赤链华游蛇形态和血液学参数及各型白细胞百分比的增龄变化

Age-Related Variations of Morphology,Hematological Parameters,and Different Subtypes of Leukocyte in Sinonatrix annularis Hallowell,1856

为阐明卵胎生的赤链华游蛇(Sinonatrix annularis)出生、第一次蜕皮和开口等关键生活史过程与血液学参数和免疫功能建立的关系,测定了出生后3、7—10(第一次蜕皮)、20、30、40和50 d其身体大小、脾脏湿重指数、血液学参数和各型白细胞的百分比的变化。结果表明:(1)赤链华游蛇的重长比3和7—10日龄组显著高于30、40和50日龄组(P<0.05),脾脏湿重指数7—10日龄组显著高于40和50日龄组(P<0.05)。(2)血红蛋白含量30日龄组最高,3日龄组最低(P<0.05)。(3)红细胞总数无组间差异(P>0.05),白细胞总数20日龄组与30日龄组接近,但显著高于其他日龄组(P<0.05)。(4)淋巴细胞的百分比和嗜碱性粒细胞的百分比占比居于前两位。淋巴细胞的百分比7—10日龄组最高,40和50日龄组最低(P<0.05),嗜碱性粒细胞的百分比40日龄组显著高于7—10和20日龄组(P<0.05);嗜中性粒细胞的百分比7—10和20日龄组显著高于50日龄组(P<0.05),嗜酸性粒细胞的百分比50日龄组与40日龄组接近,但显著高于其他日龄组(P<0.05),单核细胞的百分比50日龄组显著高于其他日龄组(P<0.05)。嗜中性粒细胞与淋巴细胞的比值未见组间差异(P>0.05)。赤链华游蛇在胚后发育早期已建立起较为完善的免疫系统,在首次蜕皮和开口摄食等关键生活史阶段,能通过调配身体和脾脏大小、血红蛋白含量、白细胞总数、各型白细胞的比例来满足特定阶段的营养和能量需求,这种发育可塑性有助于幼蛇的存活。

To explore the relationships among key life history stages including birth,first sloughing and initial feeding and hematological parameters and immune function establishment in ovoviviparous ringed water snake(Sinonatrix annularis),we measured the variations of body size,spleen wet mass index,hematological parameters and percentages of different subtypes of leukocyte on 3,7-10(first sloughing),20,30,40 and 50 days of postembryonic period.Water temperature was 29±1°C.Sampling size was 8 snakes per group.The ratio of body mass to whole body length was significantly greater at both 3 and 7-10 days of age than at 30,40 and 50 days of age(P<0.05).Spleen wet mass index was significantly higher in 7-10 days of age than that of 40 and 50 days old(P<0.05).Hemoglobin concentration was highest at 30 days and lowest at 3 days(P<0.05).Total red blood cell counts did not differ between age groups(P>0.05).Total white blood cell counts at 20 days of age were close to those of 30 days of age,but significantly higher than those of other age groups(P<0.05).Percentages of lymphocytes and basophils ranked as the two highest among leukocytes.Percentage of lymphocytes was highest in the 7-10-day age group,and lowest in the 40-and 50-day age groups(P<0.05).Percentage of basophils was significantly higher in the 40-day age group than in the 7-10-day and 20-day age groups(P<0.05).Percentages of neutrophils in the 7-10-day and 20-day age groups were significantly higher than in the 50-day age group(P<0.05).Percentage of eosinophils in the 50-day age group was close to that of 40-day age group,but significantly higher than any of the other age groups(P<0.05).Percentage of monocytes at 50 days was significantly higher than the other age groups(P<0.05).The ratio of neutrophils to lymphocytes did not vary with age.A more perfect immune system has been established in the early stage of postembryonic development in ringed water snake.To adapt the challenges from some key life cycle stages such as first sloughing and initial feeding,it can meet the nutritional and energy needs of specific stages by adjusting the body and spleen size,hemoglobin concentration,and the total number and percentage of different subtypes of white blood cells.Such developmental plasticity is helpful to the survival of young ringed water snakes.