Newt
Newts, as with salamanders in general and other amphibians, serve as bioindicators because of their thin, sensitive skin and evidence of their presence (or absence) can serve as an indicator of the health of the environment. Most species are highly sensitive to subtle changes in the pH level of the streams and lakes where they live. Because their skin is permeable to water, they absorb oxygen and other substances they need through their skin. Scientists study the stability of the amphibian population when studying the water quality of a particular body of water.
Pseudomyrmex spinicola
Pseudomyrmex spinicola is a species of red myrmecophyte-inhabiting neotropical ants which are found only in Nicaragua and Costa Rica. They live in the thorns of a tropical trees like "Acacia collinsii" or "Acacia allenii", feeding on nectaries along with the protein and lipid-rich beltian bodies. These bodies are named for Thomas Belt, a naturalist who first described the interactions between acacias and ants in his 1874 book "Naturalist in Nicaragua." Belt's book in fact described ants of this species, then unknown.