The best answer is pneumatophores.
In the environment where mangroves grow, oxygen is very limited. This necessitates mangrove root system to take up oxygen from the atmosphere. For this purpose, mangrove species have specialized above ground roots called pneumatophores or breathing roots.
In some species, these roots are pencil sized and peg-like while in others they look like a knee. These roots have numerous pores through which oxygen enters into the underground tissues. In some plants, buttress roots function as breathing roots and also provide mechanical support.
Animals are often individually consistent in their behavior, not only over time, but also across different functional contexts. Recent research has focused on phenotypic and evolutionary mechanisms explaining such personality differences through selection. Parasitism and predation induce important mortality and fitness costs, and are thus main candidates to create and maintain personality differences in the wild. Here, we present data on the behavioral consistency of the Eurasian minnow (Phoxinus phoxinus) from two populations that live in different tributaries of the same river, but whose ecological environment differs fundamentally with regard to predation and parasitism. We experimentally demonstrate that individual minnow in both study populations are consistent in their boldness and activity. However, the two study populations differ notably: in the high predation and parasitism risk population fish show higher mean boldness, but tend to be less active than fish in low predation and parasitism risk population. Parasite (Diplostomum phoxini) load was negatively, but not statistically significantly, associated with fish activity level. Our study suggests that parasitism and predation are likely important agents in the ecology and evolution of animal personalities.
it is the force with which a body is attracted toward Earth or another celestial body. This means that when you are in space, away from Earth, objects do not weight anything since they do not feel gravitational attraction to the Earth. Objects can have a large mass, but weigh nothing.
