Deep Sea Gigantism Explained

[Music] life in the deep is well known to be both diverse and strange throughout history our nightmares have been fueled by tales brought back by seafarers of giant monsters from the depths and leviathans larger than life while there may be no lovecraftian horrors lurking in our oceans it may be true that the deeper you go the larger and stranger the animals become [Music] the phenomenon of deep sea gigantism is defined as the tendency for deep sea animals to grow much larger than their shallower water relatives biologists still aren't certain why it is that some abyssal creatures grow to these immense sizes for we have still only scratched the surface of discovery in the deep but there are many theories which may help to shed light on this mystery of the oceanic deep at first look you might think that if anything the immense pressure of the deep sea would stunt the growth of animals and keep them smaller rather than larger but in fact this pressure isn't much of an issue for creatures that are themselves for the most part made of water in fact the buoyancy of ocean life means they don't need to work against gravity and it is this that allows them to grow so large this explains how deep sea organisms can become so huge but in order to find out why they do we need to delve into their biology their immense growth can be explained in general terms by two laws known as cleaver's rule and bergman's rule clebus rule states that animals that are larger will tend to be more efficient a whale for example having a mass hundreds of times that of a small fish will have a metabolism that is significantly greater this is due to the nature of blood vessels and the circulatory system of animals larger animals have smaller surface area to volume ratios so less energy is lost through heat huge animals dwelling in the ocean's depths rely on organic matter falling from above for food meaning food is scarce and energy must be conserved this is their incentive to become more efficient and thus to grow to larger sizes the bergman's rule states that sea animals tend to increase in body size with a decrease in temperature most of the large sea animals are typically found in colder regions or the small sea creatures are found in warm regions for these animals the low temperatures in their habitats lead to increased cell size and lifespan as it slows their metabolic rate [Music] the bergman's rule also explains why the phenomenon of gigantism is most prevalent at the poles where animals like sea spiders sponges and worms all grow huge compared to their relatives from warmer climates the slowing of their metabolisms means they can be described as living in relative slow motion growing to huge sizes due to the immense supply of oxygen in colder waters for well over a century zoologists and explorers to the poles have recorded their observations from dredging creatures from the deaths noting the bizarre life that they encountered including sea spiders the size of dinner plates one of the most common illustrations of deep sea gigantism is the colossal squid a 700 kilogram 15 meter long creature which dwells 2 100 meters below the surface one theory that may explain both polar and deep sea gigantism is the role of predators or more specifically the lack of predators in 2006 biologist craig r mclean examined the gradient from the shallows to the depths using the framework of terrestrial islands oceanic islands are isolated from other land masses so they tend to develop indigenous biodiversity through diversification of the organisms that arrived there due to limited resources competition and predators island fauna often follows what is known as the island rule which states that small-bodied organisms have a tendency to grow larger on islands this is demonstrated by creatures like the enormous galapagos tortoise which has been isolated for three million years charles darwin famously referred to them as inhabitants of some other planet the oldest galapagos taught us on record lived to be 152 according to mclean the deep sea is functionally similar to an island in a fashion that seems to mirror the island rule the deep sea also has limited resources limited predators and is isolated from the rest of the ocean as a result there was diversification in the depths too following a mass extinction event that occurred during the cenozoic period 65 million years ago shallow water creatures ventured deeper after the event and diversified into deep sea fauna a brilliant example to show that deep sea fauna does indeed follow this rule is the mollusc group gastropods which includes slugs and snails in the deep many species that are near symmetrical to shallower varieties grow to be huge the deep sea isopod belongs to a group that rarely grows larger than a few inches in the shallows but down here they can grow to half a meter in length and weigh approximately 1.7 kilograms one variety the giant isopod is found in the deep cold waters of the pacific ocean the atlantic ocean and the arctic ocean many of the resources in the deep ocean result from productivity in shallower water so a lot of energy is lost on the way down as a result resources in the deep sea are lesser and so larger body sizes are favorable they can better withstand long periods without food and can cover very large distances in search of prey overall deep sea gigantism largely serves to demonstrate the role of natural selection in driving evolution and survival in the sunless depths evolution tends towards the most effective adaptations to allow for the best chances of survival down here bigger is better the research that has been done into the causes of deep sea gigantism has significant implications in the human world there is evidence that climate change may have a greater impact on ocean dwellers than any other population of animals as the colder oceans warm up a change in the balance of temperature oxygen supply and what organisms are present will throw the equilibrium off course and the giants would be the first to go [Music] you

Channel: Natural World Facts

Views: 3,545,587

Rating: 4.9320993 out of 5

Keywords: deep sea, deep sea creatures, giant squid, deep sea gigantism, deep sea wonders, deep sea diving, deep ocean, giant eel, giant isopod, giant sea creatures, deep ocean creatures, giant ocean creatures, terrifying ocean, terrifying deep sea, how deep ocean, deep sea mysteries, ocean, mariana trench, deepest point of the ocean, marine snow, frilled shark, snail fish, twillight zone, titanic, abyssal, abyssal depth, abyss, abyssal plain, hadal zone, midnight zone, blobfish

Id: jwwBHgl5zJo

Length: 8min 10sec (490 seconds)

Published: Tue Oct 06 2020

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[u/Countess_Chunkula]

Did you make this? :⁾