Identification of environmental hotspots in fishmeal and fish oil production towards the optimization of energy-related processes

Funding Information: This work was supported by the AVS (The Added Value of Seafood) fund of the Ministry of Fisheries and Agriculture in Iceland (Redesign of fishmeal and fish oil factories, grant number: R18 031-18 ), the Rannís Icelandic Technology Development Fund (Product development from flexible fish processing no. 198883-0611 and BIOZOOSTAIN no. 2021267-0611 ), ERA-NET BlueBioCofund Call (BIOZOOSTAIN) and the University of Iceland research fund . The work was carried out at the University of Iceland and Matís ohf. The authors thank Síldarvinnslan hf. for access to their facilities, assistance, and raw materials. Funding Information: This work was supported by the AVS (The Added Value of Seafood) fund of the Ministry of Fisheries and Agriculture in Iceland (Redesign of fishmeal and fish oil factories, grant number: R18 031-18), the Rann?s Icelandic Technology Development Fund (Product development from flexible fish processing no. 198883-0611 and BIOZOOSTAIN no. 2021267-0611), ERA-NET BlueBioCofund Call (BIOZOOSTAIN) and the University of Iceland research fund. The work was carried out at the University of Iceland and Mat?s ohf. The authors thank S?ldarvinnslan hf. for access to their facilities, assistance, and raw materials. Publisher Copyright: © 2022This study assessed the environmental impacts of a pelagic fishmeal and fish oil production plant in Iceland with the life cycle assessment methodology. The study focused on assessing the effects of different energy sources for utility production due to the high energy intensity of fishmeal and fish oil production, as quality improved with lower cooking temperature. The environmental hotspots of three different processing scenarios were assessed, where the factory was run on hydropower (Scenario 0), heavy fuel (Scenario 1) and a composition of both (Scenario 2), from cradle-to-factory gate. Midpoint results showed that the raw material acquisition contributed the most to the environmental impact when the fishmeal factory was operating on hydropower. However, drying had the highest impact when heavy fuel oil was used for utility production. This study also demonstrated that lowering the cooking temperature from 90 to 85 °C, led to improved quality and simultaneously reduced environmental impacts during processing. This indicated that a small energy adjustment in the production can have an environmental gain, demonstrating the necessity to optimize each processing step in the fishmeal and fish oil production process both for increased product quality and minimizing environmental impacts.Peer reviewe

Dietary amino acids impact sperm performance traits for a catadromous fish, Anguilla anguilla reared in captivity

Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.[EN] Little is known about the role of dietary amino acids on male reproductive performance and gamete quality in fishes. Thus, the objective of this study was to investigate how "enhanced" feeds (EH-4, EH-5, EH-6), with modified amino acid composition, and the standard on-growing diet (DAN-EX) impact body composition, milt biochemistry, and sperm performance in male European eel, Anguilla anguilla. The fatty acid composition of EH4, EH-5, and EH-6 was similar but differed to that in DAN-EX, while amino acid composition varied between all four