Once the seahorses have been purchased and have settled into their new home there is a great possibility that they will reward the conscientious keeper by breeding on a regular basis. They will only do this, however, if conditions allow.

Refer to the ‘Feeding and dietary requirements’ in the Seahorses article. Good nutrition is essential for the seahorses to reach breeding condition in the first place, the female seahorse to produce the eggs and the male to effectively carry them full term.

In the wild many seahorses form monogamous pairs. However, this is often not the case in captivity. The male will approach the female and start displaying to her. This often entails bowing his head and paling in colour whilst trying to grasp her tail with his. If she is not ready she will usually not take the matter seriously and show far more interest in any mysis shrimp that happens to float past. This can sometimes result in a sharp, frustrated snick from the male. The female should become gravid (full of eggs) within a few days. Then the courtship takes on a new form. The male and female with often rise to the top of the tank, entwining their tails and circling each other. This is when the egg transfer takes place. See ‘Aquarium tank set up’ in the Seahorses article for the recommended tank heights.

After the female seahorse has deposited her eggs into the male’s pouch it’s up to him to nourish the embryos until they’re ready to hatch. During this period he may become more subdued than normal, spending more time in darker, quieter corners of the tank. He should, however, still respond to food as normal.

When the young are ready to be released the male will position himself in a strategic part of the tank (mine always sit next to the protein skimmer outlet). Sometimes the pouch can appear very dark or take on a pinkish hue just before birth. The male will then contract by ‘pumping’ his tail. This action contracts the pouch and pushes the babies out into the big wide(er) world. If, like many, the seahorse tank is run with external canister filters it might be an idea to cover the intake pipe with a piece of filter floss or similar. A Fluval 305 can strip a tank of babies within five minutes and my seahorses always seem to wait until my back is turned before they give birth.

After running around and squawking like a chicken for the first few seconds (maybe that’s just me?) it’s vital to remove the babies from the main tank as soon as possible. They should be transferred into a rearing tank that has been set up for a couple of weeks before the birth. The main reason for this is to put the babies into a much smaller tank where a closer eye can be kept on them. The food can also be kept at much higher concentrations in a smaller tank - it’s important that the baby seahorses use as little energy as possible when trying to catch their meals. There is no way appropriate amounts of food can be maintained in a normal adult seahorse display tank. I use a small Tupperware cylindrical container to scoop the babies out of the tank, transfer to a jug then release into the rearing tank (some people use a large turkey baster). It’s very important during this time that the babies are not exposed to the air as they have a tendency to snick air which can cause fatal air bubbles in the body cavity. These air bubbles can pin them to the surface which usually means they slowly starve to death.

To start with I use a 10 litre, bare bottomed tank with nothing but a piece of plastic plant (for benthic fry) and a sponge filter (set on a very low setting). For pelagic fry I also set up a line of rigid air tube in the opposite corner. I initially fill the tank with water from the parents’ tank if I’m caught out unexpectedly. If I’m well prepared I will set up with freshly mixed, salted RO and will cycle with a piece of sterile prawn. The baby seahorses can then be split according to sizes and transferred to larger tanks if necessary. For the first few days I do not give additional lighting to the tank, as most baby seahorses are attracted to light and (particularly the pelagic species) can have a tendency to stick where the light is and either get air bubbles from floating around the top or stress (and injure) themselves out by ‘climbing the glass’ if the light is put to one side. I carry out water changes of about 50% daily. I use a rigid air tube attached to some normal, flexible airline so I can siphon out all the uneaten food/faeces from the bottom of the tank. If you are lucky enough to have hundreds of babies and they are all insisting on being drawn through the airline (sometimes it can seem like that!) you can still carry out water changes by attaching an airstone to the intake of the siphon hose and siphoning out through that. When the babies are a bit bigger/stronger I wipe the bottom of the tank with a scourer then use an air driven hoover cleaner to suck the bits up. It’s vital to make sure that the replacement, clean water is the same salinity and temperature as the water that has just been removed.

Different species of seahorse can take different sized foods from birth - more detailed information is outlined below in the species accounts. The primary staples are rotifers (rots), newly hatched baby brine shrimp (BBS) and copepods. These can all be fairly easily cultured. For detailed information see the stickies in the ZM sponsor section and the various threads. A baby seahorse can eat up to 3,000 food items per day so it's vital that these cultures are set up well in advance of the happy event. I have something like 5 cultures of each on the go at one time. Culture vessels can be purchased and are the easiest way to culture any food items. These are an inverted cone with a tap at the bottom to aid drainage (particularly useful if the brine shrimp cysts are not de-capsulated). That said, anything that is food safe and waterproof can be used. I use a variety of purpose made culture vessels, plastic cereal containers and 5 litre water bottles. Rigid airline is useful to direct the bubbles from the air pump to the bottom of the container. It’s important to remember that the food items themselves are only a carrier for nutrition, they are not nutritious in their own right. This means that if you were to only feed the BBS or rots without enriching them the baby seahorses would not get the nutrition required to survive long term. Food items fed with phytoplankton will have a higher HUFA content which will increase the fry’s chances of survival. For detailed information on setting up all these cultures see the relevant Sponsors' sections and websites.

These are tiny enough to be taken by the smallest babies (such as H. reidi). The culture should be at a lower salinity then the average salt water mix (1.015 SG) and the bubbles should be regulated to 2/3 per second. When the cultures are set up it can take about a week before they’re ready to harvest. This means that ideally there should be 7 cultures on the go, then as you drain the first (leaving some behind to reproduce for the next batch) it has 7 days to build up the numbers again.

This is one of the commonest cultures that’s set up. I culture these at anywhere between 1.020 and 1.025 SG. Species such as H. comes, H. fuscus and H. barbouri are usually big enough at birth to take BBS immediately (there are also accounts of H. reidi taking BBS from birth). I try to harvest newly hatched BBS within 2 hours of hatching. During this period you can be reasonably sure that there is still some of the egg yolk in the BBS which will maximise their nutritional value to the baby seahorses. The BBS shell is also still soft during this time which minimises the risk of hard shells getting stuck in the baby seahorse. I also throw some phyto in the hatching container just before/after they have hatched on the assumption they might be able to absorb it through their bodies (BBS have no mouth parts until they moult 24 hours after hatching, the absorption through the skin is an assumption on my part and as far as I know is not quantified).

You can obtain either de-capsulated or whole cysts from which to hatch BBS. De-capsulation is a process where the outer shell is removed. This results in far less ‘mess’ in the rearing tank and reduces the chance of stinging hydroids setting up home with the baby seahorses as hydroids can come in on the cysts. It also reduces the risk of a baby seahorse snicking the cyst rather than the BBS and choking on it. If whole cysts are used then they can be separated from the BBS by switching off the air supply and leaving the culture for five minutes - the BBS sink to the bottom and the (now empty) cysts float to the top. The BBS can then be siphoned/drained from the bottom of the container. I fresh water dip my BBS in tap water briefly to wash them before introducing them to the rearing tank.

These are regarded as having a naturally higher nutritional value than the other foods but still require feeding themselves with a high quality phyto based food. In my experience these cultures take a little longer to get going than rots or BBS (mine weren’t ready to harvest properly for about a month). I tend to use these as an additional food rather than a sole food as it has been shown that offering a varied diet can increase the baby seahorses' chances of survival. Mine also seem to enjoy following the sides of the tank and stalking these on the sides of the glass.