Determination of the ideal volume of activating solution and the optimal ratio of spermatozoa per oocyte for Prochilodus brevis fertilization.

Prochilodus brevis is a rheophilic species with a threatened natural population that promotes studies aimed at optimizing reproduction in captivity. The correct quantity of inseminating dose and activating solution volume significantly improves fertilization rates, thereby increasing productivity in captivity. The objective of this study was to determine the proportion of sperm per oocyte and the ideal volume of activating solution to be used in the assisted fertilization of P. brevis. Gametes were collected and fertilization performed in two steps. In step 1, the ideal proportion of spermatozoa was determined based on the fertilization rate:oocyte by testing six doses of semen: D1 = 30 × 103, D2 = 150 × 103, D3 = 300 × 103, D4 = 3 × 106, D5 = 5 × 106, and D6 = 10 × 106. In step 2, the fertilization and hatching rates were evaluated using different volumes of activating solution (V1 - 25 ml, V2 - 50 ml, V3 - 75 ml,V4 - 100 ml, V5 - 125 ml, and V6 - 150 ml). A linear regression equation was estimated from steps 1 and 2. The Student-Newman-Keuls test was used to compare the means. In step 1, the percentage of fertilization increased linearly, reaching a plateau of 51.69%. In step 2, the best fertilization rates were obtained with an estimated ideal volume of 75.64 ml per 2 ml of oocytes. Therefore, the proportion of 928,410.29 sperm:oocyte, associated with the volume of 75.64 ml of water per 2 ml of oocytes, provided the maximum reproductive performance for P. brevis.

Vitrificação de sêmen de peixes teleósteos / Vitrification of teleosts fish semen

A preservação de sêmen de peixes é uma técnica promissora para o desenvolvimento daaquicultura, e consiste na conservação dos gametas masculinos a longo prazo. Dentre os procedimentosde criopreservação de sêmen de peixes, a vitrificação vem sendo desenvolvida como uma alternativa àcriopreservação convencional devido à sua rapidez, praticidade e baixo custo. Apesar dos benefícios, essatécnica possui alguns entraves que limitam seu sucesso, uma vez que consiste em mergulhar a amostradiretamente em nitrogênio líquido, necessitando de grandes quantidades de crioprotetores de ação interna,que podem ser tóxicos. Dessa forma, diferentes protocolos precisam ser testados, a fim de obterresultados satisfatórios após a aplicação da técnica. A vitrificação tem sido utilizada com sucesso parasêmen, ovócitos, embriões e tecidos de mamíferos e, atualmente, alguns protocolos de vitrificação desêmen já foram elaborados para determinadas espécies de peixes com relativo sucesso, contudo maisestudos são necessários para aumentar a viabilidade espermática após o reaquecimento. Portanto, oobjetivo desta revisão é resumir os procedimentos básicos do processo de vitrificação de sêmen de peixese apresentar os principais resultados encontrados na literatura.(AU)

The preservation of fish semen is a promising technique for the development of aquaculture, andconsists in the conservation of male gametes in the long term. Among the procedures forcryopreservation of fish semen, vitrification has been developed as an alternative to conventionalcryopreservation due to its speed, practicality, and low cost. Despite the benefits, this technique has someobstacles that limit its success, since it consists of immersing the sample directly into liquid nitrogen,requiring large amounts of internal cryoprotectants, which can be toxic. Thus, different protocols need tobe tested in order to obtain satisfactory results after the application of the technique. Vitrification hasbeen successfully used for semen, oocytes, embryos and mammalian tissues, and currently some semenvitrification protocols have been developed for certain species of fish with relative success, howeverfurther studies are needed to increase sperm viability after warming. Therefore, the purpose of thisreview is to summarize the basic procedures of the fish semen vitrification process and present the mainresults found in the literature.(AU)

Vitrificação de sêmen de peixes teleósteos / Vitrification of teleosts fish semen

