August 10, 2020 at 11:37 am #52604Pete GiwojnaModerator
Fellow Seahorse Feeders:
For those of you would like to culture live foods for your ponies, I would just like to point out that Ocean Rider is now offering 100 red feeder shrimp (Halocaridina rubra) at a special bargain price (see the following link):
What a wonderful starter culture that will make for anyone who wants to maintain a self-sustaining population of these tasty tidbits for their galloping gourmets!
This is what I advise home hobbyists regarding these irresistible feeder shrimp:
RED FEEDER SHRIMP (Halocaridina rubra)
The red volcano shrimp (Halocaridina rubra) are hardy little critters that are very easy to keep and maintain, but they reproduce very slowly which makes it challenging to raise numbers of them in batch cultures. They are great little shrimp that are perfect for seahorses — bite sized, irresistible, and highly nutritious (a natural prey item that ponies go crazy over and that will survive indefinitely in the aquarium until they are hunted down and eaten). If you just want to keep the supply of them on hand to feed to your seahorses as occasional treats, then you can’t beat the red volcano shrimp.
You will find the red feeder shrimp (Halocaridina rubra) to be extremely hardy, easy to keep, and relatively undemanding to culture, although their numbers build up very gradually due to their naturally slow rate of reproduction.
Red feeder shrimp or volcano shrimp, as they are sometimes known, prefer brackish conditions and breed best at reduced salinity (1.0114) but they adapt well to full strength saltwater and will survive indefinitely is a marine aquarium. They are a perfect “feed-and-forget” treat for large seahorses! As a rule they don’t need a great deal of room. A simple sponge filter will do. The Care Sheet for the volcano shrimp is available online at the following URL:
Feeding Hawaiian Red Volcano Shrimp to Your Seahorses
When it is time to feed your ponies, they will go absolutely crazy for Halocaridina rubra volcano shrimp. You will be surprised at how fast the seahorses can move when they are tracking down the red feeder shrimp! They are very good at hunting down the red feeder shrimp and ferreting them out of their hiding places, and they will slurp them up faster than the eye can follow once they have them in their sights within striking distance.
However, the red feeder shrimp are fast, and agile, and are excellent hiders, which makes them difficult quarry, so don’t just drop them into your seahorse tank or they will likely disappear into the substrate and decorations before the ponies get a chance to eat them. In fact, for best results, I would suggest crippling or disabling the live shrimp to slow them down and make it easier for the seahorses to target before you offer them to the ponies at feeding time. The most humane way to do this is to cool the live shrimp down so that they are barely moving when you feed them to your seahorses.
To accomplish this, put several of the red feeder shrimp (enough for one feeding) in a small container of saltwater and chill it in your refrigerator or even your freezer until the shrimp’s metabolism has slowed down to the point that they are barely moving. When you’ve done it right and chilled them down sufficiently, their legs will still be twitching and moving around enough to attract the interest of the seahorse and trigger an immediate feeding response, but the shrimp will be too lethargic and torpid for coordinated movements or evasive maneuvers. Drop the disabled shrimp right in front of the seahorse one or two at a time and they should be sitting ducks.
To save time, you can also achieve the same thing by removing most of the shrimp’s legs to cripple it and slow it down, if you are not too squeamish. The live red feeder shrimp or volcano shrimp (Halocaridina rubra) from Hawaii are ideal for this since they are bite-sized morsels that are easy to swallow.
Recommended Feeding Regimen
We suggest providing 3-5 shrimp per seahorse per feeding. We recommend feeding once or twice a week and all the time while on vacation!
Here is some additional information about these shrimp, including suggestions for feeding and raising them, that may be of interest to those of you who are interested in keeping or culturing these colorful little crustaceans:
RED FEEDER SHRIMP from Hawaii (Halocaridina rubra)
Common Name: Hawaiian Volcano Shrimp, Red Volcano Shrimp, Hawaiian Red Shrimp, Anchialine Shrimp, Opa’e-ula (Hawaiian), Red Feeder Shrimp, Red Iron Horse Feed
Scientific Name: Halocaridina rubra)
* Excellent nutritional value.
* Irresistible to all the greater seahorses.
* Feed-and-Forget — lasts forever in saltwater!
