Fish 'Moonwalks' Backward

Scientists have filmed a species of armored searobin, Scalicus engyceros, 'moonwalking' backward across the seafloor in the South China Sea, revealing novel behavioral and evolutionary adaptations. The footage was captured using a human-occupied vehicle and a remotely operated vehicle.

The Scalicus engyceros was first described in 1872, but the new footage has provided a unique insight into its behavior. The fish use their thick, stiffened fin rays to scuttle around like shrimp and even jump in a jerky leap when threatened.

The researchers also report observations of two other species of armored searobins that were sighted between 350 and 500 meters deep. These fish are part of the family Peristediidae, which share a common ancestor that lived around 60 to 70 million years ago.

Armored searobins are covered in bony plates, and the water pressure at the depth where they were spotted is around 40 atmospheres. The footage was captured using the human-occupied vehicle Shenhaiyongshi and the remotely operated vehicle Haiqin.

## Why it matters The discovery of this unique behavior is significant because it highlights the importance of exploring the deep sea and its inhabitants. The deep sea is a largely unexplored environment, and the use of submersibles has allowed scientists to observe creatures in their natural habitat without disrupting them. This has led to a greater understanding of the behavior and adaptations of deep-sea creatures, and has revealed the complexity and diversity of life on Earth.

The study of armored searobins and their behavior can also provide insights into the evolution of life on Earth. The fact that these fish have developed unique adaptations to survive in the deep sea suggests that there may be other undiscovered species with similar characteristics. Further research into the deep sea and its inhabitants can help us to better understand the natural world and the diversity of life on our planet.