| Odontobutis sinensis belongs to the genus Odontobutis(Perciformes, Gobioidei,Odontobutidae), is an endemic freshwater fish in China. O. sinensis stays succulent and tender with more muscle. It’s a traditionally rare fish in Jiangsu and Zhejiang province.“The first food of expo†makes growing demand for O. sinensis and other odontobutis fishes. However, the wild resource of O. sinensis declines sharply due to the degradation of natural waters and unrestrained fishing in China, so the present fishing production can’t satisfy the market requirement. Therefore, O. sinensis enjoys a great potential of aquiculture. To understand the cytogenetics and hematology of O. sinensis and provide fundamental information for the breeding and aquaculture of Odontobutis, we had investigated chromosome karyotype, blood cell nucleus DNA content and microstructure of peripheral blood cells of O. sinensis in Liangzi Lake by intraperitoneal injection with PHA and colchicines and flow cytometry and Wright’s-Giemsa staining. The specific research results are as follows:1. Karyotypic analysis of O. sinensisMitotic chromosome preparations were made from head-kidney tissue by intraperitoneal injection with PHA and colchicines. The chromosome number, karyotype and the fundamental number of chromosome were analyzed. Cytogenetic analyses indicated that O. sinensis has a diploid chromosome number of 2n = 44, with a chromosome formula equal to 44T(NF = 44), irrespective of sex. The karyotype exhibited large and small chromosome pairs: telocentric pairs 1(5.91%) and telocentic pair 22(3.33%). Neither the secondary constriction nor the satellites were found.2. DNA content in blood cells of O. sinensisThe DNA content in blood cells of O. sinensis was determined by external standard method and flow cytometry. The DNA content of Gallus sp.(2.50 pg/2C)was used as a standard. The results showed that the DNA content in blood cells of O. sinensis was(2.38± 0.03) pg. The genome size of O. sinensis was 1.17 × 109 bp.3. Microstructure of peripheral blood cells of O. sinensisThe quantity, microstructures and size of peripheral blood cells of O. sinensis in Liangzi Lake were investigated by hemocytometer, the conventional blood smear and Wright’s-Giemsa staining. Erythrocytes, monocytes, lymphocytes, neutrophils,thrombocytes had been identified in peripheral blood of O. sinensis under opticalmicroscope. Immature erythrocytes, dividing erythrocytes, dissolved erythrocytes andnuclear shadows also had been detected. However, neither the eosinophils nor the basophils were found. Additionally, erythrocytes were the most abundant cells in smears of the peripheral blood cells of O. sinensis with its density of(1.47 ± 0.12) × 1012/L;hemoglobin content was(51.61 ± 7.96) g/L. Thrombocytes were the predominant leukocytes, accounting for 58.65% of those in O. sinensis; lymphocytes were the second one, small lymphocytes and large lymphocytes accounted for 12.02% and 8.80%,respectively; neutrophils were the third one, accounting for 15.54% and monocytes were rare, only accounting for 4.99%. Neutrophils had the largest volume, with the cell size of (16.62 ± 1.34) μm ×(14.27 ± 2.09) μm and nucleus size of(11.03 ± 0.98) μm ×(8.61 ±0.64) μm, while thrombocytes had the smallest volume,with the cell size of(9.26 ± 0.95)μm ×(8.48 ± 0.79) μm and nucleus size of(8.86 ± 0.92) μm ×(7.22 ± 0.77) μm. The characteristics of peripheral blood cells of O. sinensis adapted with its benthic lifestyle. |
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