diets. Diet did not influence organ-somatic indices (e.g. HSI, GSI), while males fed EH-4 were heavier than other groups. Arginine, alanine, and lysine were the most abundant amino acids in milt (>11%), followed by glycine, aspartic acid, valine, glutamic acid, and leucine ( >5.66%). Diet impacted milt arginine, serine, proline, methionine, and histidine levels. Specifically, males fed DAN-EX, EH-4, and EH-5 had the highest percentages of arginine, while males fed EH-4 to EH-6 had higher percentages of serine. Proline was most abundant in males fed DAN-EX, EH-5, and EH-6. Both methionine and histidine were detected at low percentages ( 0.5 mL) for fertilization procedures. Spermatocrit (43.1 +/- 1.80%) did not differ between the diets (ranged from 37.57 to 47.21%). Dietary regime had an impact on sperm motility, such that eels fed EH-5 and EH-6 had the greatest percentage of motile cells. In addition, fish fed EH-5 and EH-6 (or DAN-EX) had the fastest swimming sperm. Spermatogenic maturity index of hormonally treated eels varied within groups but did not differ between dietary treatment groups after 9 weeks of injections (ranged from 0.54 to 0.80). The most interesting amino acids to scrutinize from PCA plots were proline, histidine, and valine as well as lysine and arginine. Here, eels with highly motile sperm had milt with high relative proportions of proline, histidine, and valine, but were particularly low in lysine and arginine. Together, our findings add evidence that certain amino acids regulate milt biochemistry, and that male ejaculate traits may be promoted by amino acid intake. Further studies to evaluate effects of supplemented amino acid diets on fertilization ability and inter-linked early developmental stages are required.This study was funded by the Innovation Fund Denmark under grant agreements no. 5184-00093B (EEL-HATCH) and 7076-00125B (ITSEEL). Butts IAE, was also supported by the USDA National Institute of Food and Agriculture, Hatch project 1013854. Gallego V has a post-doc grant from the MICIU (Juan de la Cierva-Incorporacion; IJCI-201734200).Butts, IAE.; Hilmarsdóttir, GS.; Zadmajid, V.; Gallego Albiach, V.; Stottrup, JG.; Jacobsen, C.; Krüger-Johnsen, M.... (2020). Dietary amino acids impact sperm performance traits for a catadromous fish, Anguilla anguilla reared in captivity. Aquaculture. 518:1-12. https://doi.org/10.1016/j.aquaculture.2019.734602112518Abd-Elrazek, A. M., & Ahmed-Farid, O. A. H. (2017). Protective effect of L-carnitine and L-arginine against busulfan-induced oligospermia in adult rat. Andrologia, 50(1), e12806. doi:10.1111/and.12806Akiyama, T., Shiraishi, M., Yamamoto, T., & Unuma, T. (1996). Effect of Dietary Tryptophan on Maturation of Ayu Plecoglossus altivelis. Fisheries science, 62(5), 776-782. doi:10.2331/fishsci.62.776Alavi, S. M. H., Pšenička, M., Policar, T., Rodina, M., Hamáčková, J., Kozák, P., & Linhart, O. (2009). Sperm quality in male Barbus barbus L. fed different diets during the spawning season. Fish Physiology and Biochemistry, 35(4), 683-693. doi:10.1007/s10695-009-9325-7Asturiano, J. F., Sorbera, L. A., Carrillo, M., Zanuy, S., Ramos, J., Navarro, J. C., & Bromage, N. (2001). Reproductive performance in male European sea bass (Dicentrarchus labrax, L.) fed two PUFA-enriched experimental diets: a comparison with males fed a wet diet. Aquaculture, 194(1-2), 