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Artificial reproduction is a bottleneck to produce stocking material for many species of freshwater fish. One of these species is the asp, Leuciscus aspius. Research in the field of artificial reproduction of this species is very scarce and often incomplete. There are no breeding protocols specifying optimal environmental conditions and hormonal stimulation for many species of rheophilic cyprinids, including asp. Since the number of natural asp populations is constantly decreasing, it is important to support natural stocks by restocking with high quality stocking material. For this reason, optimized protocols are needed to breed this species under controlled conditions to produce stocking material with high biodiversity and good health. Such an approach will make it possible to maintain the population of natural asp at a constant level. The aim of this study was to develop the protocol of asp artificial reproduction using optimized thermal conditions and appropriate hormonal stimulation. In experiment I, the influence of constant temperature (10.0, 12.0 and 14.0 °C) on the effectiveness of artificial reproduction of asp. In experiment II, the effectiveness of asp reproduction was checked after the application of spawning agents: Ovopel, Ovaprim or a combination of these two agents The obtained results indicate that for the final maturation of oocytes (FOM) and artificial reproduction of asp in controlled conditions, water temperatures of 10–12 °C are the most useful. Under these thermal conditions, the highest percentages of female's ovulation and embryo survival, as well as the percentage of hatching, were obtained. Hormone injections are necessary to perform final oocyte maturation (FOM) in female asp in captivity. All spawning agents used were especially useful for artificial reproduction of asp, however, the best values of the studied indices, such as ovulation rate and embryo survival, were obtained after the application of Ovaprim or the combination of Ovopel and Ovaprim in water temperature at a range of 10–12 °C. It was found that the pH of ovarian fluid may be a preliminary indicator of the biological quality of eggs in asps. The optimal pH value is 8.0–8.4. At pH below 7.4, no viable embryos were observed. • The optimum temperature range for the final gametes maturation of gametes in asp is 10–12 °C. • The shortest latency time with the lowest biological quality of eggs was recorded at 14°C. • All tested combinations of spawning agents were successful in the reproduction of wild asp. • pH of ovarian fluid can be used as a primary indicator of asp eggs quality. [ABSTRACT FROM AUTHOR]

During the 1970s and 2010, the population of Anguilla anguilla declined significantly, and the species is now classified as a critically endangered species by the International Union for Conservation of Nature (IUCN). Considering its social, economic, and ecological importance, it is necessary to understand the biological mechanism that controls population dynamics, in particular the passage from the resident phase to the migratory phase. During this phase of their life cycle, the environment plays a key role in the maturation of the spawners which will eventually undertake a long spawning migration to the Sargasso Sea. An assessment of the morphological characteristics of eels during their silvering process and reproductive activity was conducted by collecting 1513 female eels from seven lagoons in the North Adriatic Sea. Morphometric analyses show that eels classified as pre-migratory according to the Silver Index are histologically (65% of eels with oocytes in the most advanced stage of development) and morphologically ready to migrate. Accordingly, pre-migrant eels treated with hormone induction performed similarly to migrant eels. They mated and spawned spontaneously in the tank with a percentage of 81.0%, and 88.2% of them produced viable eggs. The results showed how the North Adriatic lagoons could present favourable conditions that permit the fast development of females with high reproductive potential. This data can be used to develop successful strategies to conserve and manage eel populations. • New achievements on knowledge in European eel biology and ecology. • Reproductive activity of pre-migrant eels is in line with migrant eels. • North Adriatic lagoons present favourable growth conditions. [ABSTRACT FROM AUTHOR]

Purpose: Review the experience, principles and parameters of the sturgeon assessment quality by anomalies in early ontogeny. Results: Maintaining the number of sturgeon fish in the transboundary Caspian Sea is provided by five states (Russia, Iran, Azerbaijan, Turkmenistan, Kazakhstan) at 16 Sturgeon hatcheries, where their artificial reproduction is carried out. FAO recognizes Russia’s leadership in creating the basic technology for the sturgeon artificial reproduction, but the other four Caspian states also make a significant contribution to its modern optimizations. There is almost a century of tradition behind the technological development of artificial reproduction in sturgeons. During the artificial reproduction of sturgeons, anomalies in the structure and functions may occur, such as deformities, defects in organs and tissues, edema, hematomas, etc. The sturgeon anomalies classification is based on structural and functional principles. Identification of anomalies is carried out on the basis of a previously created classification, divided into nine large classes. Identification of sturgeon anomalies during the period of their artificial reproduction makes it possible to clarify the real value of replenishment of their stock. Methods: Analysis of professional scientific literature and practical guides. Conclusions: The presence and number of Sturgeon anomalies make it possible to determine their death percentage to calculate the real number of replenishment of the Caspian Sturgeon stock.

