- This topic has 3 replies, 2 voices, and was last updated 17 years, 6 months ago by Pete Giwojna.
June 7, 2006 at 2:44 am #835myvizslaMember
Pete — apparently I have a mated pair of horses in my tank. I noticed one of them getting rather large around the belly and assumed him to be pregnant. I planned on setting up a nursery tank tonight. I had gone to an early movie and came home to fine babies in my main tank. I quickly set up a nursery tank (10 gal) fixed a small filter by putting some fine netting around areas that could suck the little fellows up — caught as many as I could find and put them in the nursery. What a surprise!! My problem is I don\’t have any food and won\’t be able to get to a store until tomorrow. Hopefully I will be able to find some baby brine shrimp already hatched. Are there any alternatives? I realize that this being my first time and the fact that the books all say raising seahorse fry can be difficult, I really want to do whatever I can to keep these little guys alive. I look forward to your response.
Barbara ReynoldsJune 7, 2006 at 3:53 am #2574Pete GiwojnaGuest
Congratulations on your surprise babies! The newborns generally have enough of a yolk supply to last them for 6-12 hours after birth, so chances are they will be alright as long as you can provide them with suitable food as soon as possible tomorrow.
Yes, you are quite correct, Barbara — all seahorse babies are challenging for the home hobbyist to raise. 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 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. 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, Barbara, Mustangs and Sunbursts 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):
Click here: Seahorse Nutrition Part IV: Feeding & Rearing the Fry
As far as alternatives to newly-hatched brine shrimp go, newborn seahorses will also eat rotifers, copepods and larval Mysis, among other things, in addition to Artemia nauplii. However, it is much more difficult and much more expensive to provide these alternative live foods in the quantities necessary to raise seahorse fry, Artemia nauplii (newly-hatched brine shrimp) are the most practical live food for the home hobbyist to provide.
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. However, you might try something along the lines of Cyclop-Eze or preserved through plankton just to get your newborns through the next day or two until you can begin hatching out your own brine shrimp nauplii.
If the newborns will accept them, which is not too likely, Cyclop-eeze and preserved zooplankton can be great time savers when rearing fry but they do have one other very big drawback. They are not feed-and-forget fry foods like Artemia nauplii or live copepods which survive until eaten and keep swimming around until they pass within striking distance of one of the babies. If the preserved zooplankton isn’t eaten quickly, it will settle out of the water column and begin to degrade the water quality in the nursery. So if you are relying on Cyclop-eeze and preserved zooplankton to make up a large portion of your frys’ diet, you need to be even more diligent about making water changes and siphoning off the bottom of the nurseries in order to stay on top of the water quality. You may need to increase the frequency of the water changes and/or increase the percentage of water you change each time, if you try such foods.
Hopefully, you’ll be a will to find an LFS that has newly-hatched brine shrimp available, which can tide you over until you can get your own brine shrimp hatcheries set up and running, as described below, Barbara:
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 links should make everything perfectly clear:
Click here: Hatching Brine Shrimp
Good homemade hatcheries here:
Click here: Culturing Brineshrimp
Click here: Brine Shrimp Technical Information 1
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
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.
Enriching Brine Shrimp at Advanced Instars
Feeding baby brine shrimp his the key to raising nutritious nauplii for your juvenile seahorses. Newly hatched brine shrimp deplete their yolk supply within 6-8 hours and must be fed regularly thereafter to maintain their food value.
Fortunately, brine shrimp are filter feeders and will take in whatever is suspended in water with them. This makes it easy for the aquarist to load the shrimp he is raising with nutritional value by giving them a healthy diet supplemented with special food additives. Commonly used foods for culturing Artemia include unicellular algae; rotifers; yeast-based emulsions; micronized egg yolk, rice bran, wheat flour or whey; and dried Spirulina algae.
Research has proven that brine shrimp can be further enriched by adding supplements such as cuttlefish liver oil, cod liver oil, corn oil, fat-soluble vitamins, amino acids, and mineral formulations to their culture water. Analysis of the nutritional content of culture animals after they had been exposed to such supplemental additives showed a dramatic increase in long-chain fatty acids and many vitamins.
