One of the Antarctic octopuses discovered by Bryan Fry and his team on the Australian Antarctic Division's research cruise
Credit: Courtesy of Bryan Fry
SYDNEY: Antarctic octopuses contain venom that is active in sub-zero climates, at temperatures which would render most other venoms useless, Australian scientists have discovered.
Enzymes in the octopuses' venom become more active at 0°C, as opposed to 37°C, which is the optimal temperature for most venom activity. This enables the octopuses’ venom to be effective in their sub-zero surroundings.
This new finding helps to explain how some animals have adapted their venom to be effective in cold climate environments. It's hoped that a better understanding of the composition of venom may also lead to new drug developments.
New species discovered, venom tested
While on the Australian Antarctic Division’s third International Polar Year research cruise, Bryan Fry from the University of Melbourne, lead author of the research published in Toxicon, and his team collected 203 octopuses, discovering in the process four new species.
Choosing four known Antarctic octopus species, they tested the composition and effectiveness of the venom in relation to the extreme temperatures of their environment.
The effectiveness of all venom is temperature dependent, with most enzyme activity peaking within certain temperatures ranges and ceasing when things become more extreme. If it reaches below 4°C, most venom is virtually inactive.
Octopus venom more effective in the cold
Most venomous animals such as snakes, spiders and jellyfish, have an optimal thermal range between 25°C and 65°C, and the further outside this range the temperature goes (on either side) the less active venom.
However, Fry and his team discovered that the venom of Antarctic octopuses peaks at 0°C.
“Not only do Antarctic octopuses have the most unique venoms out there, but there is a lot more species than we originally thought,” said Fry in a statement.
