Re:New 170 gal reef which are safe tankmates

Dear Mark:

A 170-gallon reef system can house a wonderful assortment of invertebrates and reef-safe fishes, including seahorses, and I would be happy to give you some pointers regarding which specimens may do well together.

Here here is some more information regarding seahorse-safe fish and inverts that make good companions for Hippocampus:

Tropical Tankmates.

I have prepared a list of suitable fishes and invertebrates that generally make compatible tankmates for tropical seahorses below. Avoid fin nippers and aggressive, territorial fish that would be inclined to bully or physically abuse the seahorses, such as damsels, most clownfish, triggerfish, angels, puffers, cowfish and the like, as well as any predatory fishes that are large enough to swallow a seahorses, such as lionfish, anglers, sargassumfish, rays, large groupers and morays. For best results, other fishes that would not persecute the seahorses in any way should also generally be excluded because they are active, aggressive feeders that would out-compete the seahorses for food. This includes most butterflyfish, tangs, and wrasse. Stinging animals like anemones and jellyfish are unsuitable, as are other predatory invertebrates such as lobsters, mantis shrimp, certain starfish and most crabs.

Clownfish meet many of the criteria for suitable tankmates, but should generally be regarded with caution (Giwojna, Feb. 2004). Most species, such as Tomato Clowns (Amphiprion frenatus), Maroon Clowns (Premnas biaculeatus), and Skunk Clownfish are surprisingly aggressive and territorial, and should be shunned on that basis. Others do best when keep with anemones, which are a threat to seahorses. All clownfish are prone to Brooklynella and Marine Velvet (Amyloodinium), and should be considered Ich (Cryptocaryon irritans) magnets as well (Giwojna, Feb. 2004). The only species I would recommend as companions for seahorses are Percula Clowns (Amphiprion percula) and False Percula Clownfish (A. ocellaris), and then only after a rigorous quarantine period (Giwojna, Feb. 2004). Captive-bred specimens are best.

In short, fishes that are suitable as companions for seahorses must be docile, nonaggressive specimens, which are fairly deliberate feeders that won’t out-compete them for food. Some good candidates include:

Anthias (assorted Mirolabrichthys, Pseudanthias, and Anthias sp.)
Firefish Goby (Nemateleotris magnifica)
Purple Firefish Goby (Nemateleotris decora)
Gobies (assorted small species)
Neon Goby (Gobiosoma oceanops)
Assessors (Assessor spp.)
Midas Blenny (Ecsenius midas)
High Hats (Equetus acuminatus)
Marine Betta (Calloplesiops altivelis)
Banggai or Banner cardinals (Pterapogon kauderni)
Flame cardinals (Apogon pseudomaculatus)
Pajama cardinals (Apogon nematoptera)
Pipefishes (assorted small species)
Percula clownfish (Amphiprion percula)
False percula clownfish (Amphiprion ocellaris)
Royal Grammas (Gramma loreto)
Blackcap Basslets (Gramma melacara)
Green Chromis (Chromis viridis)
Blue Reef Chromis (Chromis cyaneus)
Longnose Hawkfish (Oxycirrhites typus)
Six Line Wrasse (Psuedocheilinus hexataenia)
Flasher Wrasse (Paracheilinus sp.)
Fairy Wrasse (Cirrhilabrus spp.)
Scooter Blennies (Synchiropus spp.)
Green Mandarin Goby or Dragonet (Pterosynchiropus splendidus)
Psychedelic Mandarin Goby or Dragonet (Pterosynchiropus picturatus)
Orchid Dottyback (Pseudochromis fridmani) – avoid other Pseudochromis species!

