Another driftwood id? Even tho you have only one post, that implies to me you have posted here before. And if so, joined before. You only need to join once.
I had the same thought, I do remember awhile back a question similar to this of identifying a piece of driftwood. It is almost impossible to identify drift wood from a picture because it all looks the same, washed out and discolored, and distorted grain. It has to be exposed to raw natural wood by shaving and sawing both lengthwise and cross grain to reach a reasonable conclusion as to what it might be.
In any event I would not myself put any in a fish tank with fish, they are very sensitive to anything in the water.
A similar thing happened to us years ago, my wife bought this Norfolk Pine plant from the big box store at the end of the season on sale. It was about 3' tall and came in a large pot. I made a dolly to put under it and we set it in the living room.
We had it a year or so , and we started to find 3" long red centipedes around the house. Then one day as I was watering the tree the soil started moving and there was hundreds of centipedes of all sizes coming out of the soil.
I immediately removed the potted tree to the patio and sprayed it with a bug killer. it killed the insects and the tree.
My point is that what ever is brought into the house carries what ever in on it outside.