Reproduction of the narrow-clawed crayfish, <i>Pontastacus leptodactylus</i> () (Decapoda: Astacidea: Astacidae), in western Turkey

Abstract Monthly collections using fyke nets between July 2020 and June 2021 (2,606 females, 3,864 males) in Atikhisar Reservoir, Çanakkale, Turkey allowed us to investigate the reproduction of the narrow-clawed crayfish (Pontastacus leptodactylus ). The smallest female with visibly developed and quantifiable oocytes in the ovaries had a carapace length (CL) of 38.46 mm and a weight of 12.44 g among 568 individuals. The smallest male carrying spermatophores measured 25.06 mm in CL and weighed 18.96 g. Oocytes were observed from August to December, with enhanced development and darker colors noted from October to December. Density of female sexual maturity increased from October, reaching its peak in December. The length at first maturity (L50) for females and males was determined as 10.91 cm and 6.75 cm, respectively. Analysis of 493 pleopodal females revealed a mean of 145 fertilized eggs. The mean pleopodal egg weight was 1.47 g and ellipsoidal egg volumes varied 1.25–17.6 mm3. Samples from January 2021 exhibited the highest average egg number (190), whereas those from April 2021 had the largest mean egg size. Our results support the legal regulation of a minimum catch length of 10 cm for female crayfish in Turkey. Our research is the first comprehensive exploration of the reproductive characteristics of male and female narrow-clawed crayfish in Atikhisar Reservoir, providing valuable insights for decision-makers and fisheries managers to ensure stock sustainability. The findings furnish valuable insights for optimizing crayfish broodstock management within aquaculture systems.