Effect of Feed Additives in the Diet on the Growth and Testicular development of Male Red Claw Crayfish (Cherax quadricarinatus) Using Orthogonal Experiments

Author(s):  
Akram Ismael Shehata ◽  
Tao Wang ◽  
Jianfeng Wang ◽  
Ziping Zhang
Aquaculture ◽  
2010 ◽  
Vol 304 (1-4) ◽  
pp. 34-41 ◽  
Author(s):  
Liane Stumpf ◽  
Natalia S. Calvo ◽  
Silvia Pietrokovsky ◽  
Laura S. López Greco

2010 ◽  
Vol 60 (2) ◽  
pp. 195-208 ◽  
Author(s):  
Laura Susana López Greco ◽  
Fernanda Jimena Vazquez

AbstractThe differentiation of the male reproductive system, the copulatory structures, "red patch" and onset of sexual maturity were studied in Cherax quadricarinatus. For this characterization 353 males were observed, dissected and processed for histological analysis. Three developmental stages were identified. At stage I the testes are two parallel cords with a few lobes or acinii, connected medially by a short thin bridge (X-shape) and the vasa deferentia are straight transparent cords. In the second stage, more lobulated testes present an H-shape and the vas deferens begins to differentiate into three distinct regions: proximal, medial and distal. In the last stage testes are two parallel cords tending to fuse along their entire length and become a single structure. From this stage, the development of the "red patch" occurs and spermatophore formation is observed in the vas deferens giving it white colour. These primary and secondary sexual characters could indicate the onset of sexual maturity. The morphology of the copulatory structure is lobular at stage I and it differentiates into an elongated structure during stage II. This study shows that in C. quadricarinatus the differentiation of primary and secondary sexual characters of males starts simultaneously and very early in development (0.09-0.10g achieved nearly 1 month old) and that acquisition of sexual maturity is also an early event (6g achieved nearly 3 month old). The compared features within Astacidea and Decapoda and the possible applications in the analysis of phylogenetic relationships between different taxa are discussed.


Author(s):  
Akram Ismael Shehata ◽  
Mayada Alhoshy ◽  
Tao Wang ◽  
Jianfeng Wang ◽  
Ruoxuan Wang ◽  
...  

Author(s):  
D. Skafar ◽  
D. Shumeyko

Purpose: to study the effect of ethanol on the parameters of THC, the percentage of granulocytes and total protein in the hemolymph of the Red claw crayfish (Cherax quadricarinatus).Materials and methods. The object of this experiment was 26 males of the Australian red-clawed crayfish (Cherax quadricarinatus) weighing from 23 to 83 g. The individuals were evenly divided into two experimental groups - with an injection of ethanol and a control group without an injection of 13 crayfish for each group. The injection dose was 2515 mg per 100 g of body weight. A day after the introduction of ethanol, hemolymph was taken with a syringe from the ventral sinus, the syringe was pre-washed with a 4% EDTA-Na2 solution. Three parameters were determined: the total hemocyte count (THC), percent granulocytes and percent total protein content. Counting of hemocytes and determination of granulocytes were performed in a Goryaev chamber under a light microscope. The total protein was determined by the refractometric method.Results. Differences in THC and total protein between the groups were statistically unreliable (p>0,05). THC in the experimental group is 36% more than in the control group. The total protein after the introduction of ethanol actually increased by 0,7%, and relatively by 14%. There were statistically different indicators of the proportion of granulocytes (p<0,05) - the average value of 33,1% in the experimental group versus 24,5% in the control group. A reliable (p<0,05) strong feedback was revealed between the total protein and the mass of individuals in both experimental groups, while in the experimental group there is a visible shift in the values of dependent hemolymph indicators towards an increase in smaller individuals.Conclusion. A single injection of ethyl alcohol with a dosage of 2515 mg per 100 g of body weight into the hemolymph of C. quadricarinatus does not cause significant changes in the THC and total protein after 24 hours. At the same time, the proportion of granulocytes actually increases by 9%, relative to 37%. This may indicate that granulocytes are involved in the formation of cancer defense mechanisms when exposed to toxic substances. The effect of different dosages of ethanol injections and the duration of its effect on hematological parameters requires additional consideration. It is necessary to investigate its effect on other indicators, such as the pH and buffer capacity of the hemolymph, the concentration of hemocyanin, glucose, lactates and calcium.


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