So you want dwarfs?


I frequent a number of forums and the penchant for people to own dwarf seahorses is never ending.  I often have people contacting me asking if I will let them have some of my dwarf seahorses.

Whilst I can understand the desire to own such beautiful, fragile and genteel creatures, I am also hugely protective of them and it concerns me that so many people buy them without truly understanding or appreciating the huge amount of effort and hard work that these tiny little creatures require.

H.zosterae are most definitely not for the beginner and actually I will go a step further to say that not only should they only be kept by the advance marine keeper, but only by the advanced seahorse keeper.

So what is it that makes them hard to keep?

Dwarf seahorses are tiny.  The average size of an adult is 1 - 1.5 inches (including tail!!).  Their minute size makes them highly susceptible to perishing from things living in the aquarium that wouldn’t affect bigger seahorses or other fish.  Tiny protozoan’s or hydrozoans have the potential to wipe out an entire colony of dwarf’s without you even being aware of their presence in the tank.  This is a huge consideration when adding anything to your tank that may have been in an environment where having these organisms would have been of little consequence.  The same goes for polychaeta which can unwittingly be added to the aquarium via a tiny piece of live rock.
Beautiful but tiny..
On the flip side of this, keeping dwarf seahorses in a sterile aquarium where all you have is a sponge filter and plastic plants is just as bad.  The longevity of the dwarf seahorse cannot be sustained in a sterile aquarium.  I’ve tried it and it just doesn’t work in my opinion.  However, this seems to be the most common method of keeping dwarf seahorses....at least in the UK.  This method is fraught with problems – the plastic plants leach silicates into the water which causes problems with phosphates.  High phosphates = nuisance algae.  Nuisance algae = constant cleaning.   Constant cleaning = a tank that is perpetually trying to cycle.  It’s a vicious circle.  You want your tank to look clean, but you also want to provide your dwarfs with the best environment.

Dwarf seahorses require constant supplies of enriched, live food.  Unfortunately, there is absolutely no getting around this.  Whilst they might occasionally eat frozen food, this is the exception rather than the norm.  Many people have bought dwarf seahorses actually believing that they will be the one who will be able to truly convert their seahorses over to eating frozen food alone.  To my knowledge, no one has yet succeeded with this. 

The staple food of dwarf seahorses is live brine shrimp, which need to be hatched daily, or at least several times a week depending on hatch rates/number of dwarfs.  Supplies of live food need to be plentiful and properly enriched and when there are babies, the number of feedings needs to go up to at least 4 a day.  

Adding variety to a dwarf seahorse’s diet gives great advantage to their wellbeing – cultures of copepods are greatly worthwhile (and something I need to improve on!).

Failure to meet proper nutritional requirements will result in the slow starvation of the dwarfs, with the youngest falling first.  I've had this happen to me and its horrible watching the young die one by one.  I thought that I was doing everything right but when I revaluated everything that I was doing, I realised that I had been enriching the food incorrectly, and thus starving them of valuable nutrients.

All of the above pretty much means that if you spend any time away from home you need to have a friend who can feed them in your absence.  And unless you are away for just a couple of days, this means that your friend will need to be adept at hatching brine shrimp too. 

Dwarf seahorses really are a huge commitment, and this is something that really needs to be thought about very carefully before taking the plunge.


Dwarf seahorses made a comeback in the UK around 2 years ago, and people have been enthusing over them ever since.  Although I am sure there must be other dwarf keepers in the UK who are keeping them successfully, all of those that I have come into contact with have either lost them or found new homes for them because of the huge commitment that they warrant – this is actually how I came about owning them again myself.  Whilst, it obviously excites me that I am one of the few (to my knowledge) who has a successful breeding colony in the UK, there is also a tinge of frustration with the commitment that comes along with owning them.  On occasions I have been in the shoes of those thinking about re-homing them.  Not only this but I am constantly on edge with them.  I don't believe that I have yet developed a suitable environment for them to live in and this is presently my goal.


