scholarly journals The importance of thermoperiod for proper gametogenesis and successful egg and sperm production in meagre (Argyrosomus regius) breeders in aquaculture

2021 ◽  
Vol 22 (2) ◽  
pp. 218
Author(s):  
PAULO H. DE MELLO ◽  
STEFANO LANCEROTTO ◽  
IOANNIS FAKRIADIS ◽  
PANAGIOTA TSOUKALI ◽  
MARIA PAPADAKI ◽  
...  
Keyword(s):  
Water Temperature ◽  
Plasma Levels ◽  
Sperm Quality ◽  
Quality Parameters ◽  
Embryo Survival ◽  
Spawning Period ◽  
Stage Of Development ◽  
Argyrosomus Regius ◽  
Negative Effect ◽  
Spawning Success

We examined the effect of constant water temperature throughout the year on gametogenesis, spawning success and egg/sperm/embryo quality in meagre (Argyrosomus regius). Two broodstocks were exposed to simulated natural photoperiod, andeither attenuated seasonal water temperature (SeasT, 16.4 to 19.6ºC) or relatively constant water temperature (CoT, 19.4 ± 0.6ºC).In the spawning period (May), 4 couples per group were induced to spawn with gonadotropin releasing hormone agonist (GnRHa). Gonadal stage of development, sperm quality parameters and plasma levels of sex steroids were evaluated prior to the GnRHa treatment. Spawning success and egg/sperm quality were examined over the following 4 weeks. Constant temperature did not prevent gametogenesis, but exposure to attenuated seasonal water temperature with the inclusion of winter low temperature was beneficial to both sexes. The mean (±SD) diameter of the largest vitellogenic oocytes prior to GnRHa administration was significantly higher in the SeasT compared to the CoT group (598 ± 27 vs 520 ± 17 μm). Testosterone plasma levels in the females were significantly higher in the SeasT group, but all other hormones were similar in both sexes. SeasT females spawned more consistently with higher relative fecundity, and 24-h embryo survival of the produced eggs. A more pronounced negative effect of constant water temperature was observed in males, since CoT males exhibited a spermiation index of 0 prior to GnRHa treatment, the latter clearly having a beneficial effect over the following 4 weeks. The study demonstrated that meagre do undergo gametogenesis to a significant extent even under constant water temperatures during the year. However, a seasonal thermal regime -even an attenuated one- was necessary for the proper development of the gametes, allowing for the successful spawning induction using the established GnRHa induction protocol.

Linking fish and crustacean taxonomic composition with seasonal contrasts in the soft-bottom intertidal zone

2020 ◽  
Author(s):  
M. A. Gondal ◽  
S. Iqbal ◽  
U. Atique ◽  
N. U. Saher ◽  
N. A. Qureshi ◽  
...  
Keyword(s):  
Species Richness ◽  
Water Temperature ◽  
Fish Species ◽  
Diversity Index ◽  
Taxonomic Composition ◽  
Primary Objective ◽  
Negative Effect ◽  
Fish Species Composition ◽  
One Year ◽  
Sw Monsoon

Abstract The primary objective of this study was to investigate the seasonal fish and crustacean variations concerning taxonomic composition, species richness, and diversity in sandy beach habitat. For this purpose, we investigated the Sonmiani Hor lagoon area during four distinct seasons, i.e., northeast (NE) monsoon, pre-monsoon, south-west (SW) monsoon, and post-monsoon for one year. During each haul, the net was pulled about 100m along the beach in 0.5m depth. The results showed a strong linear correlation between the diversity index and equitability in fishes (r = 0.978). The diversity index was strong negatively correlated with the abundance and biomass (r = -0.978, -0.972, respectively). The physical attributes like sea surface water temperature and salinity showed a strong negative effect on species assemblages (r = -0.981 and -0.943, respectively). The mean air and water temperature illustrated approximately 3°C difference during NE and pre-monsoon seasons. However, salinity, pH, and electrical conductivity did not show any significant seasonal variabilities. Under the ecological indices, the fish species displayed higher diversity (H’ = 3.19) during SW monsoon, whereas the lowest diversity was observed during pre-monsoon (H’ = 1.58). The equitability and species richness, however, remained more noticeable during SW monsoon (J’ = 0.81). The total number of individuals of fish and crustaceans reached 4799 with 3813 fish individuals and 986 individuals of crustaceans. A total of 27 families of fish while five crustacean families comprising of 30 genera and 38 fish species while ten genera and 17 species of crustaceans were recorded. Liza subviridis displayed the highest abundance among the sampled fish species. In conclusion, fish species constituted a significant part of the coastal fauna in the study area. The seasonal variations displayed distinct variations in fish species composition and diversity.