* Super tough and extremely adaptable.
* Easy to enrich.
* Simple to gut-load.
* Can be cultured using simple techniques and the most basic setups.
* Reproduces slowly; difficult to build up a large population.
Specific gravity: range 1.0080-1.0168; optimum 1.0114
Salinity: range 12 ppt-23 ppt; optimum 16 ppt
Temperature: 68° F – 73° F (20° C – 23° C)
These tiny red feeder shrimp (Halocaridina rubra) are native to Hawaii where they inhabit pools of brackish water that accumulates in underground lava tubes. Brackish pools collect in the cracks, crevices and depressions in the lava below the water table, thus forming the habitat for the shrimp. The brackish water that fills these pools consists of intrusive seawater diluted by freshwater that percolates slowly downward from the surface through the porous lava rock. The water in the pools is also affected by tides and can thus vary in depth and salinity considerably depending on the amount of rainfall there has been recently in the area where they’re located and what time of month it is, which influences the highest and lowest tides according to the lunar cycle. There are no fish in these anchialine pools or ponds – they are utterly barren except for algae, bacteria and the volcano shrimp themselves. Because of their lava-tube habit, they are sometimes called Hawaiian Volcano Shrimp.
As you can imagine, these lava tubes are an extremely challenging environment to live in, which is why only bacteria, algae, and the super tough volcano shrimp can manage the feat. The salinity in the lava-tube pools can vary from pure freshwater to saltier than full-strength seawater, and the rugged red volcano shrimp can happily survive at either of these extremes, as well as everything in between. The temperature of these secluded pools is equally variable, and the supply of food they contain is always severely limited and may be nonexistent at times.
Because of the terribly harsh conditions they have evolved to live in, the red volcano shrimp are extraordinarily adaptable and tough as nails. They are durable and adaptable because they have to be in order to survive under very hostile circumstances in the very hostile habitat of the subterranean pools that form in the lava tubes. They have evolved to endure temperature extremes, survive salinity extremes, and thrive under environmental extremes (lack of food for months or years at a time). I like to describe them as “bulletproof” because they can survive almost anything you can throw at them. And because they’re so very tough and so adaptable, they have a remarkably long life span for shrimp and have been known to live up to 20 years when provided with good care and stable conditions.
Although they can survive indefinitely in pure freshwater under alkaline conditions or in full strength saltwater, they breed best at a salinity ranging from 12 ppt to 23 ppt (or a specific gravity of 1.008 to 1.016), and a salinity of 16 ppt (specific gravity of 1.0114) is ideal if you wish to culture them. The adults can survive in hard freshwater, but the larvae require some salt in their water (brackish conditions) in order to survive and develop into adults.
Native Hawaiians call them Opa’e-ula, and they are unique among the several different species anchialine pond shrimp in being small, social, herbivorous shrimp that feed mainly on algae and bacteria. When conditions are favorable, they may feed en masse at the surface in swarms of countless individuals that turn the water red.
These fabulous little feeder shrimp can be kept indefinitely in a spare 2-10 gallon tank, or even a clean, plastic bucket, that has been filled with clean saltwater and equipped with an airstone for aeration. An aquarium of 2-1/2 gallons is sufficient for a group of 15-30 adults, with plenty of room for their offspring. But for maintaining or culturing these shrimp in large quantities, an aquarium of 5-10 gallons is recommended. A 5-gallon tank will hold up to 400 adult volcano shrimp for short periods, but I recommend a minimum 10-gallon tank if you want to maintain such large numbers of these shrimp for extended periods of time.
Once you have decided on the size of the tank that is best suited for your needs and interests, neither a heater nor a fancy filtration system is required for the red volcano shrimp. They thrive at room temp and reduced salinity (1.008-1.016), and all they require is a simple air-operated foam filter or sponge filter to keep the water clean and oxygenated. A cycled sponge filter is the ideal means of filtration for Halocaridina rubra, and if you are using any type of outside filter or external filter instead, it’s important to shield the intake tube for the power filter with a sponge prefilter to make sure that none of the shrimp or their larvae get “eaten” by the filter. Water circulation should be slow, which is another reason that simple air-operated sponge filters are best, and these rugged little shrimp can withstand long periods without water changes.