A preservação de sêmen de peixes é uma técnica promissora para o desenvolvimento daaquicultura, e consiste na conservação dos gametas masculinos a longo prazo. Dentre os procedimentosde criopreservação de sêmen de peixes, a vitrificação vem sendo desenvolvida como uma alternativa àcriopreservação convencional devido à sua rapidez, praticidade e baixo custo. Apesar dos benefícios, essatécnica possui alguns entraves que limitam seu sucesso, uma vez que consiste em mergulhar a amostradiretamente em nitrogênio líquido, necessitando de grandes quantidades de crioprotetores de ação interna,que podem ser tóxicos. Dessa forma, diferentes protocolos precisam ser testados, a fim de obterresultados satisfatórios após a aplicação da técnica. A vitrificação tem sido utilizada com sucesso parasêmen, ovócitos, embriões e tecidos de mamíferos e, atualmente, alguns protocolos de vitrificação desêmen já foram elaborados para determinadas espécies de peixes com relativo sucesso, contudo maisestudos são necessários para aumentar a viabilidade espermática após o reaquecimento. Portanto, oobjetivo desta revisão é resumir os procedimentos básicos do processo de vitrificação de sêmen de peixese apresentar os principais resultados encontrados na literatura.

The preservation of fish semen is a promising technique for the development of aquaculture, andconsists in the conservation of male gametes in the long term. Among the procedures forcryopreservation of fish semen, vitrification has been developed as an alternative to conventionalcryopreservation due to its speed, practicality, and low cost. Despite the benefits, this technique has someobstacles that limit its success, since it consists of immersing the sample directly into liquid nitrogen,requiring large amounts of internal cryoprotectants, which can be toxic. Thus, different protocols need tobe tested in order to obtain satisfactory results after the application of the technique. Vitrification hasbeen successfully used for semen, oocytes, embryos and mammalian tissues, and currently some semenvitrification protocols have been developed for certain species of fish with relative success, howeverfurther studies are needed to increase sperm viability after warming. Therefore, the purpose of thisreview is to summarize the basic procedures of the fish semen vitrification process and present the mainresults found in the literature.

Capacidade fecundante do sêmen congelado de Prochilodus brevis / Fertilizing capacity of the cryopreserved sperm of Prochilodus brevis

Background: Seminal cryopreservation is a technique that optimizes aquacultural production, as it requires less breedingand enables reproduction outside of the breeding season. This technique also helps to preserve species, thus reducing thepressure on the natural stocks. Several studies have sought to develop freezing protocols that result in semen of a goodquality. However, some studies do not evaluate the ability of frozen semen to produce viable larvae. Therefore, the aimof this study was to verify the fertilizing capacity of the frozen semen of Prochilodus brevis.Materials, Methods & Results: Semen from twenty adult males of the Brazilian bocachico was collected and evaluatedto establish the total motility, curvilinear velocity, straight linear velocity, average path velocity, membrane integrity, pH,and concentration. Six pools were formed, each of which was diluted in a freezing medium containing 5% glucose with10% dimethyl sulfoxide (DMSO) or 5% glucose with 10% methyl glycol (MG). The samples were loaded into 0.25 mLFrench straws, frozen in a dry shipper, and stored in a liquid nitrogen canister. The semen was then thawed and evaluatedto establish the total motility, curvilinear velocity, straight linear velocity, average path velocity, and membrane integrity.For the fertilization test, four females were used. The oocytes from each female were divided into three batches and fertilized with either fresh or cryopreserved semen. The rates of fertilization, hatching, and larval survival were then measured.Data were expressed as the mean ± standard deviation and analyzed using SAS (2002). The frozen semen with glucose +DMSO was significantly higher (P < 0.001) than the frozen semen with glucose + MG, in all seminal quality parametersevaluated (63.95 ± 15.88% and 25.36 ± 3.53% for the motility, 36.38 ± 7.02 μm.s-1 and 20.45 ± 2.84 μm.s-1 for the curvilinear velocity, 19.26 ± 2.74 μm.s-1 and...(AU)

Capacidade fecundante do sêmen congelado de Prochilodus brevis / Fertilizing capacity of the cryopreserved sperm of Prochilodus brevis

