it's not skin it's their slime coat. My TSNs, RTC, and limas all shed it if they get overspooked. Especially the limas. RTC sheds the least out of all mine. Limas seem to do it at least once per week, but will do it everyday if spooked. RTC I rarely ever see shed. The TSNs maybe once per month, but that's even rare for them. Have never seen any of my hybrids shed. Have seen my Jau shed, and Jurense, but not filamentosum.