For the first time, scientists have unlocked some of the genetic secrets of the most peculiar fish including its unusual male pregnancy -- the seahorse.
An international team of researchers has fully sequenced the Southeast Asian tiger tail seahorse, named for its distinctive yellow-and-black striped tail.
The genome project, led by evolutionary biologist Professor Axel Meyer, sequenced and studied the genome of the seahorse, obtaining new molecular evolutionary results that could shed light on the unique characteristics of the creature.
The study, published in the journal Nature, focused on the genetic underpinning for certain peculiarities of this fish group, including its eccentric male pregnancy. What is unusual about this creatures is that males, not females, give birth to babies. Moreover, they swim upright, have horse-like snouts and have no teeth. Unlike fish, they lack tails, pelvic fins and their bodies are covered in bony plates.
"They are such iconic animals, one of the examples of the exuberance of evolution," an evolutionary biologist and genome researcher at Germany's the University of Konstanz and one of the researchers in the study, Axel Meyer, told Reuters.
"Their numbers are declining due to habitat destruction and harvest by humans," Byrappa Venkatesh, a molecular biologist at the Singapore's Agency for Science, Technology and Research (A*STAR), added.
In the study, the researchers found that seahorses do not have a gene linked to having pelvic fins, a characteristic that most fishes need for survival. They also found that when this gene is deactivated in zebrafish, it lost its pelvic fins. In terms of egg hatching, the gene family linked to this ability was expanded in the seahorse -- that is why males have a brooding pouch.
The seahorse demonstrates how genetic changes can lead to evolutionary changes in some traits. This study could shed light on understanding the genetic basis of the evolution and odd characteristics of this bizarre and beautiful organism.