Re:baby seahorses!!!

Dear hobbyist:

Congratulations on your unexpected brood of babies!

The guy from the pet store was right — there is a always a steep learning curve when it comes to rearing the newborns, and it’s quite common — perhaps even the rule — for the home breeder to lose the entire brood during his first few attempts at rearing. But as you refine your methods and become more proficient at providing suitable live foods for the newborns and work out the feeding regimen that’s most efficient for your particular circumstances, your results will get better. You will have more of the fry surviving for longer periods, until eventually you are able to raise a few of the fry from a few of the broods to maturity. It’s just a matter of patience and hard work, and now that your Mustangs have begun breeding, they will produce a new brood for you every month or so, so you are going to have lots of opportunities to practice and improve.

It’s very unlikely that the newborns are going to eat the freeze-dried rotifers. Some breeders report. Limited success rearing seahorse fry on nonliving foods such as freeze-dried or frozen Cyclop-Eze or preserved zooplankton, but the vast majority of newborns will not except such offerings, at least initially, and losses are typically very, very high for those who have tried such shortcuts. The non-living food simply doesn’t move right, and usually fails to elicit a feeding response from the fry. So the freeze-dried rotifers are not likely to be helpful at all at this point.

But don’t panic — the fry are born with a limited yolk supply that can sustain them for the first 24 hours, so they needn’t be fed immediately and that gives you a little time to get your brine shrimp hatcheries going, as I’ll explain in greater detail below.

I would recommend providing the newborns with 3-5 feedings of newly-hatched Artemia spaced 2-3 hours apart for best results. If you search this forum for the phrase "fry feeding schedule," you’ll find a lot of additional information regarding successful feeding regimens for keeping up with the voracious appetites of seahorse fry.

All seahorse babies are challenging to raise and your Mustangs (Hippocampus erectus) are no exception. How difficult or challenging they may be depends on the type of seahorses you have. Two main factors determine how easy or hard seahorse fry are to raise: (1) their size at birth and (2) whether or not they undergo a prolonged pelagic phase. The bigger and better developed the newborns are, the easier they are to raise. Seahorse fry whose average length at birth is 10 mm (0.4 inches) or more are able to take enriched Artemia as their first foods and are relatively easy to rear. Seahorse fry that are significantly smaller than 10 mm (0.4 inches) at birth need to be started on smaller foods that are more difficult to provide in copious amounts on a daily basis, such as rotifers, copepods, and larval Mysis, making them more difficult to raise. Likewise, seahorse fry that undergo an extended pelagic phase, during which they drift freely with the plankton, are much more troublesome to raise than benthic seahorse fry, which orient to the substrate and seek out hitching posts straightaway. The pelagic fry are difficult because the surface huggers tend to gulp air and suffer fatal buoyancy problems, and may even become entrapped by surface tension. As a result, most hobbyists find that mortality is very high during the pelagic phase.

The easiest seahorse fry to rear are therefore benthic fry that are large and well developed at birth. Dwarf seahorses or Pixies (Hippocampus zosterae) fall into this category, and indeed many hobbyists have closed the life cycle with zosterae. The most difficult seahorse fry to raise are relatively small and underdeveloped at birth, and must pass through a lengthy pelagic stage. Brazilian seahorse fry (Hippocampus reidi) are a good example of this category, and are notoriously difficult to raise.

Ocean Riders span the gamut in that regard, including both those species that are the easiest of all to raise and those that are the most difficult to rear, and everything in between. At the one extreme, there are Mo’Olios, which produce very large broods of tiny fry that are barely 3-4 mm at birth and remain pelagic all their lives, even as adults. Mo’Olios are very challenging for even expert aquaculturists with state-of-the-art facilities to raise. Brazileros and Gigantes likewise have enormous broods of relatively small (6-7 mm) fry that undergo a rather protracted pelagic phase lasting weeks. The average hobbyist would still be hard-pressed to regularly raise any of their fry.