Background: Seminal cryopreservation is a technique that optimizes aquacultural production, as it requires less breedingand enables reproduction outside of the breeding season. This technique also helps to preserve species, thus reducing thepressure on the natural stocks. Several studies have sought to develop freezing protocols that result in semen of a goodquality. However, some studies do not evaluate the ability of frozen semen to produce viable larvae. Therefore, the aimof this study was to verify the fertilizing capacity of the frozen semen of Prochilodus brevis.Materials, Methods & Results: Semen from twenty adult males of the Brazilian bocachico was collected and evaluatedto establish the total motility, curvilinear velocity, straight linear velocity, average path velocity, membrane integrity, pH,and concentration. Six pools were formed, each of which was diluted in a freezing medium containing 5% glucose with10% dimethyl sulfoxide (DMSO) or 5% glucose with 10% methyl glycol (MG). The samples were loaded into 0.25 mLFrench straws, frozen in a dry shipper, and stored in a liquid nitrogen canister. The semen was then thawed and evaluatedto establish the total motility, curvilinear velocity, straight linear velocity, average path velocity, and membrane integrity.For the fertilization test, four females were used. The oocytes from each female were divided into three batches and fertilized with either fresh or cryopreserved semen. The rates of fertilization, hatching, and larval survival were then measured.Data were expressed as the mean ± standard deviation and analyzed using SAS (2002). The frozen semen with glucose +DMSO was significantly higher (P < 0.001) than the frozen semen with glucose + MG, in all seminal quality parametersevaluated (63.95 ± 15.88% and 25.36 ± 3.53% for the motility, 36.38 ± 7.02 μm.s-1 and 20.45 ± 2.84 μm.s-1 for the curvilinear velocity, 19.26 ± 2.74 μm.s-1 and...

Efeito de vitaminas e aminoácidos como suplementação da solução crioprotetora para a criopreservação do sêmen de tambaqui (Colossoma macropomum) / Effect of vitamins and amino acids as cryoprotectant solution supplementation for the cryopreservation of tambaqui semen (Colossoma macropomum)

Background: The addition of antioxidant substances to a cryoprotective solution can increase its protective capacity, shielding spermatozoa from the oxidative stress caused by the seminal cryopreservation process. However, there is no record of a seminal cryopreservation protocol of tambaqui (Colossoma macropomum) using antioxidants as a supplement to the cryoprotective solution. Thus, the objective of this study was to evaluate the effects of adding vitamin C, vitamin E, cysteine, and/or taurine to the seminal cryopreservation of tambaqui.Materials, Methods & Results: Pools of semen (n = 10) were diluted in cryoprotective solutions supplemented with: vitamin C (T1), vitamin E (T2), vitamin C + vitamin E (T3), cysteine (T4), taurine (T5), and taurine + cysteine (T6). The control treatment (T7) was not supplemented. Diluted semen was loaded in 0.5 mL straws, frozen in a dry-shipper, stored in a cryogenic cylinder, and then thawed in a water bath (45ºC for eight seconds). The quality of fresh and cryopreserved semen was evaluated by measuring total motility, progressive motility, curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), linearity, and straightness using a computerized system of sperm analysis. Sperm membrane integrity parameters were analyzed using eosin-nigrosin staining, sperm morphology was assessed using pink bengal staining, and motility duration was measured by a digital timer. Data were analyzed using the statistical program SAS (2002) and the results were expressed as means ± standard error of the mean. The results showed that, in general, there was no significant increase in seminal quality when antioxidants were added to the cryoprotective solution. The T5 treatment promoted an increase (P < 0.05) in progressive motility when compared to T1 (6.33 ± 1.14% and 2.98 ± 0.88%, respectively). However, it did not differ significantly (P > 0.05) from the other treatments.[...](AU)

Efeito de vitaminas e aminoácidos como suplementação da solução crioprotetora para a criopreservação do sêmen de tambaqui (Colossoma macropomum) / Effect of vitamins and amino acids as cryoprotectant solution supplementation for the cryopreservation of tambaqui semen (Colossoma macropomum)

