A lost marine species has been hiding in photos of other animals for decades. According to scientists, the rediscovery of the inconspicuous Haplosyllis anthogorgicola occurred by accident. A careful analysis of photographs of other animals inhabiting the same ecosystem allowed us to determine that the sea worms had not disappeared, but were simply camouflaging themselves very well.
Studying marine animals is not an easy art, especially if we are dealing with small species. Small arthropods and annelids often inhabit places inaccessible to humans – spaces between stones, sand and gravel at the bottom, or even the bodies of other, larger organisms. This was discovered by a research team from Japan and Saudi Arabia who found a trace of a species considered lost. The case was recently described in the journal “Proceedings of the Royal Society B”.
Maritime connections
The analysis started with a coral sample Anthogorgia bocki collected during a scientific expedition off the coast of Japan. In the laboratory, it turned out that the body was teeming with tiny, transparent worms. Scientists managed to determine that they are dealing with Haplosyllis anthogorgicola – a marine polychaete with an elongated body. This species has only been described once, in 1956, and no other sightings or studies have been reported in scientific journals since then.
Researchers began to wonder whether the lost species had actually disappeared for several decades or had simply been hiding well. To check this, they analyzed photos of another species found in the company of the mentioned coral – seahorse Hippocampus bargibanti – published on a website where tourists or amateur scientists can post photos of fauna and flora.
A seahorse among corals with holes dug by H. anthogorgicolaChloe Fourreau
In plain sight
As it turned out, H. anthogorgicola they appeared in about three-quarters of all the seahorse photos they examined – their inconspicuous, transparent bodies simply appeared in the background, unnoticed by photographers and researchers. The marine polychaete never hid or disappeared, it was simply forgotten by scientists.
By examining photos of polychaetes and their burrows, the research team discovered that they did not only live off the coast of Japan – traces of their occurrence were found in many regions of Southeast Asia, and their numbers were large. Based on observations of the photos, the scientists also found evidence suggesting that the worms had a symbiotic relationship with the corals. The organisms cleared the water of fragments of matter that could clog the sensitive coral polyps.
H. anthogorgicola on a coralChloe Fourreau
H. anthogorgicola burrowing into coral tissueChloe Fourreau
The Royal Society, Science X Network
Main photo source: Chloe Fourreau