At the other extreme, there are Pixies, which produce small broods of large, well-developed benthic fry that hitch from day one. Pixies (H. zosterae) are probably the easiest seahorses to rear, and no doubt more hobbyists have closed the life cycle with this species than all other seahorses combined. Spikeys (Hippocampus barbouri) and Zulu-lulus (H. capensis) likewise produce large benthic babies that are relatively easy to raise. Most of the remaining Ocean Rider types (Mustangs, Sunbursts, Pintos, Fire Reds) produce fry that are fairly good sized (about 8-10 mm) and whose pelagic phase is fairly short (several days rather than weeks), and which are therefore intermediate in difficulty.

In short, your Mustangs (H. erectus) will produce fry that are moderately difficult to raise. They will be able to eat newly hatched brine shrimp right away, but they will go through a pelagic phase lasting anywhere from several days to a week or two. The link below will take you to an article that discusses how to rear them in greater detail (they are suitable for the "easy" rearing method outlined in the article). It will explain how to set up a basic nursery tank and culture the live foods you need to feed the newborns:

Click here: Seahorse.com – Seahorse, Sea Life, Marine Life, Aquafarm Sales, Feeds and Accessories – Nutrition – Feeding & Rearing the Fry

<http://www.seahorse.com/FAMA_-_Freshwater_and_Marine_Aquarium_magazine/Horse_Forum_-_Nutrition/Nutrition_-_Feeding_%26_Rearing_the_Fry_-_Part_IV/&gt;

As a Mustang keeper, you may also find the following online articles on rearing H. erectus to be especially helpful:

<http://www.seahorse.org/library/articles/seahorseCulture.shtml&gt;

<http://www.seahorse.org/library/articles/erectusfry.shtml&gt;

http://www.seahorse.org/library/articles.shtml#propagation

<http://www.syngnathid.org/articles/raisingFry.html&gt;

Fry Development Cycle – From Egg to Horse
<http://www.seahorse.org/library/articles/fry.shtml&gt;

If you don’t have a separate tank you can set up as a nursery, then you might want to try hanging a breeder net designed for livebearing fish such as mollies and guppies, or a perforated "critter keeper," inside your 55-gallon aquarium to contain the newborns an act as a makeshift nursery. This will create what is known as an in-tank nursery, which is an arrangement that can be quite effective as long as you keep them scrupulously clean, as discussed below:

The In-Tank Nursery.

In-tank nurseries enjoy all the advantages of divided nurseries and then some. For example, like divided nurseries, the tank-within-a-tank design makes it much easier to provide seahorse fry with stable conditions and optimum water quality, vastly increases filtration and equipment options, simplifies maintenance and offers enormous versatility. The idea behind the in-tank nursery is to confine the seahorse fry in a small, flow-through enclosure that can then be attached securely inside a larger aquarium. The in-tank fry enclosure must allow water to pass through it freely but not fry food such as copepods, rotifers or Artemia nauplii. The enclosure thus allows the food to be concentrated in a small space to maintain the proper feeding density, while at the same time providing the fry with all the benefits of living in a much larger volume of water. This includes greater stability in terms of water temp, pH, oxygen levels, salinity and so on.

But by far the biggest advantage of the in-tank nursery is the superior water quality it provides. The larger tanks that accommodate the fry enclosures are normally in the 10-20 gallon range, but there is no upper limit to the size of the host aquarium — the bigger, the better. Of course, for starters, the larger volume of water is naturally more resistant to pollution from the mass consumption and elimination one must deal with when rearing seahorse fry. But more importantly, with the fry safely sheltered in their nursery, the main tank can be equipped with any kind of filtration and filter media you can think of to improve water quality or safeguard the health of the fry. This includes heaters, sponge filters, inside box filters or external power filters with activated carbon, polyfilter pads, or ion-exchange resins, micron-level mechanical filtration, bio-wheels, wet/dry filtration, protein skimmers, UV sterilizers, ozonizers — you name it. Airstones, bubble wands, powerheads, filters and the like can operated full blast without worrying that they’ll buffet the fragile fry or that they filters may ‘eat’ the newborns or consume all their food. Use your imagination — anything goes!

Water quality benefits as a result, and the added filtration reduces the need for frequent water changes. When substantial water changes are called for, the main tank makes the whole process easier.

