Which of the sponge is given as a gift in Japan?

The Venus flower basket or Euplectella is a marine sponge found in the deep waters of the Pacific ocean. The shrimps live inside the sponge until they die. 

Hence, the symbiotic association of shrimps with sponge Euplectella show an example of union till death and the dried and dead sponge is given as a wedding gift in Japan to symbolise the love of 'till death do us part'.