Mandarin gobies or dragonets (Pterosynchiropus spp.) are peaceful, deliberate feeders with brilliant colors that do well with seahorses and often even learn to accept frozen Mysis in time. But they are best reserved for very large, well-established aquaria with lots of live rock that supports an adequate population of copepods and amphipods to sustain them. Your 170-gallon aquarium reef tank with lots of live rock would be a suitable habitat for a Mandarin dragonet, Mark, but first the tank would need to mature and stabilize and build up a sizable population of pods

Good inverts for seahorses include decorative cleaner shrimp like those listed below:

Peppermint Shrimp (Lysmata wurdemanni)
Scarlet Cleaner Shrimp or Skunk Cleaner Shrimp (Lysmata amboinensis)
Fire Shrimp (Lysmata debelius)
Harlequin Shrimp (Hymenocerus elegans and H. picta) – predatory on sea stars;
and/or
large ornamental snails (living sea shells) such as the following:
Tiger Cowry (Cypraea tigris)
Deer Cowry (Cypraea cervus)
and/or
Assorted Feather Dusters (Sabellastatre magnifica, Sabella sp.) whose colorful crowns resemble gaily-colored parasols.

By no means is this intended to be a comprehensive compilation. It is intended merely to give the hobbyist an idea of the types of fishes and inverts that generally make suitable tankmates for seahorses. But there are many more seahorse-safe fish and invertebrates that could have been added to the list, and no doubt many aquarists would disagree about some of the species that have been included.

Be that as it may, there is one very important precaution that should always be observed when contemplating keeping seahorses with other fishes:

(1) All fishes that are intended as tankmates for seahorses MUST be quarantined first without exception. For the same reasons we discussed earlier with regard to wild-caught seahorses, any fish you bring home from your LFS is a potential disease vector for all manner of nasty pathogens and parasites, and you need to take every possible precaution to prevent these from being introduced to your display tank.

Here are some additional guidelines that may give you a better idea as to which corals are compatible and which types you should avoid in your seahorse reef:

Setting Up a Reef Tank for Seahorses.

Seahorses typically thrive in the right type of reef system, which provides them with pristine water quality, plenty of roam to roam, and a colorful, natural setting that makes them feel right at home. The multicolored background will keep them looking their best and brightest, and nothing makes a more breathtaking exhibit than brilliant yellow and orange seahorses lazily gliding amidst the lovely corals, polyps and gorgonia in a well-established minireef, much like the butterflies adorning a beautiful flower garden.

But the hobbyist who wants to keep seahorses in a reef system must be willing to make some concessions to accommodate their special needs. For example, the reef keeper must be willing to limit himself to corals and invertebrates that meet the following criteria:

1) Avoid any stinging animals with powerful nematocysts. This means fire corals, anemones, and any corals with polyps that feel sticky to the touch must be excluded. When a seahorse brushes up against them or attempts to perch on them, the nematocysts or stinging cells of these animals can penetrate the seahorse’s skin and damage its integument. Needless to say, this causes pain and discomfort and can leave the seahorse vulnerable to secondary bacterial and fungal infections, which may take hold at the site of injury. Beware of large polyped stony (LPS) corals in particular. These include genera such as Catalaphyllia, Cynarina, Euphyllia and Trachyphyllia that have large fleshy polyps which often have tentacles equipped with powerful stinging cells..

2) The corals must be able to thrive with moderate light levels and relatively low to moderate water movement or current. Corals that require overly strong water currents are unsuitable for tanks with seahorses because the seahorses are feeble swimmers and often cannot cope with powerful currents unless there are slack water areas the can retreat to when needed.

3) The corals must be able to withstand being used as hitching posts by the seahorses from time to time; that is, they cannot be so delicate that having a seahorse’s grasping tail anchored around them could cause them any harm. For instance, soft corals may retract their polyps when a seahorse perches on them. This can be harmful to their health if it becomes a chronic problem, because the corals rely on their polyps to absorb light and convert it to energy via photosynthesis. Be sure to watch any soft corals and make sure they are not closed up for extended periods. Normally, they adjust to the seahorses’ presence and unwelcome attention after a while, and remain contracted only briefly after each contact. After repeated exposures to grasping tails, each such incident elicits a weaker response, so they tend to extend their polyps sooner and sooner after being disturbed.

4) Avoid Tridacna clams and similar bivalve mollusks. Sooner or later a seahorse will perch on them with its tail between the valves and the clam’s powerful adductor muscle will clamp down on it like a vise. At best this will be a very stressful experience for the unfortunate seahorse; it can be the devil’s own business trying to persuade the stubborn mollusk to release its struggling victim! At worst, it can result in serious injury or permanent damage to the seahorses tail.

