Lateral line

Lateral line

In fish, the lateral line is a sense organ used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail. Sometimes parts of the lateral organ are modified into electroreceptors, which are organs used to detect electrical impulses. It is possible that vertebrates such as sharks use the lateral organs to detect magnetic fields as well.Most amphibian larvae and some adult amphibians also have a lateral organ.

The Lateral line is related to the Ampullae of Lorenzini.

The receptors in the lateral line are neuromasts, each of which is composed of a group of hair cells. The hairs are surrounded by a protruding jelly-like cupula, typically 1/10 to 1/5 mm long. The hair cells and cupolas of the neuromasts are usually at the bottom of a visible pit or groove in the fish. The hair cells in the lateral line are similar to the hair cells inside the vertebrate inner ear, indicating that the lateral line and the inner ear share a common origin.

Teleosts and elasmobranchs usually have lateral-line canals, in which the neuromasts are not directly exposed to the environment, but communicate with it via canal pores. Additional neuromasts may appear individually at various locations on the body surface.

The development of the lateral-line system depends on the fish's mode of life. For instance, fish that are active swimming types tend to have more neuromasts in canals than they have on their surface, and the line will be farther away from the pectoral fins, which probably reduces the amount of "noise" that is generated by fin motion.

The lateral-line system helps the fish to avoid collisions, to orient itself in relation to water currents, and to locate prey. For instance, blind cavefish have rows of neuromasts on their heads, which appear to be used to precisely locate food without the use of sight; killifish are able to use their lateral line organ to sense the ripples made by insects struggling on the water's surface. Experiments with pollock have shown that the lateral line is also a key enabler for schooling behavior.

It has also been suggested that the lateral line may give sharks advanced warning of frontal pressure systems and that they use it to avoid severe weather conditions that may result in injury. It was observed that during Hurricane Gabrielle that struck Florida in 2001, juvenile black tip sharks moved to deeper waters as the storm approached. [cite news|url=http://news.bbc.co.uk/1/hi/scotland/north_east/7311847.stm|title= Sharks 'may predict the storms'|publisher=BBC News, Science|date=2008-03-25]

Some crustaceans and cephalopods have similar organs.


=

References

* A.N. Popper and C. Platt, "Inner ear and lateral line", in "The Physiology of Fishes", 1st ed. (CRC Press, 1993)
* N.A.M. Schellart and R.J. Wubbels, "The auditory and mechanosensory lateral line system", in "The Physiology of Fishes", 2nd ed. (CRC Press, 1998)


Wikimedia Foundation. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Lateral line — Lateral Lat er*al, a. [L. lateralis, fr. latus, lateris, side: cf. F. lat[ e]ral.] 1. Of or pertaining to the sides; as, the lateral walls of a house; the lateral branches of a tree. [1913 Webster] 2. (Anat.) Lying at, or extending toward, the… …   The Collaborative International Dictionary of English

  • lateral line — n. a row of sensory organs along each side of the head and body in fishes and a few amphibians, probably for detecting vibrations, currents, and pressure: see FISH …   English World dictionary

  • lateral line — a tube like sensory organ (usually bearing pores) extending along the side of the body from the rear of the head to the tail. Detects water movements, low frequency vibrations (lower than 160 200 Hz) and perhaps temperature changes. In some… …   Dictionary of ichthyology

  • lateral line — noun sense organs of fish and amphibians; believed to detect pressure changes in the water • Syn: ↑lateral line organ • Hypernyms: ↑sense organ, ↑sensory receptor, ↑receptor • Part Holonyms: ↑fish, ↑ …   Useful english dictionary

  • lateral line system — ▪ biology also called  lateralis system   a system of tactile sense organs (senses), unique to aquatic vertebrates (vertebrate) from cyclostome fishes (cyclostome) (lampreys (lamprey) and hagfish) to amphibians (amphibian), that serves to detect… …   Universalium

  • lateral line disease — hole in head disease (head and lateral line erosion (a nutritional deficiency seen in aquarium fish, usually of vitamin C, aggravated by stress and poor water quality. Holes develop in the head and and sometimes along the lateral line. Death may… …   Dictionary of ichthyology

  • lateral line organ — noun sense organs of fish and amphibians; believed to detect pressure changes in the water • Syn: ↑lateral line • Hypernyms: ↑sense organ, ↑sensory receptor, ↑receptor • Part Holonyms: ↑fish, ↑ …   Useful english dictionary

  • lateral line organ — one of the series of horseshoe shaped structures left on the flank of Myctophidae members when the scales become detached. A lateral line organ count is often used in place of a scale count because scales are very deciduous in this family …   Dictionary of ichthyology

  • lateral line pore — one of the series of the apertures of the lateral line canal. Usually counted from the most posterior one touching the shoulder girdle to the one wholly or mostly in front of the base of the caudal fin. Found in all fishes (except Amphioxi and… …   Dictionary of ichthyology

  • lateral line scale — on of those scales along the side of the body bearing lateral line pores (or pit organs) or in the same row as those. The count may include only the pored scales (usual method) or all scales in the same row …   Dictionary of ichthyology

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”