The disturbance was evenly distributed over all aquaria.
The aquaria were spatially interspersed in random order.
Neighbouring aquaria were separated by grey opaque partitions to prevent visual interactions.
After 5 min fish were removed, rinsed briefly in carbon-filtered water, and returned to aquaria.
Here they were maintained live in recirculating freshwater aquaria prior to their examination.
Non-infected fish were kept in similar aquaria and treated likewise except for infection.
Moreover, the generation time of this tropical fish is short and adults can be maintained at high density in laboratory aquaria.
The mean parasite load per recipient were approximately equal in the six infection aquaria, ranging from 12 to 18.