Background: The addition of antioxidant substances to a cryoprotective solution can increase its protective capacity, shielding spermatozoa from the oxidative stress caused by the seminal cryopreservation process. However, there is no record of a seminal cryopreservation protocol of tambaqui (Colossoma macropomum) using antioxidants as a supplement to the cryoprotective solution. Thus, the objective of this study was to evaluate the effects of adding vitamin C, vitamin E, cysteine, and/or taurine to the seminal cryopreservation of tambaqui.Materials, Methods & Results: Pools of semen (n = 10) were diluted in cryoprotective solutions supplemented with: vitamin C (T1), vitamin E (T2), vitamin C + vitamin E (T3), cysteine (T4), taurine (T5), and taurine + cysteine (T6). The control treatment (T7) was not supplemented. Diluted semen was loaded in 0.5 mL straws, frozen in a dry-shipper, stored in a cryogenic cylinder, and then thawed in a water bath (45ºC for eight seconds). The quality of fresh and cryopreserved semen was evaluated by measuring total motility, progressive motility, curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), linearity, and straightness using a computerized system of sperm analysis. Sperm membrane integrity parameters were analyzed using eosin-nigrosin staining, sperm morphology was assessed using pink bengal staining, and motility duration was measured by a digital timer. Data were analyzed using the statistical program SAS (2002) and the results were expressed as means ± standard error of the mean. The results showed that, in general, there was no significant increase in seminal quality when antioxidants were added to the cryoprotective solution. The T5 treatment promoted an increase (P 0.05) from the other treatments.[...]

Influência do tempo de resfriamento e soluções diluentes sobre a congelabilidade do sêmen de Prochilodus brevis / Influence of cooling time and diluents on the freezability of Prochilodus brevis semen

Background: Prochilodus brevis is a rheophilic fish of economic and ecological importance. However, anthropic action has made its population vulnerable. Thus, the development of reproductive biotechnologies, such as seminal conservation, is necessary to subsidize their fish farming. However, seminal collections are often performed in places with few laboratory resources, demanding studies to determine the maximum time for which sperm can be cooled, as well as its process until frozen. Thus, the present study aimed to evaluate the influence of cooling time and the presence of dilution solutions on cryopreservation of P. brevis semen.Material, Methods & Results: After seminal collection, nine pools were formed and analyzed for seminal pH, concentration, membrane integrity, morphology and spermatic kinetics - motility, curvilinear velocity (VCL), average path velocity (VAP) and straight line velocity (VSL). After the analysis of the pools in natura (control 1), they were processed as follows: 1)- immediate freezing (control 2); 2)- cooling: undiluted, diluted in coconut water powder (ACP-104) or diluted in 5% glucose, followed by cooling at different times (6, 12, 24 or 48 h); 3)- Post-refrigeration freezing: the pools were diluted in their respective diluents and 10% dimethyl sulfoxide. After 15 days, the samples were thawed and analyzed for the aforementioned parameters. For the cooled and post-thawed semen, a completely randomized design with 2 (diluent × cooling time) and 3 (storage form × cooling time and storage form × diluent) factors, respectively, was utilized. ANOVA and Dunnett tests were applied to compare the means. In case of seminal cooling, there was no difference (P > 0.05) in sperm motility between control 1 and the undiluted and diluted treatments in ACP-104 for up to 24 h. After 48 h, only the VCL of the sample diluted in ACP-104 was similar (P > 0.05) to that of control 1.[...](AU)

Influência do tempo de resfriamento e soluções diluentes sobre a congelabilidade do sêmen de Prochilodus brevis / Influence of cooling time and diluents on the freezability of Prochilodus brevis semen

