PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

MBARI researchers discover remarkable new swimming sea slug in the deep sea

A new glowing nudibranch species is the first known to swim through the ocean’s midnight zone and has unique adaptations for life in this environment.

MBARI researchers discover remarkable new swimming sea slug in the deep sea
2024-11-12
(Press-News.org) MBARI researchers have discovered a remarkable new species of sea slug that lives in the deep sea. Bathydevius caudactylus swims through the ocean’s midnight zone with a large gelatinous hood and paddle-like tail, and lights up with brilliant bioluminescence. The team published a description of the animal, nicknamed the “mystery mollusc,” in the journal Deep-Sea Research Part I.

“Thanks to MBARI’s advanced underwater technology, we were able to prepare the most comprehensive description of a deep-sea animal ever made. We’ve invested more than 20 years in understanding the natural history of this fascinating species of nudibranch. Our discovery is a new piece of the puzzle that can help better understand the largest habitat on Earth,” said MBARI Senior Scientist Bruce Robison, who led efforts to describe the mystery mollusc.

MBARI researchers first observed the mystery mollusc in February 2000 during a dive with the institute’s remotely operated vehicle (ROV) Tiburon offshore of Monterey Bay at 2,614 meters (8,576 feet) deep. The team leveraged MBARI’s advanced and innovative underwater technology to gather extensive natural history information about the mystery mollusc. After reviewing more than 150 sightings from MBARI’s ROVs over the past 20 years, they published a detailed description of this animal.

With a voluminous hooded structure at one end, a flat tail fringed with numerous finger-like projections at the other, and colorful internal organs in between, the team initially struggled to place this animal in a group. Because the animal also had a foot like a snail, they nicknamed this the “mystery mollusc.”

After gently collecting a specimen, MBARI researchers were able to take a closer look at the animal in the lab. Through detailed investigations of anatomy and genetics, they began to solve the mystery, finally confirming that this incredible animal is a nudibranch.

Most nudibranchs, also known as sea slugs, live on the seafloor. Nudibranchs are common in coastal environments—including tide pools, kelp forests, and coral reefs—and a small number of species are known to live on the abyssal seafloor. A few are pelagic and live in open waters near the surface.

The mystery mollusc is the first nudibranch known to live in the deep water column. This species lives in the ocean’s midnight zone, an expansive environment of open water 1,000 to 4,000 meters (3,300 to 13,100 feet) below the surface, also known as the bathypelagic zone. 

The mystery mollusc is currently known to live in the waters offshore of the Pacific coast of North America, with sightings on MBARI expeditions as far north as Oregon and as far south as Southern California. An observation of a similar-looking animal by NOAA researchers in the Mariana Trench in the Western Pacific, suggests the mystery mollusc may have a more widespread distribution.

The mystery mollusc has evolved unique solutions to find food, safety, and companions to survive in the midnight zone. 

While most sea slugs use a raspy tongue to feed on prey attached to the seafloor, the mystery mollusc uses a cavernous hood to trap crustaceans like a Venus fly trap plant. A number of other unrelated deep-sea species use this feeding strategy, including some jellies, anemones, and tunicates. 

Mystery molluscs are typically seen in open water far below the surface and far above the seafloor. They move through these waters by flexing their body up and down to swim or simply drifting motionless with the currents. To avoid being eaten, the mystery mollusc hides in plain sight with a transparent body. Rapidly closing the oral hood facilitates a quick escape, similar to the pulse of a jelly’s bell. 

If threatened, the mystery mollusc can light up with bioluminescence to deter and distract hungry predators. On one occasion, researchers observed the animal illuminate and then detach a steadily glowing finger-like projection from the tail, likely serving as a decoy to distract a potential predator. “When we first filmed it glowing with the ROV, everyone in the control room let out a loud ‘Oooooh!’ at the same time. We were all enchanted by the sight,” said MBARI Senior Scientist Steven Haddock. “Only recently have cameras become capable of filming bioluminescence in high-resolution and in full color. MBARI is one of the only places in the world where we have taken this new technology into the deep ocean, allowing us to study the luminous behavior of deep-sea animals in their natural habitat.”

Like other nudibranchs, the mystery mollusc is a hermaphrodite, possessing both male and female sex organs. The mystery mollusc appears to descend to the seafloor to spawn. MBARI researchers observed some animals using their muscular foot to attach to the muddy seafloor in order to release their eggs. 

