scholarly journals Artificial Reproduction on Taking fugu obscurus

1999 ◽  
Vol 11 (2) ◽  
pp. 129-134 ◽  
Author(s):  
CHEN Ya-fen ◽  
◽  
CHEN Yuan-gao ◽  
LIU Zhen-wen
Author(s):  
S. Assylbekova ◽  
N. Badryzlova ◽  
L. Kushnikova

The article presents the results of the first research on artificial reproduction in industrial conditions of the endemic, narrow-areal subspecies of Brachymystax lenok Savinovi, which lives in lake Markakol, East Kazakhstan region. The indicators of the heat sum characteristic for each stage of development, the rate of development and growth of the Markakolsky lenok from the moment of pre-breeding to late juveniles are described. To develop technological approaches for artificial fish reproduction, one of the most important points is to determine the optimal conditions for each stage and assess the risks (loss of fish products). At the stage of insemination and transportation of eggs to the place of incubation, the loss was 50 %. The largest losses of fish products were registered during the incubation stage. The most painlessly passed the period of holding and lifting on the float, where the loss was only 3 %. When growing pre-larvae and larvae in the pool, the daily waste did not exceed 1 %. Small-sized animals that were unable to adapt to artificial feeds fell into the waste. Losses during this period amounted to 15 % of the previous stage. In General, the yield of juveniles from the moment of fertilization to the end of the experiment was 16 %. The crucial factor in the development and growth of Lenok Markakolosky is the temperature regime. For the period of embryonic development, the most favorable water temperature is 7–8 °C. From the moment of hatching, the water temperature must be increased to 10–12 °C, and the optimal temperature for the cage growing of fingerlings varies from 12 to 14 °C.


2020 ◽  
Vol 22 (1) ◽  
pp. 93
Author(s):  
Arturo Matamoros-Volante ◽  
Valeria Castillo-Viveros ◽  
Paulina Torres-Rodríguez ◽  
Marcela B. Treviño ◽  
Claudia L. Treviño

Plasma membrane (PM) hyperpolarization, increased intracellular pH (pHi), and changes in intracellular calcium concentration ([Ca2+]i) are physiological events that occur during human sperm capacitation. These parameters are potential predictors of successful outcomes for men undergoing artificial reproduction techniques (ARTs), but methods currently available for their determination pose various technical challenges and limitations. Here, we developed a novel strategy employing time-lapse flow cytometry (TLFC) to determine capacitation-related membrane potential (Em) and pHi changes, and progesterone-induced [Ca2+]i increases. Our results show that TLFC is a robust method to measure absolute Em and pHi values and to qualitatively evaluate [Ca2+]i changes. To support the usefulness of our methodology, we used sperm from two types of normozoospermic donors: known paternity (subjects with self-reported paternity) and no-known paternity (subjects without self-reported paternity and no known fertility problems). We found relevant differences between them. The incidences of membrane hyperpolarization, pHi alkalinization, and increased [Ca2+]i were consistently high among known paternity samples (100%, 100%, and 86%, respectively), while they varied widely among no-known paternity samples (44%, 17%, and 45%, respectively). Our results indicate that TLFC is a powerful tool to analyze key physiological parameters of human sperm, which pending clinical validation, could potentially be employed as fertility predictors.


2012 ◽  
Vol 24 (6) ◽  
pp. 843 ◽  
Author(s):  
Daniel Żarski ◽  
Sławomir Krejszeff ◽  
Katarzyna Palińska ◽  
Katarzyna Targońska ◽  
Krzysztof Kupren ◽  
...  

The aim of this study was to investigate the process of the cortical reaction in eggs of pikeperch, Sander lucioperca (L.), as well as the application of microscopic assessment of this process in egg quality evaluation. The analysis was carried out with eggs obtained from 10 females by artificial reproduction, in which hormonal stimulation with hCG was applied. Subsequently, each sample of eggs (separately from each female fish) was analysed. The analysis included observation of the cortical reaction and the process of egg swelling, and determination of the effect of temperature (12, 14 and 16°C) and the presence of spermatozoa on the cortical reaction. The results indicate that the cortical reaction in pikeperch eggs is quite violent, resulting in visible deformation of eggs between 3 and 5 min after activation. No effect of temperature or the presence of spermatozoa on the cortical reaction was observed. A strong correlation was recorded for the percentage of egg deformations observed and embryo survival rate. The described method of determination of pikeperch egg quality (based on egg deformation rate between 3 and 5 min after activation) may be highly useful, both in scientific research (where high-quality eggs are required) and in hatchery practice.


It is now well established that the luminosity and blue colour of the sky on very clear days and at considerable altitudes above the sea-level can almost be accounted for by the scattering of light by the molecules of air, without postulating suspended particles of foreign matter, such as were thought necessary by the earlier writers. This conclusion depends on the measured opacity of the atmosphere, deduced from observations such as those of Abbot and Fowle of the sun’s radiation at various zenith distances. The opacities measured at Mount Wilson for different wave-lengths are found to be nearly in agreement with what would be expected if scattering by the molecules were alone operative; leaving little room for the action of larger particles.


Author(s):  
Jana Bennett

This chapter places Catholic teaching on questions of life and death against the background of a Catholic vision of salvation history, emphasizing that Catholics see no necessary opposition between Christian faith and progress in scientific understanding of the creation. The chapter then considers questions concerning abortion, contraception, and techniques for artificial reproduction. The second half of the chapter focuses on questions concerning death. Catholic teaching views human life in this world as finite, and thus sees death as intrinsic to the current human condition. After considering Catholic teaching on euthanasia, the chapter considers Catholic discussion of war, the death penalty, and care for the environment.


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