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15 Types of Seahorses: Species, Facts and Photos

Seahorses, known for their unusual reproduction, come in various sizes, colors, and shapes. This article closely examines the diversity of different types of seahorses.

Seahorse Classification

The order of ray-finned fishes, Syngnathiformes, includes a diverse range of marine life, including sea moths, trumpet fishes, and seahorses. 

Seahorses fall under the genus Hippocampus, which derives from the Greek words "horse" and "sea monster." This name encapsulates the animal's unique physical characteristics, such as its horse-like head, segmented bony armor, and curled prehensile tail.

So far, researchers have identified 46 seahorse species, with the latest additions being pygmy seahorses. Hippocampus nalu, uncovered in South Africa in 2020, marked the first pygmy seahorse recorded in the Indian Ocean1. Another addition includes the Hippocampus japapigu, discovered in Japan in 2018. The following sections discuss some notable seahorse species.

Related Read: Seahorse Facts.

15 Types of Seahorse Species

1. Common Seahorse (Hippocampus kuda)

common seahorse
Photo by Emőke Dénes on Wikimedia Commons licensed under CC BY-SA 4.0 (Cropped from original).

The Common Seahorse, or Yellow Seahorse, can grow up to 12 inches, has a 45-degree angled head, and can change color to blend into its surroundings. 

Its habitat includes shallow waters such as seagrass beds, coral reefs, mangroves, and estuaries in the Indo-Pacific region. It feeds on small crustaceans and zooplankton, using its snout to suck in food like a vacuum.

2. Long-snouted Seahorse (Hippocampus guttulatus)

 Long-snouted Seahorse
Photo by Cliff on Wikimedia Commons licensed under CC BY 2.0 (Cropped from original).

The Long-Snouted Seahorse inhabits the eastern Atlantic Ocean. It can reach up to 8.5 inches in length. Its color varies from dark green to various shades of brown and yellow, typically speckled with small white dots.

This species lives in shallow, coastal waters with seagrass beds and macroalgae, feeding on small crustaceans and other tiny organisms drifting in the seas. Moreover, the Long-Snouted Seahorse is monogamous; unlike most species, the males carry the eggs in a brood pouch until they hatch.

3. Short-snouted Seahorse (Hippocampus hippocampus)

Short-snouted Seahorse
Photo by Hans Hillewaert on Wikimedia Commons licensed under CC BY-SA 4.0 (Cropped from original).

The Short-snouted Seahorse inhabits the Mediterranean and North Sea. It measures between 5 and 7 inches and possesses a hard, bony armor, unlike other seahorse species. Its prehensile tail serves as an anchor, which it uses to latch onto seagrass beds or coral reefs, where it prefers to dwell. 

The Short-snouted Seahorse is also a master of camouflage, sporting shades of brown, green, yellow, or grey with tiny white spots.

Regarding diet, the Short-snouted Seahorse eats small crustaceans and plankton, which it sucks into its snout like a mini vacuum cleaner. 

Like other seahorses, they are monogamous; the males carry the offspring in their specialized brood pouch. A male seahorse can carry up to 200 eggs, which he incubates for about three weeks before they hatch. 

4. Lined Seahorse (Hippocampus erectus)

Lined Seahorse
Photo by Emőke Dénes on Wikimedia Commons licensed under CC BY-SA 4.0 (Cropped from original).

The Lined Seahorse or Spotted Seahorse lives in the Atlantic Ocean, inhabiting various locations from Canada to Argentina. They feature distinctive vertical stripes, elongated snouts, and prehensile tails. 

Lined seahorses exhibit many colors, from black to yellow. Their front side tends to be lighter. Their colors can alter based on environmental changes, dietary intake, anxiety, stress levels, or mood.

Moreover, they use their tails to anchor themselves and sway with the ocean's motion while feeding on tiny crustaceans and plankton.

5. Spiny Seahorse (Hippocampus histrix)

Spiny Seahorse
Photo by Nhobgood Nick Hobgood on Wikimedia Commons licensed under CC BY-SA 3.0 (Cropped from original).