Detailed examination of specific gene sequences confirmed that the mystery mollusc is unique enough from other known nudibranchs to merit the creation of a new family, Bathydeviidae. Two shallow-water nudibranchs—the lion’s mane nudibranch (Melibe leonina) and the veiled nudibranch (Tethys fimbria)—use a hood to capture prey; however, this appears to be convergent evolution of a similar feeding method, as the mystery mollusc is only distantly related to these species. In fact, genetics suggests the mystery mollusc may have split off first on its own branch of the nudibranch family tree.

“What is exciting to me about the mystery mollusc is that it exemplifies how much we are learning as we spend more time in the deep sea, particularly below 2,000 meters. For there to be a relatively large, unique, and glowing animal that is in a previously unknown family really underscores the importance of using new technology to catalog this vast environment. The more we learn about deep-sea communities, the better we will be at ocean decision-making and stewardship,” said Haddock.

The mystery mollusc is just one of many fascinating discoveries MBARI has made in the midnight zone. To date, MBARI technology has been used to document more than 250 deep-sea species previously unknown to science. 

“Deep-sea animals capture the imagination. These are our neighbors that share our blue planet. Each new discovery is an opportunity to raise awareness about the deep sea and inspire the public to protect the amazing animals and environments found deep beneath the surface,” said Robison.

This work was funded as part of the David and Lucile Packard Foundation’s longtime support of MBARI’s work to advance marine science and technology to understand a changing ocean.

 

Mystery mollusc (Bathydevius caudactylus) fact sheet 

Common name: Mystery mollusc
Scientific name: Bathydevius caudactylus
Pronunciation: bath-ee-dee-vee-us caw-dack-till-us

Habitat: midwater, in the bathypelagic zone
Depth range: 1,013 to 4,009 meters (3,323 to 13,153 feet)
Geographic range: currently known from the Northeastern Pacific Ocean, from Oregon to Southern California, but likely more widespread

Size: 14.5 centimeters (5.6 inches) (total length)
Diet: crustaceans, including mysid shrimp

Swimming: Bathydevius caudactylus swims with up-and-down undulations of the entire body, from the hood to the tail. Quickly closing the hood propels the animal backward. Most individuals have been observed in the water column at depths of 1,013 to 3,272 meters (3,323 to 10,735 feet), either swimming slowly or passively drifting. Bathydevius caudactylus is neutrally buoyant and does not sink or rise in the water column when at rest. 

Feeding: Bathydevius caudactylus uses a gelatinous hood to trap crustaceans. The bowl-shaped hood is highly elastic and may be up to 9 centimeters (3.5 inches) across. Meals are ingested through a funnel-shaped mouth at the back of the hood. Bathydevius caudactylus lacks the raspy tongue-like radula typical of bottom-dwelling nudibranchs and snails. Bathydevius caudactylus feeds on prey rich in nutrients, slowly metabolizing meals that may be few and far between in an environment where food is scarce.

Physiology: Researchers measured oxygen consumption of Bathydevius caudactylus with the Midwater Respirometer System developed by MBARI scientists and engineers. Bathydevius caudactylus has a metabolism much lower than that reported in other nudibranchs; in fact, respiration rates are more similar to those MBARI researchers have recorded in deep-sea jellies. The reduced respiration reflects the slower pace of life in the deep water column.

Bioluminescence: Researchers filmed bioluminescence from Bathydevius caudactylus in the field and the laboratory. Luminous granules in the animal’s tissues create a “starry” appearance across the animal’s back, including a diffuse glow in the oral hood and throughout the tips of the finger-like dactyls in the tail. Bathydevius caudactylus appears to drop luminescent dactyls as a decoy to distract predators, much like a lizard dropping its tail. The dactyls regenerate, with some Bathydevius caudactylus observed bearing dactyls of different lengths. Bioluminescence is uncommon among nudibranchs and snails, and Bathydevius caudactylus represents an independent evolution of this trait—just the third time bioluminescence has evolved in nudibranchs and the seventh time among gastropods.

Reproduction: Bathydevius caudactylus is a hermaphrodite with both male and female reproductive organs. Spawning individuals were observed on the seafloor at depths of 2,269 to 4,009 meters (7,444 to 13,153 feet). Bathydevius caudactylus is a solitary species, however, spawning individuals were occasionally seen in proximity to each other on the seafloor. One specimen collected by MBARI researchers released a ribbon of eggs in the laboratory. Eggs hatched three days later, developing into trochophore larvae with a round body and long hair-like cilia.

