Sep 25, 2023 16:00:00

Mysterious creatures discovered in the sea of Okinawa turned out to be a ``swarm of parasites''

A photo taken by underwater photographer

Ryo Minemizu in the sea of Okinawa in 2018 has attracted the interest of many biologists, as it ``captures an unidentified aquatic creature.'' Analysis revealed that this object was a colony formed by organisms called ' trematodes .'

Polymorphic parasitic larvae cooperate to build swimming colonies luring hosts: Current Biology
https://www.cell.com/current-biology/fulltext/S0960-9822(23)01170-3

'Mind-boggling' sea creature spotted off Japan has finally been identified | Science | AAAS

https://www.science.org/content/article/mind-boggling-sea-creature-spotted-japan-has-finally-been-identified

In 2018, Japanese underwater photographer Minemizu took photos of small creatures, only a few millimeters wide, in the sea of Okinawa.

This mysterious creature became the focus of many biologists' attention, as it did not fit into any of

the worms , molluscs, or crustaceans.

This is the second time I've seen reports of this mystery animal. @kurashitakurara
found something just like it, in the same general area, around this time last year. Here are closeups. STILL no idea what it is. pic.twitter.com/HFZ3nrv4Pf

— High Seas Science (@RebeccaRHelm) August 4, 2021

Igor Adameiko, a biologist at the University of Vienna, ordered a specimen of this creature and began analysis. Analysis by the research team revealed that this creature was not a single creature, but a colony of many creatures several millimeters in length.

The research team also stained the organism with various antibodies to analyze its internal anatomical structure. As a result, it was discovered that the cell pattern of this creature's nervous system belongs to a group called `` coronazoa, '' which includes molluscs and other animals.

The research team also conducted DNA analysis of this creature and confirmed that it is classified as

a subclass of trematodes . Trematodes, including the trematode subclass, parasitize vertebrate animals such as fish, cats, and humans by being eaten as larvae, grow inside the host's body, and release eggs into the environment.

Further investigation revealed that the tentacle-like objects extending from the hemisphere matched the DNA of the hemisphere. According to the research team, tentacle-like objects play a role in moving underwater in order to make creatures such as fish swallow themselves.

Robert Poulan of the research team said, ``More than 20,000 species of trematodes that live on vertebrates have been discovered, but we do not know much about their larval forms. 'Aspects and features may be present in the larval stage that have not been discovered before.' Adameiko also reports, ``We plan to conduct research in the future on how the fluke we discovered this time controls the movement of the colony.''