TY - JOUR T1 - Effects of salinity on growth performance and survival of second-stage juvenile Pontastacus leptodactylus (Eschscholtz, 1823) TT - İkinci evre Pontastacus leptodactylus (Eschscholtz, 1823) jüvenillerinin büyüme performansı ve yaşama oranı üzerine tuzluluğun etkileri AU - Özdoğan, Hasan Batuhan Emre PY - 2026 DA - July Y2 - 2026 DO - 10.12714/egejfas.43.3.15 JF - Ege Journal of Fisheries and Aquatic Sciences JO - EgeJFAS PB - Ege University WT - DergiPark SN - 2148-3140 SP - 307 EP - 312 VL - 43 IS - 3 LA - en AB - The narrow-clawed crayfish, Pontastacus leptodactylus, is an economically significant species recognized for its high ecological resilience, particularly its ability to thrive in brackish environments. This research investigated the impact of various salinity levels (0, 2.5, 5, and 10 ppt) on the survival and growth metrics of second-stage juveniles during a 25-day experimental trial. A total of 160 individuals (initial mean weight: 0.033±0.001 g) were allocated into four treatment groups, with each group conducted in quadruplicate. The data indicated that growth performance parameters, such as total length, final weight, and specific growth rate (SGR), were not significantly altered by the salinity treatments (p > 0.05), demonstrating that somatic growth was sustained across the tested salinity gradient. In contrast, survival was significantly affected by environmental salinity (p<0.05). The maximum survival rate was recorded at 5 ppt (52.5±2.50%), followed by the 10 ppt (45.0±6.45%) and 2.5 ppt (30.0±4.08%) groups, whereas the freshwater control group had the lowest survival (12.5±9.46%). These results indicate that moderate salinity (5 ppt) can optimize survival in juvenile crayfish without impairing growth performance. Implementing low-salinity rearing strategies could effectively address the high mortality rates often observed during the sensitive nursery phase of P. leptodactylus. KW - Pontastacus leptodactylus KW - salinity KW - growth performance KW - survival rate KW - aquaculture N2 - Ekonomik açıdan önemli bir tür olan dar kıskaçlı kerevit, Pontastacus leptodactylus, özellikle acı su ortamlarında gelişme yeteneği başta olmak üzere yüksek ekolojik dayanıklılığı ile tanınmaktadır. Bu araştırma, 25 günlük bir deneme süresince farklı tuzluluk seviyelerinin (0, 2,5, 5 ve 10 ppt) ikinci evre jüvenillerin hayatta kalma ve büyüme parametreleri üzerindeki etkisini incelemiştir. Toplam 160 birey (başlangıç ortalama ağırlığı: 0.033±0.001 g), her bir grup dört tekerrürlü olacak şekilde dört deneme grubuna ayrılmıştır. Elde edilen veriler; toplam boy, final ağırlığı ve spesifik büyüme oranı (SGR) gibi büyüme performansı ölçütlerinin tuzluluk uygulamalarından önemli ölçüde etkilenmediğini (p>0,05) ve somatik büyümenin test edilen tuzluluk gradyanı boyunca sürdürüldüğünü göstermiştir. Buna karşın, yaşama oranı çevresel tuzluluktan önemli ölçüde etkilenmiştir (p<0,05). En yüksek hayatta kalma oranı 5 ppt grubunda (%52,5±2,50) kaydedilmiş, bunu 10 ppt (%45,0±6,45) ve 2,5 ppt (%30,0 ±4,08) grupları izlemiş; en düşük yaşama oranı ise tatlı su kontrol grubunda (%12,5 ±9,46) saptanmıştır. Bu sonuçlar, orta seviyeli tuzluluğun (5 ppt), büyüme performansını olumsuz etkilemeden jüvenil yaşama oranını optimize edebileceğini göstermektedir. Düşük tuzluluk içeren yetiştirme stratejilerinin uygulanması, P. leptodactylus’un hassas kuluçkahane evresinde sıklıkla gözlenen yüksek mortalite oranlarını etkili bir şekilde azaltabilir. CR - Alvanou, M.V., & Giantsis, I.A. (2022). Pontastacus leptodactylus (narrow-clawed crayfish). CABI Compendium. https://doi.org/10.1079/cabicompendium.92630 CR - Audo, D., Hasiotis, S.T., & Kawai, T. (2023). Diversity and evolutionary history of fossil crayfishes. Journal of Crustacean Biology, 43(4), 1-17. https://doi.org/10.1093/jcbiol/ruad079 CR - Bissattini, A.M., Traversetti, L., Bellavia, G., & Scalici, M. (2015). Tolerance of increasing water salinity in the red swamp crayfish Procambarus clarkii. Journal of Crustacean Biology, 35(5), 682 685. https://doi.org/10.1163/1937240X-00002366 CR - Cherkashina, N. Y. (1975). Distribution and biology of crayfishes of genus Astacus (Crustacea, Decapoda, Astacidae) in the Turkmen Waters of the Caspian Sea. Freshwater Crayfish, 2, 553-555. CR - González, A., Celada, J.D., González, R., García, V., Carral, J.M., & Sáez-Royuela, M. (2008). Artemia nauplii and two commercial replacements as dietary supplement for juvenile signal crayfish, Pacifastacus leniusculus (Astacidae), from the onset of exogenous feeding under controlled conditions. Aquaculture, 281(1 4), 83 86. https://doi.org/10.1016/j.aquaculture.2008.06.015 CR - González, R., Celada, J.D., García, V., Carral, J.M., González, Á., & Sáez‐Royuela, M. (2011). Shelter and lighting in the intensive rearing of juvenile crayfish (Pacifastacus leniusculus, Astacidae) from the onset of exogenous feeding. Aquaculture Research, 42(3), 450-456. https://doi.org/10.1111/j.1365-2109.2010.02641.x CR - Harlioğlu, A.G., & Harlioğlu, M.M. (2009). The status of freshwater crayfish (Astacus leptodactylus Eschscholtz) fisheries in Turkey. Reviews in Fisheries Science, 17(2), 187 189. https://doi.org/10.1080/10641260802645311 CR - Hesni, M.A., Shabanipour, N., Zahmatkesh, A., & Toutouni, M.M. (2009). Effects of temperature and salinity on survival and moulting of the narrow-clawed crayfish, Astacus leptodactylus Eschscholtz, 1823 (Decapoda, Astacidea). Crustaceana, 82(12), 1495 1507. https://doi.org/10.1163/001121609X12511103974411 CR - Holdich, D.M., Harlioğlu, M.M., & Firkins, I. (1997). Salinity Adaptations of crayfish in British Waters with particular reference to Austropotamobius pallipes, Astacus leptodactylus and Pacifastacus leniusculus. Estuarine, Coastal and Shelf Science, 44(2), 147 154. https://doi.org/10.1006/ecss.1996.0206 CR - Holdich, D.M. (2002). Distribution of crayfish in Europe and some adjoining countries. Bulletin Français de la Pêche et de la Pisciculture, 367, 611-650. https://doi.org/10.1051/kmae:2002055 CR - Khoshkholgh, M.R., & Nazari, S. (2015). Genetic variation in the narrow-clawed crayfish (Astacus leptodactylus) populations as assessed by PCR-RFLP of mitochondrial COI gene. Molecular Biology Research Communications, 4(4), 225-237. CR - Kozák, P., Policar, T., Fedotov, V.P., Kuznetsova, T.V., Buřič, M., & Kholodkevich, S.V. (2009). Effect of chloride content in water on heart rate in narrow-clawed crayfish (Astacus leptodactylus). Knowledge and Management of Aquatic Ecosystems, 394 395, 08. https://doi.org/10.1051/kmae/2009022 CR - Köksal, G. (1988). Astacus leptodactylus in Europe. In D. M. Holdich & R.S. Lowery (Eds.), Freshwater crayfish: Biology, management and exploitation (pp. 365-400). Croom Helm. CR - Kuznetsova, T.V. (2013). Change of salinity of medium as a function loading in estimating functional state of the crayfish Astacus leptodactylus. Journal of Evolutionary Biochemistry and Physiology, 49(5), 