Dias M L G G, Minte-Vera C V, Eiras J C, Machado M H, Souza G T R, Pavanelli G C
Departamento de Análises Clínicas, Universidade Estadual de Maringá, Av. Colombo 5790, 870200-900 Maringá, PR, Brazil.
Parasitol Res. 2006 Nov;99(6):675-81. doi: 10.1007/s00436-006-0205-0.
The prevalence of Clinostomum complanatum Rudolphi, 1814 (Digenea, Clinostomidae) in fishes Loricariichthys platymetopon, Parauchenipterus galeatus and Hoplosternum littorale, which are second intermediate hosts, was studied at the floodplain of the high Paraná River, Brazil. Season (alternation flood-drought), habitat (lentic and semi-lotic), and sex were not related to its prevalence. For L. platymetopon, the immature and smaller fish had the lowest prevalence, whilst the opposite was observed for P. galeatus and H. littorale. This suggests that the probability of being predated is unchanged by parasitism for L. platymetopon; thus, a cumulative effect of repeated infections is observed; for the two other species, the highest parasitised fish may have higher predation mortality rates. While H. littorale is the preferred item in birds' diet, L. platymetopon is the most abundant fish species and has the highest C. complanatum prevalence, which makes it the most likely path of transmission to the bird, the definitive hosts of C. complanatum.
在巴西巴拉那河上游的洪泛平原，对作为第二中间宿主的鱼类——扁头铲颌油鲶、盖斑陶乐鲶和饰纹兵鲶体内的1814年鲁道夫复口吸虫（复殖目，复口科）的感染率进行了研究。季节（洪水-干旱交替）、栖息地（静水和半流水）和性别均与该吸虫的感染率无关。对于扁头铲颌油鲶，未成熟且体型较小的鱼感染率最低，而对于盖斑陶乐鲶和饰纹兵鲶则观察到相反的情况。这表明对于扁头铲颌油鲶而言，被寄生并不改变其被捕食的概率；因此，观察到了重复感染的累积效应；对于其他两个物种，被寄生程度最高的鱼可能具有更高的捕食死亡率。虽然饰纹兵鲶是鸟类食物中的首选，但扁头铲颌油鲶是最丰富的鱼类物种且复口吸虫感染率最高，这使其成为向复口吸虫的终末宿主——鸟类传播的最可能途径。
