The Avicennia is a plant living in mangrove swamp. As the mud of mangroves has a very low oxygen content, A. marina has roots that grow vertically from the ground called Pneumatophores to obtain oxygen. Pneumatophores have loosely packed tissues to allow effective diffusion of gases into the pith.
When the root is covered by water, the root does not allow water or air to enter, when the tide recedes, air is sucked in.
Adaptations of mangrove trees to the environment (http://ecology.hku.hk/jupas/Mangrove/adaptations.htm)
Fur: thick, oily fur coats and a layer of blubber to insulate the heat in their bodies.
Special feet: that allows them to walk properly on the ice and snow without slipping and falling.
Large teeth and claws: to prevent its prey from escaping as food is scarce in the Arctic regions.
The angler fish lives at depth so deep that there is virtually no light at all.
The angler fish uses a rod-like structure which is actually a fin ray. It emits light which attracts prey in the darkness. The prey is attracted to the light and as the prey swims closer, the angler fish will gobble up the prey.