Create rockwork formations along the back of the tank with lots of caves, crevices, ledges and overhangs for the shrimp to explore and take shelter in when they want to breed or get away from the light. Lava rock is ideal for this but live rock with lots of pits, craters, depressions and concavities will work just fine when stacked together to create crevices, caves, and ledges. If you cannot include rockwork in your red volcano shrimp habitat for any reason, then substitute opaque PVC tubing instead. Use various diameters from 1 inch to 3 inches and cut them in different lengths to create makeshift tunnels for the shrimp. This is very important because lava shrimp don’t like bright light and spawn underground in the dark. A thin layer of a calcareous gravel or sand is a suitable substrate, but a bare bottom can also be used as long as plenty of shelter is provided.
Remember, these are subterranean shrimp that are accustomed to living in dark tunnels, crevices, and craters, so use low light for your volcano shrimp. In the brackish anchialine pools they inhabit in the wild, volcano shrimp spend much of their time underground in deep, dark, subterranean crevices, but they also spend short periods of time in shallow, brightly lit areas exposed to the surface, primarily to feed on the algae and Cyanobacteria that grow in the sunlight (although they often prefer to feed at night in the dark). Ambient room light will suffice for your shrimp tank, but a good way to duplicate the conditions they encounter in nature is to keep one end of their tank dark and well shaded and the other end of the tank well lit in order to encourage the growth of algae.
Adjust your water quality parameters as indicated above. Maintain brackish conditions. Hawaiian volcano shrimp breed best at a specific gravity ranging from 1.008 to 1.016, but if you purchased your red feeder shrimp from Ocean Rider, keep your shrimp tank at a steady specific gravity of 1.0114, which they are accustomed to at the aquaculture facility. These shrimp are very hardy and do not require frequent water changes at all, but it is very important to top the shrimp tank off with freshwater regularly in order to maintain the brackish conditions. Many times they do best with very infrequent water changes, as long as the tank is topped off with freshwater routinely.
Halocaridina rubra look like miniature, bite-size Peppermint Shrimp, and all seahorses save the miniature species go absolutely nuts for them! They are very nutritious and eat a varied, omnivorous diet. They are perfect for seahorses in every way.
Converting Red Volcano Shrimp to Full-Strength Saltwater
The red feeder shrimp or Hawaiian volcano shrimp (Halocaridina rubra) are quite hardy and can adapt to a wide range of salinities without difficulty. This is a necessary trait for the red shrimp because they live in lava tubes filled with brackish water, in which the salinity is largely dependent on how heavy rainfall has been lately and how high the tides have been recently.
They will do fine as long at full strength saltwater as long as you very gradually adjust the specific gravity up to 1.025 over a period of days. Just add small quantities of your favorite aquarium salt mix to your shrimp tank once or twice a day until you have achieved the desired salinity or specific gravity. It’s best to do this over a period of several days, however, because whenever you are raising the salinity upwards, there is always a danger of dehydration as a result. So raising the specific gravity upwards must always be done gradually, in a series of small steps. The Hawaiian volcano shrimp will survive indefinitely in full strength saltwater (s.g. 1.025) and do well, but I wouldn’t count on any natural reproduction at that salinity. At least, not enough to be useful. They reproduce very slowly under ideal conditions, and the shrimp larvae undergo a complex life cycle with a number of larval stages, which makes it difficult to increase the population of these shrimp in the aquarium. So that’s one drawback to keeping them at high salinity over the long term, and most home hobbyists rightly opt to keep them under brackish conditions, especially if they wish to culture them.
But if you’ll just be feeding the volcano shrimp to your seahorses, then there is no need to acclimate them to full strength seawater because they will survive in your seahorse setup just fine regardless of the salinity until they are eaten.
Because food is so scarce in the lava tubes filled with brackish subterranean water that they inhabit, red volcano shrimp have developed multiple feeding strategies that allow them to take advantage of almost any edible material that comes their way. First and foremost, they are herbivorous shrimp that graze on the algae and Cyanobacteria that forms a crust on the lava rock where it is exposed to sunlight, and algae and bacteria form the bulk of their diet. But Halocaridina rubra is also equipped to filter feed by fanning the water into its mouth to catch any floating particulate matter, and they will even scavenge on dead insects that drown in the brackish ponds.
