Your 'clam' is not a clam but a native freshwater mussel, family Unionidae.
I don't know where you are located, and this make thye id somewhat uncertain, but from the looks of it, it appears to be a FatMucket (Lampsilis radiata, also known as Lampsilis siliquoida, or even L. radiata siliquoida).
Although fish will certainly eat it if given to them, and the possibility of introducing parasites that will affrect your fish is quite small, you should NOT DO ANY of this, and instead, you should return the fatmucket to the creek, and not collect any more. Instread, be happy that the creek where you found it is still healthy enough to support this, and hopefully other species of freshwater mussels.
FW mussels are probably the most endangered group of freshwater animals in the US. Although some species are quite common, such as the fatmucket, their populations, the very habitats where they live, and their genetic diversity is severely imperiled. Their reproduction involves stages where their larvae (glochidia) are parasitic on fish, wwith some species having very specific (unique) fish species used as suitable hosts, whereas some are somewhat more generalistic. But this is another source of imperilement, as in many cases, the mussel populations, the fish hosts, and the habitats themselves are imperiled, primarily due to human activity (mainly pollution and habitat modification).
Furthermore, there are severe restrictions in a number of states against collecting these mussels (of course very difficult to enforce), and these restrictions are for good reasons and corresponding to their severe imperiled status.
Again, please do the right thing - Return the mussel to the creek if still alive, be proud that your creek still harbors these beautiful animals, and admire them at their home when you see them in the creek. Cheers to you!