Analysis of the rates of development and growth of Brachymystax lenok Savinovi during artificial reproduction by the industrial method

2020 ◽  
pp. 40-49
Author(s):  
S. Assylbekova ◽  
N. Badryzlova ◽  
L. Kushnikova
Keyword(s):  
Water Temperature ◽  
Fish Reproduction ◽  
Optimal Conditions ◽  
Artificial Reproduction ◽  
Fish Products ◽  
Rate Of Development ◽  
Stage Of Development ◽  
East Kazakhstan ◽  
Brachymystax Lenok ◽  
The Moment

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.

Problems of Implementation of an Import Substitution Policy in the Oil Industry

2019 ◽  
pp. 50-57
Author(s):  
Yu. V. Vertakova ◽  
A. S. Evtyukhin
Keyword(s):  
Import Substitution ◽  
Oil Industry ◽  
Investment Climate ◽  
Scientific Publications ◽  
Stage Of Development ◽  
Current Economic Situation ◽  
Negative Effect ◽  
Substitution Policy ◽  
Investment Process ◽  
The Impact

The presented study addresses the issues of implementation of an import substitution policy in the Russian oil industry. Support of domestic production is a key objective specified in the message of the President of the Russian Federation in 2019. In light of the current economic situation and considering the importance of the oil industry for the Russian economy, an import substitution policy could help achieve the objective set by the President.Aim. The study aims to identify the problems and ways of implementation of an import substitution policy in the Russian oil industry.Tasks. The authors analyze scientific publications on import substitution and the state of the Russian oil industry at the current stage of development; determine the directions and fundamental trends in the development of the oil industry; identify obstacles that hinder the implementation of an import substitution policy in the oil industry; describe conditions that facilitate the development of the  investment process in the oil industry; propose comprehensive methods and ways to intensify investments and optimize costs for enterprises in the oil industry.Methods. This study uses general scientific methods of cognition, comparative and statistical analysis to identify problems in the implementation of an import substitution policy in the oil industry.Results. Examination of the current state and development prospects of the oil industry allows the authors to identify obstacles to the development of import substitution. The study shows their impact on the potential of import substitution, which has a negative effect on the prospects of intensification of investment processes, and proposes comprehensive methods and mechanisms that could neutralize the impact of the identified obstacles, thus facilitating the formation of a positive investment climate. Conclusions. Investment climate is shown to have a decisive impact on the potential of import substitution in the Russian oil industry, and ways of overcoming negative trends in the development of the oil industry are proposed.

scholarly journals The influence of perinatal and current dioxin and PCB exposure on reproductive parameters (sex-ratio, menstrual cycle characteristics, endometriosis, semen quality, and prematurity): a review

Biomonitoring ◽  
2014 ◽  
Vol 1 (1) ◽  
Author(s):  
M.M. Leijs ◽  
L.M. van der Linden ◽  
J.G. Koppe ◽  
K. Olie ◽  
W.M.C. van Aalderen ◽  
...  
Keyword(s):  
Menstrual Cycle ◽  
Sex Ratio ◽  
Gestational Age ◽  
Semen Quality ◽  
Sperm Quality ◽  
Human Populations ◽  
Menstrual Cycles ◽  
Negative Effect ◽  
Dioxin Exposure ◽  
Pcb Exposure

AbstractPolychlorinated biphenyls (PCBs) and dioxins (PCDDs/Fs) are well-known endocrine disrupters. This paper strives to elucidate the data on reproductive consequences of perinatal dioxin and PCB exposure in men and women. We focused on the following end-points: sex-ratio, endometriosis, menstrual cycle characteristics, sperm quality, and prematurity. We summarize 46 papers and compare their results including effects seen after exposure to background concentrations. Seven of twelve studies showed a decrease in sex-ratio after parental dioxin or PCB exposure. In three of the seven studies, effects were seen after paternal exposure and in three after maternal exposure. In eight of the nine studies on menstrual cycle characteristics, abnormalities were associated with PCB or dioxin exposure, however the results differed. In three studies PCB and TCDD were associated with longer menstrual cycles, while three studies indicated that an increase in PCB/PCDF exposure was associated with shorter cycles. Five studies showed effects on menstrual bleeding with higher PCB or dioxin exposure. A higher rate of irregular menstrual cycles in exposed women was seen in four studies. The conflicting outcomes probably result from variability in study design, timing of exposure and endocrine disrupting properties of the measured congeners. Nine of sixteen studies detected higher PCB or dioxin exposure in women with endometriosis. However, the manner of diagnosing endometriosis and the character of the studies varied from prospective to retrospective. Five of eight studies focusing on sperm quality showed that men, with higher serum concentrations of PCBs and/or PCB congeners and/or PCDFs, had reduced sperm quality, including increased abnormal morphology and reduced motility. The exposure timeframe seemed important here. There are two studies addressing preterm birth in relation to PCBs, one mentioned a shortening of three days of gestational age, two other studies did not find a relation. Recently one study related a shorter gestational age of half a week with overall dioxin activity measured with the CALUX method in cord blood, particularly in boys. In conclusion, exposure to PCBs and dioxins has a negative effect on the reproductive systems of human populations. Although some speculations have been made, the exact mechanism of these effects and the interactions of these compounds with other endocrine disruptors are not yet known. Age at exposure and congener specific properties are probably crucial in interpreting the observed results.

