing liquids, in such a position that there may be seen through it a ray of light proceeding from a distant slit. The telescope may be moved till a fine wire fastened in the field of view is brought to coincide with any of Fraunhofer’s lines the prismatic spectrum thus obtained, and the angle indicated by the position of the telescope on the graduated circle may he read off. In our recent joint research, as we desired measure the positions of the extreme lines A and H, it was necessary to work with the full light of the sun; its mirrored image, therefore, was kept behind the narrow slit by a heliostat, and the eye was protected from the glare of the yellow ray by means of a cobalt-blue glass.


1976 ◽  
Vol 39 (2) ◽  
pp. 132-137 ◽  
Author(s):  
JEFFREY W. BIER

All stages of the anisakine life cycle—egg, larva, and adult—have been used to initiate cultures. Eggs develop to hatching larvae at different temperatures depending on the species or strain. Newly hatched larvae of Phocanema decipiens and Contracaecum osculatum grow to an average 31.1 mm in 52 weeks and 6.5 mm in 32 weeks, respectively. Larvae from fish or those previously cultivated will molt at 35 C in a complex culture medium. P. decipiens and Anisakis marina have produced eggs in vitro. A. marina eggs from cultured females produced viable larvae. Freshness of the larvae used to initiate cultures is considered a major factor in success. The histochemistry of the composition and structure of P. decipiens cuticle in larvae from fish and cultures has been defined; experiments have demonstrated that the processes of cuticular deposition and ecdysis are independent. It has been postulated and evidence provided that a neurosecretory mechanism controls ecdysis; it has also been shown that this system can be stimulated by an insect hormone and a synthetic analog. Larvae in vitro, in fish flesh, and in fried fish fingers, do not survive heating to 60 C for 1 min. The recommended time and temperature found in Japanese and European literature for freezing fish to kill anisakine larvae is −20 C for 24 h; however, some North American species survive after 52 h at this temperature.


2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Jéssica A. Pereira ◽  
Alexandra C.S. Veronez ◽  
Gabriel C. Coppo ◽  
Charles Duca ◽  
Adriana R. Chippari-Gomes ◽  
...  

ABSTRACT Oxygen and temperature are the most limiting factors in aquatic environments. Several species are exposed to variations of these factors in water because of physical, chemical and biological processes. The objective of this study was to evaluate the metabolic profile and the tolerance to the hypoxia of Geophagus brasiliensis exposed to changes in temperature and oxygen availability. The fish were exposed to 20 and 90% of oxygen saturation combined with different temperatures (20°, 24° and 28° C) for 8 h. Hepatic and muscular glycogen, as well as the activities of lactate dehydrogenase (LDH), malate dehydrogenase (MDH), citrate synthase (CS) and their ratios were evaluated. Both glycogen and MDH activity showed a significant difference in the liver. While CS showed increased activity only in the heart. The increase in LDH activity in the white muscle shows the importance of the anaerobic pathway as energy source in this tissue. The MDH / LDH ratio increased in all tissues, while CS / LDH increased in the liver and decreased in the heart. Based on the results of the present study it may be concluded that this species used the anaerobic metabolism as the main strategy for hypoxia tolerance.


1885 ◽  
Vol 38 (235-238) ◽  
pp. 401-414

The experiments described in this paper were undertaken in the hope of obtaining some light upon the vexed question of the condition in which a solid exists when dissolved in a liquid, and were directed more especially towards the investigation of the well-known remarkable phenomena exhibited by sodium sulphate. Crystallised sodium sulphate melts at about 34°, and at this temperature the salt begins to show signs of dissociation by depositing the anhydrous compound. According to Wiedemann, indeed, indications of change are observable at a few degrees lower. He finds by observation of the volume of the crystallised salt at different temperatures, that whereas slight expansion occurs from 17° to about 30°, contraction then sets in, at first slowly, then, at 33° to 34°, very rapidly, till the salt melts. The melted salt expands regularly in proportion as the temperature is raised to near 100°. Nicol has made experiments upon the expansion of solutions of the same salt, and with similar results.


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