Summary: Knowledge of the sperm–oocyte ratio in fish fertilization serves as the basis for studies on artificial reproduction and gamete manipulation. The aim of this study was to determine the minimum insemination dose for Brycon amazonicus oocyte fertilization. Female and male gametes were used and tested with the following doses of spermatozoa oocyte–1 ml–1: 10,000, 20,000, 40,000, 60,000 and 80,000 (in triplicate). Fertilization rates were calculated and estimated from the regression equation by applying the segmented regression model 'Linear Response Plateau' to determine the appropriate proportion of gametes. Based on the equation Ŷ = 14.3415 + 0.0007836X, the fertilization rate increased up to 63.34% as it reached a plateau with a proportion of 62,524 spermatozoa oocyte–1 ml–1, which is the minimum insemination dose recommended for artificial insemination of the species. [ABSTRACT FROM AUTHOR]

The wels catfish Silurus glanis is valuable fish for aquaculture. Its production relies mainly on artificial reproduction. One of the crucial steps determining success of the reproduction is elimination of egg stickiness after fertilization. To date, the catfish egg de-adhesion is usually carried out using proteolytic enzymes. Here, we prove a novel method based on oxidation of the egg surface by means of sodium hypochlorite. An effect of different exposure times and concentrations on the egg adhesiveness and damage was tested in the first trial. The selected concentration of sodium hypochlorite 0.3 mg · l−1 with exposure time 40 s was used for comparison with the conventical de-adhesion method using alcalase treatment. The fertilization and hatching rates reached very satisfactory outcome in both treatments (98.3 ± 0.7% vs 97.5 ± 2.2% and 86.6 ± 8.3% vs 91.3 ± 8.5% in alcalase- and sodium hypochlorite-treated embryos, respectively) without any statistical differences. Thus, the de-adhesion method using sodium hypochlorite can be recommended as a suitable method for wels catfish eggs. The method is simple, cheap, very fast, and the treated eggs are disinfected. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The results of a comparative analysis of the efficiency of the artificial reproduction of Atlantic salmon (Salmo salar) individuals released to the Kola River at ages of 3 years (1980–2002) and 1 year (2003–2017) are given. After the fish hatcheries began to release artificially reared anadromous salmon individuals at the age of 1 year, their qualitative parameters did not significantly change. The value of the commercial return became somewhat lower for the released yearlings than for the 3-year-old individuals; however, it remained satisfactorily high. It is recommended to reduce the release volume to avoid the overpopulation of juveniles; it is also suggested to evenly distribute them over the nursery grounds that are most suitable for their adaptation and select spawners for broodstock according to the historically established subpopulation structure. [ABSTRACT FROM AUTHOR]

A historical review of biological enhancement and fisheries for Iturup Island demonstrates that enhancement has significantly increased numbers of chum salmon while pink salmon are produced almost entirely naturally. Fourteen hatcheries currently produce and release chum salmon fry; four of these also generate pink salmon. Favourable natural conditions make the waters near Iturup Island one of the most productive marine areas in the Russian Far East. Efficient hatcheries combined with favourable conditions resulted in increases in chum salmon catches from less than 100 tonnes in the early 1990s to more than 20 000 tonnes in the late 2010s. Becoming better informed of factors controlling salmon production in the Kuril Islands should help scientists in other regions of the North Pacific understand what controls their own salmon populations. [ABSTRACT FROM AUTHOR]

Conger eel ( Conger myriaster ) is an economically important species in China. Due to the complex life history of the conger eel, achieving artificial reproduction has remained elusive. This study aimed to explore the effect of water stimulation on hormonal regulation during the artificial reproduction of conger eel. The experiment was divided into four groups: A1 (no hormone injection, still water), A2 (no hormone injection, flowing water), B1 (hormone injection, still water), and B2 (hormone injection, flowing water). The flowing water group maintained a flow velocity of 0.4 ± 0.05 m/s for 12 h daily throughout the 60-day period. Steroid hormone levels in the serum and ovaries of conger eels were analyzed using UPLC-MS/MS and ELISA on the 30th and 60th days of the experiment. The relative expression levels of follicle-stimulating hormone ( FSHβ ) and luteinizing hormone ( LHβ ) in the pituitary were determined by quantitative PCR. The results showed a significantly lower gonadosomatic index (GSI) in B2 compared to B1 ( p < 0.05 ) on the 30th day. FSH was found to act only in the early stages of ovarian development, with water stimulation significantly enhancing FSH synthesis ( p < 0.05 ), while FSHβ gene was not expressed after hormone injection. Conversely, LH was highly expressed in late ovarian development, with flowing water stimulation significantly promoting LH synthesis ( p < 0.05 ). Serum cortisol (COR) levels were significantly higher in the flowing water group than in the still water group ( p < 0.05 ). Furthermore, estradiol (E2) content of B2 was significantly lower than that of B1 on the 30th and 60th day. Overall, flowing water stimulation enhanced the synthesis of FSH in early ovarian development and LH in late ovarian development, while reducing E2 accumulation in the ovaries. In this study, the effect of flowing water stimulation on hormone regulation during the artificial reproduction of conger eel was initially investigated to provide a theoretical basis for optimizing artificial reproduction techniques., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Li, Liu, Liu, Jiang, Ba, Li and Liu.)

In Italy for the last decade, a very interesting public debate has been conducted about artificial reproduction. An important step in this discussion was the adoption in 2004 of a special law regulating the use of the in vitro method. In 2014 the Constitutional Court cancelled the prohibition, existing in this document, of the methods of heterological artificial reproduction. A very important part of the debate in Italy are different kinds of philosophical arguments. The most interesting or very representative voices in this discussion include statements of Oriana Fallaci, Vittorio Possenti, and Gianni Vattimo.

