Published:
A new study has found that lizards eat fire ants, a highly poisonous and invasive species found in many parts of the world, to obtain some protection against their bites.
Lizards eat fire ants to develop greater immunity to their poisonous stings.
Fire ants in the US are an invasive species. Their stings kill native animals and are dangerous even to humans.
Ant stings can cause iguanas to become paralyzed or die. These lizards have no natural protection against these insects. But the eastern US lizards (‘Sceloporus undulatus’), found a way to protect themselves.
These medium-sized iguanas eat dead red ants, or fire ants (‘Solenopsis invicta’). By ingesting them they receive a small dose of their poison and thus make their body immune to possible poisoning, according to a statement from the University of Pennsylvania, USA, a group of scientists has studied the immune system of these reptiles .
By digesting and processing the ants and their venom, your immune system can be primed to fight it off, as if you had a vaccine against ant venom. This suggests that native species may adapt to protect themselves against other invasive species, allowing them to coexist rather than be eradicated by invasive insects.
“We know that lizards in areas where there are also fire ants that have different immune profiles than lizards from other areas,” said study lead author Tracy Langkilde, a professor of biology at the University. “Because the immune system is so critical to survival, we wanted to determine whether these differences in immune profiles can be directly attributed to lizards frequently being stung by fire ants and eating them, or another thing,” he explained.
To investigate this question, the biologists divided the lizards into two groups. For three weeks, the scientists fed the reptiles of the first group with ants and then were subjected to stings from these insects. The second group only suffered bites without having previously eaten the ants.
Subsequent analysis revealed that the group of lizards fed fire ants presented improvements in three immune markers compared to lizards that were only repeatedly stung: an elevation in levels of a type of white blood cell called basophils; an increase in complement activity that helps antibodies and other parts of the immune system work properly; and an increase in a type of immunoglobulin (IgM) antibody known to be reactive to fire ant venom.
“For example, antibodies and specific complement from the fire ant could help keep the venom from negatively affecting the body,” said lead study author Catherine Tylan.
