Document Type : Research Paper
Authors
1
Ph.D student, Department of Fisheries, Faculty of Natural Resources, College of Agriculture & Natural Resource, University of Tehran, Karaj, Iran.
2
Associate Prof., Department of Fisheries Faculty of Natural Resources, University of Tehran, Karaj, Iran.
3
Professor, Department of Fisheries Faculty of Natural Resources, University of Tehran, Karaj, Iran.
Abstract
The effects of cadmium and calcium carbonate concentration were investigated at different temperatures on the morphological characteristics of freshwater crabs Potamon persicum (Pretzmann, 1962) using traditional morphometrics methods, 60 samples of random sampling in the west of Mazandaran and Karaj Rivers in the Central Alborz, Iran. The crabs were exposed to zero cadmium and 205 mg/l calcium carbonate as a control treatment and 4.5 and 9 mg/l cadmium concentrations and 302.5 and 400 mg/l carbonate calcium hardnesses at 18, 24, and 30 ° C temperatures for 6-weeks as experimental treatments. We studied the effects of water physicochemical parameters on serum biochemical properties in the hemolymph of the crabs including ALT and ALP enzymes and morphometric ratios between CW/CHL, CW/CHD, and CW/MBDWt in males and CW/MBDWt in both males and females. The results showed that increasing the two factors of temperature and cadmium alone had a significant positive effect on increasing the amount of ALT hemolymph enzyme in the studied crabs (P <0.05).In this study, the interaction of cadmium and calcium carbonate on the serum level of ALT enzyme hemolymph in crabs was significant and the negative effects of cadmium on ALT enzyme decreased with increasing calcium carbonate hardness (P<0.01). However, studied physicochemical factors had no significant effects on the serum level of ALP (P> 0.05). However, the interaction of calcium carbonate with cadmium on the serum level of ALP enzyme was significant and with increasing both variables, the amount of ALP enzyme in crab hemolymph increased (P <0.05). The present study also showed that the interaction of all three variables on CW/CHD and CW/CHL ratio of male crabs was not significant (P> 0.05), but the interaction of all three variables on CW/MBDWt of male and female crabs was significant at a 95% confidence level (P <0.05). According to the values obtained in finding the optimal points of the studied variables on the maximum morphological ratios and the optimal level of ALP and ALT enzymes, recommend using high rates of desirability (80-95%) with temperature 18-20°C, Calcium carbonate hardness about 240-311 mg/l, And the absence of cadmium in the aqueous medium.
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