173-190. doi:10.1016/s0044-8486(00)00515-9Asturiano, J. F., Perez, L., Garzon, D. L., Penaranda, D. S., Marco-Jimenez, F., Martinez-Llorens, S., … Jover, M. (2005). Effect of different methods for the induction of spermiation on semen quality in European eel. Aquaculture Research, 36(15), 1480-1487. doi:10.1111/j.1365-2109.2005.01366.xBaeza, R., Mazzeo, I., Vílchez, M. C., Gallego, V., Peñaranda, D. S., Pérez, L., & Asturiano, J. F. (2014). Effect of thermal regime on fatty acid dynamics in male European eels (Anguilla anguilla) during hormonally-induced spermatogenesis. Aquaculture, 430, 86-97. doi:10.1016/j.aquaculture.2014.03.045Baeza, R., Mazzeo, I., Vílchez, M. C., Gallego, V., Peñaranda, D. S., Pérez, L., & Asturiano, J. F. (2015). Relationship between sperm quality parameters and the fatty acid composition of the muscle, liver and testis of European eel. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 181, 79-86. doi:10.1016/j.cbpa.2014.11.022Baeza, R., Peñaranda, D. S., Vílchez, M. C., Tveiten, H., Pérez, L., & Asturiano, J. F. (2015). Exploring correlations between sex steroids and fatty acids and their potential roles in the induced maturation of the male European eel. Aquaculture, 435, 328-335. doi:10.1016/j.aquaculture.2014.10.016Bahadorani, M., Tavalaee, M., Abedpoor, N., Ghaedi, K., Nazem, M. N., & Nasr-Esfahani, M. H. (2018). Effects of branched-chain amino acid supplementation and/or aerobic exercise on mouse sperm quality and testosterone production. Andrologia, 51(2), e13183. doi:10.1111/and.13183Beirão, J., Soares, F., Pousão-Ferreira, P., Diogo, P., Dias, J., Dinis, M. T., … Cabrita, E. (2015). The effect of enriched diets on Solea senegalensis sperm quality. Aquaculture, 435, 187-194. doi:10.1016/j.aquaculture.2014.09.025Benini, E., Politis, S. N., Kottmann, J. S., Butts, I. A. E., Sørensen, S. R., & Tomkiewicz, J. (2018). Effect of parental origin on early life history traits of European eel. Reproduction in Domestic Animals, 53(5), 1149-1158. doi:10.1111/rda.13219Barman, A. S., Kumar, P., Mariahabib, Lal, K. K., & Lal, B. (2013). Role of nitric oxide in motility and fertilizing ability of sperm of Heteropneustes fossilis (Bloch.). Animal Reproduction Science, 137(1-2), 119-127. doi:10.1016/j.anireprosci.2012.12.001Bromage, N., Jones, J., Randall, C., Thrush, M., Davies, B., Springate, J., … Barker, G. (1992). Broodstock management, fecundity, egg quality and the timing of egg production in the rainbow trout (Oncorhynchus mykiss). Aquaculture, 100(1-3), 141-166. doi:10.1016/0044-8486(92)90355-oBuentello, J. A., & Gatlin, D. M. (2001). Effects of Elevated Dietary Arginine on Resistance of Channel Catfish to Exposure toEdwardsiella ictaluri. Journal of Aquatic Animal Health, 13(3), 194-201. doi:10.1577/1548-8667(2001)0132.0.co;2Butts, I. A. E., Baeza, R., Støttrup, J. G., Krüger-Johnsen, M., Jacobsen, C., Pérez, L., … Tomkiewicz, J. (2015). Impact of dietary fatty acids on muscle composition, liver lipids, milt composition and sperm performance in European eel. