W-shaped pupils, eight arms, and two sucker-covered tentacles with which they secure prey.
“Every time I head to the Point Lowly coastline and dive with the giant Australian cuttlefish, I’m amazed and excited by their antics,” Bronwyn Gillanders, a professor at the University of Adelaide, wrote in an article published by The Conversation.
But as the cephalopod population drops—falling from an estimated 150,000 in the late ’90s to only 13,492 in 2013—there may soon be no cuttlefish left for Gillanders to observe.
Giant Australian cuttlefish in an intimate embrace (via Mat McMillan/Bronwyn Gillanders)
Although counts in recent years suggest the creatures have recovered, my research aims to determine what sorts of factors influence this very unique … population,” she explained.
“This may allow us to better manage and protect the species,” Gillanders continued, “important not just for science, but also for the local environment and economy.”
The rockstars of the sea, these marine animals embrace a “live fast, die young” attitude: They grow rapidly, reproduce early, and then die. Giant Australian cuttlefish (which actually reach only about three feet in size) live for one to two years.
External factors, like changes in water temperature and salinity, may also be to blame for the swift decline (specifically of the giant Australian cuttlefish). Contrarily, other cephalopods have been increasing in abundance—and no one knows why.
What scientists do know, however, is that breeding aggregation skews toward males (a four-to-one average), leaving the ladies with plenty of choices. After copulation, females deposit eggs on the underside of rocks.
About three to five months later, miniature-adult cuttlefish (about the size of your thumbnail) emerge and disperse among the Upper Spencer Gulf [the westernmost of two large inlets on the southern coast of Australia] with an even sex ratio, according to Gillanders.
“Although the apparently low population size in 2013 caused great concern, we are now cautiously optimistic,” she explained. “These creatures attract tourists from around the world, who come and snorkel or scuba dive on a unique breeding aggregation. This, in turn, injects money into the local economy and diversifies business in the region.”
Source: Geek.com