ERRATIC PRESSURE

ERRATIC PRESSURE 

Fish are able to detect changes in pressure, such as those created by a swimming fish, through a lateral line. The lateral line is a row of small pores which lead into a fluid-filled canal system running along either side of the Fishes  body below the skin. The pore openings on the skin allow the surrounding water to flow through, enabling special sensory cells called ‘neuromasts’ to sense pressure differences. As animals in the surrounding area displace water, small waves move away from the disturbance creating electrical impulses. The lateral line canals are lined with tiny hairs which are connected to the neuromasts, which in turn pick up these ripples and send signals to the brain. If the vibration is particularly erratic or the frequency is high, it may suggest that the creature is wounded or sick, alerting the shark’s attention to it.

As well as the ability to hunt prey and detect predators, the lateral line provides Fish with spatial awareness and the ability to navigate. As the lateral line runs from snout to tail, the Fish  can assess the different intensities of pressure along its body. The shark’s own body movement also creates waves, which will bounce off obstructions (such as reefs) and return to the shark. This enables them to create a pressure map of the water and sense the magnitude, distance and orientation of the source of pressure change.

The lateral line alerts the Fish  to both potential prey and predators. There is no human equivalent of this sense, because air is not dense enough to feel any pressure differences.

The small holes on the head of this Northern pike (Esox lucius) contain neuromasts of the lateral line system.

The lateral line is a system of sense organs found in aquatic vertebrates, mainly fish, used to detect movement and vibration in the surrounding water. The sensory ability is achieved via modifiedepithelial cells, known as hair cells, which respond to displacement caused by motion, movement and transduce these signals into electrical impulses via excitatory synapses. Lateral lines serve an important role in schooling behavior, predation, and orientation. For example, fish can use their lateral line system to follow the vortices produced by fleeing prey. They are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail. In some species, the receptive organs of the lateral line have been modified to function as electroreceptors, which are organs used to detect electrical impulses, and as such these systems remain closely linked. Most amphibian larvae and some fully aquatic adult amphibians possess mechanosensitive systems comparable to the lateral line.

The lateral line system allows the detection of movement and vibrations in the water surrounding an animal, providing spatial awareness and the ability to navigate in space. This plays an essential role in orientation, predatory behavior, and social schooling

Bud Karas