Seahorse Tankmates Guide - Part I: Fish

* this is for "regular-sized" seahorses only and cannot be used in determining tankmates for Dwarf Seahorses.



0 Risk Rating

• no aggressive tendencies
• no food competition (*)
• mostly benthic/cryptic and keep to themselves

1 Risk Rating

• no aggressive tendencies
• minimal food competition
• mostly in water column, but does not have a fast/erratic swimming pattern

2 Risk Rating

• no aggressive tendencies
• minimal food competition
• mostly in water column and has fast or erratic swimming pattern

3 Risk Rating

• a little assertive
• more pronounced food competition
• mostly in water column and has fast or erratic swimming pattern

4 Risk Rating

• semi-aggressive or aggressive
• direct food competition
• immaterial if aggressive or a direct food competitor
• incompatible tank requirements

If you see an asterisk* after the rating, look for additional notes in that section.


So, what's in a number? It's pretty safe to say those with the 0, 1 and 2 rating are safe to add to your seahorse tank, provided individual needs of both fish are met.

A rating of 3 is pushing the envelope and may or may not work based on the individual personality of the particular fish you are trying to introduce. Please have alternative plans to house the tankmate, should a problem arise. There are plenty of fish in the 0-2 category, so it's really best to leave these be.

Those fish with a rating of 4 have no business being housed with a seahorse, IMO.


This is a rework of a guide from some years ago on another site that my friend Kevin and I put together on Seahorse.org. Many pictures are the same, so I wanted to explain that they are mine and not lifted from the other site (in case you run across the other one). I changed the rating system, so that it was less subjective. Back then I hated the idea of tankmates and fought it tooth and nail. LOL!






























































*At this point in the game, we should be buying captive bred horses. In doing so, Mandarins are not really a food competitor and earn the rating of zero.



















*Catalina gobies require lower tank temperatures than is tolerated by seahorses.




















* Blackfoot Lionfish (Parapterois heterura) are a coldwater fish and require tank temperatures lower than a seahorse can tolerate.