Researchers recorded a previously unseen carnivorous sponge — nicknamed the “death‑ball sponge” — whose orb‑tipped arms are carpeted with spicule hooks for catching small crustaceans. The animal, a member of Cladorhizidae, was filmed at 11,814 ft (3,601 m) east of Montagu Island in the South Sandwich Islands. The April 2023 expedition has collected ~2,000 specimens from 14 phyla and preliminarily confirmed about 30 potentially new species. Specimens are being studied at a Southern Ocean workshop and by Universidad de Magallanes using morphology and DNA barcoding to verify new discoveries.
Deep‑Sea “Death‑Ball” Sponge Spotted Off Antarctica — A New Carnivorous Cladorhizid
Researchers recorded a previously unseen carnivorous sponge — nicknamed the “death‑ball sponge” — whose orb‑tipped arms are carpeted with spicule hooks for catching small crustaceans. The animal, a member of Cladorhizidae, was filmed at 11,814 ft (3,601 m) east of Montagu Island in the South Sandwich Islands. The April 2023 expedition has collected ~2,000 specimens from 14 phyla and preliminarily confirmed about 30 potentially new species. Specimens are being studied at a Southern Ocean workshop and by Universidad de Magallanes using morphology and DNA barcoding to verify new discoveries.
17:49, 05.11.2025Science
Newly Filmed Carnivorous “Death‑Ball” Sponge Emerges from the Deep
As remotely operated vehicles explore ever greater depths, researchers have recorded a previously unclassified carnivorous sponge whose limb tips end in gelatinous, orb‑like structures. The specimen — a member of the predatory sponge family Cladorhizidae — has been nicknamed the “death‑ball sponge” because the spherical tips of its many arms are covered in tiny spicules that act like hooks to snag small animals.
Where and how it was found: The animal was observed at 11,814 feet (3,601 meters) at the Trench North dive site, east of Montagu Island in the South Sandwich Islands (Southern Ocean). The sighting was recorded by the Nippon Foundation–Nekton Ocean Census team while operating the remotely operated vehicle SuBastian from the research vessel R/V Falkor (too).
Context and significance: Most sponges are passive filter feeders. That understanding began to change in the mid‑1990s when scientists documented Abestopluma hypogea, a sponge that captures and digests small crustaceans with long tendrils. The newly observed Chondrocladia sp. nov. (not yet formally named) adds to the bizarre range of feeding strategies within Cladorhizidae, whose members use hooked spicules and specialized branches to trap isopods, amphipods and other small fauna.
“Advanced tools—from precise seafloor mapping to high‑definition ROV imagery—allow us to explore and gather data from places never seen before by humans,” said Jyotika Virmani, Executive Director of the Schmidt Ocean Institute.
Since the expedition began in April 2023, teams have logged extensive video and collected thousands of images of seafloor features such as hydrothermal vents and submerged volcanic mouths that vent dark, mineral‑rich plumes. The mission has also collected roughly 2,000 animal specimens representing 14 phyla, and preliminary work has already confirmed about 30 species that appear to be new to science.
Identification and follow‑up: Specimens suspected to be new are sent to the Southern Ocean Species Discovery Workshop, a collaboration of international taxonomists and Universidad de Magallanes (UMAG) in Punta Arenas, Chile. There scientists examine morphology, compare high‑resolution images and apply DNA barcoding — short gene fragments used to match and identify species — to determine whether an organism is previously undescribed or a known species in a juvenile form.
“The Southern Ocean remains profoundly under‑sampled,” said Michelle Taylor, Head of Science at The Nippon Foundation–Nekton Ocean Census. “We have processed under 30% of the samples collected so far; finding ~30 new species already shows how much biodiversity remains undocumented.”
Why it matters: Carnivorous sponges such as the harp sponge (Chondrocladia lyra) and the ping‑pong tree sponge (Chondrocladia lampadiglobus) already demonstrate surprising morphological diversity — from harp‑like arrays of hooked branches to globular, spicule‑covered nodes. The newly filmed “death‑ball” adds another striking example and underscores how much remains to be discovered on the deep seafloor.
Final note: The specimen is still being studied and has not yet been given a formal species name. Continued morphological and genetic analyses will determine whether it represents a new species and will help place it within the broader taxonomy of carnivorous sponges.