As its name indicates, the Spiny Seahorse–not to be confused with the hedgehog seahorse– features an array of spines that act as armor.

Measuring up to 7 inches, its coloration ranges from pale yellow to dark brown, often with white or black spots, which allows it to blend into its surroundings in the Indo-Pacific region. 

Regarding diet, it feeds on small crustaceans, plankton, and other tiny marine organisms using its tubular snout. During the breeding season, the female Spiny Seahorse deposits her eggs into the male's brood pouch, which he nurtures until they hatch.

6. Pygmy Seahorse (Hippocampus bargibanti)

Pygmy Seahorse
Photo by Etienne Gosse on Flickr licensed under CC BY 2.0 (Cropped from original).

The Pygmy Seahorse, also known as the little or dwarf seahorse, is a tiny creature in Southeast Asia's Coral Triangle.  Its body measures less than an inch, roughly the size of a paperclip. The seahorse's body is covered with rounded bumps called tubercles, which mimic the color and shape of the coral polyps around it.

Marine biologists stumbled upon this camouflaging ability while examining its host coral in a lab. It often wraps itself around the gorgonian corals Muricella plectana and Muricella paraplectana

Other species known as pygmies are the pygmy thorny seahorse, the Sodwana pygmy seahorse, and the Pontoh’s pygmy seahorse. 

7. Tiger Tail Seahorse (Hippocampus comes)

Tiger Tail Seahorse
Photo by MartinThoma on Wikimedia Commons (Public Domain).

The Tiger Tail Seahorse can grow up to 7 inches and is commonly found in coral reefs, seagrass beds, and mangroves in the Western Pacific Ocean. Its tail displays stripes that resemble those of a tiger, and its body features a variety of colors in intricate patterns. 

The male seahorse carries the eggs in a specialized pouch and nurtures them for about 14 days. Then, the eggs hatch into fully formed young seahorses, ready to explore the ocean. These seahorses are also monogamous and territorial.

Regarding movement, this seahorse relies on quick, small fin movements for propulsion. It tends to stay within a few feet of its habitat.

8. Pot-bellied Seahorse (Hippocampus abdominalis)

Pot-bellied Seahorse
Photo by opencage on Wikimedia Commons licensed under CC BY-SA 2.5 (Cropped from original).

The Pot-bellied Seahorse is one of the world’s largest seahorse species, reaching up to 14 inches long. It anchors itself to underwater vegetation using its prehensile tail; seahorses are not known for their swimming abilities. 

Inhabiting the waters of Australia and New Zealand, it feeds on small crustaceans and plankton, which it captures using its snout-like mouth.

Unlike other seahorse species, this monogamous creature does not engage in elaborate courtship displays. Instead, it forms pair bonds through regular tactile and visual contact. 

9. Thorny Seahorse (Hippocampus histrix)

Thorny Seahorse
Photo by prilfish on Flickr licensed under CC BY 2.0 (Cropped from original).

The Thorny Seahorse has an armored body with long, sharp spines that often host algae and other marine growth, providing a natural camouflage. They have a slender snout and a tail that latches onto seagrass or coral. Moreover, their coloration changes according to their surroundings, ranging from yellow, brown, and green to grey. 

These types of seahorses are primarily nocturnal, emerging at night after hiding in seagrasses or coral. They live in the warm, tropical waters of the Indian and Pacific Oceans, including the Red Sea, South Africa, Fiji, and coastal areas of Southern Japan. 

Although not strong swimmers, they can change their color and texture to blend in with their surroundings. They can avoid predators and hunt more effectively. 

10. White's Seahorse (Hippocampus whitei)

White's Seahorse
Photo by Sylke Rohrlach on Wikimedia Commons licensed under CC BY-SA 2.0 (Cropped from original).

White's Seahorse or New Holland Seahorse lives along Australia's eastern coastal waters or estuaries, where its prehensile tail anchors the animal to seagrasses and corals. 

This species, usually in shades of brown or black, sometimes appears entirely yellow. It has pale markings on certain rings, enlarged tail spines, fine bars, and dusky lines on the snout that broaden near the eyes. The nasal spine and its surrounds are often pale.

