 Bigfin reef squids are also valuable sources for squid giant axons used in research in neuroscience and physiology . Unlike axons of other animals , squid axons are very large . Those of bigfin reef squids can range in diameter from 350 to 560 μm ( in contrast to the typical 1 μm for humans ) . In life , these giant axons are used by the squids to coordinate escape jetting behaviour , enabling the squid to contract its muscles in a split second directly from the brain . 