scholarly journals Research and Design of Distributed IoT Water Environment Monitoring System Based on LoRa

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Wei Chen ◽  
Xiao Hao ◽  
JianRong Lu ◽  
Kui Yan ◽  
Jin Liu ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Temperature ◽  
Real Time ◽  
Monitoring System ◽  
Water Environment ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Environment Monitoring ◽  
Long Distance ◽  
Internet Of Things Technology

In order to solve the problems of high labor cost, long detection period, and low degree of information in current water environment monitoring, this paper proposes a lake water environment monitoring system based on LoRa and Internet of Things technology. The system realizes remote collection, data storage, dynamic monitoring, and pollution alarm for the distributed deployment of multisensor node information (water temperature, pH, turbidity, conductivity, and other water quality parameters). Moreover, the system uses STM32L151C8T6 microprocessor and multiple types of water quality sensors to collect water quality parameters in real time, and the data is packaged and sent to the LoRa gateway remotely by LoRa technology. Then, the gateway completes the bridging of LoRa link to IP link and forwards the water quality information to the Alibaba Cloud server. Finally, end users can realize the water quality control of monitored water area by monitoring management platform. The experimental results show that the system has a good performance in terms of real-time data acquisition accuracy, data transmission reliability, and pollution alarm success rate. The average relative errors of water temperature, pH, turbidity, and conductivity are 0.31%, 0.28%, 3.96%, and 0.71%, respectively. In addition, the signal reception strength of the system within 2 km is better than -81 dBm, and the average packet loss rate is only 94%. In short, the system’s high accuracy, high reliability, and long distance characteristics meet the needs of large area water quality monitoring.

scholarly journals Study on physico-chemical features of water in Tarahara Fish Farm, Sunsari, Nepal

2017 ◽  
Vol 7 (1) ◽  
pp. 47-57
Author(s):  
Ganesh Bahadur Thapa ◽  
Joydeb Pal
Keyword(s):  
Water Quality ◽  
Water Temperature ◽  
Air Temperature ◽  
Physicochemical Parameters ◽  
Quality Parameters ◽  
Fish Farm ◽  
Fish Growth ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Peripheral Areas

Tarahara Fish Farm includes 37 large ponds as a fish super zone. Physicochemical parameters viz., air and water temperature, pH, DO, BOD, CO2, Cl-, TA and TH of these ponds were studied for two years (Nov. 2008 to Oct. 2010). The air temperature had positive and significant correlation with water temperature (r=0.893, P<0.01) but inverse and significant correlation with DO (r = - 0.669 P<0.05) and TH (r = - 0.673, P<0.05). Both air and water temperature showed a decreasing trend during the winter months of November to January and again September to October in both years. Similarly, positive and significant correlation showed by pH with DO (r =0.660, P<0.05) and BOD (r =0.846, P<0.05); by free CO2 with DO (r=0.854, P<0.01), chloride (r=0.648, P<0.05) and TA (r=0.616, P<0.05); by DO with TA (r =0.715, P<0.01) and chloride (r =0.625, P<0.05) and by TH with TA (r= 0.592, P<0.05) but inverse and significant correlation showed by pH with water temperature (r =-0.671, P<0.05); by free CO2 with BOD (r=-0.627, P<0.05) and by DO with BOD (r = -0.810, P <0.01). The water quality parameters were within suitable range for the fish growth and breeding with small fluctuations in different months during the first and second years. Physico-chemical parameters significantly (P<0.01; 0.05) differed between different months. However, no mass mortality of fish was recorded from this site. So, the area selected as fish super zone is fruitful to meet the expected production level of fishes and fish seeds in peripheral areas.

scholarly journals Sperm quality parameters are increased and asymmetric in house mouse hybrids

2019 ◽  
Author(s):  
Iva Martincová ◽  
Ľudovít Ďureje ◽  
Stuart J. E. Baird ◽  
Jaroslav Piálek
Keyword(s):  
Y Chromosome ◽  
House Mouse ◽  
Sperm Quality ◽  
Quality Parameters ◽  
F1 Hybrids ◽  
Secondary Contact ◽  
Male Fitness ◽  
Cross Direction ◽  
Sperm Trait ◽  
The Difference

