Question: what mamal lives in water that can weigh up to 45 kilograms and is indangered species? son's school project

Answer: 45 Kilograms sounds small - mammals living in water tend to be large, because they need insulation to counter the good conductor of heat that water is. If you mean 450Kg, then the answer is the Manatee, because it is a mammal living in water and is endangered.
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