- This topic has 1 reply, 2 voices, and was last updated 15 years, 6 months ago by Pete Giwojna.
August 22, 2008 at 11:07 am #1531Registering_DeanMember
I search on the Yahoo what is Copepods, there are some of them forming the colonies and swimming back and foward under the caves on my tank:woohoo: !!, we saw it weeks ago, you said that my tank was too new, well i guess it was, but the copepods formed because i added the right vitamins maybe?, because if it was, i should continue adding it….;)
if i turned off the waves then the copepods will swimming upon the caves, is that the right copepods?, if it was, then what should i do to keep the colonies healthy and multiply?….
i always change 30 % of my water, will that effect the copepods?:dry:
And how do i raise Amphipods on my tank?
THANKX SO MUCH FOR THE INFO AND EVERYTHING YOU\’VE DONE FOR US.
😆 :kiss: 😆August 23, 2008 at 1:47 am #4424Pete GiwojnaGuest
Yes, sir, it does sound like those may be copepods. It’s very common for copepods, amphipods, small Mysis and other crustaceans and microfauna to find their way into a marine aquarium as hitchhikers on live rock, and if conditions are right, they may establish breeding colonies and eventually become a self-sustaining population.
There are countless species of copepods and it’s very difficult to say if the ones you noticed swimming in the caves amidst your rockwork are especially desirable for a seahorse tank or not. If they are large enough to be seen by the naked eye, chances are good that your seahorses will eat them, although they often prefer to slurp up pods from macroalgae and vegetation or when they are crawling along the substrate, rather than feeding on them when they are swimming freely in the water column. Mandarin gobies normally only feed on the pods that hug the bottom and seek shelter among the rock and gravel in the aquarium.
Copepods and Gammarus amphipods prefer beds of macroalgae such as Ulva sea lettuce or Gracilaria because of the excellent shelter and feeding opportunities the clumps of algae provide for these crustaceans. But other than providing them with good shelter in the form of live rock and macroalgae, and maintaining good water quality, there’s really nothing more that you need to do to encourage them to grow and reproduce in your aquarium. They will feed on detritus and microalgae in the tank, and don’t usually require any supplemental feedings in a well-established aquarium.
It’s generally easier to establish a thriving colony’s of copepods and amphipods in a refugium or sump, where the absence of predators allows their population to grow and build up in check, though, rather than in the main tank where the seahorses will continually graze on them and reduce their numbers. Or you can also raise batch cultures of the copepods in small separate tanks, as described below, and the larval copepods are the best possible food you can provide for baby seahorses.
• Naturally high levels of essentially fatty acids.
• Natural food that forms a large portion of the seahorses’ diet in the wild.
• Elicits a strong feeding response.
• Perfect first food for seahorse fry.
• Feed-and-forget: marine species survive until eaten and will colonize live rock, filters and refugia.
• Starter cultures readily available.
• Easily collected by hobbyists with access to the seashore.
• Complex life cycle complicates home culture.
• Many species too small to interest adult seahorses.
• Some species are parasitic — can be difficult to tell the good guys from the bad boys.
Free-swimming copepods can easily be collected by anyone who lives within a reasonable distance of the ocean (in parts of the sea, larval calanoid copepods comprise the bulk of the zooplankton). Simply tow a plankton net (an elongated conical net made of fine material) slowly behind a boat in an area well away from possible sources of pollution, stopping periodically to empty its contents into a collecting container. (A mesh size of 250-500 microns will collect ‘pods that are about the right eating size for medium seahorses.) Cover the collecting bucket with a damp towel to keep it cool during the heat of the day and provide aeration to make sure the plankters stay alive until you get home.
Suitable for batch culture with greenwater (phytoplankton). See the rearing chapter for complete directions for culturing copepod nauplii.
Providing copepod nauplii as the first food for pelagic seahorse fry results in faster growth and often dramatically increases survivorship.
Copepods are an extremely diverse group of Crustacea with more than 10,000 known species with different lifestyles filling a great variety of environmental niches, both marine and freshwater (Dürbaum and Künnemann, 2000). There are three major groups of free-living copepods that are useful in aquaculture (Dürbaum and Künnemann, 2000): the Calanoida (primarily free-swimming planktonic animals), the Cyclopoida (either planktonic or demersal), and the Harpacticoida (entirely benthic).
