Aquaculture Conditions Research Articles

Clostridia in Commercial Fish of the Azov and Black Seas and in Aquaculture Facilities in the Southern Region of Russia

The paper presents studies on the infection with clostridia of fish with skin lesions and ulcers on the surface of the body. The objects of study were syrman goby from the eastern part of the Taganrog Bay of the Sea of Azov, turbot from the shelf zone of the north-eastern Black Sea and carps reared under aquaculture conditions. Using an Autoflex speed III Bruker Daltonics (Germany) mass spectrometer, by the MALDI-TOF mass spectrometry was showed that sulfite-reducing clostridia (Clostridium perfringens, C. sporogenes) have been shown to infect the organs and tissues of syrman goby with vibriosis and turbot with ulcerative skin lesions of unknown etiology. Species such as Clostridium difficile, Clostridium novyi are of clinical importance and were found in the parenchymal organs of carp suffering from chronic aeromonas infection on pond fish farms in the southern Russia. These bacteria are its cosmopolitan distribution ability them to generate heat-resistant spores and cause food poisoning, which makes control and prevention measures needed in the food chain.

Photoperiod manipulation in the induced breeding of the rabbit fish (<i>Siganus guttatus</i>)

In teleosts, reproductive development is a continuous process throughout ontogeny and is regulated by pituitary gonadotropins (GtHs). It has been established that fish has two distinct pituitary GtHs that parallel vertebrate follicle stimulating hormone (FSH) and luteinizing hormone (LH) with respective structural similarities. In the present study we investigated the spawning of the Golden rabbit fish Siganus guttatus after exposure to different photoperiod regimes. The role of photoperiod on spawning was studied by exposing female fish to three light regimes: 16h:8h light and dark; 16h:8h dark and light; and 24h continuous light. At every first quarter of the lunar cycle (new moon), the groups exposed to the photoperiod were induced to spawn by the injection of hCG at 2000 IU/kg fish. We observed that only 24 h exposure to continuous light induced successful spawning in female injected with hCG. Fish exposed to the other light: dark regimes could not be induced to spawn. Overall, these findings suggest that continuous light can be a triggering factor for the induction of maturation and spawning of this species under aquaculture conditions. 
 Keywords: Siganus guttatus, photoperiod, induced breeding, spawning.

ВЕТЕРИНАРНО-САНИТАРНАЯ ОЦЕНКА КАЧЕСТВА И БЕЗОПАСНОСТИ ТОВАРНОЙ СТЕРЛЯДИ, ВЫРАЩЕННОЙ С ИСПОЛЬЗОВАНИЕМ РЕЦИРКУЛЯЦИОННЫХ ТЕХНОЛОГИЙ

The article studies the safety of sterlet grown in recirculating aquaculture systems. The research was carried out in the research and training laboratory on reproduction and cultivation of sturgeon species of the Department of private animal husbandry, livestock and aquaculture technology of Ulyanovsk State Agrarian University named after P. A. Stolypin and Simbirsk Veterinary Reference Center in Ulyanovsk. The material for the study was chosen sterlet grown in recirculating aquaculture systems. In the recirculating aquaculture system food components and metabolites accumulate, which may affect fish health and quality and safety of fish meat. In the course of studies it has been found that hydrochemical parameters of water taken from the breeding tanks comply with the standards: ammonia content as the main indicator affecting the growth and development of fish did not exceed 0.05 mg/dm3. This is due to compliance with fish stocking density, optimum temperature (18-22°C) and pH level (7.3). The content of sulfates was also within the norm -52.78 mg/dm3. Mass fraction of chlorides was 14.82 mg/dm3 and of nitrites - 0.052 mg/dm3, which is 20 and 50 times lower than the standard values. The fish was studied for organoleptic, microbiological parameters, as well as for the content of toxic elements. Organoleptic characteristics (appearance, fish condition, smell, color of eyes and gills) fully meet the requirements of GOST 7631-2008 “Fish, non-fish objects and their products. Methods for determination of organoleptic and physical parameters”; such toxic elements as cadmium (Cd), arsenic (As), mercury (Hg) and lead (Pb) were detected in fish samples, but their content was negligible and did not exceed the maximum permissible concentrations. The presence of genetically modified organisms, pathogens, BGB (coliforms), Listeria, nematodes were not detected. According to the study results, sterlet grown in the recirculating aquaculture conditions of the research laboratory for reproduction and breeding of sturgeon species of the Department of private zootechny, technology of animal husbandry and aquaculture of Ulyanovsk State Agrarian University can be considered completely safe in terms of microbiological, parasitological and chemical indicators.