Etymology: The genus name Bathydevius reflects the “devious” nature of this deep-sea animal that fooled researchers with features unlike those of other known nudibranchs. The species name caudactylus refers to distinctive finger-like projections, or dactyls, on the animal’s tail.

 

About MBARI
MBARI (Monterey Bay Aquarium Research Institute) is a non-profit oceanographic research center founded in 1987 by the late Silicon Valley innovator and philanthropist David Packard. Our mission is to advance marine science and technology to understand a changing ocean. Learn more at mbari.org. 

END


[Attachments] See images for this press release:
MBARI researchers discover remarkable new swimming sea slug in the deep sea

ELSE PRESS RELEASES FROM THIS DATE:

Decentralized social media ‘increases citizen empowerment’, says Oxford study

2024-11-12
Researchers from the Oxford Martin Programme on Ethical Web and Data Architectures (University of Oxford) have reported findings from a paper exploring the motivations and challenges in running decentralised social media such as Mastodon, concluding such platforms offer potential for increased citizen empowerment in this digital domain. In their study, presented at the 27th ACM SIGCHI Conference on Computer-Supported Cooperative Work & Social Computing (CSCW) today, the researchers interviewed 16 administrators of Mastodon servers (otherwise known as instances), including those supporting marginalised and stigmatised communities. Their ...

Validating an electronic frailty index in a national health system

Validating an electronic frailty index in a national health system
2024-11-12
“The classification of patients according to their level of frailty allows us to adjust prevention programs and focus our limited resources on the right action for the right person.” BUFFALO, NY- November 12, 2024 – A new research paper was published in Aging (listed by MEDLINE/PubMed as "Aging (Albany NY)" and "Aging-US" by Web of Science), on October 24, 2024, Volume 16, Issue 20, titled, "Development and validation of an electronic frailty index in a national health ...

Combination approach shows promise for treating rare, aggressive cancers

2024-11-12
A research team led by UCLA Health Jonsson Comprehensive Cancer Center investigators has shown that that combining pembrolizumab, an immunotherapy drug, with standard chemotherapy can improve treatment outcomes for patients with small cell bladder cancer and small cell/neuroendocrine prostate cancer. Small cell carcinomas can arise in various tissues—including the bladder, prostate, lung, ovaries and breast—and are known for their rapid progression, tendency to relapse after initial treatment and poor overall survival ...

Raise the roof: How to reduce badminton birdie drift

Raise the roof: How to reduce badminton birdie drift
2024-11-12
WASHINGTON, Nov. 12, 2024 – Indoor badminton courts are often used for high-stakes tournaments, but even an enclosed court can affect the path of a birdie. The airflow from a court’s heating, ventilation, and air conditioning (HVAC) system and cross ventilation plays a significant role in badminton. The lightweight feathered birdie passed between the players can be affected by low wind speed in the stadium. This is known as wind drift and has been at the center of multiple tournament controversies. While shutting ...

Ouch! Commonalties found in pain vocalizations and interjections across cultures

Ouch! Commonalties found in pain vocalizations and interjections across cultures
2024-11-12
WASHINGTON, Nov. 12, 2024 – There are an estimated 7,000 languages spoken worldwide, each offering unique ways to express human emotion. But do certain emotions show regularities in their vocal expression across languages? In JASA, published on behalf of the Acoustical Society of America by AIP Publishing, an interdisciplinary team of linguists and bioacousticians led by Maïa Ponsonnet, Katarzyna Pisanski, and Christophe Coupé explored this by comparing expressive interjections (like “wow!”) ...

Income-related disparities in mortality among young adults with type 2 diabetes

2024-11-12
About The Study: In this cohort study of 1.2 million individuals ages 20 to 79 in South Korea, the risk of mortality with low income was most prominent among individuals with type 2 diabetes ages 20 to 39. These findings highlight the need for socioeconomic support to reduce income-related health disparities in younger individuals. Corresponding authors: To contact the corresponding authors, email Sin Gon Kim, MD, PhD (k50367@korea.ac.kr) and Nam Hoon Kim, MD, PhD (pourlife@korea.ac.kr). To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/ (doi: ...

