why does an archerfish need to be still
Archerfish Archerfish are remarkably accurate in their shooting; an adult fish almost always hits the target on the first shot. They can bring down insects and other prey[5] up to 3 m (10 ft) above the water's surface.[6] This is partially due to their good eyesight, but also to their ability to compensate for the refraction of light as it passes through the air-water interface when aiming at their prey.[7] They typically spit at prey at a mean angle of about 74° from the horizontal but can still aim accurately when spitting at angles between 45° and 110°.[8]
Salmon run The run up the river can be exhausting, sometimes requiring the salmon to battle hundreds of miles upstream against strong currents and rapids. They cease feeding during the run.[5] Chinook and sockeye salmon from central Idaho must travel 900 miles (1,400 km) and climb nearly 7,000 feet (2,100 m) before they are ready to spawn. Salmon deaths that occur on the upriver journey are referred to as en route mortality.[38]