Implications for introgression: has selection for fast growth altered the size threshold for precocious male maturation in domesticated Atlantic salmon?

BackgroundMature male parr (MMP) represent an important alternative life-history strategy in Atlantic salmon populations. Previous studies indicate that the maturation size threshold for male parr varies among wild populations and is influenced by individual growth, environmental conditions, and genetics. More than ten generations of breeding have resulted in domesticated salmon displaying many genetic differences to wild salmon, including greatly increased growth rates. This may have resulted in domesticated fish with the potential to outgrow the size threshold for early maturation, or evolution of the size threshold of the trait itself. To investigate this, we performed a common-garden experiment under farming conditions using 4680 salmon from 39 families representing four wild, two wild-domesticated hybrid, and two domesticated strains.ResultsDomesticated salmon outgrew wild salmon 2–5-fold, and hybrids displayed intermediate growth. Overall, the numbers of MMP varied greatly among families and strains: averaging 4–12% in domesticated, 18–25% in hybrid, and 43–74% in the wild populations. However, when the influence of growth was accounted for, by dividing fish into lower and upper size modes, no difference in the incidence of MMP was detected among domesticated and wild strains in either size mode. In the lower size mode, hybrids displayed significantly lower incidences of mature males than their wild parental strains. No consistent differences in the body size of MMP, connected to domestication, was detected.ConclusionsOur data demonstrate: 1- no evidence for the evolution of the size threshold for MMP in domesticated salmon, 2- the vastly lower incidence of MMP in domesticated strains under aquaculture conditions is primarily due to their genetically increased growth rate causing them to outgrow the size threshold for early maturation, 3- the incidence of MMP is likely to overlap among domesticated and wild salmon in the natural habitat where they typically display overlapping growth, although hybrid offspring may display lower incidences of mature male parr. These results have implications for wild salmon populations that are exposed to introgression from domesticated escapees.

Sex-related gonadal gene expression differences in the Russian sturgeon (Acipenser gueldenstaedtii) grown in stable aquaculture conditions

The Russian sturgeon (Acipenser gueldenstaedtii) is a primitive freshwater fish and a source of caviar. In the present study, the gonadal transcriptomes of male and female Russian sturgeons grown in stable aquaculture conditions were analyzed. RNA sequencing of whole-gonad transcriptomes from pools of 4-year old fish (five females, four males), resulted in the identification of 28,170 unique transcripts. Of these, 16,191 could be annotated by similarity to gene sequences from other species. There were 392 transcripts that showed differential abundance by a factor of 20-fold or more between the sexes; 272 of these were annotated; of these, 175 and 97 were in greater abundance in ovaries and testes, respectively. Functional annotation and clustering of the genes with differential abundances of mRNA allowed for identification of several clusters. Thus, a group of transcriptional regulators and factors involved in cell division, especially septins, were in greater abundance in the ovaries; while a different set of transcription factors (including sox6 and sox30) and a group of protein kinases were in greater abundance in the testes. The transcript abundances of nine highly abundant candidate transcripts, as well as of two additional genes previously known to be involved in reproduction, cyp19 (p450 aromatase) and foxl2, were assessed in the individual samples by qRT-PCR. Of these, five (including cyp19 and foxl2) were in greater abundance in ovaries, while the abundance of ighm1 mRNA was greater in testes. Phylogenetic analysis based on the k1c18 keratin gene placed the sturgeon sequence nearest those of other primitive fish species, supporting the ancient origin of the sturgeon. In conclusion, this study details transcriptome differences between male and female sturgeon and identifies key genes that may contribute to sexual determination and differentiation.

