Because a fish has its own scales.
because it has scales
because they have their own scales
There is no standard-size package for fish. It should weigh whatever is on the label.
oar fish weigh about 600 pounds (272 kilograms)
It really depends on the fish.
a lot
That depends on the weight of the fish as compared to the weight of the water their bodies displace. If it's a heavy, dense fish, then the tank with the fish would weigh more. If it's a light, less dense fish, then the tank with water only would weigh more. This assumes that the water displaced has been removed from the tank, right? If you are adding the fish to the water then I think it should increase the weight regardless of the density of your fish. The question then might be, does the fish weigh less when it is swimming than it would on a dry scale?
a flying fish weigh 3~6pounds. 8~9pounds if it's big as a koala.
69oz
2lbs
no
20