Rather than experimenting with your own concoctions, I recommend using one or more of the lipid-rich food concentrates which have recently been developed specifically for use in aquaculture. Products commonly used by professional breeders for fortifying brine shrimp nauplii include Beta Meal, amino acid and essential vitamins (liquid multi-vitamins), commercial products of (W3) highly unsaturated fatty acids such as Vibrance 1, Selcon Concentrate, Selco, Culture HUFA, Roti-Rich, Astaxanthene biological pigment Natu-Rose, AlgaMac 2000, MicroMac 70, and unicellular microalgae cultures (e.g., T-iso, T-weiss, and Nannochloropsis, Chlorella and Isochrysis sp.). Such products are typically rich in amino acids, highly unsaturated fatty acids (HUFA) and vitamins, which makes them ideal supplements for culturing Artemia. Very often, using a combination of these enrichment products provides better nutrition and produces better results that relying on any one product alone.
For best results, 24 hours after the culture tanks are seeded with newly hatched brine shrimp, begin feeding the nauplii sparingly by adding a concentrated food supplement or enrichment formula according to the instructions. Adjust the amount so that a slight haze barely clouds the water for a few hours every day. Do not feed again until the water is crystal clear and do not overfeed. As the brine shrimp grow, you may need to adjust the dosage of your favorite enrichment product by either increasing the frequency or the amount of the feedings.
The best way to harvest the enriched nauplii is to use a plankton collector or strain the culture water through a plankton screen (available from Florida Aqua Farms). As your seahorses grow, you can sift the nauplii through plankton screens with progressively larger mesh, selecting only the shrimp that are at just the right stage of development for the size of your juveniles.
Best of luck with your new pair of breeders and their offspring, Barbara!
Pete GiwojnaJune 7, 2006 at 6:23 pm #2575myvizslaGuest
Pete — thanks for your response. I was out early this morning and now have a brine shrimp hatchery set up in the tank, a sponge filter and so far only 1 death that I can tell. I also did a water change this morning while siphoning the bottom of the tank. The two adults that coupled up are a yellow and black H.B. It has been approximately 18 hours since birth . . . I am still finding babies in the main tank. I am giving small amounts of frzn baby brine shrimp in hopes that they will at least get something until the other hatch out — which hopefully will be by tomorrow. Can’t find anything live. While most of the babies are in the pelagic stage, there are some that have attached onto the hitching plant and are staying below. They move around when they see something in front of the tank. One question though . . . how do you regulate the temperature in the nursery tank? I know I can’t put a heater inside as it will burn them if they touch it. My temperature is only around 74 f. now. I turned on the light in hopes that it will have a bit of a warming effect. I hope I can save some of these little guys. They are truly amazing.
Thanks for your continued help.
BarbaraJune 8, 2006 at 2:44 pm #2577Pete GiwojnaGuest
A temperature of 74°F is perfectly acceptable for your nursery tank as long as you avoid temperature fluctuations. Due to the small volume of water in nurseries, they tend to remain at the ambient air temperature of the room the tank is in, which means there will be temperature fluctuations (warmer during the daytime and cooler at night) unless a heater is used.
Many nursery tank designs, such as divided nurseries, palpins and other in-tank nurseries, and many kriesels or pseudokreisels allow the heater to be kept in the host tank, separate from the inner rearing chambers, so the heater never comes in contact with the fry. If that’s not possible with the basic nursery tank you are using, Barbara, there should be no problem placing a small heater directly in the nursery tank itself. The barrel of the heater is far too large in diameter for the fry to hitch onto, and even if they did, modern aquarium heaters are designed, insulated and engineered so that there’s really no danger of a heater burn occurring. To eliminate even the slightest possibility of such an accident ever occurring, various sleeves and heater guards are now widely available as well. So don’t hesitate to incorporate a suitably small heater into your nursery tank in order to stabilize the water temperature.
Best of luck with your first batch of fry, Barbara! It’s encouraging that some of the newborns are hitching already. Here’s hoping your brine shrimp hatcheries are so running in high gear and producing all the Artemia nauplii you need.
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