Copepods undergo a remarkably complex life cycle. After hatching from the egg, they pass through six distinct nauplius stages, undergo a metamorphosis that completely transforms their body shape, and then go through six additional copepodid stages, culminating with the mature adult (Dürbaum and Künnemann, 2000). The first nauplius stages have only 3 pairs of appendages, which are used for locomotion and feeding (Dürbaum and Künnemann, 2000). The 6th and final naupliar stage molts into the first of the copepodid stages, and important development marked by major morphological changes (Dürbaum and Künnemann, 2000). The emerging copepodid larvae resemble the adults in large part. With the increasing number of body segments in the copepodid, more of their appendages become fully functional (Dürbaum and Künnemann, 2000). After the fifth copepodid molt adulthood is reached and the mature copepods are able to reproduce. There are two different sexes and reproduction is sexual (Dürbaum and Künnemann, 2000).
Growth is very rapid, with most species going from the embryo to mature adult in 10-12 days at 25-degrees C. The free-swimming nauplii are attracted to light, becoming less phototropic as they mature, until the adults begin to settle and attach to the substrate. As adults they swim less, remaining attached to substrates for anywhere from a few seconds to a few minutes at a time.
Marine copepods are the ideal food for rearing seahorses fry. They are a natural prey item that constitutes a large portion of the diet of fish larvae in the ocean, and many marine fishes have evolved efficient feeding strategies for preying on them as their primary foods. This includes seahorses, whose tubular snouts are adapted specifically for feeding on tiny crustaceans such as ‘pods, and which have developed a sedentary lifestyle as ambush predators that allows them to capture them with maximum efficiency and a minimum expenditure of energy. The tiny size of the copepod nauplii allows even the smallest seahorse fry to eat them, and they are a feed-and-forget food that will survive in the nursery tank until eaten. The distinctive swimming style of copepod nauplii triggers a strong feeding response from seahorse fry, and ‘pods have naturally high levels of essentially fatty acids. They are superior to rotifers in all these respects (seahorse fry often reject rotifers because they don’t move in the "right" way and simply don’t trigger their feeding instincts) and I recommend that aquarists who are raising pelagic fry concentrate on culturing copepods.
Seahorse fry alter their diet as they grow (Vincent, 1990). This may be due to the fact that they change microhabits as they develop (e.g., when pelagic fry complete their planktonic stage and begin to feed at the bottom as they begin orienting to the substrate). Or it may simply be due to the fact that they become better hunters and perfect their feeding skills as they grow, thus enabling them to tackle larger, more active prey (Vincent, 1990). Whatever the cause, one good way to keep up with the fry’s changing dietary requirements is by providing them with cultured copepods at progressively later stages of development.
Step 1: Providing Marine Microalgae (Phytoplankton).
Marine microalgae or phytoplankton is available from many sources. It can be cultured at home, and if you have a green thumb and are experienced with such greenwater cultures, that may be your best option. However, home culturing may not be for everyone. Greenwater cultures can be tricky to maintain. They are easily contaminated and are prone to "crashing" suddenly and unpredictably, which can have dire consequences if you are relying on the phytoplankton to provide food for your seahorse fry.
Alas, I am one of those unfortunates who cannot seem to maintain a decent greenwater culture for any length of time no matter what I try. Consequently, I now much prefer to obtain live marine phytoplankton from other sources rather than attempting to culture my own. Commercially available phytoplankton tends to be more concentrated than homegrown cultures as a rule, and I find purchasing it to be far more convenient, efficient, and productive. Given my repeated failures and the time I spent for naught on my own greenwater cultures, I’m certain that buying live phytoplankton is more economical for me in the long run as well. If you are inexperienced with greenwater culture or simply lack the time to culture your own, I recommend buying your live phytoplankton instead (see the Resources page for suppliers). Whichever source you decide to use, home grown or store bought, make sure you use it strictly according to instructions to prevent contamination and spoilage of the phytoplankton.
