Sea Dragons Are Incredibly Strange Creatures, And We May Finally Know Why

A sight to behold is seeing a sea dragon floating amongst the seaweed, adorned with leaf-like adornments ruffling in swaying ocean currents.

There is more to sea dragons than meets the eyes of the diver. Sea dragons have missing teeth, lack of ribs, and their spine is curved.

A group of genes that give rise to teeth, nerves, and facial features in other animals are missing from the sea dragons' genomes.

The team behind the study wrote in a new paper that the sea dragon genomes have "lifted a veil on the evolution of sea dragon-specific traits."

Sea dragons are a part of the same family as pipefish and sea horses, which are known for having evolved male pregnancies.

"This group is cool for a number of different reasons," says evolutionary genomics researcherClayton Small from the University of Oregon, who co-led the study.

Sea dragons are odd in a group of weird fish.

The leafy sea dragon and the weedy sea dragon are both found in cool waters off Australia's southern coast.

These slender fish can be difficult to spot because of their leaf-like fronds.

The third species of sea dragon, the rare Ruby sea dragon, was only seen in the wild for the first time in 2017:

The three species of sea dragons are revered for their colorful body forms and long, tubular crustacean-sucked snouts, but the Ruby sea dragon appears to have lost the leafy appendages exhibited by the others.

Sea dragons and sea horses branched off to form a new family over 50 million years ago, according to scientists.

It's not clear how they came to be so unique. The University of Oregon collaborated with scientists from the Tennessee Aquarium and the Birch Aquarium to analyze the sea dragons raised in captivity.

Sea dragons have a much larger number of jumping genes than their closest relatives, pipefish and seahorses.

Sea dragons evolved quickly because of rapid genetic changes created by mobile transposons.

Compared to two distant relatives, the genomes of leafy and weedy sea dragons are missing a chunk of genes that play important roles in other animals.

The researchers were tempted to theorize that the loss of these genes might explain how sea dragons developed their facial features.

The researchers used high-resolution X-ray microscope scans to show that the sea dragon's ornamental appendages may have evolved from the original spine.

The support structures for the leafy paddles appeared to have appendages added to them.

The team noticed that the sea dragon's bones were stiffened by a core of collagenous tissue, which adds to the story of how the sea dragon came to be.

The results of sea dragons are amazing. Sea dragons have a few more secrets hidden in their genome, which may be discovered with further genetic comparisons.

The study was published in a peer reviewed journal.