A recent study indicates that rising carbon dioxide (CO2) levels in the ocean could significantly reduce the brain volume of squid, potentially impacting their cognitive functions. The research found that squid raised in water with elevated CO2 levels experienced a nearly 50% decrease in brain volume compared to those in current ocean conditions.
The study, published in TIME, observed that the brain volume of squid in the elevated-CO2 tank was 49% smaller than the control group. This reduction was not localized to specific brain regions, with the optic lobes and optic tract showing significant decreases of 52% and 62%, respectively. The optic lobes and optic tract are crucial for processing visual information.
Researchers are exploring the underlying mechanism for this brain shrinkage. One hypothesis suggests that developing squid brains might be deprived of adequate energy, hindering their growth. An alternative theory posits that the brain volume may be reduced due to damage, possibly from oxidative stress, leading to brain atrophy.
While the squid in the experiment did not survive long enough to directly observe behavioral changes, the study’s lead, Allen, suggested potential implications based on prior research. Previous work by the team found that squid reared under similar conditions showed a reduced willingness to feed. Allen proposed that this reduced brain volume might influence decision-making, potentially making the squid more hesitant rather than less effective as predators.