## Tiny Fish, Unexpected Allies: Blackwater Photography Reveals a New Ocean relationship
- Blackwater photography reveals juvenile fish carrying or swimming with larval anemones and polyps, likely for protection from predators.
- This behavior is a newly discovered relationship between open-water juvenile fish and larval anemones and polyps.
- Thes blackwater photos of everyday movements offer rare insights into the lives of deep-sea creatures at night.
Blackwater photography captures dark interactions
Blackwater photography divers are scuba divers who plunge into the ocean at night to photograph seldom-seen small sea creatures. They’ve captured uniquely stunning undersea photos of wondrous marine organisms. And marine biologists have been studying these photos with great interest because they reveal new perspectives of ocean life.
On October 7, 2025, scientists and divers said they’ve made a new discovery using these photos. They found some juvenile fish carry larval tube anemones and button polyps in their mouths, problably for protection against predators. They’ve also documented juvenile fish swimming alongside larval anemones.
Rich Collins is a blackwater diver and photographer, aMeanwhile, scientists have documented juvenile fish in open waters seeking refuge from predators by swimming very close to large jellyfish and salps.Now, in this new study, the researchers have also documented juvenile filefish, driftfish, pomfrets, and a horse-eye jacks associated with larval tube anemones and palythoa polyps. They’ve obtained images of juvenile fish carrying larval anemones or polyps in their mouths. Plus, they have photos of the fish swimming with larval anemones.
Gabriel Afonso,the paper’s lead author and a ph.D. student at the William and Mary Virginia Institute of Marine Science, is studying this phenomenon.He said:
>As far as I know, this is the first relationship of an open water fish interacting physically with an anemone that looks to be carrying the invertebrate.
Based on these images, afonso thinks this could be a newly discovered type of mutual benefit for the fish and anemone or polyp. He suggests that while the sting of a juvenile anemone or polyp is not powerful enough to kill a predator, it is indeed a deterrent as it is unpalatable. Moreover, larval anemones and polyps carried by the juvenile fish can definitely help the invertebrates disperse more widely in the ocean.
Blackwater photography offers a new perspective on marine life
Diel vertical migration gives photographers a great chance to document these rarely seen creatures as they move through the water. Most of these animals are very small, so divers need to use a technique called macro photography-taking extreme close-up pictures-to capture them.
The photos used in this study were mostly taken in waters off Palm Beach, Florida. the divers were between 26 to 49 feet (8 to 15 meters) below the surface, in ocean depths between 548 to 748 feet (167 to 228 meters).
Blackwater photography is a challenging but rewarding way to see the hidden world of the ocean. It shows us the amazing life that exists beyond what we normally see.