Short-snouted seahorse under water
The short-snouted seahorse. Stock photo.
Photo: Hans Hillewaert

First Discovery of a Seahorse in Sweden


In July, Bovallstrand in Bohuslän received an exclusive visit from a seahorse. It was the six-year-old Hubert Berggren who managed to capture the far-traveling visitor. After reporting the find to the Kristineberg Center, researchers at the University of Gothenburg confirmed that this was the first documented discovery of a seahorse in Sweden.

It was on his grandmother's jetty in Bovallstrand that Hubert spotted something in the water. "I see a seahorse!" he shouted to his dad, Jesper, who skeptically replied, "It's probably just seaweed." However, Hubert insisted that what he saw moved just like the seahorses he'd seen on TV. As it turned out, it was to be the first documented sighting of a living seahorse in Sweden after it was captured, filmed, and released back into the sea.

Difficult to determine the species

Personporträtt Charlotta Kvarnemo
Charlotta Kvarnemo, Professor at the Department of Biology and Environmental Science at the University of Gothenburg.
Photo: Leon Green

Determining the exact species of the seahorse was not easy for the researchers, but they were certain it was one of the two types of European seahorse, either the short-snouted seahorse (Hippocampus hippocampus) or the long-snouted seahorse (Hippocampus guttulatus).

"I consulted both with Sven Kullander at the Swedish Museum of Natural History and my British colleague Dr. Lucy Woodall, from the University of Exeter, who has researched both species. By comparing the video with specimens of similar size from the Museum of Natural History collections, we were able to conclude that it's likely a short-snouted seahorse," says seahorse researcher Charlotta Kvarnemo from the Department of Biology and Environmental Science at the University of Gothenburg.

This is the first documented discovery of a living seahorse in Swedish waters.

"It also aligns with our expectations as the short-snouted seahorse has previously been found in countries like the Netherlands, Belgium, and Denmark."

More seahorses in the future

Porträtt Hubert Berggren
Hubert Berggren captured the seahorse during a visit to Bovallstrand.
Photo: Privat

In Europe, both types of seahorses are most abundant in the Mediterranean and in the waters around the English Channel. This particular specimen likely drifted in with currents from the North Sea.

"Seahorses are not strong swimmers, so they always look for something to latch onto with their tails. One guess is that it came here through a process called 'rafting,' where they latch onto and ride along with other materials in the sea, such as a piece of seaweed," explains Charlotta Kvarnemo.

Observations from the general public are essential for researchers to track how species spread.

"We're likely seeing seahorses in Sweden because the water has become warmer, allowing the species to thrive here. It follows a general trend we've observed with species that were previously found further south now appearing here. It's likely we'll see more seahorses in Swedish waters in the future," says Charlotta Kvarnemo.

Video (00:12)
A video of the captured seahorse
After Hubert captured the seahorse, it was filmed before being released back into the sea.

Report your findings

Have you seen something exciting in the sea? By reporting your findings, you can help researchers. Report by registering on SLU:s Artportal. You can also report via the mobile-friendly website Rappen.


Text: Simon Ungman
Cover photo: Hans Hillewaert, Creative Commons Attribution-Share Alike 4.0 International 

Short-snouted seahorse

The short-snouted seahorse is a fish that grows up to 15 centimeters long, and its snout constitutes less than one-third of its head length. Unlike the long-snouted seahorse, it typically lacks any flaps on its head or body.

The seahorse lacks a tail fin and instead uses its tail as a prehensile tail. The short-snouted seahorse lives in coastal, tidal-affected kelp belts, where the prehensile tail comes in handy. It feeds on zooplankton, which it sucks in with its trunk-like mouth.

The male incubates the eggs and offspring in a brooding pouch with a minimal opening, located on the tail. The young are born from the pouch after about one month. Most of their nutrition comes from the mother via the yolk in the eggs, but the male provides the offspring with oxygen, a good salt balance, and additional nourishment during development. The similarity to mammalian pregnancy is so pronounced that one can rightly speak of a male pregnancy.