Glassy, because of the crystals being clear and shiny and fast cooling
A fierce predator is removed from the ecosystem.
Hope this helps!
If it has valves then it is a vein.
This can affect the organisms living there because now, their environment is probably different than what they have been living in for a long time, so now they have to adapt to this new environment, and if they don't, the organisms will probably end up dying.
These fibers provide vis- ceral motor (parasympathetic) innervation to the viscera. The only cranial nerves that transmit parasympathetic fibers are the oculomotor, facial, glossopharyngeal, and vagus nerves.