UPDATED: 26 December 2003

As many aquarium hobbyists know, seahorses and related species have different needs than other marine fish. This fact sheet was created to assist anyone that is interested in keeping these fascinating fish. The content herein is meant to be a guideline for new seahorse keepers based upon the experience of several hundred seahorse hobbyists, Syngnathidae researchers, and commercial breeders.

IMPORTANT NOTE: Although we discuss wild caught (WC) as well as captive bred (CB) seahorse strongly advise buying CB seahorses. Captive breeding prevents decimation of wild populations and supports responsible and innovative breeding programs for those interested in becoming seahorse breeders. In addition, captive bred seahorses are much easier to keep, having been trained to accept frozen food, pre-adapted to aquarium conditions, and much less likely to carry or spread disease. Their survivability in captivity is significantly higher than that of wild caught seahorses. In the end, it is more cost effective and rewarding for the beginning hobbyist to purchase CB seahorses.

WE RECOMMEND THAT ALL BEGINNING KEEPERS PURCHASE ONLY CAPTIVE BRED SEAHORSES.

PURCHASING HEALTHY SEAHORSES

If you are buying from a local fish store (LFS), observe the seahorses carefully before you purchase. If you are buying from an e-tailer, be sure they have a reputation for supplying quality animals and a guarantee of live arrival and survival for 5-7 days. Even the smallest sign of disease or injury can result in a mortality, as seahorses are extremely sensitive and often succumb to pathogens not common to other marine ornamental fish. To make matters worse, treatments are quite different and have fewer efficacies. The following are some questions to ask of your local fish store or e-tailer, particularly if you are purchasing WC animals. If you are able to observe the seahorses onsite, the following guidelines can help you with picking out the best animals that are most likely to survive. Even with a careful eye, WC seahorses can look outwardly healthy, only to die within a few days of purchase. Though there are no guarantees when purchasing WC seahorses, this may help to minimize mortalities:

DO NOT BUY A SEAHORSE THAT IS NOT EATING. Even stressed, new arrivals should eat within 24 hours if it they are otherwise healthy and kept in a clean, well-aerated tank. Often they have only been offered brine shrimp, which is not a normal food source in their native habitats. Although this is not a healthy diet, if the seahorse will take it readily, it is the first sign of good overall health. However, if the seahorses have been in the pet store for any length of time, fed exclusively on un-enriched brine shrimp, there is a good chance these specimens will be malnourished. Seahorses only have a rudimentary stomach and must continuously absorb nutrients. Offering a non-nutritional diet for more than several days will quickly deplete the seahorse of necessary nutrients, making it more susceptible to pathogens. Most malnourished seahorses do not survive in the long term.

It is a better sign if the pet store is feeding a more adequate diet. This could include enriched brine shrimp, ghost shrimp (for larger seahorses), Hawaiian red shrimp, or frozen mysis or similar crustaceans . You are much more likely to succeed with a seahorse that is trained to eat frozen food, and it is cheaper and easier to obtain and provide frozen food. Most CB seahorses have been trained to eat frozen mysis or similar appropriate food. Of the WC seahorses, H. erectus, the lined seahorse from the North American Atlantic seaboard, has the reputation of being easiest to train to eat frozen foods. As part of a complete diet, seahorses trained to eat frozen food should regularly receive a variety of live foods as well. Examples include ghost shrimp, enriched brine shrimp, baby mollies, red shrimp, etc. Some live food should be offered every week. (Note: The dwarf seahorse, H. zosterae, is a hardy species, but requires live food cultures of brine shrimp nauplii (24+ hour post-hatched vitamin/HUFA enriched baby brine shrimp), but is very hardy if its nutritional needs are met.)

SIGNS TO OBSERVE FOR POTENTIAL PROBLEMS

aquariums. In addition, you will be rewarding an aquarium shop for poor husbandry practices and for selling unhealthy WC seahorses. Instead, urge the store to maintain and feed seahorses properly and to stock CB animals.

CB seahorses, maintained in a mature tank with good water quality (ammonia and nitrite, zero; nitrate <20 ppm) and fed an appropriate diet may be expected to live for several years without serious health problems. WC seahorses, on the other hand, often show signs of

RECOMMENDATIONS FOR THE MEDICINE CABINET

Essential tools to have on hand:
Fine gauge IV catheter flexible tubing (without needle)
Tuberculin syringe with needle removed
Loose hairpin with soft plastic tip

ACCLIMATION AND QUARANTINE

Acclimation procedures do not differ from other fish except for the use of nets, as netting often damages the bony plates and the delicate dermal layer of the seahorse. Preferable methods include gently coaxing them into a plastic container for transfer or hand transfer. If the latter method is used, it is advisable to make the transfer quickly to avoid undue stress.

