Imagine swimming through the ocean and finding yourself faced with a meter-wide (3 foot) ball of miscellaneous goo. This is what divers in the northeast Atlantic Ocean have been experiencing since 1985 – but despite 90 similar reports, the origin and purpose of these alien-like ocean orbs have remained a mystery. Now, thanks to a year-long study supported by citizen scientists published in Scientific Reports, researchers have proven that the gooey globes act as a sac for thousands of eggs from the common squid species Illex coindetii.
The study reviewed 90 reports of the blobs that occurred between 1985 and 2019, but it wasn’t until recently that tissue samples were obtained which could be used for DNA analysis. The results proved Illex coindetii to be the architect behind the giant blobs, over 50 percent of which were observed with a dark streak that ran through the blob’s center. The study authors remain unclear as to what these streaks represent, but suggestions include ink from males fertilizing the egg sacs, or something meant to better camouflage the enormous balls from predators by mimicking a large fish.
Interestingly, those samples of the thousands of eggs enveloped within the orb contained embryos at different stages of development, but with limited samples, it's difficult to make sweeping statements about the entirety of the jelly ball’s residents. “Without tissue samples from each and every record for DNA corroboration we cannot be certain that all spherical egg masses are conspecific, or that the remaining 86 observed spheres belong to Illex coindetii,” wrote the authors on the paper. “However, due to similar morphology and size of these spheres, relative to the four spheres with DNA analysis, we suspect that many of them were made by I. coindetii.”
- I. coindetii is from the Ommastrephidae family which contains some of Earth’s most common squid species. In the paper, the researchers describe a slightly stomach-churning reproductive strategy that sees the female laying an enormous egg mass that’s encased in protective mucus, keeping the eggs buoyant and inaccessible to predators.
While the sightings will no doubt have left a lasting impression on the witnesses, their rarity made it hard to pin down the source. When reports made it into the Norwegian press, scientists hatched a theory that they could be some kind of Ommastrephid egg mass, but they needed samples to confirm.
To get them, the researchers on the paper enlisted the help of citizen scientists, asking that anyone who spotted such a jelly ball try to collect a sample for DNA analysis. They were eventually able to run tests on four samples taken from different jelly balls, the removal of which wasn’t reported to have any observable impact on the egg mass as a whole.
07/04/21 This article has been updated to correct that Ommastrephidae is a family of squid not a genus.