The type of phytoplankton or microalgae you use is not that crucial. Chlorella is one of the most popular microalgae used in mariculture (Wilkerson, 1995), but Dunaliella also works extremely well and is recommended by Dr. Amanda Vincent (Vincent, 1995c), an authority on the breeding habits of seahorses. Serious breeders often use a mixture of different types of phytoplankton to feed copepods or rotifers, rather than a microalgae monoculture, with the goal of enhancing the nutritional profile of the ‘pods or rotis as much as possible (David Warland, pers. com.).
There is a great deal of merit to that approach, but in the past, maintaining separate cultures of different species of microalgae was beyond the capabilities of most home hobbyists, myself included. I prefer to keep things simple and I have always used Nannochlroposis as the phytoplankton I feed to copepods, both because it produces good results and because it is commercially available from a number of sources. To simplify things all the further, I purchase my Nannochlroposis in quantity as needed, rather than struggling with phytoplankton cultures.
The product I like best at the moment for this now includes a concentrated mixture of live marine phytoplankton (two species of Nannochlroposis, N. oculata and N. salina, as well as a Chlorella sp.) in every bottle (DT’s Live Marine Phytoplankton, 2003). That makes it a simple matter to provide my ‘pods with a diversified diet to maximize their nutritional value as fry food — I just unscrew the cap on the bottle and pour the requisite amount of this phytoplankton mixture into my culture tank whenever it’s losing its greenish tinge, and I’m in business (DT’s Live Marine Phytoplankton, 2003)! No muss, no fuss. Quick, easy and effective — just the way I like it!
Step 2: Culturing Zooplankton (copepods and/or rotifers).
We will be using standard 10-gallon glass aquaria as our batch culture tanks. It’s a good idea to run at least 2 such tanks simultaneously; that way, if one of the cultures falters, the other tank can pick up the slack and you won’t miss a beat. Depending on how many seahorse fry you are rearing, you many need to operate several such tanks to assure you will be producing sufficient food for them all.
Fill each of these culture tanks slightly less than half full with synthetic saltwater, adjust the salinity of the culture tank to match the salinity of your nursery tanks, and maintain the pH at 7.9 or below (Rhodes, 2003). This will assure that the copepods (or rotifers) we are culturing do not experience any salinity shock when we feed them to our seahorse fry. No heater is necessary — the cultures will do just fine at room temperature (24C-28C is optimum). Provide very low aeration (Rhodes, 2003). Airstones are unnecessary — a naked bubbler stem is sufficient. Adjust the airflow so it produces a slow, steady stream of coarse air bubbles (slow enough so that you can count the individual bubbles). Ambient room lighting is adequate or you may provide low wattage fluorescent lighting if you prefer.
Add enough greenwater (either commercially produced phytoplankton you’ve purchased or your own homegrown microalgae) to tinge the culture tanks green, and you’re ready to start culturing copepods. All that remains at this point is to "seed" the culture tanks with copepods. Add a starter culture of marine copepods to each tank, acclimating the ‘pods if necessary exactly as you would acclimate a new aquarium fish. They will do the rest.
To nurture the copepods, simply maintain a nice green tint to the culture water by adding more phytoplankton whenever the water in the tanks begins to clear in color. (Be conservative with these phyto-feedings. One dose of phytoplankton every 7-10 days is generally adequate, depending on production and your copepod harvest rates; Rhodes, 2003.) The ‘pod population in the culture tanks will double every 2-3 days, depending on the temperature and how well they are fed (Rhodes, 2003), and as soon as the population builds up sufficiently, we can begin to harvest copepods to feed to our seahorse fry. When you begin to notice numbers of copepods gathering on the tank glass, that’s a good indication that their population density can support daily harvesting.
The best way to harvest copepod nauplii is to strain the desired amount from the culture tank using a 35-micron sieve and then rinse or backwash the strainer in the nursery tank (Rhodes, 2003). Alternate which culture tank you harvest the copepods from for each feeding in order to avoid depleting the ‘pod population too much in any given tank.