Interreligious relations between Christianity and Islam are rapidly changing on both theoretical as well as practical fields. The paper is dealing with bioethical issue of artificial reproduction as it is discussed in the world of Islam. The paper is focused on the methodological approaches to bioethical issues in a context of Sharia law in general. In particular it deals with cultural aspects of decision making process. The interpretation and understanding the process is presented in the Christian way of discernment.

Purpose. To determine main the technological parameters of artificial reproduction of sterlet (Аcipenser ruthenus) and Siberian sturgeon (Acipenser baerii) with a combined use of industrial aquaculture methods. Methodology. The material for the study were brood sterlet and Siberian sturgeon reared in cage conditions in a water body with natural temperature regime of the forest-steppe of Ukraine. The experiments were performed at a regulated water temperature regime at different periods of the spring (March-May) with the use of natural gonad-stimulating hormones for the stimulation of the maturation of sexual products in fish. During the process of the preparation of brood fish for fish breeding works, a recirculating water supply facility was used. The determination of technological parameters and study of physical-chemical factors of the environment were performed according to generally accepted methods. Findings . At a water temperature of 14-16оС, high efficiency of gonad maturation was observed in sterlet and Siberian sturgeon females with mean weight of 2.8 and 11.6 kg, respectively. The mean weight of eggs obtained from the brood fish was 0.45 kg in sterlet and 1.48 kg in Siberian sturgeon. The mean working fecundity was 43.29 thousand eggs in sterlet and 83.75 thousand eggs in Siberian sturgeon at a relative working fecundity of 15.44 and 7.49 thousand eggs/kg of fish body weight, respectively. During the process of egg incubation, development of fish embryos at the gastrulation stage was on average 87.17% in sterlet and 84.50% in Siberian sturgeon. The output of free embryos of both species from the quantity of embryos on the stage 15 of embryonal development was close to 83-84%. Originality . Peculiarities of the production of embryos from brood sterlet and Siberian sturgeon with a combined use of different methods of industrial aquaculture in the conditions of a sturgeon farm of the forest-steppe physical-geographical zone of Ukraine have been studied. Practical value . The results of the study are of interest for the devolvement of modern methods of sturgeon aquaculture in the conditions of an industrial type farm.

The article provides a comparative assessment of traditional and developed fish-breeding tanks for keeping bester yearlings. As a result of growing fish in different reservoirs, it’s been found that when using the “ICA-2” and “INTEX” tanks, there is practically no difference. When comparing the use of "ICA-2" and a semi-buried adaptive reservoir, it’s been found that the weight of fish was higher in the second case, when compared with the benchmark, by 1.5%, the average daily gain - by 5.3%, the coefficient of nutrition - by 1, 2%.

From the start of her career, contemporary Japanese writer Murata Sayaka1 has been writing novels that dismantle the existing politics of gender, family and sexuality through stories set in dystopian or surrealistic worlds. In Satsujin shussan (The Birth Murder) she depicts a society in which a person can kill another if s/he gives birth to other ten. Women are given a contraceptive implant at the time of their first menstruation, sex is conceived as an act of lust, and pregnancy occurs exclusively by assisted fertilization and is also possible for men through the use of artificial uteri. This paper proposes a textual analysis, arguing how Murata creates a feminist “reproductive eutopian dystopia” and breaks both the concept of reproductive body as exclusive to females and the concepts of pregnancy and motherhood. The novel will be explored from a feminist perspective.

Information on the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has amplified quickly since its spread; however, many issues remain unclear. SARS-CoV-2 is mainly transmitted through respiratory secretions. However, the potential for SARS-CoV-2 sexual transmission by semen is worthy of study. The cell-receptors of SARS-CoV-2, the angiotensin-converting enzyme-2 receptors, are highly expressed in human testis and may enable this virus to cause testicular tissue damage with bad effect on male fertility. SARS-CoV-2 presentation ranges from asymptomatic carriage to acute respiratory distress and fatal pneumonia, and elderly persons with underlying comorbidities usually suffer from a severe clinical picture. Asymptomatic individuals can spread the virus through their respiratory secretions and possibly through sexual transmission. SARS-CoV-2 can persist viable if cryopreserved in semen samples in sperm cryobankes. As far as I know, there is a gap in knowledge about SARSCoV- 2 transmission through semen, indicating the need for further research. This review attempts to understand the SARS-CoV-2 sexual transmission by semen. One recent study confirmed the theoretical risk of SARS-CoV-2 transmission by semen, but few studies negate this theory. Given that, an increasing number of asymptomatic and reactivated SARS-CoV-2 cases are being reported, attention to semen safety and SARS-CoV-2 transmission should be considered particularly in high-risk areas, to ensure the safety of male gametes for artificial reproduction and the general public. Avoiding cryopreservation of male gametes, condom use or even abstinence might be of paramount importance for these persons. [ABSTRACT FROM AUTHOR]

