Abstract:

Biological accumulation and release of the two heavy metals Cd and Cu in gill, hepatopancreas and muscle of
Procambarus clarkii were studied with initial Cd2+ concentrations of 0, 0.05 and 0.10 mg/L, and initial Cu2+ concentrations
of 0, 0.5 and 1.0 mg/L, respectively. Kinetic parameters such as heavy metal uptake rate constant (k1), extraction rate
constant (k2), bio-concentration factor (BCF) and biological half-life (T1/2) and equilibrium concentration (ρAmax) in vivo of
the heavy metals were obtained by non-linear curve fitting. The results showed that obvious accumulation of Cd and Cu was
observed in Procambarus clarkii and the concentrations of heavy metals in gill, hepatopancreas, and muscle exhibited an
apparent positive correlation between accumulation time and exposure concentrations. But the concentrations of both heavy
metals revealed different levels in different tissues following the decreasing order: hepatopancreas ＞ gill ＞ muscle for Cd,
and gill ＞ hepatopancreas ＞ muscle for Cu. The maximal heavy metal contents (ρAmax) in gill, hepatopancreas and muscle
were positively correlated to the exposure concentration. The BCF of Cd and Cu in the tissues ranged from 2 to 207 and
from 3 to 226, respectively. The T1/2 of Cd and Cu in the tissues ranged from 3 to 29 d and from 7 to 36 d, respectively.

Key words: Procambarus clarkii, Cu, Cd, accumulation, release