Medical board discipline of physicians for spreading medical misinformation

2024-11-12
About The Study: The frequency of discipline for physician-spread misinformation observed in this cross-sectional study was quite low despite increased salience and medical board warnings since the start of the COVID-19 pandemic about the dangers of physicians spreading falsehoods. These findings suggest a serious disconnect between regulatory guidance and enforcement and call into question the suitability of licensure regulation for combatting physician-spread misinformation. Corresponding author: To contact the corresponding author, Richard S. Saver, J.D., ...

First-ever randomized clinical trial uses telehealth for suicide prevention

First-ever randomized clinical trial uses telehealth for suicide prevention
2024-11-12
COLUMBUS, Ohio – Suicide remains a pressing public health concern. An estimated 703,000 people die by suicide each year worldwide, according to The World Health Organization. In 2022, there were 49,449 suicides in the United States.  A new study found that brief cognitive behavioral therapy for suicide prevention – when delivered remotely via video telehealth – reduces suicide attempts and suicidal ideation. Researchers at The Ohio State University Wexner Medical Center and College of Medicine led the study that is published online in the journal JAMA Network Open. The randomized clinical ...

DNA packaging directly affects how fast DNA is copied in cells

2024-11-12
Researchers from the Mattiroli group have found that the way DNA is packaged in cells can directly impact how fast DNA itself is copied during cell division. They discovered that DNA packaging sends signals through an unusual pathway, affecting the cell’s ability to divide and grow. This opens up new doors to study how the copying of the DNA and its packaging are linked. These findings, published in Molecular Cell, may help scientists to find therapies and medicines for diseases such as cancer in the future. Chromatin as a guide Every day, our cells divide. Each time they need to copy both their DNA and the structure in which the DNA is packed. This packaging, ...

Scientists develop advanced catalyst for self-driven seawater splitting with enhanced chloride resistance

2024-11-12
Seawater electrolysis has long been seen as a promising pathway for sustainable hydrogen production but has faced significant limitations due to chloride ion (Cl⁻) corrosion, which can degrade a catalyst's performance. Now scientists from the Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) of the Chinese Academy of Sciences, along with their collaborators, have developed an efficient electrocatalyst called Co-N/S-HCS that demonstrates remarkable activity and stability in ...

LAST 30 PRESS RELEASES:

​​​​​​​Urgent need to enable more farmers and contractors to revive England’s network of hedgerows

ASH inclusion program retained and engaged hematologists underrepresented in field, 20-year analysis shows

How anti-obesity drugs are linked to food waste

Discovery explains kidney damage caused by blood pressure drugs

NYU Langone performs world’s first fully robotic double lung transplant

APSS accepting sleep and circadian research abstracts and session proposals for SLEEP 2025 in Seattle

DNA repair: A look inside the cell’s ‘repair café’

Astronomers take the first close-up picture of a star outside our galaxy

Here’s something Americans agree on: Sports build character

Engineering nature’s blueprint: Dendron-based assemblies for chlorophyll’s materials

Study reveals how cell types shape human brain networks

New genetic explanation for heart condition revealed

Poor mental health linked to browsing negative content online

People with migraine at high risk of depression during pandemic

Climate-driven hazards increases risk for millions of coastal residents, study finds

Females sleep less, awaken more frequently than males

Most Americans want primary care providers to address mental health

Millions of Americans hurt by others’ drinking, drug use: study

Plasma-derived atomic hydrogen advances low-temperature CO2 methanation at high yield

Photon qubits challenge AI, enabling more accurate quantum computing without error-correction techniques

Single gene causes embryo notochord deformity in zebrafish

Sylvester Cancer Tip Sheet - Nov 2024

AI speaks volumes when it comes to detecting Parkinson’s disease

Signals of inflammation during pregnancy linked to aging and memory changes 50 years later

Two million ex-smokers currently vape in England

When trees 'talk:' Researchers probe ancient wood for clues about massive solar storms

High nurse and doctor turnover linked to increased patient deaths in NHS hospitals

History of endometriosis and fibroids linked to heightened risk of early death

High nurse and doctor turnover rates linked to increased patient deaths in NHS hospitals

Research highlights the pressures human activities place on tropical marine ecosystems

[Press-News.org] MBARI researchers discover remarkable new swimming sea slug in the deep sea
A new glowing nudibranch species is the first known to swim through the ocean’s midnight zone and has unique adaptations for life in this environment.