5) Beware of unwanted hitchhikers that may have come in on your live rock unbeknownst to you and which can harm seahorses, such as fireworms, mantis shrimp, or Aptasia rock anemones. When setting up a reef system for seahorses, it’s a wise precaution to pre-treat your live rock with a hypersaline drip and/or a dose of fenbendazole to eliminate such pests beforehand because they can be very difficult to remove or eradicate once they make themselves at home in your aquarium.

6) Small powerheads can be used to create and direct water currents wherever needed — just be sure to screen off the intake for the sake of your seahorses. Seahorses tolerate moderate currents very well providing there are sheltered spots and slack water areas they can retreat to when desired.

Soft corals have very little stinging ability and generally make good choices for a modified mini reef that will include seahorses. This includes most zoanthids and mushroom anemones (corallimorpharians) in general. However, as Charles Delbeek cautions, "One notable exception is the elephant ear mushroom anemone (Amplexidiscus fenestrafer). This animal is an active feeder on small fish and will envelope them whole with its mantle then slowly digest them by extruding its digestive filaments into the space created. No small fish are safe with these animals in the tank.". Some of the soft corals that generally do well with seahorses in a low/moderate light, low/moderate flow reef tank with PC lighting are listed below:

Finger Leather Coral (Lobophyton sp.)
Flower Tree Coral – Red / Orange, (Scleronephthya spp.)
aka: Scleronephthya Strawberry Coral, or Pink or Orange Cauliflower Coral
Christmas Tree Coral (Sphaerella spp.)
aka: the Medusa Coral, Snake Locks Coral, or French Tickler
Cauliflower Colt Coral (Cladiella sp.)
aka: Colt Coral, Soft Finger Leather Coral, Seaman’s Hands or Blushing Coral.
Toadstool Mushroom Leather Coral (Sarcophyton sp.)
aka: Sarcophyton Coral, Mushroom, Leather, or Trough Corals.
Bullseye Mushroom Coral (Rhodactis inchoata)
aka: Tonga Blue Mushroom, Small Elephant Ear Mushroom (rarely)
Clove Polyps (Clavularia sp.)
Stick Polyp (Parazoanthus swiftii)
Green Daisy Polyps (Clavularia sp.), Indonesia
Orange & Green Colony Button Polyps (Zooanthus sp.), Fiji
Pulsing Corals (Xenia spp.)
Red Ricordea (Ricordea sp.), Indonesia, occasionally Solomon Islands
Lavender Hairy Mushroom (Actinodiscus sp.), Tonga
Pimpled Mushroom (Discosoma sp.), Indonesia
Purple Gorgonians

Other low light corals that should be suitable include genera such as Cynarina, Scolymia and Trachyphyllia, as well as non-photosynthetic gorgonians such as Subergorgia and Didogorgia, and perhaps wire corals such as Cirripathes spp.. However, supplemental feedings of zooplankton may be required to maintain these corals in good health.

The small polyped stony (SPS) corals generally have weak stings that should not pose a threat to seahorses. Depending on conditions in the tank, SPS corals such as Acropora, Montipora, Pocillipora, Porities, Seriatopora and Stylophora can be tried at your discretion.

The two part series of articles that Leslie mentioned on keeping seahorses in reef tanks, which is now running in the January and February 2007 tissues of Tropical Fish Hobbyist Magazine, provides much greater detail regarding the best way to seahorse-proof a reef tank and stock it with suitable seahorses and specimens, including water circulation and lighting systems. If you have any trouble locating copies of the magazine articles, just let me know and I would be happy to e-mail the text of the manuscript from the articles to you. You would miss out on Leslie’s magnificent photographs, but at least you would have the information you need to prepare your reef system for seahorses. You can contact me off list at the following e-mail address: [email protected]

I think it’s an excellent idea to include a refugium/sump in your reef tank, Mark, and I would suggest that you set it up as a dual-chamber sump with an algal filter as described below:

The Aquarium Sump

A sump is simply a large external, watertight container connected to your aquarium so that both the aquarium and the sump share the same water supply. Most sumps are smaller aquariums that are set in place beneath the main tank and connected to it with PVC pipes or tubing.