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 183, 87-96. doi:10.1016/j.cbpa.2015.01.015Cabrita, E., Ma, S., Diogo, P., Martínez-Páramo, S., Sarasquete, C., & Dinis, M. T. (2011). The influence of certain aminoacids and vitamins on post-thaw fish sperm motility, viability and DNA fragmentation. Animal Reproduction Science, 125(1-4), 189-195. doi:10.1016/j.anireprosci.2011.03.003Cabrita, E., Martínez-Páramo, S., Gavaia, P. J., Riesco, M. F., Valcarce, D. G., Sarasquete, C., … Robles, V. (2014). Factors enhancing fish sperm quality and emerging tools for sperm analysis. Aquaculture, 432, 389-401. doi:10.1016/j.aquaculture.2014.04.034Ciereszko, A., Piros, B., Dabrowski, K., Kucharczyk, D., Luczynski, M. J., Dobosz, S., & Glogowski, J. (1998). Serine proteinase inhibitors of seminal plasma of teleost fish: distribution of activity, electrophoretic profiles and relation to proteinase inhibitors of blood. Journal of Fish Biology, 53(6), 1292-1305. doi:10.1111/j.1095-8649.1998.tb00249.xDabrowski, K., Luczynski, M., & Rusiecki, M. (1985). Free amino acids in the late embryogenesis and pre-hatching stage of two coregonid fishes. Biochemical Systematics and Ecology, 13(3), 349-356. doi:10.1016/0305-1978(85)90048-1Da Silva, F. F. G., Støttrup, J. G., Kjørsvik, E., Tveiten, H., & Tomkiewicz, J. (2016). Interactive effects of dietary composition and hormonal treatment on reproductive development of cultured female European eel, Anguilla anguilla. Animal Reproduction Science, 171, 17-26. doi:10.1016/j.anireprosci.2016.05.007F.G. da Silva, F., Jacobsen, C., Kjørsvik, E., G. Støttrup, J., & Tomkiewicz, J. (2018). Oocyte and egg quality indicators in European eel: Lipid droplet coalescence and fatty acid composition. Aquaculture, 496, 30-38. doi:10.1016/j.aquaculture.2018.07.008Diemer, O., Bittencourt, F., Barcellos, L. G., Boscolo, W. R., Feiden, A., & Romagosa, E. (2014). Lysine in the diet of Rhamdia voulezi male broodstocks confined in net cages. Aquaculture, 434, 93-99. doi:10.1016/j.aquaculture.2014.07.029Dong, H.-J., Wu, D., Xu, S.-Y., Li, Q., Fang, Z.-F., Che, L.-Q., … Lin, Y. (2016). Effect of dietary supplementation with amino acids on boar sperm quality and fertility. Animal Reproduction Science, 172, 182-189. doi:10.1016/j.anireprosci.2016.08.003Dzyuba, V., & Cosson, J. (2014). Motility of fish spermatozoa: from external signaling to flagella response. Reproductive Biology, 14(3), 165-175. doi:10.1016/j.repbio.2013.12.005Finn, R. N., & Fyhn, H. J. (2010). Requirement for amino acids in ontogeny of fish. Aquaculture Research, 41(5), 684-716. doi:10.1111/j.1365-2109.2009.02220.xForster, I., & Ogata, H. Y. (1998). Lysine requirement of juvenile Japanese flounder Paralichthys olivaceus and juvenile red sea bream Pagrus major. Aquaculture, 161(1-4), 131-142. doi:10.1016/s0044-8486(97)00263-9Gallego, V., Mazzeo, I., Vílchez, M. C., Peñaranda, D. S., Carneiro, P. C. F., Pérez, L., & Asturiano, J. F. (2012). Study of the effects of thermal regime and alternative hormonal treatments on the reproductive performance of European eel males (Anguilla anguilla) during induced sexual maturation. Aquaculture, 354-355, 7-16. doi:10.1016/j.aquaculture.2012.04.041Gallego, V., & Asturiano, J. F. (2018). Sperm motility in fish: technical applications and perspectives through CASA-Mot systems. Reproduction, Fertility and Development, 30(6), 820. doi:10.1071/rd17460Gallego, V., & Asturiano, J. F. (2018). Fish sperm motility assessment as a tool for aquaculture research: a historical approach. Reviews in Aquaculture, 11(3), 697-724. doi:10.1111/raq.12253He, S., & Woods III, L. . (2003). Effects of glycine and alanine on short-term storage and cryopreservation of striped bass (Morone saxatilis) spermatozoa. Cryobiology, 46(1), 17-25. doi:10.1016/s0011-2240(02)00159-1Heinsbroek, L. T. N., Støttrup, J. G., Jacobsen, C., Corraze, G., Kraiem, M. M., Holst, L. K., … Kaushik, S. J. (2013). A