Periodically, it will be necessary to restart the copepod culture tanks to filter out the detritus that accumulates on the bottom. This is typically done every month or two (Rhodes, 2003) and is a surprisingly simple process. Just siphon out the water from the culture tank, straining the water in the process in order to retain the copepods. A 125 -micron sieve works well for a strainer. That size mesh will retain all the reproductive adults you need to restart your culture (Rhodes, 2003). It’s a good idea to use a small diameter siphon at first, being careful to suck up as little of the detritus as possible since it will clog up your strainer and your goal at this point is to recover as many copepods as you can. Once you’ve strained out most of the ‘pods, backwash them into container of clean saltwater and set them aside to seed the culture tank after you’ve finished cleaning it. Having saved as many pods as possible, switch to a larger siphon and drain the culture tank completely, removing all of the accumulated detritus. Fill the tank half way with freshly mixed saltwater you’ve prepared in advance and adjust the aeration. Then return the copepods you strained out previously and add enough concentrated phytoplankton to tinge the water green, and your culture is ready to begin producing again. If you restart your culture tanks on alternate months, one or more of them will be in full production at all times, and you can keep a thriving copepod population going indefinitely in this manner.
If you so desire, rotifers can be cultured in exactly the same manner. The only difference is that the 10-gallon culture tanks should each be seeded with a quart of live rotifers initially (Giwojna, Jan. 1997). When necessary, add enough concentrated phytoplankton or greenwater to keep the rotifer culture tanks slightly green. As long as the rotifers are being fed algae, about 25% of the rotifer cultures can be harvested each day to feed to your seahorse fry (Wilkerson, 1995). Try to keep more than one rotifer culture going at all times in case of crashes, and be sure to keep the bottom of the culture tanks scrupulously clean (Giwojna, Jan. 1997).
In fact, you can even maintain a dual culture of copepods and rotifers in the same tank if you wish. But you must avoid cross-contamination of your culture tanks with brine shrimp at all costs! Newly hatched brine shrimp (Artemia nauplii) are considerably larger than either copepods or rotifers, and the Artemia will happily fed on them as well as the phytoplankton. So if any brine shrimp ever find their way into your culture tanks, you will very shortly thereafter be culturing Artemia instead of ‘pods or rotis, leaving you with nothing but live food that’s too large for pelagic fry to eat.
Harpacticoid copepods such as Nitokra lacustris go through 6 naupliar stages as they grow, followed by 6 copepodite stages, before they become reproductive adults. They range in size from 45 microns (smaller than rotifers) up to 270 microns as full-sized adults. The many different stages of development copepods undergo is actually a blessing for the aquarist since it makes it possible to provide progressively larger ‘pods to the seahorse fry as they grow simply by using sieves with different sized mesh to harvest them. For instance, a 35-micron sieve will gather up even the smallest copepod nauplii for newborn fry, while a 125-micron will collect only adult-sized pods for older fry and juveniles, leaving the smaller ‘pods behind to develop further. An 80-micron sieve will take intermediate-size ‘pods along with the adults.
Whether you’re culturing rotifers or copepod nauplii, pelagic seahorse fry should be fed continuously starting 6-12 hours after birth (Giwojna, Jan. 1997). Dr. Amanda Vincent recommends feeding 2 plankton nets of rotifers (or ‘pods) 5-7 times daily or whenever no plankton is visible in the nursery tanks (Vincent, 1995c). In addition, she keeps a drip of diluted plankton (i.e., rotifers or copepods) going at the rate of 10 liters/day at all times (Giwojna, Jan. 1997). (A bucket of copepod-laden or rotifer-rich saltwater set on top of the nursery tank will suffice for this–just use a length of airline tubing as a siphon and adjust the drip rate with a valve; Vincent, 1995c.)
You can raise Gammarus amphipods in your main tank, a refugium, or a small separate aquarium as explained below, Dean:
Pros (Giwojna, Oct. 1996):
• Highly nutritious, hard-bodied crustaceans.
• Favorite food of many larger seahorse species.
• Good tolerance for saltwater (marine Gammarus survive indefinitely and even freshwater Gammarus will last until eaten if your sea horses are fond of them).
• Live Gammarus are increasingly available as fish food.
• Starter cultures are widely available through the mail.
Cons (Giwojna, Oct. 1996):
• Slow reproductive rate makes it difficult to raise them in large quantities.
