Mutani A, Christensen N O, Frandsen F
Acta Trop. 1985 Dec;42(4):319-31.
The viability of a hybrid between male Schistosoma haematobium (Dar es Salaam, Tanzania) and female S. intercalatum (Edea, Cameroun) was studied for up to the F7 hybrid generation and the biological characteristics of the hybrid were compared with those of each of the parental species. Using the total cercarial production/100 exposed snails/5 weeks value (TCP) as an index the hybrid miracidial infectivity to Bulinus forskalii (Kinshasa, Zaire), the host snail for S. intercalatum, remained comparable to that of S. intercalatum for up to at least the F5 generation and the TCP values for the hybrid/B. wrighti combination remained for up to the F7 generation intermediate between those of the parental species in B. wrighti. The hybrid also retained the infectivity for up to at least the F5 generation to B. globosus (Mazeras, Kenya), the host snail for S. haematobium, but the TCP values for the hybrid/B. globosus combination remained consistently lower than that of the S. haematobium/B. globosus combination. The hybrid cercarial infectivity to hamsters was for up to the F7 generation comparable to that of both parental species and the egg production capacity/worm pair/day of production of the F1 hybrid generation exceeded in both hamsters and mice that of both parental species. However, the egg production capacity subsequently decreased with that of the F3 to F6 generations in hamsters and with that of the F2 and F5 generations in mice being comparable to that of S. intercalatum. The pattern of distribution of eggs in tissue of hamsters of the F1 and F2 generations resembled that of S. haematobium and S. intercalatum, respectively, but the distributional pattern of the F3 to F6 generations deviated markedly from that of both the parental species and the preceding hybrid generations. The hybrid cercarial infectivity to mice and the pattern of egg distribution corresponded to that of S. intercalatum. The egg morphology of the P1 generation corresponded to that of S. intercalatum while that of the F1, F2 and F3 hybrid generations exhibited great polymorphism with a range of shapes through those of the parental species but with most eggs being intermediate in shape. However, the eggs of the F4 to F7 hybrid generations exhibited less polymorphism and resembled those of S. bovis in both size and shape.
对雄性埃及血吸虫（坦桑尼亚达累斯萨拉姆）与雌性间插血吸虫（喀麦隆埃代阿）杂交种的生存能力进行了研究，直至F7杂交代，并将杂交种的生物学特性与每个亲本物种的特性进行了比较。以每100只暴露蜗牛5周内的尾蚴总产量（TCP）为指标，该杂交种对间插血吸虫的中间宿主福氏泡螺（刚果金沙萨）的毛蚴感染性，至少在F5代之前仍与间插血吸虫相当，且杂交种/赖氏泡螺组合的TCP值在F7代之前一直介于亲本物种与赖氏泡螺组合的TCP值之间。该杂交种对埃及血吸虫的中间宿主球形泡螺（肯尼亚马泽拉斯）的感染性至少在F5代之前也得以保留，但杂交种/球形泡螺组合的TCP值始终低于埃及血吸虫/球形泡螺组合的TCP值。该杂交种尾蚴对仓鼠的感染性在F7代之前与两个亲本物种相当，且F1杂交代每对虫体每天的产卵量在仓鼠和小鼠中均超过两个亲本物种。然而随后，仓鼠中F3至F6代的产卵量下降，小鼠中F2和F5代的产卵量与间插血吸虫相当。F1和F2代仓鼠组织中虫卵的分布模式分别类似于埃及血吸虫和间插血吸虫，但F3至F6代的分布模式明显不同于亲本物种和之前的杂交代。该杂交种尾蚴对小鼠的感染性以及虫卵分布模式与间插血吸虫一致。P1代的虫卵形态与间插血吸虫一致，而F1、F2和F3杂交代的虫卵形态表现出高度多态性，形状范围涵盖亲本物种的形状，但大多数虫卵形状居中。然而，F4至F7杂交代的虫卵多态性较小，大小和形状类似于牛血吸虫。
