Not furry, but we like them anyway.
Lined Seahorse
Hippocampus erectus Perry, 1810
Also called Northern seahorse, Spotted seahorse
From Western Atlantic, from Nova Scotia to Venezuela and Brazil, including the Gulf of Mexico, the Caribbean and the US east coast. Aquarium fish are usually captive-bred.123
At a glance the quick version
Adults usually 12 to 17 cm; maximum recorded about 19 cm.
One to four years in the wild; around four years is typical in captivity.
Looks how to spot one
Bony-plated seahorse
An upright seahorse whose body is armoured in roughly fifty bony plates. Fine white lines trace the neck and tiny white dots speckle the tail, and a crown-like coronet tops the head. Colour is highly variable and adapts to its surroundings.23
Personality what they are like
Peaceful and unhurried. Pairs bond for life and renew their bond each morning with a short dance, and they make soft clicking sounds with the coronet.23
Daily activity how busy a day looks
A slow, upright swimmer that beats its small fins very quickly and spends most of its time anchored by its prehensile tail to grasses and other holdfasts.23
Grooming and care the hands-on bits
Rated difficult. It needs calm, clean water, several small meals a day and prompt removal of leftover food. Captive-bred fish already eat frozen foods.32
Home where they are happiest
A tall species aquarium (at least about 40 cm high) of about 115 litres (30 US gallons) for a pair, with gentle flow and plenty of hitching posts. Water about 20 to 26 °C, pH 8.1 to 8.4, dKH 8 to 12, specific gravity 1.020 to 1.025.32
Food basics what goes in the bowl
Small crustaceans such as frozen mysis shrimp, offered two or more times a day. It suction-feeds through its long snout.321
Company who they like around
Best kept as a mated pair or a small group of its own kind in a species-only tank, away from fast or boisterous fish.32
The story where it all began
George Perry described the species in 1810. It is the only seahorse native to Chesapeake Bay, and it has been bred in captivity for many years, supplying most aquarium fish.21
Fun facts for the dinner table
Recognised by the official bits
- IUCN Red List
- Vulnerable (assessed 3 October 2016)1
- CITES
- Appendix II1
- Taxonomy
- Family Syngnathidae; described by George Perry in 18102
The care rhythm Furry Diary remembers it for you
A typical home-care rhythm for a Lined Seahorse. It is our own starting plan, not a vet's advice, and you can change every line in the app.
- FeedingSmall amounts once or twice a dayevery day
- Temperature checkevery day
- Salinity checkevery week
- Top-upTop up evaporation with fresh RO water, not salt waterevery day
- Water testevery week
- Water changeAbout 10 to 20% of the waterevery 2 weeks
- Glass cleanevery week
Owner questions the things everyone asks
How often should I feed my Lined Seahorse?
Feed your lined seahorse two or more times a day with small amounts of frozen mysis shrimp. Furry Diary's starting plan is to offer small amounts once or twice daily, and it's important to remove any uneaten food promptly to keep the water clean.321 Furry Diary plan
What does a Lined Seahorse eat, and what should it never eat?
Your lined seahorse eats small crustaceans like frozen mysis shrimp, which it suction-feeds through its long snout. It should never be given large or live foods that could harm its delicate digestive system, and always avoid any food not specifically recommended for seahorses.321
How much space does a Lined Seahorse need?
A pair of lined seahorses needs a tall aquarium of at least about 115 litres (30 US gallons) with a height of around 40 cm. The tank should have gentle water flow and plenty of hitching posts like seagrasses for them to anchor with their tails.32
What temperature, light or water does a Lined Seahorse need?
Keep the water temperature between 20 and 26 °C, with a pH of 8.1 to 8.4, dKH of 8 to 12, and specific gravity of 1.020 to 1.025. Furry Diary's plan suggests checking temperature daily and salinity weekly, and using only fresh RO water for top-ups.32 Furry Diary plan
How often should I clean a Lined Seahorse's home?
Furry Diary's starting plan recommends a weekly glass cleaning and a 10 to 20% water change every two weeks. Promptly remove any leftover food after each feeding to maintain the calm, clean water they need.32 Furry Diary plan
Can a Lined Seahorse live with others?
Lined seahorses are best kept as a mated pair or a small group of their own kind in a species-only tank. They should not be housed with fast or boisterous fish, as they are peaceful and unhurried swimmers.32
How long does a Lined Seahorse live?
A lined seahorse typically lives between 1 and 4 years. Providing calm, clean water and a proper diet can help them reach the upper end of that range.2
Can I handle a Lined Seahorse?
Handling a lined seahorse is not recommended, as they are delicate bony-plated fish that can be easily stressed or injured. It's best to observe them peacefully in their aquarium and avoid any physical contact.32
Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Furry Diary's own starting care plan. A friendly guide, not a vet's advice.
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Where this comes from
Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at support@furrydiary.app and we will fix it.
- FishBase: Hippocampus erectus summary fishbase.seused for distribution, depth, length, gestation, IUCN and CITES status, captive rearing
- Wikipedia: Lined seahorse en.wikipedia.orgused for names, description, colours, behaviour, lifespan, reproduction, fun facts
- LiveAquaria: Lined Seahorse, Captive-Bred liveaquaria.comused for aquarium care level, tank size, water parameters, diet, tankmates
- VCA Animal Hospitals: Feeding times and frequency for your dog vcahospitals.comused for owner questions
- ASPCA: Dog grooming tips aspca.orgused for owner questions
- ASPCA: Cat grooming tips aspca.orgused for owner questions
- ASPCA: People foods to avoid feeding your pets aspca.orgused for owner questions
- RSPCA: What to feed your rabbit rspca.org.ukused for owner questions
Checked 2026-09-30. Text is written in our own words from these sources.