Discovered the new animal set that was mistaken for an anemone

(a deep sea creature once thought to be one of the largest sea anemones in the world, with 6.5 feet (about 1.98m) longer tentacles, actually belongs to a new set of animals.

This discovery is part of a new DNA-based study led by scientists from the American Museum of Natural History, which introduced the first life tree of the sea. Sea kneeling, a group of more than 1,200 species. The report presented in PLOS ONE magazine on May 7 reshaped scientists' understanding of the relationships in these unknown animals.

'The discovery of this new creature belongs to the Cnidaria set - an animal industry that includes jellyfish, corals, anemones and related relatives - is the equivalent of discovering the first member of a group of species like spirits chief or rodent ' , Estefanía Rodríguez, an assistant in charge of the Museum's Division of Invertebrate Zoology, and the lead author of the new study, said. 'The difference is, most people are much more familiar with animals like chimpanzees and rodents than with life on the bottom of the sea. But this great finding tells us that we have a lot to learn and explore in the ocean. "

Rodríguez, along with a group of researchers, conducted a four-year study of sea anemone arrangement in a 'natural' or genealogical way, based on their evolutionary relationships. Sea anemones are lighting up polyps, which spend most of their time sticking to the rocks on the sea floor or coral reefs. Although they are diverse in size and color, anemones have very few clear structures.

So it is difficult to classify this animal based solely on morphology.

'Anemones are very simple animals , ' said Rodríguez. 'So they are grouped together by the lack of their properties' - such as the lack of a skeleton or lack of corporate structure, as you see in corals. So it is not surprising that we began to observe their molecular data and found that the traditional classification of anemones was wrong. "

The researchers compared specific DNA fragments of more than 112 species of anemones collected from across the world's oceans. Based on genetic data and the arrangement of structures inside the anemone, scientists reduced the number of sea anemones from 4 to 2.

They also found that one of the species they analyzed was not an ocean anemone. This animal, formerly known as Boloceroides daphneae , was discovered in 2006 in the deep waters of the Eastern Pacific and is believed to be one of the largest sea anemones today.

But this new study has pushed this species out of the anemones tree of life. Instead, scientists have placed this species in a new set - a classification equal to that of reptile mammals or crocodiles - under the sub-Hexacorallia , including rock corals. , anemones and black corals. The new name of the animal that lives near these hydrothermal vents is named Relicanthus daphneae .

Relicanthus daphnea is a classic example of convergent evolution, independent evolution of similar properties in organisms of different lines.

'Although this animal looks very much like an anemone, it is not an anemone,' Rodríguez commented. 'Both of these animal groups lack the same characteristics, but our research has demonstrated that while sea anemone loses those traits over millions of years of evolution, R. daphneae has not yet ever have those characteristics. Placing these two animals in the same group is like sorting worms and snakes together because they have no legs. '

So far, Relicanthus daphneae is the only species in this new set, but researchers hope to change that in the future.'Although we have known for a long time about the existence of this giant creature, only in recent years have we really begun to understand where these organisms are located in the tree of life,' Rodríguez said. . 'So imagine what else we can discover.'