their populations increased greatly. During drought,
fish may be confined to pools containing predatory
fish and consequently their numbers can decline
greatly (Power et al., 1985). The threatened Arkansas
darter (Etheostoma cragini Gilbert) can tolerate drought
in upstream pools free of northern pike (Esox lucius L.),
an introduced predator, but in downstream pools, that
the pike can tolerate, darters are greatly reduced by
predation