How often do I need to feed my Lined Seahorse?

They should be fed at least two to three times a day. Because they lack a true stomach, food passes through their digestive tract very quickly, so they require constant nourishment.

Can I keep Lined Seahorses in a normal reef tank?

It is not recommended. Reef tanks usually have high water flow and stinging corals (like anemones or large polyp stony corals) which can injure or exhaust a seahorse. They also struggle to compete for food with typical reef fish.

Why is my seahorse changing colour?

Lined Seahorses can change colour based on their environment, mood, stress levels, or diet. They often shift to match their hitching posts or to communicate with a mate during courtship.

What is the best food for them?

High-quality, frozen mysis shrimp enriched with vitamins and HUFAs (Highly Unsaturated Fatty Acids) is the staple diet for captive-bred seahorses.

Do I need a tall tank for seahorses?

Yes. A tank should be at least 45cm (18 inches) tall. Seahorses swim vertically, and they require this height to comfortably perform their courtship and mating dances.

MarineMarineAdvanced

Lined Seahorse

Hippocampus erectus

The Lined Seahorse is an iconic, highly adapted marine species that charms dedicated aquarists with its upright posture and unique reproductive biology.

List this species for sale Find Lined Seahorse near me

Ideal Conditions

Temperature: 22 – 24 °C
pH range: 8.1 – 8.4
Hardness: 14 – 22 dGH
Salinity: 1.02 – 1.025 SG
Adult size: 12 – 17 cm
110L minimum for a pair; requires a tank with tall vertical height (at least 45cm).: 110 litres+
Lifespan: 2 – 4 years
Diet: Carnivore. Requires multiple daily feedings of highly nutritious, meaty foods such as enriched frozen mysis shrimp.
Water flow: low
Preferred setup: Provide numerous vertical hitching posts such as gorgonians, fake corals, macroalgae, or branching live rock.

About the Lined Seahorse

Hippocampus erectus, commonly known as the Lined Seahorse, is a captivating marine fish native to the Western Atlantic. Distinguished by its upright swimming posture, prehensile tail, and horse-like head, this species relies on camouflage and patience rather than speed. They frequently display thin, white lines along their neck and back, though their base colour can shift dramatically depending on their mood and environment. Due to their specialised needs, they are best suited to dedicated aquarists willing to maintain a species-specific aquarium.

Find Lined Seahorse

Search current listings in your chosen area. If none are available, save an alert and we’ll let you know when a match is listed.

Find locally Check compatibility Add to a Setup

Availability alerts only use public sale listings. Adding this species to a Setup updates your private records.

Is it right for your tank?

Check Lined Seahorse against a habitat you already keep. We compare water type, temperature, pH, adult size, group needs and everything living there.

Where Lined Seahorse comes from

Native range

Western Atlantic Ocean, Gulf of Mexico, Caribbean Sea

Countries / regions

United States, Canada, Mexico, Bahamas, Cuba, Brazil

Habitat

Coastal seagrass beds, mangrove roots, sponge reefs, and floating Sargassum mats in shallow marine waters.

They boast a vast latitudinal range from as far north as Nova Scotia in summer, down to Venezuela and Brazil.

Similar species

Dwarf Seahorse
Hippocampus zosterae
Kuda Seahorse
Hippocampus kuda
Tiger Tail Seahorse
Hippocampus comes

We’re adding more full species guides as the catalogue grows.

Compatible tank mates

Reviewed guidance based on this species' recorded traits.

View all compatibility

Bluestripe Pipefish
Doryrhamphus excisus
Closely related and shares similar gentle feeding habits and low flow requirements, ensuring neither outcompetes the other.
Great
Green Mandarin
Synchiropus splendidus
A slow, deliberate feeder that grazes on copepods and will not bother or outcompete the seahorse for mysis shrimp.
Great
Astrea Snail
Lithopoma tectum
Excellent cleanup crew that will not harass the seahorses while safely keeping the tank clear of algae.
Great
Peppermint Shrimp
Lysmata wurdemanni
Can sometimes steal food directly from the seahorse's snout if not well-fed, though generally considered safe in moderation.
Compatible with caution
Ocellaris Clownfish
Amphiprion ocellaris
Far too active and aggressive during feeding; will rapidly consume food before the slow-moving seahorses have a chance to eat.
Not recommended
Emerald Crab
Mithraculus sculptus
Possesses pincers and may opportunistically grab or pinch the delicate tails of resting seahorses.
Not recommended

Current marketplace listings

Checking the marketplace…

See all Lined Seahorse listings

Public Wanted requests

No open requests for Lined Seahorse in this market yet.

Looking for Lined Seahorse?

Search current listings near you, or post a wanted request so local sellers know what you’re looking for.

Search Lined Seahorse listings Post a wanted request