Effect of dietary seaweed supplementation on growth performance, antioxidant and immune responses in European seabass (Dicentrarchus labrax) subjected to rearing temperature and salinity oscillations

The current study evaluated the effects of dietary seaweed supplementation in European seabass juveniles (Dicentrarchus labrax) subjected to rearing temperature and salinity oscillations, simulating natural variations in pond aquaculture conditions. Two experimental diets where formulated: a control diet (CTRL) with no supplementation and one supplemented with 7.5% seaweed mix (SW 2.5% Fucus sp., 2.5% Gracilaria sp. and 2.5% Ulva sp.). Seabass from both dietary groups (40.7 g initial body weight) was subjected to either combined salinity and temperature oscillations, or to fixed conditions. Growth performance, innate immune, and oxidative stress responses were evaluated. Results showed that seaweed supplementation had no significant effect on the analyzed parameters. However, environmental oscillations revealed significant effects on growth performance and oxidative stress response. Fish subjected to salinity and temperature oscillations had a significantly lower weight gain and daily growth index than those subjected to fixed conditions, regardless of dietary treatment. Total glutathione, oxidized glutathione, and catalase increased in fish subjected to oscillatory conditions. Lysozyme and peroxidase were not influenced by either diet or environmental conditions. In conclusion, this particular dietary seaweed mix supplementation did not mitigate the negative effects of environmental oscillations on growth performance and innate immune responses in European seabass.

Feed contamination with zearalenone promotes growth but affects the immune system of rainbow trout

To investigate the effects of feed contamination with zearalenone (ZEN) at the current European Commission (EC) guidance value (2 mg⋅kg−1 feed) on the growth and health of rainbow trout, we performed a long-term feeding trial under aquaculture conditions. It started with the external feeding of the fish larvae, and continued for 96 weeks, at which point the fish had reached market size. To assess the growth of fish and their feeding efficiency throughout this period, the fish were regularly weighed and measured, and their feed consumption was monitored. Additionally, to investigate potential health effects, after 72 weeks of the exposure to ZEN, the fishes' blood was analyzed for major hematological and biochemical indices, and their head kidney, spleen, and liver were examined for morphological, histopathological, cytological, and molecular changes. Finally, to gain insight into the metabolism and distribution of ZEN in fish, the content of free and glucuronidated forms of ZEN and its major metabolites was measured in the intestine, liver, and muscles of the exposed fish. The feed-borne exposure of rainbow trout to ZEN at a dose of 2 mg⋅kg−1 feed resulted in higher feeding efficiency and growth rate, most probably due to the anabolic properties of the ZEN metabolite. Importantly for the consumers of fish, despite absorption and metabolism of ZEN in the digestive system of the fish that had been exposed for 72 weeks, the residuals of ZEN were not transferred to the fishes’ muscles, which rules out a potential risk to human health related to the consumption of fish meat. However, the increased growth of fish fed with the contaminated feed may come at some cost, as the exposure to ZEN was associated with modulation of key components of the adaptive and innate immune systems. Moreover, the trunk kidney of ZEN-fed fish showed massive inflammation that was likely caused by pathogen infection. These findings raise concerns about fish health under the current recommended EC guidance values.

Description of the Annual Reproductive Cycle of Wreckfish Polyprion americanus in Captivity

Successful spontaneous reproduction and the production of viable offspring of wild fish in captivity can take some years of adaptation, and may also involve different environmental conditions, sex ratios and densities compared to natural populations. We followed the reproductive cycle of wreckfish Polyprion americanus—a late maturing, deep-sea benthic species—in captivity in three different broodstocks in Spain under natural photoperiod and temperature, and one broodstock in Greece under a constant temperature of 16 °C for two consecutive years, to describe the reproductive cycle of the species and the associated sex steroid hormone profiles. Oogenesis begun in the fall and post-vitellogenic oocytes of 1250 μm were present between March and June. Males were in spermiation condition and produced good-quality sperm throughout the year, regardless of the temperature profile to which they were exposed. Some females completed oogenesis, underwent oocyte maturation, and spawned spontaneously under both constant and fluctuating temperatures. The sex steroid hormones of both males and females followed the already-known profiles during fish gametogenesis, except for 17,20β-dihydroxy-progesterone, which did not seem to be related to either female or male maturation. The female reproductive dysfunctions that were identified included (a) the arrest of oogenesis at the cortical alveoli stage in certain females; (b) the failure to undergo oocyte maturation in others; and (c) the production of large percentages of unfertilized eggs from the females that spawned spontaneously. Our study suggests that reproduction in captivity is possible in wreckfish maintained under typical marine aquaculture conditions, but that reliable spawning and production of high-quality eggs may require some years of adaptation to captivity, before the reproductive dysfunctions will be overcome.

