The ocean's largest predators may rely on its smallest secrets
In short: In the vast emptiness of the open ocean, life has evolved to master a bizarre culinary strategy: filtering microscopic particles like dust from the air. From transparent larvae absorbing nutrients through their skin to mudflats that funnel energy into the deep sea, the tiniest organisms are the foundation of everything.
In the mudflats of French Guiana, an invisible feeding ground exists beneath the surface. Billions of algae and bacteria provide a base of energy for microscopic predators like nematodes, rotifers, and flatworms. These compact organisms navigate the sediment to pass energy upward. As tides shift, this concentrated energy moves from the mud into copepods, shrimp, and young fish, eventually reaching larger marine predators offshore.
In the open ocean—the least known habitat on Earth—food is scarce. Many pelagic animals have evolved 'filter' strategies similar to walking through a house with a window screen to catch dust. Some seafloor creatures, like feather stars and feather duster worms, remain stationary in currents to trap particles. Others, such as eel larvae, appear as long transparent leaves; researchers believe they may actually absorb nutrients directly through their skin to fuel their metamorphosis into glass eels.
Understanding these complex food webs is a major scientific challenge because the deep sea is so vast and inaccessible. Traditionally, scientists mapped these connections by 'looking into guts'—dissecting animals to find stomach contents or using biochemical tracers like stable isotopes. However, gelatinous creatures are difficult to study this way because they are mostly water and digest quickly.
A recent study of 30 years of underwater video footage from remotely operated vehicles (ROVs) has provided a clearer map. Because jellyfish do not flee from light or sound, researchers could observe them preying on up to 22 different types of marine organisms. This reveals that these 'invisible' inhabitants are far more integral to the global food web than previously understood.
Opens the Intellect+ feed with this card first. Swipe up for the next one.
Sources
- Summary by Intellect · source: The Living Mud: How Tiny Predators Feed the Ocean | Part 2 | SLICE EARTH
- Also: 'An ancient, complex, and very serious game is going on': The weird ways creatures feed in the open ocean | Live Science
- Also: Deep-Sea Creatures Found Eating Each Other in Remote Video - Jellyfish Predators | National Geographic
To cite this card, link to https://intellectplus.co.uk/app/nature-the-living-mud-how-tiny-predators-feed-the-ocean-part-2-slic.
How we source, check and correct cards: Editorial standards.
General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.
Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?
Related
More in Nature · Latest · A–Z · All topics
