Clam growing on my Clam

[dustinc]

Notice my clam hasn't been opening as much as lately and upon further investigation I noticed this... Some type of mollusk?
https://lh3.googleusercontent.com/6aO-CT_qbp2rZUmqsMg3YGcOqEh48uKBQqP_o50GosFUERpd_ltxtO yQq9vG5_6QeMxOrfzeSSjEJNAWmnGQp7erG_6gE7NOr3iVorub akgnermX1eYpJuMDExCtQWhA6DcHYGTR885-h99NSVuEluJRBQ4Bp9y2VDoNn5FCN6nTyJJJdR-a0urg_NqV2r1KwhnZUvoNvQnw6i2Ylw7G4yutV54bBibuDz2s9 BQntN7XRz6hxz_JRBLX_neBrOzQWSQJvfee_Iq3aMEE9B1vfbW fXqJHzWrDB5fl86ZXxh0OcalYkis-hixCOKaEC6O54vlcX569ZCyfcHTPa3xZ1bC9NSI84GsrOtwJQ4 Mh62x6VwNREqFoypWDOGbTs7nH-2rbuuMlZ2fORN_RujBCfvRVSX-UMaWK4FlTYh44D2rDCNr2GR4tbTEp8zx3t44e8i7N672tVb8S_ HBF-zAztwTT5UTLA6NINdM_uHtumPo0SMVha3xnP4xhJcRZXJjHnAK 58TdF-hEe43VydMtUpIi2nzXL8fD9e3tGAjBrsaWh5zS_czGl7vT1ud9 h0keGv7KhNDq_jAouyOB7RpNiGn6y8oNpET49OFhKjLXhb8fTj XCaEy-g-GnmkSFRyWM6H7arZOFltvzGgBlB0COJDvPaNs25GHSlrP6yxdH YaqY=w959-h639-no

[iamfrontosa]

sweet

[DKoKoMan]

Whoa! Did it spawn?

[IronChefItaly]

Do clams reproduce asexually or would you need to have more than one squamosa clam? Could otherwise be a standard hitchhiker. Maybe try to count the ribs and see if its the same number.

[NU-2reef]

Looks like an oyster. Should be easy enough to deal with but I don't think that's why the clam hasn't been opening up much recently