Cleaner shrimp remove parasite eggs on fish cages

Benthic stages of cultured fishes' ectoparasites are a major contributor to persistent reinfections in aquaculture. These stages are resistant to chemical therapies and are costly to manage in terms of time and labour. Cleaner shrimp, unlike cleaner fishes, prey on benthic stages, suggesting they have the potential to reduce parasite reinfection pressure without having to be in direct contact with the client fish. Cleaner shrimp have never been used as biocontrols in commercial aquaculture, but offer an advantage over cleaner fishes in that they are not susceptible to the ectoparasites of their clients. We present the first investigation of a cultured cleaner shrimp, Lysmata vittata, as a biocontrol agent against the eggs of the economically important cosmo politan ectoparasite Neobenedenia girellae infecting cultured juvenile grouper, Epinephelus lanceolatus, under simulated recirculating aquaculture conditions. L. vittata removed the eggs of N. girellae entangled on the mesh of the culture cages and significantly reduced N. girellae recruitment to fish by similar to 87%. Our results demonstrate the value of cleaner shrimp in addressing ectoparasite problems and highlight the importance of investigating novel biocontrol strategies in aquaculture.

Present status of traditional aquaculture and socio-economic condition of fish farmers at Paba upazila in Rajshahi District, Bangladesh

Data were collected from 50 fish farmers through questionnaire interview and Focus Group Discussion (FDG) in Paba upazila, Rajshahi district of Bangladesh during the period of October, 2015 to May, 2016 to evaluate the present status of traditional aquaculture and socio-economic condition of fish farmers. In the study area, average pond size was 0.83 ha (2-7 feet depth) and 80% of the ponds were characterized with loamy soil. Ground water was the main source for 70% of the ponds where about 90% of the fish farmers were engaged in polyculture of carp species. Majority of fish farmers were in the age group of 41-50 years with fish farming experience of 16 years (44%). Activities of DoF were minimum regarding fish farming of the fish farmers. In the present study, 80% of the respondents were related to fish culture as their principal occupation and majority of the fish farmers (50%) have the annual income of BDT 51,000 to 100,000. 30% of the respondents were educated up to secondary level of education. Health and sanitary status are in good condition than before. 94% of fish farmers have improved their socio-economic condition through fish farming. Therefore, proper training on fish farming and advanced technical knowledge are necessary to improve high pond productivity.Res. Agric., Livest. Fish.5(2): 269-277, August 2018

One cryptic species of grey mullet (Mugil cephalus mitotype: NWP3) from Taiwan’s waters is worth cultivating for large roes using aquaculture

The grey mullet, Mugil cephalus, is an important aquaculture species in Taiwan. They were thought to be a single fish species in terms of the morphology-based taxonomy; however, three cryptic species of grey mullet (mitotype: NWP1, NWP2 and NWP3) have been identified within the Taiwan waters. In general, the NWP2 females are known to have small body sizes with large developed ovaries regardless of the cultivation time, whereas the NWP1 females have large body sizes with small ovaries. In this study, the NWP3 females are found to have significantly larger body and ovary weights than do the NWP2 females under the same aquaculture conditions. Therefore, even though the NWP2 females are good fish for producing large ovaries, this study indicates that the NWP3 females have even more potential to produce huge ovaries than do the NWP2 females.

Assessment of Holothuria arguinensis feeding rate, growth and absorption efficiency under aquaculture conditions

ABSTRACTHolothuria arguinensis is a potential species for sea cucumber aquaculture in Europe. In a first experiment, feeding rate (FR), growth, absorption efficiency (AE) and survival of adults (135.01 ± 10.87 g eviscerated weight) were assessed under sediment tank conditions. In a second experiment, the feasibility to use sea bream (Sparus aurata) biodeposits as a food source was studied for adults (168.69 ± 14.59 g eviscerated weight). Individuals in the first experiment showed an increase of weight (specific growth rate (SGR) = 0.2% d−1), positive FRs and mean value of AE close to 80% with a mean organic matter content of 90.07 ± 11.5 mg/g in the offered sediment. Sea cucumbers fed with fish biodeposits showed a reduction of weight (SGR < −0.14% d−1), low FRs and negative values of AE. The influence of low salinity and temperature during experiments should be considered to explain these results. Indeed, sea cucumbers can be affected by a decrease of these parameters during winter months resulting in a period of inactivity.

