Ink squirts make squid swim for their lives

时间:2017-06-19 07:00:18166网络整理admin

By Matt Kaplan Video: Ink squirts make squid run for their lives Squid can’t shout out in alarm to their comrades when danger threatens, but they certainly can squirt out, and this, it seems, serves the same purpose. It is assumed that the main reason squid squirt ink is to have a “cloaking device”, allowing them to escape from predators – but other squid may pick up on it as well. “When fish bleed, the scent of their blood has been proven to alert nearby fish of danger, so I wondered if ink was also being used as some form of alarm,” says marine biologist James Wood of the Bermuda Institute of Ocean Sciences, who was well aware of the complexities of cephalopod communication. Wood and colleagues collected ink from individual squid by scaring them with a shake of their aquaria. The team then either added a dose of ink to a squid’s aquarium, to a nearby unoccupied aquarium, or added ink that had had the dark melanin colouring removed. In the first two cases, the Caribbean reef squid (Sepioteuthis sepioidea) took evasive action. However, ink that lacked melanin had no effect on squid behaviour, suggesting that it was a visual, not a chemical, signal. Unlike these reef squid, which are social and live where it is light, “the majority of squid are asocial and live in darkness, so it would be interesting to carry out similar work in other species,” says Stephanie Bush, of Monterey Bay Aquarium Research Institute. Journal reference: Journal of Experimental Marine Biology and Ecology, DOI: 10.1016/j.jembe.2008.08.004 Mysteries of the Deep Sea -The deep sea is one of the harshest habitats on Earth, but is home to many remarkable creatures. Learn more in our comprehensive special report. More on these topics: