Discovered in the deep: the ‘forest of the weird’

More than a mile beneath the Pacific Ocean, is a seascape of oddly shaped corals and a glass sponge named after ET

In 2017, on a submerged volcano a mile and a half underwater in the middle of the Pacific Ocean, a team of scientists were left gasping in wonder at a scene they called the “forest of the weird”.

Instead of trees, the forest was made up of oddly shaped corals, including some that resembled frizzy bottlebrushes (Rhodaniridogorgia) and others that were flattened and harp-shaped (Narella) with leggy, pink brittlestars, relatives of starfish, wrapped around their branches.

The corals were dotted among glass sponges. One, Aspidoscopulia, looked like a frilly white petticoat caught in a breeze, hoisted aloft on a zigzag stalk. But perhaps the most intriguing was a glass sponge on tall stalks, with what looked like a melon-shaped head with two holes, reminiscent of goggly eyes. This species was nicknamed “the ET sponge”, after the eponymous character in Steven Spielberg’s hit movie. In 2020, it was given the scientific name Advhena magnifica – the magnificent alien.

The ocean is one of the world’s last truly wild spaces. It teems with fascinating species that sometimes seems to border on the absurd, from fish that look up through transparent heads to golden snails with iron armour. We know more about deep space than deep oceans, and science is only beginning to scratch the surface of the rich variety of life in the depths.

As mining companies push to industrialise the sea floor and global leaders continue to squabble over how to protect the high seas, a new Guardian Seascape series will profile some of the most recently discovered weird, wonderful, majestic, ridiculous, hardcore and mind-blowing creatures. They reveal how much there is still to learn about the least known environment on Earth – and how much there is to protect. 

Sponges may look like plants but they are in fact simple animals. They have no face, brain, heart, muscles or any other kind of body organ. Most of them spend their lives stuck to the seabed, straining tiny floating particles of food through their spongy bodies.

The ET sponge had been seen only once before, a year earlier, thousands of miles to the west near the Mariana Trench. A specimen was taken to the Smithsonian National Museum of Natural History, where the postdoctoral researcher Cristiana Castello Branco immediately knew she was looking at something different. “It’s a unique shape,” she says.

Advhena magnifica builds its body from tiny structures, called spicules, made of silica. Examining these intricate structures under a microscope, Castello Branco saw they were shaped like spiky snowflakes and daisies with drooping petals. “I found some of these very specific spicules very different,” she says. This was not only a new species but a whole new genus of deep-sea sponge that nobody had seen before.

The ET sponge Castello Branco studied had been collected using the mechanical arm of a deep-diving robot, controlled via cable by a ship on the surface. In the past, researchers had to make do with studying the often damaged samples of sponges caught in trawl nets. She says the remote technologies are a gamechanger for her work. As well as getting her hands on intact specimens, she can study the animals in their habitats and learn much more about their lives.

Video footage of the forest of the weird shows all the ET sponges facing in the same direction. Castello Branco thinks they could be orienting themselves to feed on floating particles brought in on the current sweeping over the tall ridge of the seamount.

An ET sponge attached to a rock at the bottom of the ocean
ET sponge in the ‘forest of the weird’ more than a mile under the surface of the Pacific Ocean. Photograph: ‘National Oceanic and Atmospheric Administration (NOAA) | Office of Exploration and Research (OER)‘

Sponges in shallow seas, including the ones divers collect for use in the bath, draw in seawater through tiny holes all over their bodies. They filter out food particles, then exhale water through larger openings. It is likely the ET sponges are doing things differently. Inhaling water through the large surface area of their gaping “eyes” could be an important survival tactic for living in the deep ocean where food is much harder to come by.

So far, ET sponges have only been found in these two places, but Castello Branco thinks there is a good chance they will show up on other seamounts, which she describes as islands of wildlife. “It’s just a matter of time,” she says. “These kinds of environments with this diversity of sponges are more common than we used to think.”


Helen Scales

The GuardianTramp

Related Content

Article image
Discovered in the deep: the ‘Elvis worms’ that sparkle in the darkness
In 2020, scientists found sparkling Peinaleopolynoe on hydothermal vents in the eastern Pacific – and were irresistibly reminded of the king of rock’n’roll

Helen Scales

07, Sep, 2022 @5:00 AM

Article image
Discovered in the deep: is this the world’s longest animal?
A submersible off the coast of Western Australia chanced upon a 45-metre-long deep-sea siphonophore arranged in a feeding spiral, trailing its deadly tentacles

Helen Scales

30, Nov, 2022 @6:00 AM

Article image
Discovered in the deep: the crustacean with eyes for a head
Shrimp-like Cystisoma are protected from predators by being virtually invisible – thanks to unique retina and a body that casts almost no shadow

Helen Scales

14, Sep, 2022 @5:30 AM

Article image
Discovered in the deep: the extraordinary sawshark with a weapon-like snout
With the help of fishers in Madagascar and Tanzania, scientists named two new species of rare sixgill sawsharks

Helen Scales

07, Dec, 2022 @6:00 AM

Article image
Discovered in the deep: the rainbow fish that’s born female and becomes male
Scientists in the Maldives were only able to reach the rose-veiled fairy wrasse by using specialised diving gear

Helen Scales

19, Oct, 2022 @5:00 AM

Article image
Discovered in the deep: the squid that makes a decoy out of its own skin
Self-camouflage is just one of the tricks of Brenner’s bobtail squid, a newly found species that is also helping research into microbes in the human gut

Helen Scales

23, Nov, 2022 @6:00 AM

Article image
Discovered in the deep: the sea cucumber that lives a jellyfish life
The Pelagothuria natatrix is an extremely rare species of sea cucumber – with a gelatinous body, it spends most of its time swimming

Helen Scales

03, Oct, 2022 @5:00 AM

Article image
Nobel-winning stock market theory used to help save coral reefs
Portfolio selection rules on evaluating risk used to pick 50 reefs as ‘arks’ best able to survive climate crisis and revive coral elsewhere

Karen McVeigh

28, Nov, 2021 @3:00 PM

Article image
Scientists discover ‘world’s largest’ seagrass forest – by strapping cameras to sharks
New study, carried out using tiger sharks in the Bahamas, extends total known global seagrass coverage by more than 40%

Laura Paddison

05, Nov, 2022 @8:00 AM

Article image
Discovered in the deep: the anglerfish with vampire-like sex lives
A deep trawl has brought up a potentially new species of a fish whose extreme mating methods include permanent physical fusion

Helen Scales

01, Feb, 2023 @6:00 AM