Changes in stool color alone do not cause symptoms. The underlying cause of the change in stool color, texture, or form is responsible for any symptoms. Bowel movements are usually light to dark brown in color, and there is moderate variation among individuals with respect to stool color, quantity and form.
Plants in the Twilight Zone As the amount of light decreases, the size and complexity of plant life also decreases. So whereas there may be flowering plants growing in the entrance zone, the twilight zone is typically marked by mosses and ferns.
the mesopelagic, or twilight, zone: a dim zone where some light penetrates, but not enough for plants to grow. the bathypelagic, or midnight, zone: the deep ocean layer where no light penetrates. the abyssal zone: the pitch-black bottom layer of the ocean; the water here is almost freezing and its pressure is immense. the hadal zone: the waters found in the ocean's deepest trenches. Plants are found only in the sunlit zone where there is enough light for photosynthesis, however, animals are found at all depths of the oceans though their numbers are greater near the surface where food is plentiful.