The first in-tank nurseries were ready-made breeder nets intended for livebearing freshwater tropicals (Abbott, 2003). I know several hobbyists who use breeder nets for rearing dwarf seahorse fry. They tend to get a bit dirtier than bare-bottomed nurseries (uneaten brine shrimp and fecal pellets will accumulate on the netting and cling to the mesh) so you’ll need to be diligent about siphoning the netting clean of such wastes and debris, just as you would be when cleaning the glass of a bare-bottome nursery. The dirty water should be replaced with cleaned, newly mixed saltwater you’ve prepared and aged/aerated overnight. These small water changes will help maintain good water quality in the nursery.

Many hobbyists who used these breeder nets for rearing fry keep two of the nets, one which is in use as a nursery, and a clean spare which they transfer the fry into when the breeder net that’s currently in use gets too dirty despite the siphoning. The dirty net is then cleaned and disinfected thoroughly and held in reserve until the other breeder net needs to be replaced. The two breeder nets are then switched back and forth as often as necessary to assure that fry are always contained within a reasonably clean enclosure.

These breeder nets worked very well for dwarf seahorses, which produce small numbers of babies (Abbott, 2003), but they are not well suited for the huge broods of fry many of the greater seahorses produce. Hobbyists soon began to improvise in order to overcome the limitations of such breeder nets and accommodate larger broods in their fry enclosures. Breeders began to experiment with in-tank refugia, “critter keepers,” and various plastic containers to meet their needs. They modified these by drilling them full of holes and covering the holes with plastic mesh. If necessary, an airline is added to the fry enclosure for better circulation and a drip line brings filtered water in from the main tank or an external power filter.

The versatility of in-tank nurseries is one of their biggest assets. They allow almost any existing aquarium to “host” a fry enclosure and there is also great flexibility in the design of the inner nursery tank. They can easily be modified to accommodate either benthic or pelagic seahorse fry, and multiple in-tank nurseries can be housed in one big main aquarium. Endless variations on this basic concept are possible. The in-tank nursery is simply a much more versatile and adaptable design than the divided nurseries that preceded it.

For starters, here are some tips on hatching and enriching the baby brine shrimp you’ll need to feed the newborns:

Hatching Out Brine Shrimp (Artemia)

Many commercially made hatcheries are available or you can easily improvise your own from 2-liter soda pop bottles or quart jars. Fill the jars or bottles about 4/5 full with saltwater or brine solution and equip each container with an airstone connected to a length of rigid airline tubing that reaches all the way to the bottom. An inexpensive vibrator air pump with a set of gang valves with put out enough air for the entire battery of hatching containers. Add 1/8-1/4 teaspoon of brine shrimp eggs to each container and adjust the valves so the airstones bubble vigorously, keeping the eggs in suspension at all times. Shine a light directly on the hatching bottles and keep them illuminated 24 hours a day. A temperature of 80-82 degrees F is optimum for hatching brine shrimp.

The eggs will begin hatching after 1-24 hours, and the emerging nauplii should be harvested and used as soon as possible after incubation while they still retain their full nutritional value. (The yolk supply lasts about 6-8 hours after hatching, and the food value of the nauplii deteriorates steadily as the yolk sac is consumed. Once it has been exhausted after about 8 hours, the nutritional worth of the nauplii drops drastically.)

However, before they can be used as food, the nauplii must first be separated from the indigestible egg shells. Otherwise the empty shells may be accidentally ingested by the seahorse fry, which has been known to cause intestinal blockages and death.

The brine shrimp nauplii can be separated from the eggs simply by turning off the air for a few minutes and allowing the water to settle. The unhatched eggs will sink to the bottom of the hatching jar while the empty egg shells will float to the top. The nauplii can then be concentrated in the center of the jar by darkening the room and shining a flashlight on the jar’s midsection. (Brine shrimp are attracted to light and will be drawn together in midwater where the light is focused.) Harvest the nauplii by using a siphon or turkey baster to suck up the concentrated mass of shrimp. The shrimp-laden water can then be strained through a plankton screen or fine-meshed brine shrimp net.

Return the strained water to the hatching container, add more eggs, and readjust the aeration. The same hatching solution can be used for a week’s worth of hatchings before it has to be replaced.