The present study aimed to characterize the embryogenesis and larval development of matrinchã (Brycon orthotaenia), through the analysis of egg and larval morphology. Fertilized eggs had a mean diameter of 1.17 mm, with yolk occupying most of the egg (1.06 mm). Embryogenesis lasted for 15 hr at an average temperature of 27°C. At hatching, yolk‐sac larvae measured 3.67 mm in mean standard length (SL). Pre‐flexion, flexion and post‐flexion larva had 5.01, 8.24 and 11.88 mm mean SL, respectively, with significant increases observed particularly in head length, head height, and eye diameter. The yolk persisted in the yolk‐sac and pre‐flexion stages (5.96 mm SL). The mouth opening could first be observed 13 hr after hatching, and cannibalism was observed 29 hr after hatching in pre‐flexion larvae after absorption of the yolk sac; in such cases, the larvae had already developed teeth and a complete digestive tract. For an endangered species such as matrinchã, early life history studies are important because they provide researchers with a better understanding of critical stages of development and thus enhance captive management by rearing and restocking of the species. [ABSTRACT FROM AUTHOR]

Summary: The present study aimed to evaluate two different methods of artificial reproduction induction, and characterize the embryonic development of Salminus hilarii. Different than observed for other tropical fish species, artificial reproduction induction followed by hand-stripping of gametes was considered unfeasible for S. hilarii, as no gamete fertilization was observed. However, females that were induced and spawned naturally presented a fertilization rate of 65.64 ± 0.54%. With a mean temperature of 26.20 ± 0.90ºC it was possible to clearly distinguish a large perivitelline space at 14 min after fertilization (AF) and at 49 min AF more than 50% of the embryos presented two blastomeres, and these cleavages occurred until 1 h 54 min AF. The gastrula phase was characterized at 3 h 56 min AF, and blastopore closure was observed at 8 h 31 min AF. At 9 h 1 min, organogenesis started, with a clear distinction of the yolk mass, embryonic axis, cephalic and caudal regions; at 11 h 51 min AF the embryos already had advanced segmentation and a free tail. Total hatching occurred at 21 h 17 min and after opening the mouth, which occurred at 33 h 9 min, the larvae of S. hilarii presented a strong and characteristic cannibalism. This information can be considered fundamental to improving S. hilarii production in captivity and for collaboration with a conservation programme in the upper Tietê river basin. [ABSTRACT FROM AUTHOR]

Various assisted reproductive techniques (ARTs) are now available for infertile couples. Obtaining a large amount of highly active sperm is critical for successful ART operations. Our purpose is to use polydimethylsiloxane (PDMS) microfluid biochip to collect highly active sperm from semen with the characteristic of laminar flow. With a fixed diluted semen viscosity and a fixed flow rate ratio of buffer and diluted semen, this microfluid biochip can sort diluted semen into two groups: sorted and waste. Results of flow cytometry analysis showed that the viability of the sorted group is higher by at least 10% for both normal and oligozoospermia samples. Our biochip, compared with the traditional centrifuge, is a novel tool for preparing live sperm for ARTs. [ABSTRACT FROM AUTHOR]

Copyright of Studia Ecologiae et Bioethicae is the property of Uniwerystet Kardynala Stefana Wyznskiege w Warzawie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Within the research of efficiency of Atlantic salmon the artificial reproduction, feeding rate, distribution and growth of farm-raised one-year-old Atlantic salmon have been examined. The fish has been released into nursery areas with different hydrological characteristics located in the Rivers Kola, Umba, Srednyaya and Akkim in the Murmansk region. The observations have being conducted for 1–5 months since the moment of fish release. In natural habitat, juveniles rapidly distribute downstream and upstream regardless of water temperature, depth and current velocity. In all examined nursery areas adapting one-year-old juveniles prefer to stay at weak current sites close to the shore, hiding in the gravel. In all the cases farmed parr shows high feed rate, but qualitative composition of their food differs significantly from food composition of wild juveniles. Revealed peculiarities of adapting parr's distribution and qualitative food composition indicate the impact of long-term rearing at hatcheries on fish behavior. Growth rate of one-year-old juveniles is arcwise connected with fraction composition of gravel and the level of bottom fouling: the bigger bottom rocks are and the thicker the fouling is, the more intensive fish growth is. The revealed correlations have been described with equations of linear regression. Connections between juvenile growth and water temperature, current velocity and depth of the area have not been detected. The research outcomes could provide a basis for scientific advice for planning release sites and number of released one-year-old Atlantic salmon by hatcheries in the Murmansk region.

Feeding of masu parr in the natural river habitat on 8-9 days after their release from hatchery is considered on the data obtained in the Lyutoga River tributaries in 2014-2015. No fish with empty stomach were found that indicated successful transition of artificially hatched fish to feeding in the natural environments. More than 40 species of prey were found in their stomachs, mostly terrestrial and aerial invertebrates and the river bottom dwellers as mayflies and chironomids. The diet corresponded to biotopes features. For better feeding (higher stomach filling) gradual releasing is recommended over wide areas by the parties no more than 4,000 ind. The juveniles should be transported in isothermic boxes to the lower or middle parts of streams and in packages with oxygen (for 600-1000 ind. each) to the upper streams. Involving of volunteers from fishermen to the releasing is desirable that attracts additional attention to the species protection.

