Reply To: Dwarf seahorse

Pete Giwojna

TriWolf –

Overall, that sounds like a very good approach for a dwarf seahorse setup.

Yes, sir, the Nassarius snails do best with a sand substrate. In this case, you might consider keeping a few Nassarius snails in the refugium, which will have a sand substrate.

And, in your main tank, you might want to substitute 6-12 Hawaiian volcano shrimp (Halocaridina rubra) as useful scavengers that are are safe with dwarf seahorses and their fry.

I would recommend Nitokra lacustris as a good species of copepods for you to culture.

If you are going to be culturing copepods in large quantities for your rearing program, sir, you may want to acquire a copy of the Aquaculture Desk Reference Manual by Leroy Crestwell to provide you with additional guidance.

In addition, there is a good online article by Adelaide Rhodes (September 26, 2003) titled “instant Algae — Copepods: Nitokra lacustris Starter Cultures” that you may find helpful. Just copy the following URL, paste it in your web browser, and press the “Enter” key, and it will take you directly to the right webpage to read this article:

When it comes to copepods, the Harpacticoid copepods are generally preferred for aquaculture, and one of the most useful species is Nitokra lacustris.

It’s been quite a while since I ordered starter cultures, TriWolf, but two good sources I have used in the past are Reed Mariculture and Florida Aqua Farms, so those would be good places to try.

Here are some suggestions from Bill Stokely for culturing Nitokra lacustris to get you started:

Species Nitokra lacustris (Harpacticoid)
Motility Planktonic (in the water column)
Size 40 – 270 microns
Application Larval and Adult Fish
Larval and Adult Seahorses
Zooplankton feeding corals
Wide aperture filter feeders

Life Cycle Eggs ->
Nauplii ->
Copepodites (Juveniles) ->
Adults – Females bearing egg sacs
Reproduction The females only need to mate once in order to have 3 to5 sacs of eggs with 35 eggs each.
How long can a culture be maintained? Indefinitely if treated correctly
What is the doubling time? 2-3 days, depending upon temperature and feed
Culturing Technique
In batch cultures use very low aeration. Treat water with chlorine or filters (to 1 micron) before using. The water sho Mariculturry 9 to 10 days, depending on level of productivity. It is important to be conservative with the feed.
Periodically (every one to two months) filter and restart the cultures to remove detritus. Filter for small juveniles with 35 micron sieve and adults with 125 micron sieve. Use smaller stages for fish feed, retrieve females with egg sacs for restarting cultures.
Restart cultures with females bearing egg sacs. (About 10/L if you have low numbers, 50 to 100/L will result in faster population growth.)
This formula works for every size container, used in batch culture (meaning no recirculation). It may be possible to increase population growth by removing ciliates by filtration – this is not known yet.
These copepods are about the same size as rotifers which means that they will be hard to see with the naked eye. This product is only recommended for customers that are interested in culturing copepods – not for customers that need an immediate feed source.
better would be keeping Stockley’s seed culture growing,
Reed Mariculture’s algae paste or disks from Florida Aqua Farms…here goes:

