9. Bar bellied seasnake, elegant sea snake (Hydrophis elegans)
LD50: 0.27
This aquatic species is indigenous to northern and eastern coasts of Australia. It inhabits fresh waters equally as the sea, preferring muddy soft estuarine surroundings. It is the longest aquatic snake species, whose length reaches 2 meters. It is also known under the common name the elegant sea snake for its slender body, usually gray or olive in color, with darker dots which form banded patterns.