Because the fish was dying it represented the grenade without its pin.Therefore you have little time to throw it before it explodes and in this casethe fish was suffocating and had a set time before it died.
In the fall of the House of Usher is a short story written by Edgar Allan Poe. The story has portrayed the love of two siblings where one is ill and the other is sadly demised by the death. Roderick is sadly in deep sorrows because of Madeline illness. She is decaying from inside because of her illness and is gradually moving towards death.