498-502. https://doi.org/10.1134/S0022093013050058 CR - Li, B., Wang, H., Shi, H., Zhao, Q., Li, S., Wusiman, A., Aizizi, M., He, M., Zhang, K., Zhang, Y., & Li, N. (2025). Genetic structure analysis of a newly discovered wild population of Pontastacus leptodactylus in Xinjiang, China, based on the mitochondrial COI gene. Molecular Biology Reports, 52(1), 788. https://doi.org/10.1007/s11033-025-10883-8 CR - NRC. (2011). National Research Council. Nutrient requirements of fish and shrimp. National Academies Press. https://doi.org/10.17226/13039 CR - Özdoğan, H.B., & Koca, H.U. (2023). Effects of different diets on growth and survival of first feeding second-stage juvenile Pontastacus leptodactylus (Eschscholtz, 1823) (Decapoda, Astacidea). Crustaceana, 96(7), 673-682. https://doi.org/10.1163/15685403-bja10306 CR - Sáez-Royuela, M., Carral, J.M., Celada, J.D., Pérez, J.R., & González, A. (2007). Live feed as supplement from the onset of external feeding of juvenile signal crayfish (Pacifastacus leniusculus Dana. Astacidae) under controlled conditions. Aquaculture, 269(1 4), 321 327. https://doi.org/10.1016/j.aquaculture.2007.04.053 CR - Savolainen, R., Ruohonen, K., & Railo, E. (2004). Effect of stocking density on growth, survival and cheliped injuries of stage 2 juvenile signal crayfish Pasifastacus leniusculus Dana. Aquaculture, 231(1-4), 237-248. https://doi.org/10.1016/j.aquaculture.2003.09.045 CR - Scholtz, G. (1999). Freshwater crayfish evolution. Freshwater Crayfish, 12, 37-48. CR - Sevgili, H., Sezen, S., Kanyılmaz, M., Aktaş, Ö., & Pak, F. (2019). Dietary protein requirements of zebrafish (Dania rerio). Journal of Limnology and Freshwater Fisheries Research, 5(1), 34 40. https://doi.org/10.17216/LimnoFish.440537 CR - Sladkova, S.V., Kuznetsova, T.V., Lyubimtsev, V.A., & Kholodkevich, S.V. (2023). Cardiac activity of Pontastacus leptodactylus (Decapoda) under prolonged exposure to high salinity: on the possibility of using freshwater crayfish in testing brackish waters. Inland Water Biology, 16(5), 939-944. https://doi.org/10.1134/S1995082923050164 CR - Skurdal, J., & Taugbøl, T. (2002). Astacus. In D. M. Holdich (Ed.), Biology of Freshwater Crayfish (pp. 467–510). Blackwell Science. CR - Susanto, G.N., & Charmantier, G. (2001). Crayfish freshwater adaptation starts in eggs: Ontogeny of osmoregulation in embryos of Astacus leptodactylus. Journal of Experimental Zoology, 289(7), 433-440. https://doi.org/10.1002/jez.1024 CR - Taugbøl, T., & Skurdal, J. (1992). Growth, mortality and moulting rate of noble crayfish, Astacus astacus L., juveniles in aquaculture experiments. Aquaculture Research, 23(4), 411 420. https://doi.org/10.1111/j.1365-2109.1992.tb00785.x CR - Ulikowski, D., & Krzywosz, T. (2006). Impact of food supply frequency and the number of shelters on the growth and survival of juvenile narrow-clawed crayfish (Astacus leptodactylus Esch.). Fisheries & Aquatic Life, 14(2), 225-241. CR - Veselý, L., Hrbek, V., Kozák, P., Buřič, M., Sousa, R., & Kouba, A. (2017). Salinity tolerance of marbled crayfish Procambarus fallax f. virginalis. Knowledge & Management of Aquatic Ecosystems, (418), 21. https://doi.org/10.1051/kmae/2017014 CR - Yildiz, H.Y., Köksal, G., & Benli, A.C.K. (2004). Physiological response of the crayfish, Astacus leptodactylus to saline water. Crustaceana, 77(10), 1271-1276. https://doi.org/10.1163/1568540043166056 UR - https://doi.org/10.12714/egejfas.43.3.15 L1 - https://dergipark.org.tr/en/download/article-file/5973622 ER -