Giant Seahorse
Hippocampus ingens
Also known as: Pacific giant seahorse, Pacific seahorse
The largest seahorse in the Pacific, built for life among deep coral branches.

About
The giant seahorse (Hippocampus ingens) is the largest seahorse species found along the eastern Pacific coast, ranging from the waters off southern California all the way down to Peru, with populations also established around the Galapagos Islands. In the wild, these fish tend to live in deeper offshore waters, typically anchoring themselves among the branches of gorgonians and black coral with their prehensile tails. A behavior that doubles as camouflage and gives them stability in the current. They are naturally nocturnal, which is worth keeping in mind when setting up a feeding schedule in captivity. Like all seahorses, males are the ones that carry and incubate the eggs in a specialized brood pouch, making for one of the more fascinating reproductive strategies in the fish world. In the aquarium, H. ingens is considered manageable even for keepers relatively new to seahorses, which is somewhat surprising given how demanding the genus can be overall. Their size means they can handle larger, more robust live or frozen food items than smaller species. They do best with calm tankmates and a well-structured environment that gives them plenty of hitching points. A peaceful, species-focused setup tends to bring out their best behavior.
Similar species
Other fish you might consider
Good tank mates
Species that tend to coexist peacefully with Giant Seahorse
From the same region
Share the same natural habitat. Great for a biotope-themed tank
Frequently asked questions
- How big does the Giant Seahorse get?
- The Giant Seahorse reaches about 8–10" as an adult.
- What size tank does the Giant Seahorse need?
- A minimum of 30 gallons is recommended for the Giant Seahorse.
- What water parameters does the Giant Seahorse need?
- The Giant Seahorse does best with a temperature of 68–77°F, a pH of 8.2–8.4, hardness around 8–12 dGH.
- Is the Giant Seahorse aggressive?
- The Giant Seahorse is generally peaceful and suits a community tank with similarly calm tankmates.
- What does the Giant Seahorse eat?
- The Giant Seahorse is a carnivore. It needs a meaty, protein-rich diet of frozen or live foods.
- How long does the Giant Seahorse live?
- With good care, the Giant Seahorse typically lives 4-6 years.
- Is the Giant Seahorse reef safe?
- The Giant Seahorse is generally considered reef safe.