review on broodstock nutrition of marine pelagic spawners: the curious case of the freshwater eels (Anguillaspp.). Aquaculture Nutrition, 19, 1-24. doi:10.1111/anu.12091Higuchi, M., Celino, F. T., Tamai, A., Miura, C., & Miura, T. (2011). The synthesis and role of taurine in the Japanese eel testis. Amino Acids, 43(2), 773-781. doi:10.1007/s00726-011-1128-3Izquierdo, M. ., Fernández-Palacios, H., & Tacon, A. G. . (2001). Effect of broodstock nutrition on reproductive performance of fish. Aquaculture, 197(1-4), 25-42. doi:10.1016/s0044-8486(01)00581-6Jobgen, W. S., Fried, S. K., Fu, W. J., Meininger, C. J., & Wu, G. (2006). Regulatory role for the arginine–nitric oxide pathway in metabolism of energy substrates. The Journal of Nutritional Biochemistry, 17(9), 571-588. doi:10.1016/j.jnutbio.2005.12.001Kaushik, S. J., Fauconneau, B., Terrier, L., & Gras, J. (1988). Arginine requirement and status assessed by different biochemical indices in rainbow trout (Salmo gairdneri R.). Aquaculture, 70(1-2), 75-95. doi:10.1016/0044-8486(88)90008-7Kawabata, K., Tsubaki, K., Tazaki, T., & Ikeda, S. (1992). Sexual Behavior Induced by Amino Acids in the Rose Bitterling Rhodeus ocellatus ocellatus. NIPPON SUISAN GAKKAISHI, 58(5), 839-844. doi:10.2331/suisan.58.839Keller, D. W., & Polakoski, K. L. (1975). L-Arginine Stimulation of Human Sperm Motility in vitro. Biology of Reproduction, 13(2), 154-157. doi:10.1095/biolreprod13.2.154Kjørsvik, E., Hoehne-Reitan, K., & Reitan, K. I. (2003). Egg and larval quality criteria as predictive measures for juvenile production in turbot (Scophthalmus maximus L.). Aquaculture, 227(1-4), 9-20. doi:10.1016/s0044-8486(03)00492-7Kwasek, K., Dabrowski, K., Nynca, J., Takata, R., Wojno, M., & Wick, M. (2014). The Influence of Dietary Lysine on Yellow Perch Female Reproductive Performance and the Quality of Eggs. North American Journal of Aquaculture, 76(4), 351-358. doi:10.1080/15222055.2014.911223Kwasek, K., Dabrowski, K., Nynca, J., Wojno, M., & Wick, M. (2014). The Influence of Dietary Lysine on Yellow Perch Maturation and the Quality of Sperm. North American Journal of Aquaculture, 76(2), 119-126. doi:10.1080/15222055.2013.856826Labbe, C., Maisse, G., Müller, K., Zachowski, A., Kaushik, S., & Loir, M. (1995). Thermal acclimation and dietary lipids alter the composition, but not fluidity, of trout sperm plasma membrane. Lipids, 30(1), 23-33. doi:10.1007/bf02537038Lahnsteiner, F., Patzner, R. A., & Welsmann, T. (1993). The spermatic ducts of salmonid fishes (Salmonidae, Teleostei). Morphology, histochemistry and composition of the secretion. Journal of Fish Biology, 42(1), 79-93. doi:10.1111/j.1095-8649.1993.tb00307.xLahnsteiner, F. (2009). The role of free amino acids in semen of rainbow troutOncorhynchus mykissand carpCyprinus carpio. Journal of Fish Biology, 75(4), 816-833. doi:10.1111/j.1095-8649.2009.02317.xLahnsteiner, F., Mansour, N., McNiven, M. A., & Richardson, G. F. (2009). Fatty acids of rainbow trout (Oncorhynchus mykiss) semen: Composition and effects on sperm functionality. Aquaculture, 298(1-2), 118-124. doi:10.1016/j.aquaculture.2009.08.034Lahnsteiner, F. (2010). A comparative study on the composition and importance of free amino acids in semen of gilthead sea bream, Sparus aurata, and perch, Perca fluviatilis. Fish Physiology and Biochemistry, 36(4), 1297-1305. doi:10.1007/s10695-010-9442-3Li, P., Mai, K., Trushenski, J., & Wu, G. (2008). New