RETRACTED ARTICLE: Occurrence, spread and control measures of Bothriocephalus acheilognathi (Bothriocephalidae: Cestoda)

Fish infections can be readily detected at autopsy, with the recovery of entire tapeworms followed by microscopic examination of the scolex. The examination of faecal material may reveal detached segments from adult tapeworms or eggs, which possess an operculum at the apex. The presence of Bothriocephalus acheilognathi may also be achieved by a squash plate method. Glass slides or plates are used to flatten the intestinal tract and the worms are detected by reflected light and low-power microscopy. Although mature parasites may be conspicuous within the intestine of infected fish, the detection of light infections or presence of juvenile parasites and plerocercoids requires microscopic examination. While these infections may hold little importance to the disease status of individuals, detection may be critical for effective disease control and limiting the spread of infected fish. The pathology may be divided generally into: (i) damage caused by scolex attachment; and (ii) damage caused by the presence of strobila within the intestine lumen. Other organs may exhibit signs of pathological change. For example, infected fish can show signs of nutritional deficiency, with atrophy of hepatocytes within the liver. In severe cases, these changes are consistent with starvation. B. acheilognathi causes a number of physiological changes in juvenile fish. These include: (i) protein depletion; (ii) altered digestive enzyme activity; (iii) elevated muscle fatigue in heavily infected hosts; and (iv) mortality of young fishes. B. acheilognathi can have pronounced detrimental effects on fish. These include severe damage to the intestinal tract, physiological disturbance, reduced growth, condition loss and death. Records of 100 % mortality in hatchery reared common carp (Cyprinus carpio) highlight the pathogenic potential of this parasite.