There are many advantages to adding a sump to your seahorse setup. For starters, it increases the overall water volume of your system with all the benefits that implies. A good-sized sump can easily double your carrying capacity, increasing your safety margin accordingly. It makes an ideal place to put a protein skimmer, heater(s), air stones, and other equipment so they don’t have to be hidden in the display tank. (A well-designed sump does a great job of trapping and eliminating the microbubbles emitted from skimmers and preventing them from entering the aquarium, and provides an excellent way of increasing the aeration/oxygenation, which is so important for a seahorse setup.) It’s the perfect place to perform additional mechanical and chemical filtration, tailoring the filter media to meet ones exact needs, or to add a calcium or nitrate reactor or even a Deep Live Sand Bed (DLSB) to your seahorse setup. Because the sump is a large body of water separated from the aquarium itself, it facilitates water changes, dosing supplements, adding top-off water to the tank and other maintenance tasks, all of which can be carried out in the sump without disturbing the main tank or stressing its inhabitants. Entire sections of the mechanical filtration can be cleaned at one time without affecting your primary biofilter, and water changes can be performed gradually without causing stress to the fish or invertebrates. A sump/refugium can also be used to grow a lush bed of macroalgae using a reverse lighting cycle to stabilize the pH and absorb wastes.

To take advantage of these benefits, I suggest adding a two-chambered sump to your tank. This can be accomplished by installing a perforated tank divider across the width of the sump, thereby separating it into two isolated compartments. One side accommodates all of your equipment (in-sump skimmer, return pump, heaters, titanium grounding probe, UV sterilizer, etc.) while the other side can be used to establish a deep live sand bed (DLSB) with plenty of Caulerpa, or better yet Chaetomorpha spaghetti algae and/or Gracilaria. The DLSB/macroalgae side serves as a refugium and will soon become populated with countless critters (copepods, Gammarus and other amphipods, larval crustaceans, etc.). With the Caulerpa/Chaetomorpha acting as an algal filter and the anaerobic layers of DLSB providing denitrification, the aquarist never need be concerned about nitrates or nuisance algae with this type of sump/refugium.

In addition, the biological refugium/sump can be maintained on an opposite light cycle to the main tank to offset the daily fluctuations in pH, photosynthesis, dissolved oxygen/carbon dioxide, and redox levels that otherwise occur in the aquarium. Daily variances in chemical, physical and biological phenomena are a fact of life in aquaria, linked to the light and dark cycles and the diurnal rhythms of captive aquatic systems. As one example, the pH of aquarium water typically peaks after the lights have been on all day at a maximum of perhaps 8.4, only to drop to low of below 8.0 overnight. This is related to photosynthesis and the fact that zooanthellae and green plants consume CO2 and produce O2 when there is adequate light, but in essence reverse that process in the dark, consuming O2 and giving off CO2. Redox levels, available calcium and other water quality parameters are affected in similar ways. Needless to say, these variations are far greater is a small, closed-system aquarium than they are in the ocean, so it’s beneficial to minimize such fluctuations by reversing the photoperiod in the main display and the sump/refugium. This is easily accomplished by timing the lighting in the sump so that the bed of macroalgae is illuminated after dark when the lights on the display tank are off, and vice versa. Just use alternating timers on the main tank and the refugium tank so that when one is on, the other is off. Voila! Just like that the roller coaster ride is over: no more daily fluctuations in pH or highs and lows in calcium levels, oxygen minima, or peaks and valleys in redox potential. Or you can easily accomplish the same thing simply by keeping the Chaetomorpha or Caulerpa algae bed of illuminated 24/7, around the clock.

Because it is separate from the main system yet shares the same water, the sump/refugium can also be used as a nifty acclimation tank for new arrivals or a handy isolation tank for separating incompatible specimens. For seahorse keepers, the refugium compartment of a divided sump or dual chamber sump makes an ideal grow-out tank for juvenile seahorses that have outgrown their nurseries but are still too small to be kept in the main tank. A dual-chamber sump is a very versatile design that lends itself to multiple purposes. Just use your imagination.

Best of luck with your new reef system, Mark!

Happy Trails!
Pete Giwojna