The following is the standard
procedure for culturing algae and copepods. I use a 5-gallon plastic water
bottle for the algae culture and a 30-galloon plastic trash can for the
copepods. The temperature range is 75 to 85 F and the salinity is 1.022. Air
pump and air stones are used in both for circulation.
By the way, you can enrich newly hatched Artemia with this algae culture.
A. Algae culture
Microscopic, single-celled algae (phytoplankton) is cultured for use as a
food for filter feeders such as the Tridacna clam and various corals, and
for feeding microinvertebrates such as brine shrimp (Artemia), rotifers, and
copepods. Microinvertebrates are used for feeding larval and juvenile fishes
and corals. We culture several families of phytoplankton; the techniques for
their culture are almost identical. The species we use are Tetraselmis
1) Clean the containers. Bottles should be acid cleaned and flushed. Large
vats should be scrubbed lightly and rinsed out. The object here is to remove
most of the surface-bound organic matter so that the chlorine sterilization
(next step) is more effective. Be sure to fill acid cleaned bottles
completely with tap water to remove acid vapors.
2) Fill containers with seawater, and add 1.0 ml of Clorox (5.25 % sodium
hypochlorite) for every litre of seawater. Let the containers sit unaerated
away from strong light overnight. If water is needed sooner, add 5 ml of
Clorox per litre and let stand at least 2 hours. The object here is to
maintain a chlorine residual of > 10 ppm overnight. Residual chlorine is
affected by organic load, so more will be needed in dirtier water. A
swimming pool test kit is adequate for measuring residual. Strong light and
aeration will disperse chlorine and reduce its strength.
3) Neutralize the chlorinated seawater by adding 1.0 ml of sodium
thiosulfate solution (1N, 250 g Na2S2O3-5H2O per litre of distilled water)
for every 4.0 ml of Clorox that was added earlier. Neutralization is
complete when water is mixed (i.e. turn on air). Airstones are not
recommended for algae cultures because they take too long to clean. A
plastic pipette or piece of lead on an airhose will do. If airstones are
used, soak them in full-strength Clorox between batches and rinse them
thoroughly before use.
4) Add nutrients to the sterile seawater. Our “F/2” nutrient stocks
(Guillard, 1975) are made up at 500 times final concentration. Thus, 2 ml of
nutrient should be added to each litre of sterile seawater. Nutrients are
kept in a plastic bottle in the refrigerator. Normally, 2L bottles get 4 ml
of F/2; 100L buckets get 200 ml of F/2, etc.
Alternate nutrients: Put 2 level tablespoons Miracid in 300ml tap water.
Store this in any clean, capped plastic bottle at room temperature. Use 1ml
of this blue solution for every liter of algae for dense TE growth. This is
“F/1” strength, and works very well with outdoor Tetraselmis in partial
shade. It may not work for all species. (Stockly’s Aquariums method)
5) Add algae inoculant. It is best to check microscopically and record cell
counts and health occasionally. You can usually tell by color if a 2L
culture is healthy and dense enough to use as inoculant for 100, 200, or
600L cultures. Note the date, inoculant source, inoculant quantity, and
algal species on a piece of tape (or directly on glass bottles) whenever a
new culture is started. This procedure will help you to determine how well a
culture is doing, and is good for inventory control.
C. Copepods
The harpacticoid copepod, Euterpina acutifrons, is a nearly ideal food for
larval marine fishes due to its size, trophic ecology, nutritional value,
culturability, and (most importantly) acceptability by pelagic marine fish
larvae. There are few literature references to successful copepod culture.
Suggested readings include Theilacker and Kimball (1984); and Zurlini et aL
(1978). Culture techniques are easy, using the following suggestions.
1) Do not use an algae that gets too slimy and settles heavily. You will
want to aerate sufficiently to suspend the algae, but not so much that you
interupt sexual coupling. Slimy surfaces will trap nauplii. Chaetoceros
gracilis (4 x 4 x 5um) works well. So does TE. You may get faster growth and
a higher fecundity if a dinoflagellate or other flagellated green
phytoplankter is present. Normal growth rates at 25oC are 10-15 % per day
(up to 100 fold increase in 8 days), with harvest densities of 20 to 50
adults copepods per ml.
2) Partial shading helps, if cultures are outdoors. Keep the cultures in a
growth phase, and change them over to a clean container every few weeks.
3) Inoculate with 1-10% of your harvest. I like to keep the density above 1
per ml so I can count them with a 1 ml. pipette, but they will grow fast at
densities of 1 per litre. Algal densities of 5 x l0e4 to 2 x lOe5 cells per
ml will give good growth rates. You can approximate these densities as
visibilities of 7 to 10 cm.
4) Do not let rotifers enter the system. They will usually outproduce the
copepods. It is difficult to keep these two zooplankters separate with
screens because their sizes overlap. If you do get a rotifer takeover,
isolate 10-100 gravid female copepods and start over in 2 to 40L of new
medium (check them in a microscope to make sure there are no rotifers).
5) There are 6 naupliar stages, and 6 copepodite stages, including the
adult. Size is 50 x 50 x 70um (N1) to 150 x 175 x 700um(C6). I use a 37um
screen to harvest N1 & N2, and a 100um screen for copepodites. Generation
time is about 8 to 11 days under best conditions, at temperatures of
24-26oC. If you stock your rearing container with all sizes of copepods, new
nauplii will be produced by the adults to replace those consumed by the fish
Good Luck,
Bill Stokely

When it comes to the mushroom corals, the Panacur should not do them any harm at all.