developments in fish amino acid nutrition: towards functional and environmentally oriented aquafeeds. Amino Acids, 37(1), 43-53. doi:10.1007/s00726-008-0171-1Mai, K., Lu Zhang, Ai, Q., Duan, Q., Zhang, C., Li, H., … Liufu, Z. (2006). Dietary lysine requirement of juvenile Japanese seabass, Lateolabrax japonicus. Aquaculture, 258(1-4), 535-542. doi:10.1016/j.aquaculture.2006.04.043Mansour, N., McNiven, M. A., & Richardson, G. F. (2006). The effect of dietary supplementation with blueberry, α-tocopherol or astaxanthin on oxidative stability of Arctic char (Salvelinus alpinus) semen. Theriogenology, 66(2), 373-382. doi:10.1016/j.theriogenology.2005.12.002Martinage, A., Gusse, M., Bélaïche, D., Sautière, P., & Chevaillier, P. (1985). Amino acid sequence of a cysteine-rich, arginine-rich sperm protamine of the dog-fish Scylliorhinus caniculus. Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 831(2), 172-178. doi:10.1016/0167-4838(85)90032-9MATSUNARI, H., HAMADA, K., MUSHIAKE, K., & TAKEUCHI, T. (2006). Effects of taurine levels in broodstock diet on reproductive performance of yellowtail Seriola quinqueradiata. Fisheries Science, 72(5), 955-960. doi:10.1111/j.1444-2906.2006.01243.xMozanzadeh, M. T., Yaghoubi, M., Marammazi, J. G., Safari, O., & Gisbert, E. (2018). Effects of dietary protein and essential amino acid deficiencies on growth, body composition, and digestive enzyme activities of silvery-black porgy (Sparidentex hasta). International Aquatic Research, 10(1), 45-55. doi:10.1007/s40071-017-0187-9Mylonas, C. C., Duncan, N. J., & Asturiano, J. F. (2017). Hormonal manipulations for the enhancement of sperm production in cultured fish and evaluation of sperm quality. Aquaculture, 472, 21-44. doi:10.1016/j.aquaculture.2016.04.021Nandi, S., Routray, P., Gupta, S. D., Rath, S. C., Dasgupta, S., Meher, P. K., & Mukhopadhyay, P. K. (2007). Reproductive performance of carp, Catla catla (Ham.), reared on a formulated diet with PUFA supplementation. Journal of Applied Ichthyology, 23(6), 684-691. doi:10.1111/j.1439-0426.2007.00874.xPatel, A. B., Srivastava, S., Phadke, R. S., & Govil, G. (1998). Arginine Activates Glycolysis of Goat Epididymal Spermatozoa: An NMR Study. Biophysical Journal, 75(3), 1522-1528. doi:10.1016/s0006-3495(98)74071-8Peñaranda, D. S., Pérez, L., Gallego, V., Jover, M., Tveiten, H., Baloche, S., … Asturiano, J. F. (2010). Molecular and physiological study of the artificial maturation process in European eel males: From brain to testis. General and Comparative Endocrinology, 166(1), 160-171. doi:10.1016/j.ygcen.2009.08.006Poupard, G. P., Paxion, C., Cosson, J., Jeulin, C., Fierville, F., & Billard, R. (1998). Initiation of carp spermatozoa motility and early ATP reduction after milt contamination by urine. Aquaculture, 160(3-4), 317-328. doi:10.1016/s0044-8486(97)00301-3Perez, L., Aturiano, J. F., Tomas, A., Zegrari, S., Barrera, R., Espinos, F. J., … Jover, M. (2000). Induction of maturation and spermiation in the male European eel: assessment of sperm quality throughout treatment. Journal of Fish Biology, 57(6), 1488-1504. doi:10.1111/j.1095-8649.2000.tb02227.xPolitis, S. N., Mazurais, D., Servili, A., Zambonino-Infante, J.-L., Miest, J. J., Sørensen, S. R., … Butts, I. A. E. (2017). Temperature effects on gene expression and morphological development of European eel, Anguilla anguilla larvae. PLOS ONE, 12(8), e0182726. doi:10.1371/journal.pone.0182726Politis, S. N., Mazurais, D., Servili, A., Zambonino-Infante, J.