Gajenje karaša (Carassius carassius) u ribnjacima

Uzgoj juvenilnih jedinki karaša (C. carassius) analiziran je u pet ribnjačkih objekata veličine 100 m2. Karaš je gajen u monokulturi u dva, dok je sa linjakom gajen u bikulturi u tri ribnjačka jezera. Stopa preživljavanja karaša u monokulturi iznosila je 21.15±6.86 %, a u bikulturi 47.07±16.86%. Kod linjaka je zabeležena veca stopa preživljavanja (69.33±16.76) i brži rast u odnosu na karaša. Iako je prema dobijenim rezultatima teško proceniti razlike između uzgoja u monokulturi i bikulturi, može se zaključiti da linjak nije značajan kompetitor karašu

Testing cryopreserved European eel sperm for hybridization (A. japonica × A. anguilla)

[EN] The objective of this study was to assess impact of cryopreserved European eel sperm and Japanese eel native sperm on early fertilization, hatch, survival, and malformation rates of larvae, as well as develop molecular techniques to distinguish different eel species. Eggs from Japanese eel females (Anguilla japonica) were artificially fertilized with sperm of Japanese eel males and cryopreserved sperm from European eel (A. anguilla, extender was modified Tanaka solution and methanol as cryoprotectant). There were no statistical differences (p¿>¿0.05) among the measured parameters such as fertilization, hatch and survival after 10 days post-hatch rates due to large individual differences. The malformation rate of larvae compared to the hatching rate was higher in cryopreserved groups than in the control indicating that the methodology needs further refinement. Genetic analyses (PCR-RFLP, PCR-HRM) proved a clear result in the detection of paternal contribution in hybridization between the Japanese and the European eel and applied PCR-HRM method is a quick and cost effective tool to identify illegally imported A. anguilla at the glass eel stage, which can be transported from Europe to Asia.The research was supported by The Ministry of Education, Culture, Sports, Science and Technology (MEXT)/Japan Society for the Promotion of Science (JSPS) Kakenhi Grant No.15K07562 and Tokyo University of Agriculture Strategic Research Program (TUA-SRP), Mohamed bin Zayed Species Conservation Fund (grant number 12252178), GINOP-2.3.2-15-2016-00054 project of the National Research, Development and Innovation Office of Hungary and EFOP-3.6.3-VEKOP-16-2017-00008 project. The project is co-financed by the European Union, the European Social Fund and KMR_12-1-2012-0435.Müller, T.; Matsubara, H.; Kubara, Y.; Horváth, Á.; Kolics, B.; Taller, J.; Stéger, V.... (2018). Testing cryopreserved European eel sperm for hybridization (A. japonica × A. anguilla). Theriogenology. 113:153-158. https://doi.org/10.1016/j.theriogenology.2018.02.021S15315811