In the deep sea, organisms must be adapted to survive stresses absent in surface waters such as extreme pressure, lack of light, food scarcity, flows of toxic chemicals and other factors that make it difficult to thrive in life. Symbiotic relationships – the interaction between two different organisms that share a close association with each other – allow organisms to better survive predation, starvation and habitat variability. In cases involving mutualism, both parties benefit from the association in various ways. By studying these different interactions between species, it can reveal how adapted organisms are to evolve and acclimatise in this extreme environment to persist here, co-dependent or simply exploiting some of the characteristics of others. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay In established mutualistic relationships, species can shape their morphology to support their interactions. This can be seen in the case of the hydrothermal shrimp Rimicaris exoculata. The crustacean has a dense covering of bristles in the mouthparts that host the bacterial epibionts - Epsilonproteobacteria and Gammaproterobacteria - necessary to oxidize the sulfur and iron compounds expelled from the vent fluids. To support even as many ectosymbionts as possible, the species has developed a large cephalothorax, the inner side of which supports the setae. R. exoculuta obtains a rich source of nutrition from these symbiotic chemoautotrophic bacteria, presumably through transepidermal mechanisms. In turn, the ectosymbionts live in an optimal microenvironment exposed to a constant supply of electron donors and acceptors from source ejections, as the shrimp migrate to richer waters where ventilation currents are stronger to enhance the productivity of the bacteria ( Jillian Peterson). GURI studied the ectosymbiont structure during various life stages in hatchling shrimp. Shrimp have been found to interact with bacteria from the beginning of the life cycle, as gammaproteobacteria in the mucus surrounding the eggs can act as a protective element allowing for detoxification and defense against pathogens. Peterson's study of these epibionts revealed that there was variation in the dominance of the bacteria as the geochemical locations of the shrimp changed between oxidized seawater and chemical flows, suggesting that comparing the distribution patterns of these symbiotic bacteria will help to understand the evolutionary processes of migration and symbiont-host associations. From these studies we see that the two organisms have developed a stable mutualistic relationship that allows both to survive in this difficult environment. Allantactis parasitica and various deep-sea gastropods along the east coast of Canada, at depths up to 1100 m, have established facultative mutualism resulting from predation pressures on both species. A. parasitica selects specific locations on the shells depending on the size of its body. Mainly, gastropod species deter predators such as Leptasterias polaris with the presence of one or more anemones present in its whorl. The anemone almost always has its tentacles extended, creating a shielding effect that makes the gastropod even more invisible to such predators. Mericer Hamel 2008 found that in 100% of cases studied, predators made no obvious effort to approach gastropods with anemones present. In turn, A. parasitica is protected by the Crossaster papposus as the movements of the disturbedgastropods make it more difficult for starfish to capture the anemone. Although the two species are not co-dependent on each other, studies have shown that throughout the life cycle of A. parisitica, even from the juvenile stages, the species will choose to move on a living surface rather than on a with soft sediments. Other advantages of this symbiotic relationship are that the life of the anemone associated with a gastropod results in greater reproductive and growth success (reproduction+settle). The researchers found that A. parasitica developed twice as fast as juveniles as a result of greater food availability made available by upwelling nutrients while the gastropod counterpart moved. The species also reached its adult maximum after 6-7 years, unlike its asymbiotic relatives, which reached this level of growth after at least 11 years. It has also been observed that the larger anemones position themselves on the last turn of the shell in order to have optimal access to the food made available by the burrowing action of the basibiont. Smaller anemones, including young ones, are located further from the ground because they are not as likely to be pushed out of their shells or smothered by the amount of particles disturbed by gastropod movements. It was observed during studies on Rhinoclavis articulare that 4-6 anemones could also be found in shell thickets as the siphonal canal could protect the epibionts from scraping during the gastropod's journey, it was also seen that A. parasitica synchronizes the periods of oviposition with that of gastropods in 52% of the cases studied by Reproduction People. The congregation of species such as Neptunea despecta and Colus stimpsoni to breed meant that the anemone species were in close association while positioned on the eddies. Even by laying eggs during this period, fertilization rates were maximized. The anemone was also affected by the diet of its basibiont as Feeding People found that the asymbiotic counterparts had a much less diverse diet, with fewer bathyl organisms present in their gastrovacular cavity. This suggests that snail sediment foraging makes different food particles available to A. parasitica, more often throughout the day. With predators deterred, gastropods can feed for longer, uninterrupted periods, and anemones can take advantage of a constant supply of rich food sources. There are up to 17 evolutionary accounts of bioluminescence in ray-finned fishes in association with symbiotic bacteria, however, it is still unknown whether the participants coevolved together over time. The relationships between host and bacteria are quite fluid, with fish organs harboring several bacterial populations, not just one, and microbial symbionts found in contact with many other species. While there is little to no specificity between bioluminescent bacteria and their hosts, this relationship is clearly important to the two parties as it has continued to develop. The fish, which obtain the bacteria from their local environment, use the light produced to attract prey, camouflage, defend themselves and communicate. The bacteria, which decompose luciferin compounds using luciferase in the presence of oxygen to generate light, are well hosted by their hosts, who have evolved many structures to concentrate, control and display bioluminescence. Here the microbes receive nutrients and a safe environment. Because intra-species encounters in the vast deep sea are unpredictable, organisms must maximize their ability to successfully reproduce and produce viable offspring. Sex-specific bioluminescent displays have been.