During the day, it hunts small crustaceans, plankton, and other tiny marine creatures. Then, it returns to its resting spot at night. 

White's Seahorse also performs a dance of love;  males and females engage while changing colors. After mating, the males carry the eggs in a pouch until they hatch.

Endangered White Seahorses face significant threats from human activities, such as coastal development, pollution, and destructive boating practices. Recent reports suggest an alarming decline, over 90% in some areas, primarily due to marine habitat loss. These seahorses risk being listed as Critically Endangered if such trends persist.

11. Great Seahorse (Hippocampus kelloggi)

The Great Seahorse lives in the warm waters of the Indo-Pacific region, where it blends into coral reefs, mangroves, and seagrass beds. 

It can grow up to 11 inches and features yellowish-brown coloring that helps it blend into its surroundings. It can also change its color to match its surroundings, and its prehensile tail helps it anchor itself in place.

Moreover, the Great Seahorse moves slowly using its dorsal and pectoral fins to glide through the water. Its movements are almost hypnotic. 

12. Knysna Seahorse (Hippocampus capensis)

Knysna Seahorse
Photo by Brian Gratwicke on Wikimedia Commons licensed under CC BY 2.0 (Cropped from original).

The Knysna Seahorse lives in the estuaries of the Knysna and Swartvlei rivers in South Africa, where level of salinity varies. Moreover, its green or brown color helps it blend into the eelgrass beds.

The Knysna Seahorse is endangered due to a restricted habitat spread over three locations2. Declines in habitat quality and mature individuals also suggest it's at risk. To ensure sustainability, habitat protection, water management plans, and further tracking are paramount for this species' survival.

13. Zebra Seahorse (Hippocampus zebra)

The Zebra seahorse inhabits coral reef areas in Northern Australia. Favoring inshore environments with mud or sandy bottoms, this species is aptly named for its zebra-like alternating bands of yellow-white and black-brown.

Its color scheme enables effective camouflage, crucial for its survival. Mimicking the appearance of black and white basket stars, the seahorse becomes undetectable among native coral fans and gorgonians.

14. Pacific Seahorse (Hippocampus ingens)

Pacific Seahorse
Photo by Alberto Alcalá on Wikimedia Commons licensed under CC BY-SA 4.0 (Cropped from original).

The Pacific Seahorse, also called the giant seahorse, grows up to 12 inches and displays an array of colors from maroon to green to grey. This marine creature dwells among mangroves, coral, and rocky reefs in the expansive Pacific, stretching from Baja California to Chile.

Unfortunately, since the early 2000s, the Pacific Seahorse population has seen drastic dips. Current population data isn't available, but harsh realities such as continuing fishing pressure and illegal trading ominously signal a downward trajectory in their numbers.

15. Giraffe Seahorse (Hippocampus camelopardalis)

The giraffe seahorse inhabits coastal waters stretching from South Africa to Tanzania. It is possible to find these creatures even further north, up towards Kenya. This type of seahorse prefers estuarine seagrass beds, algal beds, and shallow reefs as habitats. 

Detailed studies are lacking, but initial data suggest the species is being exploited for aquarium use, traditional medicine, and trade. Some fishers report a decline, signaling a need for more research and monitoring.

1

Short, G., Claassens, L., Smith, R. E., De Brauwer, M., Hamilton, H., Stat, M., & Harasti, D. (2020). Hippocampus nalu, a new species of pygmy seahorse from South Africa, and the first record of a pygmy seahorse from the Indian Ocean (Teleostei, Syngnathidae). ZooKeys, 934, 141–156.

2

Pollom, R. (2017). Hippocampus capensis. The IUCN Red List of Threatened Species 2017: e.T10056A54903534. 

By Mike Gomez, BA.

Mike is a degree-qualified researcher and writer passionate about increasing global awareness about climate change and encouraging people to act collectively in resolving these issues.

Fact Checked By:
Isabela Sedano, BEng.

Photo by Chaojie Ni on Unsplash.
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