When I lived in China, I purchased many live shells at wet markets.
Rather than saying self-collected, on my labels I wrote (for example):
Personally collected live at:
Tongchuan Lu Wet Market, Shanghai, China. May 17, 2013.
Giving the judge the discretion to decide if it is self-collected or not.
The shells I found on the shores, in water, or on trees, etc., were labeled as self-collected.
Les