Speed view shooting shrimp was a record among aquatic animals: on average, they saw flashes of light with a frequency up to 160 Hz, and the retina of individuals responded to the 200-Hz flicker. The authors of the work published in the journal Biology Letters, believe that such a vision helps fast-moving shrimp to distinguish objects in murky water.
Shooting shrimp Alpheus heterochaelis of the family cancers-beetles have recently considered blind. However, it turned out that they have a spatial vision and use it to determine the size of the claws of the opponent. Shrimp-beetles is especially important to correctly assess the enemy’s strength, because their fights can be deadly. However, the characteristics of the visual system of these animals has not yet determined exactly. Thus, in previous studies, shooting shrimp were able to see flashes of light, which was blinking with a frequency of 49 Hz (these are average values for decapod), but the maximum temporal resolution view of these crustaceans is unknown.
Biologists from the South Carolina University under the guidance of Alexandra Kingston (Alexandra Kingston) using electroretinography were assessed by temporal resolution of the view of A. heterochaelis. In the eyes of the shrimp put the electrodes and registers the biopotentials of the retina in response to flashes of light: first single flash of varying intensity, and then flashing with increasing frequency of light (from 30 to 200 Hz). Just spent four samples with six to eight animals each.
Retina shrimp respond to light intensity from 2.2×1012 to 9.6×1016 photons per square meter per second, which corresponds to the range from the twilight world (one Suite) to direct sunlight (one hundred thousand Lux).
The amplitude of the response to a light intensity of 1.57×1017 photons per square meter per second, flickering with a frequency of 30-100 or 60-130 Hz, exceeded the threshold of five percent of the maximum response. The eyes of the shrimp, which showed a flashing 100-200 times a second, the light, the average discern flickering up to 160 Hz, but the reaction of three of the eight animals were above the threshold and at a frequency of 200 Hz.