For commercial aquaculture, the obtainment of all-female salmonid populations is important in fish farms. After freezing process, variable spermatozoa maturity, higher sperm concentration, low sperm quality, and reduced fertilization success have been observed in sex-reversed female rainbow trout. For these reasons, the objective of this study was to assess effect of dilution rate and supplementation of a N-(2-Mercaptopropionyl)-Glycine (MPG)-based extender on sperm motility and fertilizing capacity of sex-reversed rainbow trout (Oncorhynchus mykiss). The supplementation of MPG [0 (control, 0), 1 mM; 2 mM; 4 mM] to extenders and dilution ratio (1:9, 1:15 and 1:25) were tested in sex-reversed female rainbow trout spermatozoa during cryopreservation. For thawing, the straws (0.5 ml) were placed in a water bath at 37°C for 30 s. Our results showed that the best concentration of MPG was 2 mM for post-thaw motility duration (120.67±9.07%), fertilization (62.67±3.10%) and hatching rate (54.33±3.10%) at 1:15 dilution rate. Overall, MPG provided improvements during cryopreservation process and could be used as protective agent.

Ascorbic acid (Vitamin C) is one of the important antioxidants, which naturally present in seminal plasma of fish. On the other hand, whether its effect may improve sperm quality following cryopreservation process still remains its uncertainty. Thus, the present study aimed to analyse the effect of different extenders supplemented with different ascorbic acid concentrations on post-thaw motility and fertility of frozen-thawed rainbow trout (Oncorhynchus mykiss) sperm. Selected sperm samples were pooled and diluted at 1:3 ratios with two different extenders (E) composing such as (E-1) 300 mM glucose, 10% egg yolk and 10% DMSO and (E-2) 0.6 mM sucrose and 10% DMSO. Each extender was supplemented with vitamin C at 1, 5 and 10 mM concentrations. Following dilution, the sperm was loaded into 0.25 ml straws and frozen in liquid nitrogen vapour. The straws were then plunged into liquid nitrogen for storage. Fertilization was carried out using the dry fertilization technique. Highest post-thaw motility (50±5.77) and fertilization (56±1.00) results were obtained with the extender-1 (E-1) containing 10% DMSO concentration. In conclusion, the present study indicated that addition of ascorbic acid to the extenders improved rainbow trout sperm motility resulting higher fertilization of the eggs.

The present study aimed to evaluate the activation characteristics of the leaping mullet spermatozoa and diluted with four different media (D1, D2, D3, D4) for 250 h at 4±2°C. The semen was collected from nine wild fish in Homa Lagoon, İzmir, Turkey in July, during reproductive season. In each trial (n = 9), semen samples were collected and mixed to reduce sperm quality variation to obtain the required gametes for the experiment. The semen was activated with natural seawater (salinity of 34, pH 7.9 and 4±2°C) to determine: motility time, motility rate and viability of sperm. Dilution with inactivation media 1:3 increased motility time of diluted semen than control group. At the end of the experiment, no significant difference was found for the duration of survival in the D2 and D4 groups. The highest survival rate was found in D2 group.

The present study aimed to evaluate the activation characteristics of the leaping mullet spermatozoa and diluted with four different media (D1, D2, D3, D4) for 250 h at 4±2°C. The semen was collected from nine wild fish in Homa Lagoon, İzmir, Turkey in July, during reproductive season. In each trial (n = 9), semen samples were collected and mixed to reduce sperm quality variation to obtain the required gametes for the experiment. The semen was activated with natural seawater (salinity of 34, pH 7.9 and 4±2°C) to determine: motility time, motility rate and viability of sperm. Dilution with inactivation media 1:3 increased motility time of diluted semen than control group. At the end of the experiment, no significant difference was found for the duration of survival in the D2 and D4 groups. The highest survival rate was found in D2 group.

Araştırmada İzmir ili Balıklıova beldesinde bulunan bir üretim çiftliğinden temin edilen çipuralardan alınan sperm örnekleri 0°C’de buz içinde muhafaza edildikten sonra her altı saatte bir faz kontrast tip mikroskopta incelenmiştir. Çalışmada sperm muhafaza süreleri, hız, konsantrasyon, meristik karakterler ve sperm hacmi ile ilgili datalar elde edilmiş ve bu sonuçlar ebeveyn ile ilişkilendirilmiştir. Denemelerde kullanılan balıkların ağırlıkları 405-625 g, boyları ise 25-37 cm sperm hacmi 3,1-8,3 ml.kg-1 olarak tespit edilmiştir. En yoğun konsantrasyon 5,35x109 spz.ml-1 ile 2 numaralı denekte, en düşük sperm konsantrasyonu 0,16×109 spz.ml-1 ile 24 numaralı denekte saptanmıştır. Çalışma süresince tüm denek ve zamanlarda baş boyuna endeksli en yüksek hız 35.5 baş boy.sn-1 (210,16 µm.sn-1), en düşük hız 2,6 baş boy.sn-1 (15,39 µm.sn-1) olarak belirlenmiştir. Çalışma toplam 126 saat sürmüştür. En kısa muhafaza süresi 26-50 saat, en uzun muhafaza süresi 126-150 saat olarak tespit edilmiştir.

