Dear Whitney,
some news from Italy: byssal threads of Pinna can be used to obtain a
smooth, sericeus and brown-golden tissue called "sea-silk"; till XVIII
century people living along the coast of Sicily, Calabria, city of Taranto
(south of Italy) and Malta used this tissue to make gloves, ties, etc...
I have heard also that the one of Mitilus were used to make ropes, but I
have no scientific confirmation of it.
Ciao
Sandro