3618446 TTX-R tetrodotoxin-resistant 205 3618445 TTX-R TTX-resistant 53 3618444 TTX-R tetrodotoxin 5 3618451 TTX-R tetrodotoxin-sensitive(TTX-S) and tetrodotoxin-resistant 1 3618452 TTX-R than two-fold reduction of tetrodotoxin-resistant 1 3618450 TTX-R transient tetrodotoxin-resistant 1 3618453 TTX-R Two TTX-resistant 1