I've seen plenty of photos of gigs in Singapore (via Wild Singapore) living in very turbid water. Some photos show them at low tide exposed to direct sunlight.Are they typically found in silty/unclear water in the wild? If I remember correctly, giganteas in Singapore are found in similar conditions.
Makes me wonder how much they have to adapt for our reefs, and if their native conditions actually foster greater opportunity for rampant spread of infection during transport.
Obviously they've adapted to less than optimal living conditions. However, even under these conditions they have plenty of seawater to flush out pathogens, which typically doesn't happen once they enter the supply chain.