AbstractSpermatogenesis is a tuned cascade of processes producing sperm; impairment of any phase of this process can affect fitness of males. The level of impairment can be pronounced in hybrids between genetically divergent populations. To explore the effect of hybridization on sperm quality we produced F1 hybrids from 29 wild derived strains of two house mouse subspecies, M. m. musculus and M. m. domesticus, which diverged 0.5 MY ago. The measured sperm quality traits did not significantly differ between intrasubspecific crosses. Effects of intersubspecific hybridization were dependent on sperm trait and cross direction. The proportion of sperm head abnormalities was increased in F1 intersubspecific hybrids. The frequency of dissociated sperm heads was increased in the M. m. musculus × M. m. domesticus (♀×♂) F1 but decreased in M. m. domesticus × M. m. musculus (♀×♂) F1 hybrids, with the difference in medians being more than 180%. We deduce that the dissociated sperm heads trait is associated with the X chromosome and modulated by interaction with the Y chromosome; nevertheless, the high proportion of unexplained variance (55.46 %) suggests the presence of polymorphic autosomal interactions. The reported differences in sperm quality between cross types may be highly relevant to male fitness in zones of secondary contact between the two subspecies. The cross direction asymmetry in frequency of dissociated sperm heads should favour the M. m. musculus Y chromosome. This is consistent with the spread of the M. m. musculus Y chromosome in nature across the hybrid zone between these two subspecies.

scholarly journals Evaluating bull fertility based on non-return method

2012 ◽  
Vol 66 (1-2) ◽  
pp. 27-40
Author(s):  
Igor Prka ◽  
Dragan Vukovic ◽  
Stevan Perkovic
Keyword(s):  
Semen Quality ◽  
Sperm Quality ◽  
Quality Parameters ◽  
Semen Parameters ◽  
Service Period ◽  
Microscopic Evaluation ◽  
Live Sperm ◽  
Return Method ◽  
The Impact ◽  
First Time

In order to evaluate the results of reproductive cows and heifers, different parameters of fertility are used, such as the service period, insemination index, intercalving time and others, and of the breeding bulls the values obtained through non-return. An ejaculate is taken up for further processing by veterinary centres only provided it meets the prescribed quality parameters. Rating semen parameters includes a macroscopic (volume, colour, consistency, smell and pH) and a microscopic evaluation (mobility, density, percentage of live sperm and abnormal and damaged sperm). In addition to sperm quality and the fertility of the female animal, the results of the non-return method are also influenced by a number of exogenous causes (season, age, race, insemination techniques) that have no small impact on the end result of insemination - pregnancy. In order to obtain more objective results of the fertility of bulls the following tasks were undertaken, namely: 1. to calculate with the non-return method the fertility of bulls in over 10,000 cows inseminated for the first time during a period of 6 years; and 2. to analyze the impact of semen quality, season, age of cow and bull, and the bull breed on the results of fertility.

Fluoxetine treatment of prepubertal male rats uniformly diminishes sex hormone levels and, in a subpopulation of animals, negatively affects sperm quality

2018 ◽  
Vol 30 (10) ◽  
pp. 1329 ◽  
Author(s):  
María E. Ayala ◽  
Ayari Gonzáles ◽  
Rodrigo M. Olivarez ◽  
Andrés Aragón-Martínez
Keyword(s):  
Adult Stage ◽  
Sperm Quality ◽  
Membrane Integrity ◽  
Graphical Analysis ◽  
Quality Parameters ◽  
Male Rats ◽  
Serum Concentrations ◽  
Sperm Density ◽  
Sexual Steroids ◽  
Fluoxetine Treatment

Fluoxetine (Flx) is a selective serotonin reuptake inhibitor that alters the male reproductive system when administered at the adult stage or after maternal exposure. In the present study we evaluated the effects of Flx administration on reproductive parameters during juvenile–peripubertal development when treated male rats reached adulthood. Groups of rats were treated daily with Flx (5 mg kg−1, i.p.) or saline (0.9% NaCl), or were left untreated. Rats were treated between 30 and 53 days of age and were killed at 65 days of age. Serotonin concentrations were determined in the hypothalamus, hypophysis and testis. Gonadotrophins, sex steroids and sperm quality (membrane integrity, sperm with functional mitochondria, sperm density, sperm motility and morphological abnormalities) were also evaluated. Flx did not affect bodyweight, but significantly diminished LH, FSH, progesterone and testosterone serum concentrations. After graphical analysis, a subgroup of rats was identified whose sperm quality parameters were greatly affected by Flx. In the present study we show that Flx administered to juvenile rats disrupts the hypothalamic–hypophyseal–testicular axis and its effects on sperm quality are not homogeneous in adults. In contrast, Flx altered concentrations of gonadotrophins and sexual steroids in all treated rats. These results suggest caution should be exercised in the prescription of Flx to prepubertal males.

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