The blue bream Ballerus ballerus (L.) is one of two species of the Ballerus genus occurring in Europe. The biotechnology for its reproduction under controlled conditions needs to be developed to conserve its local populations. Therefore, a range of experiments were performed to obtain valuable gametes from blue bream following hormonal stimulation with carp pituitary homogenate (CPH), Ovopel and Ovaprim. CPH and Ovopel were injected twice and Ovaprim—once, under a pectoral fin. The spawners were inspected 12 h after the last injection, and the gametes were collected. Eggs were collected from spawning females and fertilized with sperm from three males. The smallest number of ovulating blue bream (four females) was obtained from individuals stimulated with Ovaprim. There were six to nine ovulating females in the other groups, accounting for 60–90% of the females in the respective groups. The latency period was the shortest in the spawners stimulated with Ovopel. The fish in this group ovulated 14 h after the hormonal injection. Spawning was synchronized and all females spawned simultaneously. The highest average weight of eggs per fish (75.4 g) was obtained from the females stimulated with Ovopel, whereas the individuals stimulated with Ovaprim provided the smallest average amount of eggs (49.5 g). The study showed that blue bream spawners are not very sensitive to reproduction-related handling under controlled conditions.

Aquaculture of red swamp crayfish, Procambarus clarkii (Girard, 1852), has developed rapidly worldwide in recent years with promising prospects. However, limited knowledge about temperature effects on reproductive performance and embryonic development has hindered the development of crayfish aquaculture. The two present studies were conducted to identify optimal water temperatures (17 °C, 21 °C, 25 °C, 29 °C and 33 °C) for reproductive performance (experiment 1) and embryonic development (experiment 2) of P. clarkii. Totally, there were 12 replicates, with 480 adults and embryos from 60 ovigerous crayfish selected for experiment 1 and 2, respectively. In the first experiment, the survival of adult crayfish was not significantly affected by the temperatures tested. However, significantly higher feeding rates, spawning rates, and fecundity were obtained at 21 °C and 25 °C when compared to those at 29 °C and 33 °C. Polynomial models and loess regression fitted to the experimental data showed that highest spawning rates and fecundity occurred at 21 °C while shortest duration from mating to spawning was found at 33 °C. In the second experiment, we found that optimal embryonic development was at 25 °C with shorter hatching time and no abnormalities observed. However, while embryos showed abnormalities and subsequently died at 29 °C and 33 °C. We further built a temperature-dependent developmental model for P. clarkii embryos: D (developmental time, days) = 3,140,837(T- 2.03)−3.76. Based on these results, the temperature range 21 °C – 25 °C was recommended for adult crayfish reproduction and 25 °C was recommended for embryonic development. This study indicates that manipulating water temperature is an effective alternative to current artificial reproduction techniques (e.g. eyestalk ablation and injection hormones) to induce spawning and embryonic development and thus provides mass production of juvenile P. clarkii for aquaculture. • 21 °C – 25 °C was recommended for crayfish reproduction and 25 °C was recommended for embryonic development. • Embryos showed abnormalities and subsequently died at higher temperatures (29 °C and 33 °C). • The temperature-dependent developmental model allows predicting juveniles recruitment in aquaculture. • Manipulating water temperature is an effective alternative to traditional artificial reproduction techniques to induce spawning and embryonic development. [ABSTRACT FROM AUTHOR]

Although several papers were dealing with intensively reared broodstocks, most of the published artificial reproduction protocols were applied in wild pikeperch breeders. Therefore, we aimed to evaluate the effects of ovulation induction agents, namely human chorionic gonadotropin (hCG) and salmon gonadotropin–releasing hormone analogue (sGnRHa) on the reproductive performance in pre-seasonal artificial propagation of cultured pikeperch. Breeders were harvested from an outdoor in-pond circulation system in mid-September and transferred to indoor facility in late January, conditioned and injected with either 50 μg kg−1 of sGnRHa or 500 IU kg−1 of hCG, with six females in each hormonal group. Stripped eggs from each female were sampled for chemical composition analysis, fertilised with the milt of two males, incubated and obtained larvae were further reared. No significant differences were noticed between the treatments in any of the analysed parameters of embryo survival nor larviculture performance. Rather high differences in intragroup variation were seen between the treatments, expressed in several-fold higher coefficients of variation in embryo survival in experimental and commercial conditions in the hCG group. Eggs obtained from females treated with hCG had a significantly higher lipid content (31.1% ± 2.0%) compared to sGnRHa-treated females (27.4% ± 1.8%). Fatty acid profiles of the eggs revealed differences in total n − 6 and linoleic acid 18:2n − 6 content while n − 3/n − 6 was significantly lower in the hCG group. Gonadoliberins reduced the variability in the spawning outcome. It appears that hormones can modify the eggs' fat content during the pre-season artificial reproduction. [ABSTRACT FROM AUTHOR]

Orestias ascotanensis Parenti is a critically-endangered fish species endemic to the Ascotán salt pan springs. Given the importance of reproduction and early development in effective conservation of fish populations, this study describes the embryonic development of O. ascotanensis under laboratory conditions. Between 2014 and 2015, 50 individuals were captured and maintained under controlled conditions, including temperature, photoperiod and feeding regimen, to induce spawning for artificial fertilization. Females were subjected to hormone therapy with Ovaprim®. Water temperature was maintained at 20 °C (± 1 °C), conductivity at 2800–3600 μS·cm−1 and photoperiod at 16:8 (light hours: dark hours). Males showed changes in color and courtship behavior, and females developed a slightly bulging belly. Eggs were 1.55–2.5 mm in diameter, with abundant yolk and dozens of adhesion filaments. Embryonic development lasted 14–18 days; it was divided into five periods, which can be sub-divided into 21 stages, from fertilization to hatching. O. ascotanensis showed indications of partial spawning species, including oocytes at different stages of development, relatively large eggs as compared to adult fish length and low batch spawning. Characteristics such as partial spawning, highly-pigmented eggs and larvae and advanced larval development at hatching could be adaptations to the extreme conditions of the salt pan springs, including high levels of ultraviolet radiation and salinity as well as significant daily temperature changes. [ABSTRACT FROM AUTHOR]

