Fish:
* Ammonia: Most fish excrete waste in the form of ammonia, which is toxic. This is why fish live in water, as ammonia quickly dilutes in water.
* Through their gills: Fish release ammonia directly into the water through their gills.
* Urine: Some fish also have kidneys and release urine through a small opening near the anus.
Marine Mammals:
* Urine: Like land mammals, marine mammals (whales, dolphins, seals, etc.) produce urine. They have kidneys that filter waste products from the blood and produce urine.
* Through a urinary opening: They release urine through a small opening near the anus.
* Special adaptations: Some marine mammals, like sea otters, have adapted to have very concentrated urine to conserve water in their marine environment.
Other Sea Animals:
* Invertebrates: Some invertebrates like jellyfish and starfish don't have specific organs for excretion. They release waste directly into the surrounding water through their body surface.
* Other methods: Different species have different methods. Some, like sea turtles, have cloacas, a single opening for excretion, reproduction, and waste removal.
Here are some interesting facts about sea animal waste:
* Whale pee: A blue whale can produce up to 100 gallons of urine in a single urination!
* Fish urine: Fish urine is often very dilute to minimize the toxicity of ammonia in their environment.
* Sharks' urine: Sharks use their urea, a component of urine, to help regulate their body's salt levels.
Overall, sea animals have evolved different ways to excrete waste depending on their environment and species.