The objective of the study was to obtain baseline data on haematological parameters, blood cell sizes and morphology in cultured male and female Gymnocypris eckloni Herzenstein, 1891. Forty-eight healthy 3-year-old G. eckloni (26 males: 525.79 AE 48.56 g weight, 34.51 AE 1.88 cm total length; 22 females: 507.60 AE 54.48 g weight, 33.97 AE 1.84 cm total length) were used for this study. Both male and female gonadal maturity were at stage III (maturing). The fish were reared in 25-36 m 2 outdoor tanks at dissolved oxygen 6.86 AE 0.48 mg L À1 , pH 7.22 AE 0.58, temperature 12.40 AE 0.94°C and stocking density 50-80 fish m À3 during November 2014. The fish were fed commercial carp floating foods containing 35% crude protein three times daily. Haematological values were performed manually on heparin anticoagulated blood specimens using standard methods. The morphological features of blood cells and differential cell counts were done on WrightGiemsa stained blood smears with no anticoagulants. Erythrocytes, leucocytes (neutrophils, eosinophils, lymphocytes and monocytes) and thrombocytes were distinguished and characterized under light microscope. The percentage of the different leukocytes revealed predominance of small lymphocytes (male: 62.31 AE 2.06%; female: 63.00 AE 2.25%) and nurophiles (male: 23.85 AE 1.51%; female: 23.49 AE 1.67%) followed by fewer monocytes (male: 4.81 AE 0.68%; female: 4.80 AE 0.77%) and few eosinophils (male: 3.73 AE 0.82%; female: 3.52 AE 0.67%). The nurophile percentages of each stage showed that metamyelocyte accounted for the most (male: 13.29 AE 0.88%; female: 13.07 AE 0.98%), followed by banded ones (male: 7.18 AE 0.49%; female: 7.00 AE 0.58%). The microstructure of G. eckloni blood cells was similar to that of other fish. Sex-dependent differences for the erythrocyte counts, haemoglobin, haematocrit and mean corpuscular haemoglobin were found (P < 0.05 or P < 0.01); while differences in other haematological parameters (P > 0.05) and blood cell morphology between male and female fish were not significant. Hematologic parameters and knowledge of morphological characteristics of male and female G. eckloni blood cells could be utilized to evaluate the health status of this species in captivity.

The ultrastructural and cytochemical properties of peripheral blood cells of Gymnocypris eckloni were investigated by transmission electron microscopy and a range of cytochemical techniques to provide clear insight into the structure and function of blood cells from this fish. Ultrastructurally, erythrocytes, leucocytes (neutrophils, eosinophils, lymphocytes, monocytes), thrombocytes and plasma cells were identified in the peripheral blood of G. eckloni. The most special ultrastructural characteristics of blood cells in this fish were that neutrophils exhibited only one type of cytoplasmic granules containing an eccentric, spherical or oval electron-dense core, and eosinophils presented two types of granules with non-uniform electronic density and without crystalloids in their cytoplasm. Neutrophils, eosinophils, lymphocytes, monocytes and thrombocytes were positive for periodic acid-Schiff and α-naphthyl acetate esterase staining. Intense peroxidase positive staining was observed in neutrophils and monocytes, but not in eosinophils, lymphocytes and thrombocytes. Neutrophils, eosinophils and monocytes were stained positively for acid phosphatase, whereas lymphocytes and thrombocytes did not stain. Leucocytes and thrombocytes were negative for alkaline phosphatase and Sudan black B staining. Erythrocytes were negative for all cytochemical staining. The cytochemical and ultrastructural features of peripheral blood cells of G. eckloni were similar to those of other fish species. However, some important differences were identified in G. eckloni.

The aim of this study was to obtain a basic knowledge of the hematology of Schizothorax (Racoma) davidi (Sauvage). The results showed that red blood cell and white blood cell counts as well as mean cellular hemoglobin concentration were significantly higher in females than in males, while mean cell volumes were significantly lower in females than in males. No significant differences were seen in other hematological parameters in relation with gender. Under light microscope, erythrocytes (mature and immature), leukocytes (neutrophils, lymphocytes, and monocytes), and thrombocytes were distinguished. Mature erythrocytes were ellipsoidal cells with oval, central nucleus. Neutrophils contained banded or segmented nuclei. Small lymphocytes had a very thin rim of basophilic cytoplasm. Monocytes often possessed vacuoles in their cytoplasm. Thrombocytes existed in several forms with relatively large nucleus surrounded by a pink-stained or hyaline cytoplasm. The percentage of the different leukocytes revealed predominance of neutrophils and small lymphocytes, followed by monocytes and large lymphocytes. The neutrophil percentages of each stage showed that metamyelocyte accounted for the most, followed by banded neutrophils. This investigation could be used for evaluation of the health status of cultured male and female S. davidi and will provide early detection of clinical pathology.