Nuclear and Cellular Abnormalities of Erythrocytes in Response to Thermal Stress in Common Carp Cyprinus carpio.

Md Shahjahan,Saleha Khan,S M Majharul Islam,Most Sabia Khatun,Muhammad Badruzzaman,Md Helal Uddin,Mim Mostarin Mun

doi:10.3389/fphys.2020.00543

Abstract

As a consequence of global warming, increase of water temperature is likely to alter physiological functions of fish. Hence, we examined the effects of high temperature on blood glucose, hematological parameters [hemoglobin (Hb), red blood cell (RBC), and white blood cell (WBC)], and nuclear and cellular structure of blood cells of common carp (Cyprinus carpio) after exposure to three temperature regimes (27, 31, and 35°C) for 14 days. Fish were sacrificed on 3, 7, and 14 days of exposure. The blood glucose level increased significantly in the fish exposed to 35°C compared to 27 and 31°C. The Hb and RBC contents decreased but WBC increased significantly in the blood of fish exposed to 35°C compared to 27 and 31°C at 7 and 14 days of exposure. Consequently, the frequencies of erythroblasts (Ebs), erythrocytic nuclear abnormalities (ENA), and erythrocytic cellular abnormalities (ECA) were found to be increased in the blood of fish exposed to 35°C compared to 27 and 31°C. There was a significant increase in neutrophils and decrease in lymphocytes in the highest temperature (35°C). With increasing temperature, dissolved oxygen (DO) decreased but free CO2 increased significantly during the study period. The present study demonstrated that common carp are better adapted to 27 and 31°C environmental temperatures, while the higher temperature 35°C is likely stressful to this fish species.

Highlights

The common carp (Cyprinus carpio) is a native fish species in temperate regions of Asia, especially in China (Gunther, 1868), Turkestan (Jenkins, 1961), and Japan (Okada, 1960)
The blood glucose level of fish exposed to 35◦C elevated significantly (p < 0.05) compared to those in 27 and 31◦C during all the sampling days (Figure 1)
In days 7 and 14, the values of Hb (g/dL) and number of red blood cell (RBC) decreased significantly (p < 0.05) in fish treated with 35◦C compared to 27 and 31◦C, while in day 3, no distinct changes were found among three temperature treated groups (Table 1)

Summary

Introduction

The common carp (Cyprinus carpio) is a native fish species in temperate regions of Asia, especially in China (Gunther, 1868), Turkestan (Jenkins, 1961), and Japan (Okada, 1960) This fish species has been acclimatized to various environments and habitats. Its high growth rate and Temperature-Induced Abnormalities of Erythrocytes in Commom Carp productive breeding in confined water make highly edible and ideal cultivable species in the world. It is the third most widely cultured freshwater fish species in the world (FAO, 2018). Best growth is obtained when water temperature ranges between 23 and 30◦C (Sapkale et al, 2011; Oyugi et al, 2012)

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Discussion

Conclusion