Its hard to tell from your pics, but if they are in fact sponges and they were exposed to air for too long, they will most likely die. You might want to reconsider putting them in your tank. Its probably a good idea to set up a seperate tank for them and see how they do.
i assume they are dead from being washed up, would nt harvest from ocean i think thats illegal. just wonder if they will be able to be used as a decoration or will they rot in a tank, currently in an isolation tank