Scientists discover new species of tiny pygmy seahorse that will grow to just one-inch long

Everybody loves baby animals, especially when they naturally exist in a diminutive form in the first place. So take a look at this newly discovered, impossible-to-resist pygmy seahorse from the wild oceans of South Africa. This adult male Hippocampus nalu will eventually grow to a maximum of less than one inch long, essentially the width of a human fingernail.

First encountered by diving instructor Savannah Nalu Olivier back in 2017, this miniature seahorse was found while exploring South Africa's eastern coast in Sodwana Bay. Once pygmy seahorse expert Dr. Richard Smith and biologist Louw Claassens observed photos of Olivier's discovery, they quickly ascertained that she'd stumbled upon a never-seen species.

Credit: © Richard Smith

Pygmy seahorses are a rare group of eight species of miniature syngnathids (the official name for seahorses and pipefish), fish that normally reside in southeastern Asia's Coral Triangle region.

Their sizes range in length from a half-inch to one inch, measured from the end of the tail to the tip of the snout. This precious South African species makes its home some 5,000 miles away from the group's most populated marine address, and is the first pygmy seahorse ever located in the Indian Ocean.

The research crew's findings on Hippocampus nalu were published last month in the online scientific journal ZooKeys, where the paper's authors decided to use Olivier's middle name, "Nalu," in the official naming of the tiny creature, which means "here it is" in the local isiXhosa and isiZulu languages.

"Pygmy seahorses have received very little research focus since their discovery in 1970," study co-author and marine biologist Dr. Richard Smith tells SYFY WIRE. "I conducted the first study on their ecology and found them to have fascinating reproductive and social lives, something that you might not expect from an animal of their size. Adults of most pygmy seahorse species barely stretch across a nickel, so the lack of information about them is understandable, but worrying given the conservation risks they face. Degradation of their fragile coral reef homes is widespread."

In 2011, Dr. Smith became the first person to be awarded a Ph.D. on the biology of pygmy seahorses. His latest book, "The World Beneath," has a specific chapter about his illuminating pygmy seahorse research.

"Scuba divers, like Savannah, have brought this little-known group to the attention of scientists, and since the millennium seven of the eight known species have been discovered thanks to their observations," he adds. "This is just one group of fishes that illustrates how little we know about the oceans, especially in the western Indian Ocean, which may be the next hotbed of discovery for marine fishes."