Alternating the hatching container from which you harvest each day’s supply of nauplii will assure that you have a nonstop supply of newly hatched brine shrimp available at all times.

If you’re still uncertain about how to proceed, the information at the following link should make everything perfectly clear:

Click here: Brine Shrimp Technical Information 1

http://www.brineshrimpdirect.com/brineshrimpdirect-faq-1-2-13.html#hatching

The best eggs or cysts to use for your brine shrimp factory are decapsulated eggs which have had their hard, outer shells stripped away. These shell-less eggs have many advantages over ordinary Artemia cysts. For starters, they simplify the task of separating the live nauplii from the unhatched eggs, since there are no empty shells, and the decapsulated eggs eliminate the possibility of clogged intestines due to the indigestible cysts. Secondly, the decapsulation process destroys virtually all known pathogenic organisms. Since the shell-less eggs have been disinfected, there is much less risk of introducing disease or parasites to the aquarium when you feed your seahorses with brine shrimp from decapsulated cysts. More importantly, the nauplii produced from decapsulated eggs have greater caloric value than the nauplii from unaltered cysts. This is because the nauplii from decapsulated eggs do not have to waste energy struggling to break free of their shells, and thus emerge with 20% greater food value, primarily in the form of additional amino acids and essential fatty acids. This extra nutritional value can make a crucial difference to the rapidly growing seahorses.

Decapsulated brine shrimp eggs are now available from some manufacturers. Although the shell-less eggs are expensive to buy, it is easy for the serious hobbyist to decapsulate his own brine shrimp eggs at home.

Decapsulating Brine Shrimp Eggs.

Decapsulating brine shrimp cysts — the process of dissolving away their hard outer shell — may sound intimidating at first and may seem awkward when you first attempt it. No doubt you will have these instructions open, your eyes glued to the page, with all of your supplies at the ready the first few times you perform this procedure. Relax, this is not difficult at all, and after you’ve done it a couple of times, you will see how truly easy it is and realize decapping is well worth the extra few steps. I will walk you through each numbered step. Measurements do not have to be exact. Regular strength bleach is best, but ultra bleach can be used at lesser portions. You can estimate this yourself. Decapsulating your cysts is beneficial for a number of reasons:

· Reduces the risk of hydroids.

· Removes the outer shell, which means less mess and no fouling of your tank.

· Eliminates intestinal blockages from accidental ingestion of indigestible shells.

· Kills off any and all unwanted contaminants.

· Slightly quicker hatching times.

· Better hatch rates.

· Increased nutritional value secondary to less energy expenditure during hatching.

Supplies Needed for Decapsulating:

· Brine shrimp net

· Air pump

· plastic clip or paper clip wrapped in baggie to clip airline into the container

· Approximately 2 teaspoons brine cysts.

· Approximately 2/3 cup of bleach

· Approximately 2 cups of water

Procedure:

1. Pour your water into a container and clip airline tubing to the side. (No air stone is needed for this). This will keep the cysts in motion. Allow the cysts to aerate this way for approximately 1 hour or a little more.

2. Add in your bleach and continue aerating. As the outer shell gradually dissolves, the eggs go through a series of color changes from brown to gray to white and finally to orange–the color of the nauplii within. This process takes about 7 minutes. The decapsulation process is complete when your cysts become an orange-yellowish color.

3. Pour decapsulated eggs into a brine shrimp net. Add a dechlorination product if you want and rinse until you no longer smell bleach.

4. Drop eggs into your hatching container. You can also refrigerate eggs for about 1 week prior to use in a supersaturated saline solution.

You will need to either feed the bbs to your seahorses immediately after hatching, when their yolk supply is virtually intact and they have their maximum nutritional value, or feed bbs that are 2-days old or older and have been enriched prior to feeding.

Best of luck with your bonus babies! Keep a close eye on your Mustangs for the next day or two, since it is typical for a stallion to remate within 24 hours or so of delivering his latest brood. If you’re lucky, you will be able to witness the fascinating mating ritual and transfer of the eggs.

Happy Trails!
Pete Giwojna