Background: Prochilodus brevis is a rheophilic fish of economic and ecological importance. However, anthropic action has made its population vulnerable. Thus, the development of reproductive biotechnologies, such as seminal conservation, is necessary to subsidize their fish farming. However, seminal collections are often performed in places with few laboratory resources, demanding studies to determine the maximum time for which sperm can be cooled, as well as its process until frozen. Thus, the present study aimed to evaluate the influence of cooling time and the presence of dilution solutions on cryopreservation of P. brevis semen.Material, Methods & Results: After seminal collection, nine pools were formed and analyzed for seminal pH, concentration, membrane integrity, morphology and spermatic kinetics - motility, curvilinear velocity (VCL), average path velocity (VAP) and straight line velocity (VSL). After the analysis of the pools in natura (control 1), they were processed as follows: 1)- immediate freezing (control 2); 2)- cooling: undiluted, diluted in coconut water powder (ACP-104) or diluted in 5% glucose, followed by cooling at different times (6, 12, 24 or 48 h); 3)- Post-refrigeration freezing: the pools were diluted in their respective diluents and 10% dimethyl sulfoxide. After 15 days, the samples were thawed and analyzed for the aforementioned parameters. For the cooled and post-thawed semen, a completely randomized design with 2 (diluent × cooling time) and 3 (storage form × cooling time and storage form × diluent) factors, respectively, was utilized. ANOVA and Dunnett tests were applied to compare the means. In case of seminal cooling, there was no difference (P > 0.05) in sperm motility between control 1 and the undiluted and diluted treatments in ACP-104 for up to 24 h. After 48 h, only the VCL of the sample diluted in ACP-104 was similar (P > 0.05) to that of control 1.[...]

Dose inseminante e resfriamento de embriões de peixes de água doce / Insemination dose and conservation of freshwater fish embryos

A aquicultura tem sido utilizada como importante ferramenta para suprir o constante aumento doconsumo de pescado. Um dos principais aspectos para a intensificação da produção piscícola, acompanhada dasustentabilidade tanto econômica quanto ambiental, é a utilização de técnicas de propagação artificial. Dessaforma, para otimizar a reprodução artificial têm-se investido em estudos afim de definir a proporção ideal deespermatozoides por ovócito e os melhores métodos de conservação para embriões de espécies de peixes de águadoce. Objetivou-se fazer uma breve revisão sobre as doses inseminantes e a biotecnologia de resfriamento deembriões de peixes de água doce que já foram estabelecidas.(AU)

Aquaculture has been used as an important tool to meet the steady increase in fish consumption. Amajor aspect for the intensification of fish production, accompanied by both economic and environmentalsustainability, is the use of techniques of artificial propagation. Thus, to optimize artificial reproduction havebeen invested in research in order to define the optimal ratio the sperm to oocyte and the best conservationmethods for embryos species of freshwater fish. The objective was to make a brief review of the inseminationdoses cooling biotechnology freshwater fish embryos that have already been established.(AU)

Dose inseminante e resfriamento de embriões de peixes de água doce / Insemination dose and conservation of freshwater fish embryos

A aquicultura tem sido utilizada como importante ferramenta para suprir o constante aumento doconsumo de pescado. Um dos principais aspectos para a intensificação da produção piscícola, acompanhada dasustentabilidade tanto econômica quanto ambiental, é a utilização de técnicas de propagação artificial. Dessaforma, para otimizar a reprodução artificial têm-se investido em estudos afim de definir a proporção ideal deespermatozoides por ovócito e os melhores métodos de conservação para embriões de espécies de peixes de águadoce. Objetivou-se fazer uma breve revisão sobre as doses inseminantes e a biotecnologia de resfriamento deembriões de peixes de água doce que já foram estabelecidas.

Aquaculture has been used as an important tool to meet the steady increase in fish consumption. Amajor aspect for the intensification of fish production, accompanied by both economic and environmentalsustainability, is the use of techniques of artificial propagation. Thus, to optimize artificial reproduction havebeen invested in research in order to define the optimal ratio the sperm to oocyte and the best conservationmethods for embryos species of freshwater fish. The objective was to make a brief review of the inseminationdoses cooling biotechnology freshwater fish embryos that have already been established.