Chronic exposure to increased water temperature reveals few impacts on stress physiology and growth responses in juvenile Atlantic salmon

Fish are subjected to a variety of stressors under common cage aquaculture conditions. While short-term exposure to a stressor often results in an adaptive response to cope with stress, repeated and/or chronic exposure to stress can result in negative impacts on fish welfare and production. In fish, little is known about the impact of long-term exposure to stressors, including elevated water temperature. In this study we examined and developed temporal response profiles of physiological indicators of stress and growth in juvenile Atlantic salmon (Salmo salar) exposed to 12 °C, 16 °C, and 20 °C for 99 days. Five times throughout the study we quantified plasma cortisol, glucose and cholesterol levels, and growth. Fish body mass and fork length were not significantly different amongst temperatures after 99 days. Plasma cortisol was significantly elevated at 16 °C when comparing day 8 with 99, while at 12 °C plasma cortisol increased from day 1 to day 8, then returned to initial levels (day 1 and 8) after 99 days. Plasma glucose and cholesterol were not significantly different amongst the temperatures throughout the experiment. In addition, at the end of the experiment we quantified eye darkening, and identified the development of a bimodal growth distribution in all temperatures. Fish with a fork length ≤ 240 mm were categorised as lower mode (LM) and those with a fork length > 240 mm as in the upper mode (UM) of growth. Plasma cholesterol was significantly lower in the LM group in all three temperatures, but plasma cortisol and glucose levels did not differ between modes. Eye darkening also did not differ between modes, but increased significantly in the groups exposed to 16 °C and 20 °C when compared with 12 °C. This study showed a clear physiological stress response (elevated levels of cortisol) and eye darkening in fish maintained at 16 °C but not at 12 °C or 20 °C, suggesting that some aspects of the physiological responses available to deal with chronic stress are affected by temperature.

Online Monitoring of Shrimp Aquaculture in Bangka Island Using Wireless Sensor Network

In this paper, it will be described the design and realization of online water quality monitoring system based on wireless sensor network (WSN). The new system has been implemented specifically to monitor parameters Dissolved Oxygen (DO), pH and temperature in one spot shrimp aquaculture in Bangka island. The aim was to create suitable water conditions for shrimp aquaculture and save the cost of energy consumption using an automated aeration system, by maintaining the value of the DO above 5 mg/L. On the other hand, water quality data collected from sensor measurements are sent to a data logger using WSN, and then the data is sent to a data center using cellular network (GPRS) such that this data can be viewed using the website. The experimental results show that the system has great prospects and can be used for shrimp aquaculture by providing information that is relevant and timely. The resulting data the collection can be used for research and analysis.

Intestinal incomplete process on the osmoregulation system during Salmo salar smoltification in a productive conditions

Smoltification under intensive aquaculture conditions involves important physiological changes to intestinal structures that facilitate acclimation to hyperosmotic environments. This study evaluated if genic expression of primary contributors during the smoltification process in the intestine are in synchrony with gill Na+/K+-ATPase activity. Discordance was found between gill Na+/K+-ATPase activity levels and intestinal genic expressions. In particular, the intestine showed increased mRNA expression for prolactin, a hormone that participates in hypoosmotic environments, and in mRNA expression of the growth hormone, which mediates the hydromineral balance in hyperosmotic environments. These findings indicate a lack of sufficient intestinal maturation in the fish at the moment when they were transferred to seawater environments in the normal aquaculture practices. This intestinal immaturity is a possible explanation for the high rates of desadapted individuals in the seawater phase in Chilean salmon aquaculture.

Effects of Salinity and Temperature on Growth and Survival of Juvenile Iwagaki Oyster Crassostrea nippona

Iwagaki oyster Crassostrea nippona occurs naturally along the coasts of Japan and Korea. Because of its unique flavor, delicious taste, edibility during the summer and high commercial value, it has been identified as a potential aquaculture species. To determine the optimum aquaculture conditions and provide necessary information for mass production of the juvenile, the effects of six salinities (15, 20, 25, 30, 35 and 40) and five temperatures (16, 20, 24, 28 and 32°C) on growth and survival of juvenile C. nippona were examined in this study. In the salinity experiment, the largest values of mean shell height and growth rate were observed at salinity 25 (20.96 ± 0.36 mm and 172.0 μm d−1, respectively), which were significantly different (P 0.05). The maximum survival rate 84.44% was always observed at salinity 20, and there was no significant difference (P > 0.05) in survival rate among salinities varying between 15 and 35. In the temperature-related experiments, the highest growth and survival rates of juvenile were observed at 24°C (180.8 μm d−1 and 84.4%) and 28°C (190.7 μm d−1 and 83.3%), respectively, on day 20, and showed significantly (P < 0.05) larger size and higher survival rate than any other groups. Both juvenile survival and growth were significantly depressed at extreme salinities (15, 40) and temperatures (16°C, 32°C). Based on the results of the present study, a salinity range from 25 to 30 and a temperature range from 24°C to 28°C are considered optimal conditions for survival and growth of juvenile C. nippona.

