what is the bathypelagic zone?
Welcome to solsarin site ,Keep reading and find the answer about “what is the bathypelagic zone? ”.
Stay with us.
Thank you for your support.
Bathyal zone
The bathyal zone or bathypelagic – from Greek βαθύς, deep – is the part of the pelagic zone that extends from a depth of 1000 to 4000 metres below the ocean surface. It lies between the mesopelagic above, and the abyssopelagic below. The average temperature hovers at about 39 °F. Although larger by volume than the euphotic zone, the bathyal zone is less densely populated. Sunlight does not reach this zone, meaning there can be no primary production. It is known as the midnight zone because of this feature. Because of the lack of light, some species do not have eyes, however those possessing eyes in this zone include the viperfish and the frill shark.
Many forms of nekton live in the bathyal zone, such as squid, large whales, and octopuses, but this zone is difficult for fish to live in. Sponges, brachiopods, sea stars, and echinoids are also common in the bathyal zone. The fish in this zone have become very energy efficient, since it is especially hard to find nutrients. Many have slow metabolic rates to conserve energy. The fish here have weak muscles, soft skin and slimy bodies. Animals in the bathyal zone are not threatened by predators that can see them, so they do not have powerful muscles.
Animals need to have the right adaptations to survive in this lethal area. There are no plants because of the lack of sunlight necessary for photosynthesis. In the bathyal some of the world’s largest whales feed. The adaptations of some of the fish that live there include small eyes and transparent skin.
A layer of the oceanic zone lying below the mesopelagic zone and above the abyssopelagic zone, at depths generally between about 1,000 and 4,000 m (3,280-13,120 ft). The bathypelagic zone receives no sunlight and water pressure is considerable. The abundance and diversity of marine life decreases with depth through this and the lower zones.
Bathypelagic zone, Worldwide zone of deep ocean waters, about 3,000–13,000 ft (1,000–4,000 m) below the surface. It is inhabited by a wide variety of marine forms, including eels, fishes, mollusks, and others.
Science, any system of knowledge that is concerned with the physical world and its phenomena and that entails unbiased observations and systematic experimentation. In general, a science involves a pursuit of knowledge covering general truths or the operations of fundamental laws.
Science can be divided into different branches based on the subject of study. The physical sciences study the inorganic world and comprise the fields of astronomy, physics, chemistry, and the Earth sciences. The biological sciences such as biology and medicine study the organic world of life and its processes. Social sciences like anthropology and economics study the social and cultural aspects of human behaviour.
Science is further treated in a number of articles. For the basic aspects of the scientific approach, see physical science, principles of; and scientific method.
In the bathypelagic zone (1,000–4,000 metres deep) there is a total absence of sunlight. Bioluminescence (light produced by living creatures) is the only source of light.
Food is even scarcer than in the mesopelagic zone above. With less energy available, most of the fish are ‘sit and wait’ predators, or actively attract prey with bioluminescent lures. Bathypelagic organisms are mostly black, red or transparent, rendering them essentially invisible in the weak biological light.
Bristlemouths and deep-sea angler fish are the commonest fish, typically less than 10 centimetres long. Their small size reduces metabolic demands. Compared with their mesopelagic relatives, bathypelagic fish tend to have lower metabolic rates, less developed gills and muscles, and small eyes – if they have them at all.
Surface shock
Adapted to great depths, bizarre-looking fish from the bathypelagic zone look even less pretty when hauled to the surface, where the pressure is several hundred times lower. Their eyes bulge, and gases in their system expand, causing the fish to burst.
More posts for passionate readers:
Feeding strategies
Because only 5% of the food produced up in the epipelagic zone reaches the deep sea, many deep-sea fish will eat anything that comes their way, exhibiting extraordinary adaptations to enable this. The swallower eel (Saccopharynx lavenbergi) and the gulper eel (Eurypharynx pelecanoides) have gigantic jaws, mouths lined with many teeth, and highly elastic stomachs that can accommodate prey larger than themselves.
Related to the gulper eel is the remarkable monognathid eel (Monognathus bertini), with a hooked fang made from fused frontal bones and linked to what may be venom glands. Glands in the snout and dorsal fin secrete substances that attract shrimps which the eel grasps, forces against the fang and injects with venom. This meal provides enough nutrients for the eel to mature, after which the lower jaw degenerates and the eel eventually dies.
Mating
Finding a mate is also difficult in the deep ocean. Angler fish have developed an unusual solution. The female releases pheromones that the tiny male fish home in on. When they reach the female they bite her and hold on, never to let go.
In some species the male’s jaw fuses with the female tissue, the two circulatory systems join up and the male degenerates until he is little more than a bag of testes subject entirely to the hormonal regime of his host. Being smaller, the male requires much less food, leaving more for the female’s reproduction requirements.
Other deep-sea fish are hermaphroditic (with male and female sex organs), ensuring that a chance encounter between any two fish will provide both eggs and sperm. However, most deep-sea invertebrates do not use such strategies. They may depend on bioluminescence to attract each other.
Fish in the Bathyl Zone
Most fish that live in the bathyal zone are either black or red in color. This is as a defense against predators — with only minute amounts of blue-green light, red is not reflected and appears black. There is no primary production of plant life in the bathyal zone, so all creatures that live there are carnivorous, eating each other or feeding on carcasses that sink down from above.
Examples include the hagfish which have rasping mouthparts for tearing flesh from carcasses, viperfish which have large eyes to detect prey and scavenging sharks, such as the frill shark and sleeper shark. Other fish attract prey with bioluminescent (light produced by a living organism) lures, including the dragonfish and the angler fish.
Eels
The long, thin bodies of eels are adaptable to the pressures of the bathyal zone. The two most common species are the swallower eel and the gulper eel. Both have large mouth lined with teeth that are capable of accommodating prey much larger than themselves.
Crustaceans
Crustaceans scavenge organic debris that floats down from above. They are either open water dwellers, such as the amphipod which is transparent for camouflage (although it still provides an important food source for other, larger bathyal zone animals, such as jellyfish), or bottom-dwellers like the slimestar which sifts for organic matter amid the silt on the ocean floor.
Squid
The most common squid found in the bathyal zone is the vampire squid, so named for its hunting strategy of descending on prey and draping its tentacles over it like a cloak or net. The vampire squid’s tentacles are lined with sharp spines to catch it prey with. The bathyal zone is also home to the elusive giant squid which, though rarely seen in its natural habitat, is estimated to grow to more than 40 feet in length.
Whales
No whale species live permanently in the bathyal zone, but sperm whales, with the large proportion of tissue in their heads protecting them from the immense pressures at depth, are capable of diving into the bathyal zone to hunt. They prey on squid, including the giant squid.