Worldwide, there is a dramatic decline in freshwater eel populations (Anguilla spp.), resulting in an urgent need to improve eel management and artificial reproduction protocols. Unfortunately, eels in captivity do not reproduce spontaneously as they remain in a (pre)-pubertal state resulting from a strong neural blockage. Eel propagation is possible to some extent by applying extensive, expensive, unnatural hormonal treatments. However, the success rates are still far too low to support a sustainable farming industry, due to low gamete quality and low survival rates of larvae. Artificial reproduction of eels has been pursued for almost 80 years, and maturation protocols have changed little. In order to improve current protocols it is clear that a different approach towards stimulating sexual maturation is required. In many fish species, changes in external environmental cues, such as photoperiod and temperature, are crucial to induce gonadal recrudescence and development. Still, the natural triggers involved in the gametogenesis of eels are poorly understood. The time-keeping hormone melatonin is a well-known transmitter of external cues, and influences various physiological processes, including reproduction. In eels, we hypothesize that melatonin is an important key player in the regulation of sexual maturation. Thus far, its mode of action is still an area which needs to be explored. In this review, we provide an overview of the current knowledge of studied natural cues possibly affecting reproductive function and the plausible role of melatonin in the regulation of puberty in eels. [ABSTRACT FROM AUTHOR]

The Zingel asper or apron is one of Europe's most threatened freshwater fish (classified as critically endangered by the International Union for Conservation of Nature, IUCN). It is also listed in appendices II and IV of the European Habitats Directive (1992) and in appendices II and III of the Berne Convention (1979). The geographical distribution of this percid, endemic to the Rhône basin, is extremely limited, making it particularly vulnerable. Since 2005, the Besançon Natural History Museum has been involved in conservation programmes (LIFE Apron II and a national action plan) to improve the knowledge on its ex situ reproduction, the aim being to produce individuals with which to conduct experimental studies (toxicity tests, design of fish passes, etc.), carry out public presentations (aquariums, nature reserves, etc.) and implement pilot reintroduction schemes, without having to systematically take samples from the natural environment. Innovative devices were designed in the Besançon Citadelle Aquarium to enable replication of complete reproduction cycles in artificial conditions. Control of thermal and zootechnical parameters associated with the development of “artificial spawning grounds" have allowed us to understand the different phases involved in reproducing and maintaining this species in captivity. We were able to observe numerous behaviours, which have never been seen in natural environments, in particular during spawning and early life stage development phases. Several experiments were conducted to study how hatching rates varied according to the duration of the winter cold period, known as “vernalization", applied to broodstock. Hatching rates in the order of 80% were obtained with broodstock subjected to a cold period of 120 days at 5°C, from the beginning of November to the end of February. In contrast, hatching rates dropped rapidly for groups of broodstock subjected to vernalization periods of less than 90 days, and with a cold period of only 30 days, the eggs deteriorated before hatching. A precise annual thermal cycle has therefore been identified, corresponding to the different life phases of Z. asper in captivity. A particular focus of our work was on breeding of fry to ensure that they achieve survival rates in the order of 80% during the first month, and 90% the following month. The results of these experiments have supported other studies and more than 26,000 juveniles have been released into the Drôme River. Regular genetic monitoring of this reintroduced population has allowed us to ensure that they are reproducing naturally. Z. asper born in captivity are also widely used in initiatives to raise public awareness (exhibitions, etc.). To date, the Z. asper breeding programme in the Besançon Natural History Museum is the only one of its kind for this percid, but the high sensitivity of broodstock to the intensity and duration of the vernalization period should raise concerns about the sustainability of its populations in the face of climate change. [ABSTRACT FROM AUTHOR]

The aim of the research is to increase the survivability of reproductive cells of sturgeon at cryopreservation and developing reliable technology suitable for use on an industrial scale.Methods. We have used standard methods of freezing, thawing reproductive cells, fertilization and incubation of eggs and larval rearing of sturgeon. Fundamentally new is cryoprotective composition: for sperm we have adjusted the composition of cryoprotective medium (for beluga 3% of dimethyl sulfoxide, for Russian sturgeon 4% of dimethyl sulfoxide); for freezing the eggs we have used cryoprotective mixture of unrefined vegetable and animal oils.Results. Survivability of defrosted sperm sturgeon has been increased: for Beluga it is up to 20%, for Russian sturgeon - 47%. At insemination of cryopreserved eggs of Russian sturgeon with native sperm the fertilization rate has made 41%.Main conclusions. The research proves the effectiveness of reducing the toxic effect of cryoprotective substances, thus leading to increased survivability of reproductive cells of sturgeon. During the insemination of eggs, stored in liquid nitrogen, the resulting offspring were viable and by the reactivity of the central nervous system and receptor complex it does not differ from the young obtained by conventional technology.