• Slight risk of introducing disease with Gammarus collected in the wild.
Marine Gammarids–Gammarus locusta, a marine amphipod, can often be found in large numbers at the seashore by overturning rocks and coral rubble at low tide (Giwojna, Oct. 1996). Also know as scuds or beach-hoppers, scads of the land-dwelling form of these amphipods (Talitrus saltator) can often easily be collected from the mats of seaweed washed up on shore at the tide line. Simply gather up clumps of the freshly deposited seaweed and shake it vigorously over your collecting bucket to dislodge the amphipods.
Freshwater Gammarids–Gammarus fasciatus can be collected from vegetation and leaf litter on the bottoms of ponds and slow-moving streams (Giwojna, Oct. 1996).
Marine Gammarus will maintain a self-sustaining colony if established in a standard saltwater aquarium with coral gravel and rubble and left undisturbed while their population grows (Giwojna, Oct. 1996). Encourage a lush growth of green algae and restock periodically.
Under the right conditions, these small, shrimplike crustaceans mate and reproduce readily in captivity. Provide them with a lush green mat of Ulva macroalgae as natural habitat, and they will soon take up residence and establish a breeding colony of amphipods (Indo-Pacific Sea Farms, 2003). Provide them with low light levels, good aeration, and a pinch of flake food twice a week and you’ll soon have a growing population of Gammarus to dole out to your seahorses (Indo-Pacific Sea Farms, 2003).
Freshwater Gammarus can be cultured in a plastic wading pool or similar spacious receptacle equipped with an airstone (Giwojna, Oct. 1996). Feed sparingly with chopped raw spinach, Spirulina, or a pinch of dry fish food. Include plenty of algae-covered rocks and driftwood for shelter, and position where strong direct sunlight will produce heavy algal growth (Giwojna, Oct. 1996).
To feed these 1/4"-5/16" crustaceans to your fish, siphon water from around the rocks, shells, and gravel in the culture tank and strain it through a net to separate the Gammarus from the debris (Giwojna, Oct. 1996). Commonly known as side-swimmers, these hard-shelled amphipods have a herky-jerky, sidestroke swimming style that most large sea horses find irresistible (Giwojna, Oct. 1996). Their seemingly frantic movements and tendency to dart out from hiding suddenly seldom fail to trigger a sea horse’s feeding response, and this is one food hungry Hippocampines will actively pursue and search out. Some sea horses will even accept freshly killed or dead Gammarus (Giwojna, Oct. 1996). An ideal food: substantial enough to be your sea horses’ staple diet, if you can obtain it in sufficient quantity!
When mating, the male amphipod carries the smaller female grasped between its legs, a breeding method known as amplexus (Biology of Amphipods, 1996). Thus, when you see pairs swimming together while locked in amplexus, it’s a sure sign your amphipod colony is growing. The female subsequently releases the fertilized eggs into a ventral brood chamber where the unattached eggs are held by extra branches of her walking legs and incubated during development (Biology of Amphipods, 1996).
Unlike crab and shrimp larvae, baby amphipods are not released as zoea that develop into adults after several stages of metamorphosis (Biology of Amphipods, 1996). Instead, the young look like miniature versions of their parents when released, and some species even show parental care of their young after they leave the brood chamber (Biology of Amphipods, 1996).
Different types of amphipods move differently, depending on the arrangement of their legs. Most species can walk upright, scuttling along by using most of their thoracic legs, but this is a slow, rather cumbersome method of locomotion (Biology of Amphipods, 1996). Practicing their sidestroke and swimming along using three pairs of pleopods is much faster (Biology of Amphipods, 1996). But the true specialty of amphipods is the tail-flip, a rapid escape response where the abdomen flicks the animal away after the uropods are dug into the substrate (Biology of Amphipods, 1996). Terrestrial amphipods (scuds, sand fleas, beach hoppers, etc.) are especially adept at this startling maneuver. It is this variety of frantic movements and escape maneuvers that triggers the seahorse’s feeding response and makes amphipods so irresistible to Hippocampus. Seahorses love to hunt them!
Best of luck establishing an abundant supply of copepods and amphipods to supplement the diet of your seahorses and Mandarin Dragonet, Dean!
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