All WC purchases should be given a freshwater dip or formalin bath and ideally be kept in a separate display or quarantine tank for 2-4 weeks before introducing them to a tank with other seahorses. Seahorses are more sensitive than most fish to the FW dip, thus if they show signs of distress (e.g. thrashing, lying on bottom) lasting more than around 15 seconds, remove them immediately, regardless of the maximum 3 -5 minutes required to remove or kill external parasites. We do not advocate mixing CB and WC seahorses in a tank, as even apparently healthy WC seahorses may be asymptomatic carriers of disease that could decimate CB seahorses that may not have resistance to the disease. Observe all new purchases carefully for any odd behaviour or external lesions, spots or other anomalies. Usually the first sign of illness is cessation of appetite, but this is not a hard and fast rule. If any signs of illness are suspected, there is a comprehensive disease guide at www.seahorse.org.

Alternately, you can post the problem on the discussion board under Emergency if anything seems amiss. There are several expert keepers who will be around to help you with the problem and answer your questions. Please do not treat a seahorse without knowing what pathogen is affecting it. Additionally, never use copper-based solutions on seahorses or pipefish. Their internal organs are too delicate to withstand copper treatments.

THE SEAHORSE TANK

Seahorses should be introduced into a mature, cycled aquarium. Numerous filtration methods and tank set-ups can result in a healthy, stable seahorse aquarium. A seahorse tank must have gentle to moderate currents. Be sure there is adequate biological filtration and do regular, partial water changes of 5-20 percent per week as you would with any fish-only aquarium, to keep water parameters as listed below. Water parameters should be stable before animals are added:

pH - 8.0 to 8.3
Specific gravity - 1.021 to 1.024
Ammonia - 0
Nitrite - 0
Nitrate - <20 ppm

Optimum temperature is dependent on whether the seahorse species being kept are tropical, subtropical or temperate. Generally, most beginners should start with tropical species unless the tank is equipped with a chiller unit. Heating tanks is much less expensive than cooling them. Use a high quality submersible heater. Many Seahorse.org members use Ebo Jaeger heaters as they have more reliable than average performance and do not feel hot to the touch, minimizing the chance of burning a seahorse that hitches to the heater. Allow about 4-watts per gallon when selecting an aquarium heater.

This is not a hard and fast rule, but most seahorse aquarists use taller tanks. Seahorses need height (2.5 to 3 times the UNCURLED length of the animals) in their tanks to court and mate. At a minimum, the depth of the tank, excluding the substrate, should be at least 2x the uncurled length of the animal. Further, leave a path along the substrate as some seahorses courting rituals require them to scoot along the bottom of the tank in tandem. Several pairs of pygmy seahorses can be maintained in a 5-10 gallon tank (a 10G is recommended because of the difficulties of keeping water parameters stable in a small capacity aquarium. Two to three pairs of medium sized seahorses can be maintained in a 24-gallon tank although a larger tank is preferable to keep water parameters more stable.

Temperature Requirements and Stocking Density of Commonly Available Seahorse Species
Note: This is to be used as a guideline. Keeping temperature constant is extremely important and although it is typically better to keep them at the lower ranges below, stability is key. One degree more or less is not a problem as long as temperature swings do not exceed 2 degrees maximum in a 24-hour range. Surface turbulence using power heads (water pumps), air pumps, and fans can help to lower and stabilize temperatures if necessary.

Here is a list of commonly avaliable seahorse species grouped by their temperature range. You can not mix species from differing temperature ranges. Also listed is the recommended minimum tank size for two pairs of adult seahorses of each species, as well as the 'additional' space required by each additional pair. These are guidelines. Several people keep seahorses successfully in much smaller tanks, but we do not recommend this.

1) Tropical species - kept at 74-78 degrees F (24-26 degrees C)
zosterae, 1 pair/1.5 gallons (6 liters) - recommended 5 gallons (20 liters)
kuda, 1 pair/8 gallons (30 liters)- minimum size 15 gallons (60 liters)
barbouri, 1 pair/8 gallons (30 liters)- minimum size 15 gallons (60 liters)
erectus, 1 pair/8 gallons (30 liters)- minimum size 15 gallons (60 liters)
reidi 1 pair/8 gallons (30 liters)- minimum size 15 gallons (60 liters)
fuscus 1 pair per 5 gallons (20 liters)- minimum size 10 gallons (40 liters)
comes 1 pair/8 gallons (30 liters)- minimum size 15 gallons (60 liters)
procerus 1 pair/8 gallons (30 liters) - minimum size 15 gallons (60 liters)

2) Subtropical species - kept at 70-74 degrees F (22-25 degrees C)
whitei, 1 pair/8 gallons (30 liters)- minimum size 15 gallons (60 liters)
ingens1 pair/13 gallons (50 liters)- minimum size 45 gallons (180 liters)
tuberculatus, 1 pair/5 gallons (20 liters)- minimum size 15 gallons (60 liters)

3) Temperate species - kept at 66-72 degrees F (19-22 degrees C)
abdominalis, 1pair/13 gallons (50 liters)- minimum size 60 gallons (240 liters)
capensis 1 pair/5 gallons (20 liters)- minimum size 10 gallons (40 liters)
breviceps, 1 pair/5 gallons (20 liters)- minimum size 10 gallons (40 liters)

CHOOSING SAFE TANK MATES

NOTE: Be sure you research the requirements of any compatible animals you wish to add to the seahorse tank before purchasing. For example, many corals, sponges, and gorgonians require special reef lighting or high water flow to thrive.

