Stocking density affects the growth, survival, and cheliped injuries of third instars of narrow-clawed crayfish, Astacus leptodactylus Eschscholtz, 1823 juveniles
Yükleniyor...
Tarih
2007
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Brill
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
The effect of stocking density on the growth and survival of Astacus leptodactylus juveniles was evaluated. Newly hatched third instars of A. leptodactylus with an average total length of 11.4 mm (TL) and an average weight of 22.4 mg were stocked in 0.14 m(2) tanks in a recirculation system at 50, 100, and 200 specimens/m(2) and reared for 120 days at 22.8 degrees C. Crayfish growth was inversely correlated with density. The mean final weights for the crayfish were 1.26, 1.16, and 0.91 g for crayfish densities of 50, 100, and 200/m(2), respectively. Survival of the crayfish was also affected by stocking density; it decreased as initial stocking density increased. The proportion of lost chelipeds was also found to be dependent on the stocking density and increased with increasing stocking density. The differences in the proportion of crayfish with cheliped injuries among animals stocked at 50/m(2), 100/m(2), and 200/m(2) were found to be 7.1%, 16%, and 29%, respectively. The yield was directly related to density (P < 0.05, R-2 = 0.95). No evidence was found for feed conversion ratio (FCR) being affected by density. Astacus leptodactylus had a normal length distribution of 11-12 mm at the beginning of the experiment. However, at the end of the experiment, the length distribution varied among animals in the three density treatments. At the densities of 100/m(2) and 200/m(2), animals had a final length range of 16-40 mm TL, showing a distinct peak at 21-25 mm TL; however, at the density of 50/m(2), the animals had a final length range of 16-41 mm TL with a distinct peak at 26-30 mm TL. In addition, the implications of the above findings for optimal intensive culture conditions for juvenile Astacus leptodactylus are discussed.
Açıklama
Anahtar Kelimeler
Fresh-Water Crayfish, Pacifastacus-Leniusculus Dana, Procambarus-Clarkii Girard, Decapoda, Shelter, Size
Kaynak
Crustaceana
WoS Q Değeri
Q4
Scopus Q Değeri
Q3
Cilt
80
Sayı
7
