Effect of water temperature on hemocytes and histopathological findings in freshwater Crayfish (Astacus leptodactylus)

In this research, the effect of different water temperature on THC (Total hemocyte count), variety of hemocyte cells and histopathological differences in Crayfish Astacus leptodactylus were studied. This study was designed in three groups in triplicate with 20 Crayfish in each glass aquarium. The rate of temperature in three groups were 10,15, 20, and 25 °C, respectively. The results indicated that the differences of THC value between Group1 (69± 19.00) and Group 3 (18± 12.49) were significant after 48 h . After 168 h, also the differences of THC value between Group 3 (9± 6.24) with Groups 1 & 2 (35.33± 7.02 &32.33± 8.73) were significant. The highest and lowest density of hemocyte cells were belong to semigranular cells (SGC), granular cells (GC) and hyaline cells (HC), with estimated values of 59-64%, 28-36% and 3-8% respectively. The result of histopathology in heaptopancreas, gill and heart in Group 3 affecting of high temperature showed the distribution of hemocyte aggregation and pyknosis of nucleus within vaculation of hepatopancreas. In Groups 1 and 2 the differences of hepatopancreas and gill lamella were lower and no pathological changes of heart were observed. No significant changes of digestive tract were observed in all treatments.