Fan worms including Feather Dusters (Phylum Annelida)
Astrea Snail (Lithopoma [Astraea] spp.)
Turbo Snail (Turbo spp.)
Nassarius Snail (Nassarius vibex)
Trochus Snail (Trochus niloticus)
Cerith Snail (Family Cerithiidae)
Nerite Snail (Nerita spp.)
Fighting Conch (Strombus alatus)
Blue-legged Hermit Crab (Clibanarius tricolor)
Skunk Cleaner Shrimp (Lysmata amboinensis)
Peppermint Shrimp (Lysmata wurdemanni)
Scarlet/Blood Shrimp (Lysmata debelius)
Rockpool Shrimp (Palaemon elegans)
Grass Shrimp (Palaemonetes vulgaris)
(Shrimp are not considered safe around seahorse fry or H.zosterae (dwarf seahorse).

Notable groups that should be avoided:
Tangs, Triggerfish, Groupers, , Eels, Nudibranchs, Filter-feeding Sea Cucumbers, Sea Urchins with sharp spines, Fireworms, Spanish Dancer Flatworms, Fire Corals, Lace Corals, Anemones, Tube Anemones, all Cephalopods (Squids, Octopuses, Cuttlefish, and Nautilus-), Mantis Shrimp, Lobsters, Heliofungia spp. Corals, Cataphyllia spp. Corals, Euphyllia spp. Corals, Goniopora/Alveopora spp. Corals, Galaxea spp. Corals, and Hydnophora spp. Corals.

NUTRITION

With a little patience, WC seahorses can be trained to eat dead/frozen foods. There are numerous ways to coax them into taking it. (You can find a "how-to" at www.seahorse.org under "Articles" which explains the procedure.) This not only makes the job of feeding them a great deal easier and less expensive, it increases their chances of long-term survival, particularly with less experienced seahorse keepers. If you are having a lot of trouble getting your new seahorses to take frozen food, a short-term solution is to feed enriched artemia, (brine shrimp), ghost shrimp for larger species; and Hawaiian red shrimp. (See Seahorse.org for enrichment procedures.) The need to start with live food is usually necessary when purchasing WC seahorses unless the staff at your LFS has already trained them. It is good husbandry to continue to regularly offer live foods to seahorses that primarily subsist on frozen foods. Try to offer live foods at least once or twice a week.

The enriched artemia should always be rinsed in freshwater prior to feedings to kill or remove any harmful bacteria, and offered two to three times per day at three to six hour intervals. Some larger seahorse species may not readily take the brine shrimp, and will require live ghost/glass shrimp. These are a much more nutritional food source (or supplement) than the artemia-only diet. Finally, if you don't want to go to all this trouble maintaining the WC seahorses, your other option is to purchase only CB (captive bred) species that have already been trained to eat frozen foods, such as mysis (Mysis relicta), or mysids making feeding a much more simple task. Offer the frozen food, pre-thawed and rinsed, once or twice daily. Initially watch the seahorses carefully to see that all are getting their fill, and then adjust the amount of food offered accordingly. Again, remember to supplement a diet of frozen food with live foods offered at least once per week.

KNOW YOUR SPECIES

Often, temperate species are available for the home aquaria. One of the most popular species currently being sold is the pot-bellied seahorse, H.abdominalis or H.bleekeri. This is a wonderfully active, curious seahorse that has captured the heart of many hobbyists. If you choose to carry them, it is critical to hold them at optimum temp ranges (66-70F/19-21C). You will need to purchase a chiller to maintain optimum temperatures. Be forewarned that chillers are very expensive pieces of equipment.

NOTE: Any fact sheets purporting that these species can be kept at tropical temperature ranges is false and will, without exception, cause the demise of a subtropical and temperate species within a few days. It is in your own best interest not to purchase from breeding facilities that claim otherwise, nor to disseminate this misinformation.

BEFORE YOU BUY, be sure you understand the basic principles of how to keep seahorses in the home aquarium. Again, the best overall source for this is at Seahorse.org. Keeping marine fish of any type requires a solid knowledge of basic marine chemistry. There are many books available and sources on the internet on this topic. If you prepare adequately and take the time to set up an appropriate sized, fully cycled, and stable tank environment for your seahorses, you will greatly improve your chances of success.

NOTE: Although temperature ranges may be similar, it is not wise to keep tropical seahorses in a captive reef environment. They cannot compete for