Saltwater Fish
Spiny Seahorse

Species Description…

Scientific Name: Hippocampus histrix
Common Name: Spiny Seahorse
Species Group: Seahorse
Habitat: Reef Safe
Care Level: Intermediate
Temperament: Peaceful
Diet Type: Carnivore
Role in Aquarium: Showpiece Fish
Max Fish Length: 6 (inches)
Min Aquarium Size: 30 (gallons)
Native Range: Indo-Pacific, including Indonesia, the Philippines, and Papua New Guinea
Hippocampus histrix - Spiny Seahorse

Hippocampus histrix (Spiny Seahorse)

Overview

  • Native to the Indo-Pacific, inhabiting coastal reefs, seagrass beds, and sandy ocean floors.
  • Named for its distinct spiny protrusions along its body, which provide camouflage among coral and seagrass.
  • Unlike smooth-bodied seahorses, its spines help it blend into its environment and deter predators.
  • Swims upright and relies on its prehensile tail to anchor itself to coral, seagrass, and artificial structures.
  • Highly sought after in the aquarium trade due to its striking appearance and captivating behavior.

Feeding

  • Carnivorous, primarily feeding on small crustaceans such as copepods, amphipods, and mysis shrimp.
  • Requires frequent feedings (at least 3-4 times per day) due to its lack of a stomach and fast digestion.
  • Best fed with live or frozen enriched foods, as they are slow, deliberate feeders.
  • May struggle in tanks with fast-moving fish that outcompete them for food.
  • Uses a unique suction feeding mechanism, rapidly drawing in prey through its tubular snout.

Habitat

  • Commonly found in shallow coastal waters, coral reefs, and seagrass meadows.
  • Requires an aquarium with an abundance of hitching posts, such as live rock, coral branches, and artificial plants.
  • Prefers a low-flow environment, as strong currents can make swimming difficult.
  • Best housed in a species-specific tank or with other slow-moving, non-aggressive tank mates.
  • A minimum tank size of 30 gallons is recommended for a pair, with additional space needed for groups.

Fish Care

  • Optimal water temperature: 72-78°F (22-26°C).
  • Ideal pH range: 8.1-8.4, with a specific gravity of 1.022-1.025.
  • Highly sensitive to water quality and requires stable tank conditions.
  • Must be housed in a mature, well-established aquarium with excellent biological filtration.
  • Frequent water changes and proper filtration are essential for maintaining long-term health.

Compatibility

  • Best suited for a peaceful, species-only tank or with other slow-moving, non-aggressive fish.
  • Compatible with pipefish, small gobies, and certain blennies that do not compete for food.
  • Should not be housed with fast-swimming, aggressive, or territorial fish.
  • Avoid housing with stinging corals or anemones, as seahorses may accidentally latch onto them.
  • Pairs and small groups thrive in aquariums where they can interact and exhibit natural social behaviors.

Aquarium Behavior

  • Spends most of its time clinging to structures with its tail rather than actively swimming.
  • Known for unique courtship displays, where pairs engage in synchronized movements and tail-wrapping rituals.
  • Exhibits social behavior, often forming strong pair bonds.
  • Fascinating to observe due to its slow, deliberate movements and method of capturing prey.
  • Requires a stable and stress-free environment with plenty of hiding spots and hitching posts.