I doubt that Zetsu just went on and destroyed the bodies. I'm sure Obito gave them a burial somewhere as they had done so much for Akatsuki. And btw, Zetsu only disposed off a clone of Kisame, not the original. Other than that he didnt gulp down any other member. If you see how the others died,
1) Sasori was probably taken back to the hidden sand.
2) Deidara exploded so i think that one is still unclear. But i have a feeling that oro managed to get some DNA out of him and kabuto used that to bring him back to life.
3) Itachi's body was taken away by Obito i guess but kabuto must have managed to get a hold of it somehow.
4) Kisame was not brought back as his body was eaten/destroyed.
5) Nagato got a burial
7) Kakuzu's body was probably stolen somehow.
thanks for the comment, youre right but i thought of the ones, that have been controlled by (idk sasoris or pains) technique... with that they turned into kisame and itachi right at the beginning of shippuuden (gaara arc)