Bristle Worms Unique But Weird Anatomical Structure Suggests Adaptation of Fungal Lifestyle

Ramisyllis multicaudata is a marine worm known to have 1,000 rear-ends, which is a bit awkward for us humans but beneficial for the worm. A new study shows that the multiple rear-end of the worm have a significant value in the anatomical aspect and biological activity of the species.

What Is Ramisyllis Multicaudata?

Ramisyllis multicaudata, also known as the bristle worm, can typically be in another sponge species called Petrosia. The bristle worm is somewhat buried at the sponge's water passage, where it lives naturally. Most of the Ramisyllis multicaudata are located at the shallow reef formations in the oceans near northern Australia.

The bristle worm has an unusual anatomical feature that allows its body to branch in a series of additional parts. These additional parts are what sticks out of the holes of the Petrosia sponges and make themselves extend to the seawater.

According to Smithsonian Magazine, the biologists have identified one specific specimen of the sponge with an abnormal amount of rear-ends, with a count of over 100 butts crawling out of its body and tubes. The harnessed data from the worms present in the small sponge were selected for the research.

The worms were also determined to have intestinal organs existing in their parts. What is surprising is that the organs in these parts are similar to their newly mutated branches. One of the organs inside the worms is also found connected throughout the entire body of the bristle worms, which is a unique feature considering that it continues to connect even with the young branches.

However, these organs, specified as the worm's guts, are empty. There are no other tissues or food particles noted from the organ extension of the animal. The study of the bristle worm's anatomical structure was published in the Journal of Morphology titled "Integrative Anatomical Study of the Branched Annelid Ramisyllis multicaudata (Annelida, Syllidae)."

The bristle worm's gut in its rear-end, as opposed to the other extensions, is observed to have some fingerlike covering that also acts as an expansion of the organ in case of additional nutrient absorption. These gut extensions are also known as the cilia and microvilli, both of which are also found in the human body.

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Ramisyllis Multicaudata and Fungi Lifestyle, Compared

The gut features at the rear-end of the Ramisyllis multicaudata suggest that alongside its emptiness throughout the body of the worm, the gut itself may still have a function. Even though bristle worms eat micro foods that are almost invisible to the naked eye, it is baffling why they still have a gut that is ready to take a seemingly larger form of food.

According to a report by Scientific American, bristle worms do not act in a lifestyle similar to other worms but by a state similar to fungi. The similarity between the Ramisyllis multicaudata and fungal organisms is evident in the branching tubes that manifest on both bodies.

Soft-bodied marine invertebrates are known in the biological community to be great absorbers of liquid foods and other organic nutrients. They exhibit their food intake directly from the seawater into their skin. These traits were also found in the Ramisyllis multicaudata, which make them a strong contender for fungal lifestyle adapters.

One of the strong pieces of evidence that could confirm the correlation of fungi and bristle worm lifestyles is that the Ramisyllis multicaudata's body is actually covered with microvilli, the anatomical component which is supposed to be attached to the guts inside a body.