Misconceptions of owning dwarf seahorses

1.       Dwarf seahorses only require a small tank and so don’t take up much room
Let me answer each statement separately:
Dwarf seahorses only require a small tank.   Well yes, while you can keep several pairs of seahorses in a tiny 1 gallon pico tank, you have to ask the question of just because you can, should you?  You can keep a person in a garden shed but it doesn’t mean that person will be happy and thrive.   Trying to maintain perfect water conditions in a tiny tank is quite difficult.  The simple factor is that the more water, the easier it is to keep clean. This isn’t to say that it’s a good idea to keep a pair of dwarf seahorses in a 10 gallon tank, but its about finding the right balance.
Dwarf seahorses don’t take up much room.  On the contrary, dwarf seahorses can actually take up large amounts of space when you take into account all of their requirements.  You need to have somewhere to mix the saltwater, and keep a ready supply for water changes.  You need at least one brine shrimp hatchery.  You need at least one enrichment container.  You should have at least one copepod culture.  You should have at least one phytoplankton culture.  You should have room in the fridge for storing enrichment (although minimal). 
2.       Dwarf seahorses rapidly breed and the babies are easy to keep
Provided that you meet the bare minimum requirements for seahorses then they are likely to breed and as the babies eat the same food as adults they can be kept with the adults.  However, you still need to allow for the fact that these are babies, and as such need to have several feedings a day. I like to feed the dwarf babies between 4 – 5 times throughout the day.  My success rate with the fry is presently between 0% - 60%.  As you can see it’s hugely variable and much of this depends on how much commitment I give them.
3. I don’t need much equipment to keep dwarf seahorses

This is another area where I think a lot of people go wrong. Because the tank that they are in is so small, it still needs to be able to sufficiently handle a huge bio-load and the dissolved organics created by seahorses. If you look at the tiny pico/nano tanks that are just coming into the market now, many of them have weirs with protein skimmers/fuge/mechanical filtration and this is on top of the biological filtration that they have without fear of the repercussions that could be witnessed in a dwarf tank. Yet for some reason there is an expectation for a tiny little tank with next to no filtration to be able to handle the pressure that the dwarf seahorses will throw at it. This is something that I am learning the hard way, and now my recommendations for a dwarf tank would consist of nothing less than filter (ideally a fuge but this is something that I am still researching), oxydator, skimmer and at least one airline.
4.       Dwarf seahorses can live in a simple tank with sparse/fake decoration
This is a tricky one.  Whilst many people who have owned dwarf seahorses will tell you that you can keep dwarf seahorses in a 5 gallon tank with a bare bottom, sponge filter and plastic plants, you need to ask them how long they had dwarf seahorses for.  I bet the answer won’t be longer than 4 – 6 months.  Sterile tanks with little filtration are not a long term solution. 
5.       When something goes wrong, it’s easy to fix
This is true to an extent. The problem is that you need to know what’s wrong in order to fix it.  From my observations, most of the time when people lose dwarf seahorses, they have absolutely no idea what is wrong with them.  One of the big problems with dwarfs is because they are so small it’s much harder to diagnose a physical problem with them than it is with some of their bigger cousins.



Plastic plants are hard to keep clean
Although I have had my dwarfs now for around 1.5 years, I am far from a successful keeper and still have much to learn.  In the seahorse world, success is measured by how long we have kept the seahorses, and not how many babies we have or whether we can keep them alive in conditions that aren't generally recommended.  Given the right conditions, there is no reason why a dwarf seahorse can't live beyond 2 years in your aquarium.


Are you ready for dwarf seahorses?

So what are the minimum requirements?
You could easily home several pairs in a 5 gallon tank, however I believe that an ideal setup would consist of an external method of filtration, a protein skimmer, and oxydator as a bare minimum.

Preparing for H.zosterae

If you can answer all of the following questions with a resounding "yes", then you are well on your way to being a great dwarf seahorse keeper.  If not, I would urge you to either reconsider your chosen species or continue to research until you can answer "yes" to all of these questions. 



1. I understand the basics of marine aquaculture
2. I have the space and time to hatch brine shrimp daily
3. I am able to feed the seahorses at least twice a day (more if there are babies)
4. I am confident that I can meet the nutritional requirements
5. I understand that any living thing that is added to the tank (macro algae, live rock, etc) must be treated for hydroids and quarantined.
6. I have someone who can look after them for me when I go on holiday and they are willing/able to hatch brineshrimp in my absence.



Final Thought
Whilst I understand that this article may seem incredibly negative and against people owning dwarf seahorses, that is not actually my objective.  As long as their requirements are properly taken care of, I think that more people could own them but it is important that people understand at an early stage the huge commitment that H.zosterae require.


I feel very strongly about animal welfare it is our responsibility, as owners, to make sure that any animal is given every chance to live a full and happy life.  

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