Giant freshwater prawn Macrobrachium rosenbergii (De Man, 1879) is cultivated in Crimea since 2000 and technology of complete cycle of its cultivation from planting material to saleable product is successfully applied nowadays. This area is located beyond of the species native habitat and has other environments, so the larvae and juveniles can harvested in controlled conditions only: the open water bodies with the water temperature above 20оC are recommended. Growing of the larvae in artificial conditions is the most difficult stage of the biotechnological process, with high mortality because of diseases, grazing by planktophages, and poor water quality. These factors were studied in conditions of spawn farm in 2001-2013 and the main reasons of the prawn mortality at the larval stage were revealed. They were the gas-bubble disease, low oxygen content in tanks, and penetration of predatory hydromedusae Sarsia tubulosa to tanks. All these problems were caused by failures in the cultivation technology. Measures for prevention of the prawn larvae disease because of external factors are proposed.

Purpose. The study was aimed at raising young-of-the-year European grayling and improving the industrial technology with the use of specialized artificial feeds. Methodology. The work on raising young-of-the-year European grayling was carried out in 2014 at the fish hatchery “Lopushno”, Chernivtsi region, during five months (May – September). YOY were obtained from 22 age-3–4 brood fish, which were kept in ponds of the natural reserve “Synevir”. Culture-biological parameters of brood fish were determined based on Pravdin (1966) method for salmonids. To avoid traumatization of fish, they were kept in the anesthetic “Propiscin” before the collection of sexual products. The condition factor was determined by Fulton’s formula. Findings. The mean weight of brood fish used for spawning was 110 g with the mean body length of 22 cm. Fulton’s condition factor of European grayling was: 1.1 in females and 1.0 in males. Feeding of larvae was as follows: starting feeds — live feeds (Cyclops, Moina), then the alternation of live feeds and a specialized starting feed for 30 days, and the artificial feed after. Raising European grayling from larvae to young-of-the-year was carried out in trays of different sizes from 0.5 m2 to 4.5 m2, water level in trays was increased according to fish growth from 20 cm to 42 cm. Water supply was 60 L/min, thus the rate of water exchange was from 0.5 to 1.7 times/hour that corresponded to technical norms for salmonids. Mean weight of the young-of-the-year on September 10 was 17.1 g, mean length was 11.8 cm. Originality. Consists in the comprehensive assessment and development of an integral mechanism of scientific principles and methodical recommendations on artificial reproduction of European grayling. Practical value. The results of the work will be used for the works on the reproduction of valuable fish species in aquaculture facilities of the Carpathian region.

We investigated the effects of breeding water pH on the spermatic motility, artificial fertilization, and initial development of offspring in curimba, Prochilodus lineatus. After hormonal induction, we conducted gamete activation, artificial fertilization, and embryo incubation in water with pH values of 4.43 ± 0.13, 5.82 ± 0.14, 7.37 ± 0.10, 8.21 ± 0.06, and 9.57 ± 0.16. When the water pH was 6.65, spermatic motility was maintained for ?25.21 s (P < 0.05). The highest fertilization rates (P < 0.05) were obtained when the water pH ranged from 5.82 ± 0.14 to 8.21 ± 0.06, and the highest hatching rates (P < 0.05) were observed when the water pH was 7.37 ± 0.10. A water pH of between 7.37 ± 0.10 and 8.21 ± 0.06 resulted in more complete formation of the perivitelline space (P < 0.05); additionally, embryos incubated in alkaline waters produced a higher percentage of normal larvae (P < 0.05), despite increased mortality levels. Our results indicate that the pH of the water used for gamete activation, artificial oocyte fertilization, and incubation of eggs and larvae of P. lineatus should be ~7, in order to promote successful breeding and normal larval production.

Abstract: Controlled reproduction is a requirement for developing effective mollusc cultivation for commercial or restoration purposes. In this study, a protocol for spawning induction using noninvasive methods in limpets was developed, using the common Mediterranean species, Patella caerulea Linnaeus, 1758. Six nonlethal spawning induction treatments were tested: three chemical (two concentrations of H2O2 and KCl) and three physical (bubbling, warm and cold thermal shock). All treatments, except thermal shocks, induced the spawning of fertile gametes. Bubbling resulted the best treatment in providing spawning response, being the easiest and least invasive method tested. After eggs fertilization, larval development was followed until metamorphosis, testing fed and unfed conditions. Settlement took place after 7 days. The developed protocol represents a benchmark for further application to other limpets, for aquaculture or repopulation. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to test the use of hormonal preparations, which are commonly used in the artificial reproduction of various fish species, on Perca fluviatilis in order to develop and optimize an artificial reproductive technology under controlled conditions. The hormonal preparations used in the experiment were carp hypophysis and Nerestin 6A, and the biological material consisted of 20 females and 6 males. The females were divided into two lots: (L1) carp hypophysis (4 mg / kg female body weight) and (L2) Nerestin 5A (0.25 ml / kg females body weight). Hormonal stimulation was done by intraperitoneal syringe administration for the carp hypophysis and intramuscular injection for Nerestin 5A, both in two divided doses as follows: 20% of the total dose in the first injection and 80% in the second. Males did not require hormonal stimulation. The average body weight of females was 399.1 ± 9.66 g (L1) and 425.10 ± 25.77 (L2). The average latency time between the first injection and the ovulation time was 121.43 ± 10.87 hours in L1 and 84.71 ± 6.12 hours in the case of L2. The mean value of the relative fecundity index was 209±66.5 x103 eggs/kg in L1 and 273.1±34.5 x103 eggs/kg in L2. The mean value of the absolute fecundity index was 87.2±23.4 x103 eggs/female in L1 and 109±11.1 x103 eggs/female in L2. The fertility rate had average values of 87.80 ± 2.63 for group L1 and 91.14 ± 2.87 for L2. The survival of females during the experiment was 80% in the L1 group, 90% in the L2 group and 100% in the males. The hatching rate averaged 36% in the first group (L1) and 52% in the second group (L2). Significant statistical differences between the two groups were recorded for the amount of harvested eggs and latency time, these indicators being higher for the L2 group, while insignificant differences were recorded for the other indicators. The results have shown that artificial reproduction is possible under controlled conditions and can be used to develop aquaculture of the species. [ABSTRACT FROM AUTHOR]