Meagre's melatonin profiles under captivity: circadian rhythmicity and light sensitiveness.

The present study reveals the first characterization of the plasma melatonin rhythms of the meagre (Argyrosomus regius) under aquaculture conditions. Melatonin levels were monitored during a 24h cycle under a photoperiod of 16L:8D and under constant darkness (DD), respectively to characterize the daily rhythm of this indoleamine and to test its endogenous origin. Besides, to identify which light intensities are perceived as night or day by this species, the degree of inhibition of nocturnal melatonin production caused by increasing intensities of light was tested (3.3, 5.3, 10.5, and 120μW/cm2), applying 1h light pulses at Mid-Dark. The result for melatonin daily rhythm in plasma showed a typical profile: concentration remained low during all daytime points, increasing greatly during dark points, with maximum values at 16:00 and 22:00h, zeitgeber time. Under DD conditions, the plasma melatonin profile persisted, with a similar acrophase but with a lower amplitude between subjective day and night periods, indicating this rhythm as being endogenously driven. Moreover, meagre seemed to be very sensitive to dim levels of illumination during the night, since an intensity of just 3.3μW/cm2 inhibited melatonin production. However, only the pulse of 5.3μW/cm2 caused a melatonin drop till daytime concentrations. Thus, the threshold of light detection by the pineal organ was suggested as being located between 3.3 and 5.3μW/cm2. Such results are an added value for this species biology knowledge, and in consequence to its adaptation to aquaculture conditions, allowing the improvement of culture husbandry protocols.

Influence of temperature andArtemiaenriched with ω-3 PUFAs on the early ontogenesis of Atlantic sturgeon,Acipenser oxyrinchusMitchill, 1815

Successful breeding of fish species in aquaculture depends on several factors, among which the temperature and feed are the most significant ones. This study was designed to evaluate the effect of temperature in the range of 14–18°C on the rate of embryogenesis and duration of larva period and to estimate the efficiency of Artemia nauplii enriched with PUFAs in growing sturgeon larvae. The temperature of 16°C is the most suitable for both egg incubation and Atlantic sturgeon prelarvae maintenance under aquaculture conditions. Even minor temperature fluctuations of 1 degree up or down leads to increased loss both of eggs and prelarvae. Increased temperature shortens the incubation period but has a lesser impact on the duration of prelarvae onset of external feeding. The technology of Artemia nauplii bioencapsulation with a PUFA-containing supplement in A. oxyrinchus rearing increases sturgeon larvae weight by 1.5 times at a constant survival dynamic.

Конструирование функционального рыбного продукта в условиях индустриальной аквакультуры

Конструирование функционального рыбного продукта в условиях индустриальной аквакультуры

Influence of Nanoparticles on the Yield of Embryos of the Roe Rainbow Trout (Oncorhynchus mykiss Walbaum) in the Fermentation Process

Nanoparticles can get into the aquatic environment at different stages of the life cycle of water organisms and these interactions can cause an urgent need for the biochemical balance of the organism and the adaptation of the species to the changing environment. The goal of the current research is to investigate the effect of nanoparticles of Fe3O4 (20-30 nm) and Al (18 nm) on the processs of fertilization of sexual cells of rainbow trout (Oncorhynchus mykiss Walbaum) in the aquaculture condition and the effects of embryonic developmental stages after fertilization, as well as absorption of nanoparticles by feedstuffs and entry into the food chain and investigating possible bioaccumulation. According to the results of the experiments it was concluded that, when Fe3O4 (20-30 nm) and Al (18 nm) nanoparticles are added in roe of rainbow trout prior to fermentation, the percentage of fertilization of roe was higher, and the release of free embryos was higher than in the control variants. Fe3O4 (20-30 nm) nanoparticles have a stimulating effect at amount of 0.05 g (2018) and Al (18 nm) nanoparticles at the amount of 0.005 g (2018). It can be assumed that these nanoparticles have a catalytic effect on spermatozoid acrosomes, accelerate energy activity, and eventually increase the activity of spermatozoids, which leads to an increase in the rate of fertilization of the roe.