As you can imagine, this makes the red volcano shrimp easy to feed in the aquarium. Encourage green algae to grow on the sides of the tank and the rockwork, and they will require little else.
They will take finely ground flake food, algae wafers or vegetable-based pellets, such as various Spirulina products, or even freeze dried fish food. Being efficient filter feeders, they can take advantage of any edible particles suspended in the water, so you can also feed them with anything that would be suitable for brine shrimp (Artemia sp.). But such supplemental foods should be used VERY sparingly once algae begin growing in your shrimp tank. Once your shrimp tank is well-established and there is algae growth on the sides of the tank and the live rock, it’s important to feed the shrimp very little! They will get virtually all of their nourishment from the algae and bacteria that grow on the rocks and viewing surfaces of the tank.
When the shrimp tank is new and there is little or no algae growth, many people find an easy way to feed volcano shrimp is to place a small piece of algae-encrusted live rock in their aquarium; once they clean it off, it is simply replace with a new piece of algae rock. As filter feeders, they can also be fed sparingly with yeast or commercially prepared foods for filter-feeding invertebrates. But if you want to culture them, I’d recommend ordering the special shrimp food formulated just for them when you order your feeder shrimp from Hawaii. It’s called Shrimpgro and is designed to meet all their needs and requirements:
When food is abundant, these rugged shrimp may swarm over it in a sort of a feeding frenzy, and they can be quite entertaining to watch as they feed. Should a morsel of food fall to the bottom and startle the shrimp, they will immediately dart up to the water surface and then back down again, setting off a sort of chain reaction as a ripple of activity spreads through any nearby shrimp in quick succession.
Although their rate of reproduction is low, red volcano shrimp will readily reproduce in the aquarium and the young will feed on liquid fry food.
Unfortunately, it can be difficult to culture these shrimp in large quantities, since they reproduce slowly and even large females only carry 12 to 14 eggs at a time. They spawn but 4 or 5 times each year, and produce an average of only 5-10 larvae per spawn. This slow rate of reproduction is very likely an adaptation to the limited food supply available to the shrimp in the anchialine pools they inhabit. However, this is partially compensated for by an unusually long life span (up to 20 years), which allows females to produce plenty of offspring over the course of their lifetime.
As mentioned earlier, red volcano shrimp are adapted to an underground existence, and spawning takes place in the dark in subterranean areas. It is important to provide the shrimp with caves and tunnels and crevices that will provide them with the proper habitat in which to breed. The larvae hatch as free-swimming, yolked zoeae after a brooding period of 38 days. Unlike the adult shrimp, which shun the light, the newly hatched larvae have well-developed eyes and are attracted to the light. They swim up out of the dark cracks and crevices and caves toward the light, which triggers their four-stage larval development.
Fortunately, although few in number, the larvae are rather easy to raise. Larval development is abbreviated with four zoeal stages and one megalopial stage occurring before they reach the first juvenile stage. The larvae retain a large yolk sac when they hatch, and this yolk supply is sufficient to sustain them throughout their larval development. The larval volcano shrimp normally do not feed until becoming benthic post-larvae (i.e., miniature shrimp). This transformation takes only a few days, during which the surface-swimming planktonic larvae metamorphose into post-larval shrimp, and these juvenile shrimp then settle down to the bottom and assume a benthic way of life like the adults. The newly transformed juveniles are 3-4 mm in length and look like miniature versions of the adults, except for their large eyes. (Due to their underground habitat, the eyes of adult volcano shrimp are greatly reduced and all but unnoticeable.) The juvenile shrimp gradually lose their well-developed eyes as they pass through a series of molts. In the aquarium, it takes about 24 to 27 days for the young to complete their development and become mature adults at 22°C-23°C. (Note: the development of the planktonic larvae from one stage to another, and their transformation into benthic juveniles cannot take place in freshwater; rather, brackish conditions are required for proper larval development and metamorphosis.)