This study is performed to determine some of sperm quality after applying freezing / thawing process. Thus, the aim of this study is to examine different cryprotective agents with additives in terms of their effects at different pH on the cryopreservation process of longspine scraper (Capoeta trutta). The present study, twelve media were prepared by mixing three different cryoprotectants (dimethyl sulfoxide (DMSO, (CH3)2SO); methanol (CH3OH); methyl glycol (MG, CH3O (CH2)2OH)) with an extenders (glucose) at four different pH (7.2, 7.6, 8.0 and 8.4) for longspine scraper semen. Considering the findings from the examination (The motility rate after thawing process and duration of motility obtained in DMSO as 81% and 20 min, in methanol as 73% and 12 min, in methyl glycol as 60% and 15 min.), we can conclude that the DMSO is the best freezing media in order to create new essays in cryopreservation for sperm of Capoeta trutta in the future.

This study is performed to determine some of sperm quality after applying freezing / thawing process. Thus, the aim of this study is to examine different cryprotective agents with additives in terms of their effects at different pH on the cryopreservation process of longspine scraper (Capoeta trutta). The present study, twelve media were prepared by mixing three different cryoprotectants (dimethyl sulfoxide (DMSO, (CH3)2SO); methanol (CH3OH); methyl glycol (MG, CH3O (CH2)2OH)) with an extenders (glucose) at four different pH (7.2, 7.6, 8.0 and 8.4) for longspine scraper semen. Considering the findings from the examination (The motility rate after thawing process and duration of motility obtained in DMSO as 81% and 20 min, in methanol as 73% and 12 min, in methyl glycol as 60% and 15 min.), we can conclude that the DMSO is the best freezing media in order to create new essays in cryopreservation for sperm of Capoeta trutta in the future.

Ascorbic acid (Vitamin C) is one of the important antioxidants, which naturally present in seminal plasma of fish. On the other hand, whether its effect may improve sperm quality following cryopreservation process still remains its uncertainty. Thus, the present study aimed to analyse the effect of different extenders supplemented with different ascorbic acid concentrations on post-thaw motility and fertility of frozen-thawed rainbow trout (Oncorhynchus mykiss) sperm. Selected sperm samples were pooled and diluted at 1:3 ratios with two different extenders (E) composing such as (E-1) 300 mM glucose, 10% egg yolk and 10% DMSO and (E-2) 0.6 mM sucrose and 10% DMSO. Each extender was supplemented with vitamin C at 1, 5 and 10 mM concentrations. Following dilution, the sperm was loaded into 0.25 ml straws and frozen in liquid nitrogen vapour. The straws were then plunged into liquid nitrogen for storage. Fertilization was carried out using the dry fertilization technique. Highest post-thaw motility (50±5.77) and fertilization (56±1.00) results were obtained with the extender-1 (E-1) containing 10% DMSO concentration. In conclusion, the present study indicated that addition of ascorbic acid to the extenders improved rainbow trout sperm motility resulting higher fertilization of the eggs.

For commercial aquaculture, the obtainment of all-female salmonid populations is important in fish farms. After freezing process, variable spermatozoa maturity, higher sperm concentration, low sperm quality, and reduced fertilization success have been observed in sex-reversed female rainbow trout. For these reasons, the objective of this study was to assess effect of dilution rate and supplementation of a N-(2-Mercaptopropionyl)-Glycine (MPG)-based extender on sperm motility and fertilizing capacity of sex-reversed rainbow trout (Oncorhynchus mykiss). The supplementation of MPG [0 (control, 0), 1 mM; 2 mM; 4 mM] to extenders and dilution ratio (1:9, 1:15 and 1:25) were tested in sex-reversed female rainbow trout spermatozoa during cryopreservation. For thawing, the straws (0.5 ml) were placed in a water bath at 37°C for 30 s. Our results showed that the best concentration of MPG was 2 mM for post-thaw motility duration (120.67±9.07%), fertilization (62.67±3.10%) and hatching rate (54.33±3.10%) at 1:15 dilution rate. Overall, MPG provided improvements during cryopreservation process and could be used as protective agent.