The answer is excess water from entering their bodies.
*Some freshwater animals have adapted flame cells, watery urine production, and salt pumps to prevent excess water from entering their bodies.
*Flame cells- this is a specialized excretory cell that acts like kidneys that remove waste material through filtration.
*Watery urine production- helps the freshwater water animals to maintain their blood osmotic pressure as well as their blood concentration levels. They typically have more salt concentration compared to their environment which is the cause why water enters their body through osmosis. Their urine becomes dilute because of the large water uptake.
*Salt pumps- this helps the freshwater animals to maintain homeostasis.
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