35 Facts About Pelagic fish

Much of the zone lacks nutrients for supporting fish, so epipelagic fish tend to be found in coastal water above the continental shelves, where land runoff can provide nutrients, or in those parts of the ocean where upwelling moves nutrients into the area.

Epipelagic fish can be divided broadly into small forage fish and larger predator fish that feed on them.

Predator Pelagic fish are usually fusiform with large mouths, smooth bodies, and deeply forked tails.

Many forage Pelagic fish are facultative predators that can pick individual copepods or Pelagic fish larvae out of the water column, and then change to filter feeding on phytoplankton when energetically, that gives better results.

Since the continental shelf is usually less than 200 metres deep, it follows that coastal fish that are not demersal fish, are usually epipelagic fish, inhabiting the sunlit epipelagic zone.

Forage Pelagic fish thrive in those inshore waters where high productivity results from the upwelling and shoreline run off of nutrients.

Oceanic Pelagic fish can be contrasted with coastal Pelagic fish, who do live above the continental shelf.

However, the two types are not mutually exclusive, since there are no firm boundaries between coastal and ocean regions, and many epipelagic fish move between coastal and oceanic waters, particularly in different stages in their life cycle.

Oceanic epipelagic fish can be true residents, partial residents, or accidental residents.

The swimbladder is inflated when the fish wants to move up, and, given the high pressures in the mesopelagic zone, this requires significant energy.

Mesopelagic fish are adapted for an active life under low light conditions.

Some deeper water Pelagic fish have tubular eyes with big lenses and only rod cells that look upward.

Antarctic toothPelagic fish have large, upward looking eyes, adapted to detecting the silhouettes of prey Pelagic fish.

Brownsnout spookPelagic fish is a species of barreleye and is the only vertebrate known to employ a mirror, as opposed to a lens, to focus an image in its eyes.

Indeed, lanternPelagic fish are among the most widely distributed, populous, and diverse of all vertebrates, playing an important ecological role as prey for larger organisms.

Bathypelagic fish have special adaptations to cope with these conditions – they have slow metabolisms and unspecialized diets, being willing to eat anything that comes along.

The behaviour of bathypelagic fish can be contrasted with the behaviour of mesopelagic fish.

Mesopelagic are often highly mobile, whereas bathypelagic fish are almost all lie-in-wait predators, normally expending little energy in movement.

Bathypelagic fish are sedentary, adapted to outputting minimum energy in a habitat with very little food or available energy, not even sunlight, only bioluminescence.

Since so much of the Pelagic fish is water, they are not compressed by the great pressures at these depths.

Swimbladders of deep sea fish are either absent or scarcely operational, and bathypelagic fish do not normally undertake vertical migrations.

Female Haplophryne mollis anglerPelagic fish trailing attached males that have atrophied into a pair of gonads, for use when the female is ready to spawn.

Demersal Pelagic fish are found by the seafloor in coastal areas on the continental shelf, and in the open ocean they are found along the outer continental margin on the continental slope and the continental rise.

Main diet of deep sea benthic Pelagic fish is invertebrates of the deep sea benthos and carrion.

Deep sea benthic fish can be divided into strictly benthic fish and benthopelagic fish.

Usually, strictly benthic fish are negatively buoyant, while benthopelagic fish are neutrally buoyant.

Robust benthopelagic fish are muscular swimmers that actively cruise the bottom searching for prey.

Benthic fish are not pelagic fish, but they are discussed here briefly, by way of completeness and contrast.

Deepest-living Pelagic fish known, the strictly benthic Abyssobrotula galatheae, eel-like and blind, feeds on benthic invertebrates.

Small pelagic fish are usually forage fish that are hunted by larger pelagic fish and other predators.

Forage Pelagic fish are generally short-lived, and their stocks fluctuate markedly over the years.

Many large pelagic fish are oceanic nomadic species that undertake long offshore migrations.

Examples of larger pelagic fish are tuna, billfish, king mackerel, sharks, and large rays.

Ocean currents can shape how Pelagic fish are distributed, both concentrating and dispersing them.

Epipelagic fish generally move long distances between feeding and spawning areas, or as a response to changes in the ocean.