What is an adaptation another species have developed to resist the toxic sting of a nematocyst?

The mucus coat of clownfish protects the fish from sea anemone's sting which is an adaptation clownfish developed.

Nematocysts are cells found in which is use for locomotion and for defence and capturing prey.

Therefore, The mucus coat of clownfish protects the fish from sea anemone's sting which is an adaptation clownfish developed

For more details on nematocysts check the link below.

link

The mouth covered by chitin and intracellular granules of chitin (i.e. spindles) in nudibranchs

Explanation:

Nudibranchs are marine gastropod molluscs (Opisthobranchia, Mollusca). These organisms are carnivorous, so they feed on sponges, coral, anemones, hydroids, fish eggs, etc. On the other hand, cnidarians have specialized cells called cnidoblasts or cnidocytes that contain nematocysts made up of toxins that serve as a defense mechanism. Nematocysts are found in many species of Cnidarians such as, for example, in the tentacles of sea anemones. Interestingly, nudibranchs have developed some adaptations for feeding on these species. In the first place, nudibranchs have the mouth covered by a substance named chitin that allows them to chomp and swallow anemone tentacles. Second, they (nudibranchs) also have intracellular granules of chitin (i.e. spindles) in the digestive system that function as biological sandbags which maintain nematocyst toxins away from sensitive body parts.

oxygen is the first element in group 16 (via) of the periodic table. the periodic table is a chart that shows how chemical elements are related to each other. the elements in group 16 are said to belong to the chalcogen family. other elements in this group include  sulfur, selenium, tellurium,  and  polonium.  the name chalcogen comes from the greek word  chalkos,  meaning "ore." the first two members of the family, oxygen and sulfur, are found in most ores.

oxygen is by far the most abundant element in the earth's crust. nearly half of all the atoms in the earth are oxygen atoms. oxygen also makes up about one-fifth of the earth's atmosphere. nearly 90 percent of the weight of the oceans is due to oxygen. in addition, oxygen is thought to be the third most abundant element in the universe and in the solar system.