If you would like to learn more about rearing other species of shrimp, such as cleaner shrimp, there is a very interesting and informative book that explains exactly how to go about raising such shrimp that I recommend you read. It’s called “How To Raise & Train Your Peppermint Shrimp” by April Kirkendoll and it can be obtained at the following URL:
You’ll find lots of excellent information on raising peppermint shrimp in April’s book, and much of it will apply to your volcano shrimp as well.
And here is the product description for the red volcano shrimp as it appears on the Ocean Rider website:
Red Volcano Shrimp (Halocaridina rubra)
Also known as Red Iron Horse Feed, Live Red Hawaii Shrimp!
Excellent source of nutrition for your seahorses and other delicate fish. These shrimp are full of long chain fatty acids and beta carotenes. Adults are 1/2 to 1 cm long, mate 4 to 5 times a year spawning about 6-8 offspring.
These shrimp are endemic to Hawaii and a few other South Pacific Islands where they inhabit underground lava tubes where rain water mixes with the ocean water into open anchialine ponds creating a very unique environment with low salinity (16 ppt) and varying temperatures (65F to 75F). Here they feed at night on the bacteria and fungus that grows on the lava walls and rock crevices that are exposed to light during the day.
Ocean Rider aquafarms these shrimp in our own anchialine pond. At home you can house up to 600 shrimp in 5 gallon tank with a sponge filter, very little light, gravel substrate, and sea lettuce for habitat. You can feed them small amounts of Shrimpgro, being careful not to overfeed. Or you can cultivate your own fungus and bacteria on the tank walls and floor for them to graze on. Be sure you use a hydrometer to check the specific gravity which should be 1.0114. Water temperature can range from 60F – 75F, Ammonia and Nitrites must be kept at 0, Nitrates should be less then 10ppm, PH 8.2 – 8.4
Feeding: 3-5 shrimp per seahorse per feeding. We recommend feeding once or twice a week and all the time while on vacation!
Quantity is measured volumetrically so expect to receive between 20 and 30 pieces depending on biomass of each individual shrimp.
Finally, here is the Care Sheet with the acclimation instructions for the red volcano shrimp, just as it appears on the Ocean Rider website:
Live Hawaii Red Shrimp (Halocaridina rubra)
… also known as Ocean Rider Red Iron Horse Feed or Opae ulua.
Please adjust your salinity to 1.0114 for holding these shrimp!!
Unless you are planning on feeding all your red shrimp all at once to your seahorses, please prepare a separate tank (or bucket) with a minimum of 5 gallons of new water for holding 400 shrimp for a short period and 10 gallons for longer periods. This tank needs to be cycled before adding your shrimp. You may use simple filtration, aeration and low light, habitat such as rocks or gravel and tubes for hiding and getting away from the light (which they hate!) .
Water quality parameters are: Temperature 60F –80F, Ammonia 0, Nitrites 0, Nitrates less then 10ppm PH 8.2 – 8.4, Specific gravity 1.0114 to 1.0122.
ACCLIMATION PROCEDURES: Be Sure to:
Check the specific gravity to 1.0114!!
Prepare NEW water. Do NOT rely on the water the animals are shipped in for holding these shrimp. Check that the salinity of your holding tank is the same as the shipping water. If it is not, adjust your holding tank so it is the same as the shipping water BEFORE acclimating. If you do not do this you will kill the shrimp. All other parameters must be within acceptable ranges.
Please acclimate slowly. The best way is to:
1. Float the bag in your tank for about 20 – 30 minutes to equalize temperatures.
2. Then partially open the bag and add 1 cup of tank water.
3. Wait 10 minutes.
4. Remove 1 cup of water and add another cup of water from the tank.
5. Wait 10 minute.
6. Gently release the animals into the tank, discarding the water left in the bag.
7. Do not feed until the day after arrival and acclimation.
Okay, hobbyists, that’s the rundown on keeping and raising these amazing anchialine shrimp.
Most people simply dole them out of their seahorses as live treats, but they certainly can be carefully cultivated in a refugium or a small tank of their own in order to allow their numbers to build up slowly in a predator-free environment.
Pete Giwojna, Ocean Rider Tech Support
©Copyright 2009. All rights reserved. Permission to reproduce is granted by the author (Peter Giwojna) for your personal use only and is not transferable without written permission by Ocean Rider and the original author.
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