Advice You Might Be Given By Your Local Fish Shop
About Seahorses

By Keith Gentry


“They eat pellet or flake food”

Ask for a demonstration. Seahorses do not eat flake or pellet foods.


“They’ll do fine on brine shrimp”

Brine shrimp (artemia) is not a staple food for seahorses. It needs to be enriched with a HUFA (highly unsaturated fatty acids) emulsion or similar for it to have any nutritional profile at all. Seahorses fed on unenriched brine will starve to death.

Wild caughts may not even recognize live brine shrimp as food.

Dwarves will be OK on newly hatched or enriched instar II/III brine. All other species require mysis, gutloaded ghost/river shrimp, or similarly sized crustaceans. There is a comprehensive article on live foods in the library at


“Seahorses will survive on a population of copepods/amphipods on the live rock.”

The species of copepods you expect to see on live rock are the benthic (surface dwelling) kind, which on average will be about <1mm in size. These are far too small to feed adult seahorses with. Most will ignore them – the ones that do eat them will quickly decimate the copepod population. You cannot rely on a “self sustaining” population of copepods or amphipods to feed your horses with.


“They’re easy to train to frozen foods”

Some wild caught seahorses will never take frozen foods, no matter how hard you try to train them. Do not buy wild caught seahorses unless you have year-round access to suitably sized live foods (not just adult brine). Even if they are eating frozen in the shop, there is no guarantee they will still eat frozen when you get them home (the stress of moving them is sometimes enough for them to refuse frozen). A seahorse should not go for more than a couple of days without being fed – this does not give you any time to source live food if they won’t eat frozen for you at home.


“Our yellow seahorses are captive bred.”

If the store carries captive bred seahorses, they will know the name of the species, not just the common name for them – simple as that. If the horses are labelled as “yellow seahorse”, “atlantic seahorse” etc – odds on that they are wild caught. Beware of “Hippocampus kuda” – it has been used generically to describe just about any species of seahorse.

Different species come from different temperature zones – a temperate seahorse will quickly die if kept at tropical temperatures. It is important to know the species so you can provide the correct environment.

Some shops get defensive when you politely question them about the origin of their "CB" seahorses. Ask who the breeder is, and the scientific name. If they cannot give you all of this information, they are not captive bred seahorses. If in doubt, leave them in the store.

If the seahorse is not priced at LEAST $40-90 it is probably not CB, although WC can be and are often priced this high or higher, especially the large, colourful Brazilians (H. reidi). One exception to is in the UK, where WC seahorses are for some reason often more expensive than CBs.

If the seahorse is a large, mature specimen, it is probably WC. Seahorses are expensive to raise and feed, so breeders try to sell them fairly small, when they are just eating frozen. If they guarantee other marine fish, but don't offer the same one on "CB" seahorses, chances are they know they are WC and are more than likely to die, no matter what the hobbyist does, so they won't guarantee them.

If the seahorses won't eat anything, or will only eat live food, they are probably WC. Captive breds should be trained to eat frozen mysis. Ask to see a demonstration of this in the shop. Beware of shops carrying seahorses that do not sell frozen mysis or nutritious live food (e.g., appropriate sized ghost/glass shrimp). Brine shrimp, especially if not enriched with Selcon or similar HUFA supplement, does not count. If the shop doesn’t carry the foods they eat, then what are they feeding their seahorses with? If they’ve been in store for a week or so without being fed properly, chances are they won’t live long.

Another common sight is seahorses kept with unsuitable tank mates (anemones, crabs, damsels, tangs, other aggressive or fast swimming fish). Again this should give cause for concern, as it shows a lack of understanding of basic care and increases the chances of their fish being in poor condition.


“Buy the tank and the seahorse together. This 1 gallon tank will do – they don’t move about much.”

In order for your aquarium to support life, it must be cycled (see “nitrogen cycle”). This takes up to eight weeks depending on the method used. You cannot buy a seahorse and put it into an uncycled aquarium, neither can you cycle a tank with relatively delicate marine fish –they will be dead within five days or so from ammonia poisoning depending on the size of the tank.

If you do not know about the nitrogen cycle, you are not yet ready to keep seahorses. An article explaining this can be found in the library at

Seahorses are sessile, but require fairly large tank space for relatively slow moving fish. A good minimum size for a pair of medium sized horses is 20 gallons. Also bear in mind that the smaller the tank, the faster water quality can degrade.

Seahorses are social animals and should not be kept singly.


“Seahorses normally: float, have bubbles under their skin, have white cottony patches, lie on their sides on the bottom of the tank etc. They’re just tired, they’ll be fine once you get them home.”

If the seahorse appears to have a disease, or if you are unsure, do not buy it. Ask to see the seahorse eating. Watch it swim. If there is anything unusual, don’t buy.


“Half of the seahorses in this tank are wild caught, the other half are captive bred.”

Few LFS’s understand the need to keep wild caught and captive bred seahorses separately. Captive breds have not built up a resistance to the pathogens carried by wild caughts. Mixing them – or even putting captive breds in a tank which has had wild caughts in it at some point in time – can cause problems.

Ask the LFS if the tank with the captive breds in has ever had wild caught seahorses in, or whether it is on a shared circuit with any wild caught syngnathid tank.


Rescuing seahorses

It’s quite common to see seahorses kept in terrible conditions by some LFSs – in with aggressive fish, stinging corals, anemones etc or just not being fed at all.

Most LFSs will only have them for a short space of time. Often they will know little about the long term care of seahorses.

You may be tempted to “rescue” them, thinking you can provide better care for them yourself. While this is probably true, the LFS will then perceive a demand for them and order twice as many the next time.

If you do need to “rescue” the seahorses, refuse to pay for them. If they insist on charging you, leave them in the store. You may end up compounding the problem otherwise.

Other points to consider:

  • Do you have access to antibiotics and antiparasitic medication? These are available over the counter in the US. They are very difficult to come by in the UK and Australia for example.
  • Do you have anyone to feed the seahorses when you are away from home for more than a day?
  • When the fish is being bagged up, ask them to put a hitch in for the journey home.
  • Any fish should be quarantined before being added to the tank. A QT tank can double as a hospital tank, and is a vital piece of equipment. Captive breds should be quarantined for a minimum of three weeks, wild caughts for a minimum of six weeks.

Most recent revision: February 17, 2004

Copyright 2004
Keith Gentry &
All Rights Reserved

Seahorse fact: The female produces the eggs and transfers them to the male during the courtship.
Help | Links | Site Map

Often copied, never matched.
Copyright 2001 to 2021
All rights reserved.