南京所见一种裂体吸虫与日本血吸虫形态及生活史比较

DESCRIPTION OF A KIND OF SCHISTOSOMA IN NANJING REGION

用自然环境中钉螺逸出的尾蚴感染小鼠和兔 ,获得了一种比日本血吸虫小的裂体吸虫。雄虫大小(7.1 4± 0 .64 ) mm× (0 .58± 0 .0 3 ) mm,口吸盘较大 0 .54mm× 0 .59mm;腹吸盘更大 0 .65mm× 0 .68mm,超过虫体宽度 ,且圆边构造不明显 ;睾丸 4～ 8个 ,多为 8个 ,重叠排成两行 ;背部有密集杵状小棘。雌虫 (7.1 9±1 .1 2 ) mm× (0 .3 7± 0 .0 2 ) mm,子宫内有虫卵 2 0～ 80个。雌雄合抱寄生在肠系膜下静脉、肠系膜上静脉、肝内门脉血管和膀胱静脉丛的小静脉和末梢静脉中。虫卵有钩状或环状微侧刺。终宿主小鼠的虫卵开放前期3 2 .6d± 1 .2 d,比日本血吸虫短 1 .4 d。中间宿主钉螺的开放前期比日本血吸虫长 1周以上。与钉螺的相容性差 ,钉螺的感染率 3 .7%～ 6.6% ,显著低于日本血吸虫的感染率 3 1 .7%～ 4 6.6% (P值均 <0 .0 1 )。

In the paper, some morphological and biological materials of a kind of Schistosoma obtained from mice or rabbits experimentally infected with cercariae from natural snail living in Nanjing are presented as follows: (1) Adult worms superficially resemble to Schistosoma japonicum but smaller in size. For instance, male worms from mice 45d after infection measure (7.14±0.64) mm × (0.58±0.03) mm. In average, oral sucker is 0.54 mm ×0.59 mm, and ventral sucker 0.65 mm×0.68 mm which goes beyond the body width and no pronounced rim found. There are usually 8 testes in two series. Dosal integument presents densely clublike spines. Females from mice 45d after infection measure (7.19±1.12) mm×(0.37±0.02) mm. Oral suckers are bigger than ventral ones. The uterus contains as many as 20～80 eggs at one time. Egg has lateral hook-ring spine. (2) The typical habitat for oviposition is in small and terminal veins of superior and inferior mesenteric veins, potal veins in liver and vesical venous plexus. (3) In mice, the patent period is 32.6 d±1.2 d which is shorter than that of S. japonicum while in Oncomelania snails it is 9 wks under 26℃ which is 1 wk longer tahn that of S. japonicum. (4) Study on snail compatibility showed that infection rate of this Schistosma was 3.7%～6.6% but of S. japonicum 31.7%～46.6%.