From the start of her career, contemporary Japanese writer Murata Sayaka1 has been writing novels that dismantle the existing politics of gender, family and sexuality through stories set in dystopian or surrealistic worlds. In Satsujin shussan (The Birth Murder) she depicts a society in which a person can kill another if s/he gives birth to other ten. Women are given a contraceptive implant at the time of their first menstruation, sex is conceived as an act of lust, and pregnancy occurs exclusively by assisted fertilization and is also possible for men through the use of artificial uteri. This paper proposes a textual analysis, arguing how Murata creates a feminist "reproductive eutopian dystopia" and breaks both the concept of reproductive body as exclusive to females and the concepts of pregnancy and motherhood. The novel will be explored from a feminist perspective. [ABSTRACT FROM AUTHOR]

Interreligious relations between Christianity and Islam are rapidly changing on both theoretical as well as practical fields. The paper is dealing with bioethical issue of artificial reproduction as it is discussed in the world of Islam. The paper is focused on the methodological approaches to bioethical issues in a context of Sharia law in general. In particular it deals with cultural aspects of decision making process. The interpretation and understanding the process is presented in the Christian way of discernment. [ABSTRACT FROM AUTHOR]

The in vitro fertilisation method is widespread in fish aquaculture. In general, calculated doses of different hormones are injected intramuscularly or intraperitoneally, by using a syringe and needle, to induce ovulation and spermiation. We tested a novel approach to delivering sperm and hormone together to eggs, in African catfish, and concluded that sperm plus carp pituitary extract injection into the ovary lobes (through the oviduct) leads to successful ovulation and recovery of developing embryos in all of the experimental conditions applied. These results indicate that injected spermatozoa with suspended carp pituitary are stored in the ovary lobes for up to 10 h without loss of biological activity and that the ovulated eggs could be fertilised by the injected sperm, after being released from the body cavity. In addition, the seminal fluid was an appropriate delivery vehicle for the ovulation inducing hormone (i.e. carp pituitary) via ovarian lavage. [ABSTRACT FROM AUTHOR]

In this study the comparison of spontaneous and hormone-induced reproduction of burbot under controlled conditions was made. During the first two years of the study, burbot spawned spontaneously and artificially after hormonal treatment. The application of sGnRHa resulted in a 100% ovulation rate within 4 to 5 days. Over the 20 days of the experiment, in both years, 65% of females (13 from 20) spawned spontaneously. The biological quality of eggs, expressed as a percentage of live embryos (58.6–60.3%), was generally lower than in only hormone-induced spawned groups (84.2–89.2%). The embryo survival in groups spawned spontaneously decreased in time during the spawning season. Hormonal stimulation of non-ovulated females caused 43–57% of ovulation but with low embryo survival rates (34.2–44.2%). In the third year of the study, 55% of females ovulated spontaneously during the first 10 days of the experiment. Stimulation of non-ovulated females resulted in final oocyte maturation and ovulation in 78% of females. The embryo survival rate was higher (63.2%) than in fish stimulated hormonally after 20 days of spontaneous spawning (but not after 10 days). The application of hormonal treatment in burbot reproduction under controlled conditions shortened latency time, synchronized final oocyte maturation and resulted in high embryo survival rate. [ABSTRACT FROM AUTHOR]

Motility of spermatozoa in most freshwater teleost species is suppressed by the osmolality of the seminal plasma in the testes, sperm ducts and initiated by a decrease of osmolality upon spawning in fresh water. We hypothesized that, similarly to internally fertilising fish species, spermatozoa of freshly stripped sperm, when injected directly into the ovary through the oviduct, will remain inactivated and maintain its fertilisation capacity for extended periods. Fertilisation is expected to occur after ovulated oocytes with spermatozoa on their surfaces are released into the water. To test this hypothesis, experiments were carried out on carp ( Cyprinus carpio ) as a model fish. Stripped and pooled sperm samples were injected by catheter into the ovarian cavity through the oviduct 2 h and 12 h before expected spawning. To prevent any loss of gametes the genital area of treated females were stitched by a standard protocol used in large-scale hatchery systems. At ovulation, eggs were stripped and fertilised with salt-carbamide solution. All sperm-injected females produced some fertilised eggs that developed normally while fertilisation rates varied considerably (24.2–81.2%). This proof of principle experiment demonstrates the potential for routine use as alternative to in vitro fertilisation for the propagation of fish species. [ABSTRACT FROM AUTHOR]