Del océano al verso. Las caracolas de Pablo Neruda

gigas (Linnaeus, 1758), today critically endangered, maintains a symbiotic relation with the zooxanthellae algae, a species that provides the mollusc with nutrients thanks to photosynthesis. In turn, Tridacna gigas offers protection and proximity to sunlight. 29 The shells of the molluscs are made up of calcium carbonate obtained from the water, their food and their environment. When they die, the calcium returns to the water, which results in the benefit of other organisms. Some species produce nacre, also called mother of pearl, a biomineral formed by the accumulation of fine layers of calcium carbonate and other minerals. Its brightness is produced as sunlight decomposes while crossing those layers. 30 This substance is smooth and soft, and it coats the shell’s interior to protect the soft part of the mollusc. There are species that cover foreign objects that enter the shell to avoid any damage to their internal parts, this is why some molluscs species produce pearls. The iridescent beauty of nacre has called the attention of human beings for thousands of years and they have used it to create all sorts of ornaments. There are species like Rochia nilotica (Linnaeus, 1767), farmed to extract nacre through a process in which acid is applied. Because of the dangers associated with the overexploitation of this species, some countries in the Pacific Ocean have regulated their extraction, with the aim of avoiding further damage to its population. [29] Mei Lin Neo et al., "The Ecological Significance of Giant Clams in Coral Reef Ecosystems", Biological Conservation 181 (2015): 111-123. [30] Micheline Cariño y Mario Monteforte. "De la sobreexplotación a la sustentabilidad: Nácar y perlas en la historia mundial". El Periplo Sustentable 12 (2007): 85. 114 universidad de chile