Mar 10, 2025
The seahorse: the ocean’s most extraordinary father
A fascinating yet fragile species: why we must protect them and safeguard their habitat
Seahorses are among the most fascinating creatures in our seas. Beyond their unmistakable appearance and incredible camouflage abilities, they play a unique role in the animal kingdom: the male carries the pregnancy and gives birth to the offspring!
Seahorses belong to the Syngnathidae family and are easily recognizable due to their distinctive shape. Their elongated bodies are covered in bony plates forming an armor-like structure, lacking typical fish scales. Their heads resemble those of horses, while their prehensile tails allow them to anchor themselves to corals, algae, and aquatic plants, helping them resist currents at depths of up to 40 meters.
Although they are fish, they swim in an upright position, using their dorsal fin to move slowly. Their eyes can move independently, allowing them to spot both prey and predators with remarkable precision. Experts in camouflage, they can change color to blend into their surroundings and avoid danger.
Seahorses vary in size depending on the species: the smallest, Hippocampus denise, measures just 16 mm, while the largest, Hippocampus abdominalis, can grow up to 35 cm. Their lifespan typically ranges from 4 to 7 years.
Before mating, seahorses engage in courtship dances that can last for days. During this time, the partners change color and intertwine their prehensile tails. When the moment arrives, the female deposits her eggs (up to 1,500!) into the male's brood pouch, where he fertilizes and incubates them until they hatch.
After an incubation period of 9 to 45 days, the male gives birth to hundreds of tiny seahorses through abdominal contractions—a rare phenomenon in the natural world.
Two seahorse species are found in the Mediterranean: the long-snouted seahorse (Hippocampus guttulatus), which prefers seagrass meadows, and the short-snouted seahorse (Hippocampus hippocampus), more commonly found in muddy seabeds or Posidonia oceanica habitats. Their coloration varies from brown to yellow, red, or orange, depending on their surroundings.
Seahorses inhabit nearly all the world’s waters, except for polar seas, but they are among the marine species most vulnerable to environmental changes. Pollution, acidification, and rising water temperatures are altering and reducing their habitats, putting their populations at risk. Despite being protected under the Washington Convention, seahorses are often illegally fished for souvenirs or used in traditional Asian medicine.
Since 2004, all Hippocampus species have been protected under CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora), and in the Mediterranean, they are safeguarded by various international agreements.
Protecting their habitats is crucial to ensuring the survival of these extraordinary marine creatures. This is why, since 2023, One Ocean Foundation— in collaboration with ROCKWOOL, local institutions, and with the scientific support of the University of Bari—has been supporting a multi-year project to safeguard seahorses. The goal is to restore and protect the repopulation of endemic seahorse species in the Mediterranean Sea.
To learn more, click here.