-L., Miest, J. J., Tomkiewicz, J., & Butts, I. A. E. (2018). Salinity reduction benefits European eel larvae: Insights at the morphological and molecular level. PLOS ONE, 13(6), e0198294. doi:10.1371/journal.pone.0198294Politis, S. N., Servili, A., Mazurais, D., Zambonino-Infante, J.-L., Miest, J. J., Tomkiewicz, J., & Butts, I. A. E. (2018). Temperature induced variation in gene expression of thyroid hormone receptors and deiodinases of European eel (Anguilla anguilla) larvae. General and Comparative Endocrinology, 259, 54-65. doi:10.1016/j.ygcen.2017.11.003Politis, S. N., Sørensen, S. R., Mazurais, D., Servili, A., Zambonino-Infante, J.-L., Miest, J. J., … Butts, I. A. E. (2018). Molecular Ontogeny of First-Feeding European Eel Larvae. Frontiers in Physiology, 9. doi:10.3389/fphys.2018.01477Pourkhazaei, F., Ebrahimi, E., & Ghaedi, A. (2016). Arginine effects on biochemical composition of sperm in rainbow trout, Oncorhynchus mykiss. Aquaculture Research, 48(7), 3464-3471. doi:10.1111/are.13172R�nnestad, I., Fyhn, H. J., & Gravningen, K. (1992). The importance of free amino acids to the energy metabolism of eggs and larvae of turbot (Scophthalmus maximus). Marine Biology, 114(4), 517-525. doi:10.1007/bf00357249Ruchimat, T., Masumoto, T., Hosokawa, H., Itoh, Y., & Shimeno, S. (1997). Quantitative lysine requirement of yellowtail (Seriola quinqueradiata). Aquaculture, 158(3-4), 331-339. doi:10.1016/s0044-8486(97)00215-9Rurangwa, E., Kime, D. ., Ollevier, F., & Nash, J. . (2004). The measurement of sperm motility and factors affecting sperm quality in cultured fish. Aquaculture, 234(1-4), 1-28. doi:10.1016/j.aquaculture.2003.12.006Safafar, H., Hass, M., Møller, P., Holdt, S., & Jacobsen, C. (2016). High-EPA Biomass from Nannochloropsis salina Cultivated in a Flat-Panel Photo-Bioreactor on a Process Water-Enriched Growth Medium. Marine Drugs, 14(8), 144. doi:10.3390/md14080144Sangeeta, S., Arangasamy, A., Kulkarni, S., & Selvaraju, S. (2015). Role of amino acids as additives on sperm motility, plasma membrane integrity and lipid peroxidation levels at pre-freeze and post-thawed ram semen. Animal Reproduction Science, 161, 82-88. doi:10.1016/j.anireprosci.2015.08.008Silva, J. V., Freitas, M. J., Correia, B. R., Korrodi-Gregório, L., Patrício, A., Pelech, S., & Fardilha, M. (2015). Profiling signaling proteins in human spermatozoa: biomarker identification for sperm quality evaluation. Fertility and Sterility, 104(4), 845-856.e8. doi:10.1016/j.fertnstert.2015.06.039Sørensen, S., Gallego, V., Pérez, L., Butts, I., Tomkiewicz, J., & Asturiano, J. (2013). Evaluation of Methods to Determine Sperm Density for the European eel,Anguilla anguilla. Reproduction in Domestic Animals, 48(6), 936-944. doi:10.1111/rda.12189Støttrup, J. G., Jacobsen, C., Tomkiewicz, J., & Jarlbaek, H. (2012). Modification of essential fatty acid composition in broodstock of cultured European eelAnguilla anguillaL. Aquaculture Nutrition, 19(2), 172-185. doi:10.1111/j.1365-2095.2012.00967.xStøttrup, J. G., Tomkiewicz, J., Jacobsen, C., Butts, I. A. E., Holst, L. K., Krüger-Johnsen, M., … Kaushik, S. (2015). Development of a broodstock diet to improve developmental competence of embryos in European eel,Anguilla anguilla. Aquaculture Nutrition, 22(4), 725-737. doi:10.1111/anu.12299Dayal, J. S., Ahamad Ali, S., Thirunavukkarasu, A. R., Kailasam, M., & Subburaj, R. (2003). Nutrient an