As you know, TriWolf, fenbendazole (i.e., Panacur) is an inexpensive anthelmintic agent (dewormer) used for large animals such as horses, and the de-worming granules can be obtained without a prescription from stores that carry agricultural products (e.g., farm and ranch equipment, farming supplies and products, veterinary supplies, livestock and horse supplies, livestock and horse feed). If you live in a rural area, those would be good places to obtain it as well.

However, there are a couple of things you should keep in mind when treating an aquarium with fenbendazole, TriWolf. Administering a regimen of fenbendazole (FBZ) or Panacur will eradicate any hydroids, Aiptasia rock anemones, or bristleworms from live rock or live sand, thereby rendering them completely seahorse safe. The recommended dose is 1/8 teaspoon of the horse dewormer granules (22.2% fenbendazole) per 10 gallons of water. Dose the live rock with 1/8 teaspoon/10 gallons every other day until you have administered a total of 3 such treatments (Liisa Coit, pers. com.). Even one dose will do a fine job of eradicating bristeworms, but Aiptasia rock anemones and hydroids are a bit tougher and may require 2-3 doses to eliminate entirely.

Because fenbendazole is essentially a de-worming agent, it will destroy any bristleworms, flat worms, spaghetti worms or the like. The FBZ or Panacur treatments are best administered to the live rock in a bucket or hospital tank before the LR is introduced in the main tank. Otherwise, the massive die-off of the worm population in the aquarium may require large water changes in order to prevent a dangerous ammonia spike! And after the treatment is completed, its a good idea to add a portion of newly purchased live sand to the system in order to help restore its normal diversity of fauna and microfauna again (Liisa Coit, pers. com.).

Fenbendazole does not have any adverse effects on biological filtration, but be aware that it is death to many Cnidarians besides hydroids. Mushrooms and related corals are generally not affected, but expect it to have dire effects on other corals (e.g., sinularias), polyps, gorgonians, and anemones. In general, any Cnidarians with polyps that resemble the stalked family of Hydrozoans are likely to be hit hard by fenbendazole, so don’t use this treatment in a reef tank!

Also be aware that fenbendazole seems to soak into the porous live rock and be absorbed indefinitely. I know one hobbyist who transferred a small piece of live rock that had been treated with fenbendazole (Panacur) months earlier into a reef tank, where it killed the resident starfish and Astrea snails. So enough of the medication may be retained within treated live rock to impact sensitive animals months after the fenbendazole was administered. Don’t treat live rock intended for reef systems with fenbendazole (Panacur)!

At the lower dosage recommended for nursery tanks and dwarf seahorse tanks with fry (1/16 tsp. per 10 gallons), fenbendazole normally does not harm cleaner shrimp and decorative shrimp. With the exception of Astrids (Astrea), Coit and Worden have found it does not usually affect the types of snails typically used as cleanup crews (e.g., Nassarius, Ceriths, and Nerites). It will kill starfish but copepods, hermit crabs, and shrimp are normally not affected.

Macroalgae such as the feathery or long-bladed varieties of Caulerpa or Hawaiian Ogo (Gracilaria) are not harmed by exposure to fenbendazole at even triple the normal dose. In fact, if you will be using Caulerpa in your nursery tanks to provide hitching posts for the fry and serve as a form of natural filtration, it’s a very wise precaution indeed to treat them with a regimen of fenbendazole beforehand.

So fenbendazole (FBZ) or Panacur is primarily useful for ridding bare-bottomed nursery tanks and dwarf seahorse setups of hydroids and Aiptasia anemones, ridding Caulerpa and other macroalge of hydroids or Aiptasia before its goes into the aquarium, and cleansing live rock of bristleworms, hydroids, and Aiptasia rock anemones before it is introduced to the aquarium.

It can also be used to eradicate bristleworms, hydroids, an Aiptasia from an established aquarium if it does not house sensitive animals such as live corals and gorgonians, starfish, Astrea snails, or tubeworms and other desirable worms that may be harmed by FBZ, providing you monitor the ammonia levels closely and are prepared to deal with the ammonia spike that may result from the sudden death of the worm population.

Best of luck with your dwarf seahorse tank, TriWolf!

Happy Trails!
Pete Giwojna, Ocean Rider Tech Support

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