Re:Reidi not eating

Dear Sindy:

Okay, that all sounds very good. A partial water change should help and the live Mysis are very hard for even the most fastidious feeders to resist.

Yes, I would perform a series of small partial water changes, perhaps one every other day until the seahorses are eating again.

No, don’t put all of the live mysids into the aquarium at once. The seahorses might gorge themselves and then proceed to hunt and kill the remaining Mysis even after they are stuffed to the gills and can’t swallow another bite. With irresistible live prey, sometimes the seahorses can’t resist stalking and striking at the live shrimp even after they’re filled to capacity. When that happens, they will slurp up the live shrimp only to spit it out again immediately afterwards, and repeat the process until the shrimp is dead and has stopped moving. Then they’ll move on to the next live shrimp and repeat the process even know they are so full they can’t actually consume the prey they have just killed.

To prevent that from happening and makes the live mysids last as long as possible, you’ll want to set them up in a separate tank or bucket of their own, and then dole them out a little at a time. For two Brazilian seahorses (Hippocampus reidi), I would suggest adding about 10-12 of the live Mysis twice a day, assuming they eat the first batch greedily, which I expect will happen. That will be plenty to sustain the seahorses and keep them healthy while you are working on weaning them back on to the frozen food again.

Yes, you can try mixing a little of the frozen Mysis in with the live mysids to see if they seahorses will go ahead and eat the frozen shrimp as well as the live ones. Just add the frozen shrimp sparingly and if it goes on uneaten, be sure to remove any leftovers promptly so that they don’t begin to degrade your water quality or get slurped up after they have begun to spoil.

For best results, Sindy, try imparting a little movement to the frozen Mysis to make it appear as if it’s alive and kicking. Many times seahorses that don’t seem to be interested in the frozen food while it isn’t moving and being swirled around can be tricked into eating it by making it moves. You can overcome that problem very easily by target feeding your seahorses with a baster, as described below. The baster can be used to impart movement to the frozen Mysis by dangling them from the tip of the baster enticingly, and then releasing them right in front of the seahorses snouts. If the seahorses don’t snap them up while they are drifting down through the water right in front of their noses, then you can use the baster to gently blow or swirl the frozen Mysis around a bit after it has settled on the bottom to attract their interest. This usually works like a charm. Here is some additional information on target feeding seahorses with a baster that should give you a better idea of how to proceed, Sindy:

Target Feeding

The individual personalities of seahorses naturally extend to their feeding habits. Some are aggressive feeders that will boldly snatch food from your fingers, while some and shy and secretive, feeding only when they think they’re not being observed. Some like to slurp up Mysis while it’s swirling through the water column, and some will only take Mysis off the bottom of the tank. Some are voracious pigs that greedily scarf up everything in sight, and some are slow, deliberate feeders that painstakingly examine every morsel of Mysis before they accept or reject it. Some eat like horses and some eat like birds. So how does the seahorse keeper make sure all his charges are getting enough to eat at mealtime? How does the hobbyist keep the aggressive eaters from scarfing up all the mouth-watering Mysis before the slower feeders get their fair share? And how can you keep active fishes and inverts with seahorses without the faster fishes gobbling up all the goodies before the slowpoke seahorses can grab a mouthful?
Target feeding is the answer. Target feeding just means offering a single piece of Mysis to one particular seahorse, and then watching to see whether or not the ‘horse you targeted actually eats the shrimp. Feeding each of your seahorses in turn that way makes it easy to keep track of exactly how much each of your specimens is eating.
There are many different ways to target feed seahorses. Most methods involve using a long utensil of some sort to wave the Mysis temptingly in front of the chosen seahorse; once you’re sure this has attracted his interest, the Mysis is released so it drifts down enticingly right before the seahorse’s snout. Most of the time, the seahorse will snatch it up as it drifts by or snap it up as soon as it hits the bottom.
A great number of utensils work well for target feeding. I’ve seen hobbyists use everything from chopsticks to extra long tweezers and hemostats or forceps to homemade pipettes fashioned from a length of rigid plastic tubing. As for myself, I prefer handfeeding when I target feed a particular seahorse.
But no doubt the all-time favorite implement for target feeding seahorses is the old-fashioned turkey baster. The old-fashioned ones with the glass barrels work best because the seahorses can see the Mysis inside the baster all the way as it moves down the barrel and out the tip. By exerting just the right amount of pressure on the bulb, great precision is possible when target feeding with a turkey baster. By squeezing and releasing the bulb ever so slightly, a skillful target feeder can keep a piece of Mysis dancing at the very tip of the baster indefinitely, and hold the tempting morsel right in front of the seahorse’s mouth as long as necessary. Or if the seahorse rejects the Mysis the first time it drifts by, a baster makes it easy to deftly suck up the shrimp from the bottom so it can be offered to the target again. In the same way, the baster makes it a simple matter to clean any remaining leftovers after a feeding session. (You’ll quickly discover the feeding tube is also indispensable for tapping away pesky fish and invertebrates that threaten to steal the tempting tidbit before an indecisive seahorse can snatch it up.)
In short, target feeding allows the hobbyist to assure that each of his seahorses gets enough to eat without overfeeding or underfeeding the tank. And it makes it possible to keep seahorses in a community tank with more active fishes that would ordinarily out-compete them for food, since the aquarist can personally deliver each mouthful to the seahorses while keeping more aggressive specimens at bay.
The key to keeping active specimens like firefish or cleaner shrimp successfully with seahorses is to feed the other fish and inverts with standard, off-the-shelf aquarium foods first, and once they’ve had their fill, then target feed the seahorses.

Here is some additional information on culturing the live Mysis in case you would like to try maintaining them long term in order to supplement your seahorses’ diet. It’s an excerpt from my new book (Complete Guide to the Greater Seahorses in the Aquarium, unpublished) that discusses the pros and cons of live Mysis, and outlines one method for culturing them that is suitable for the home hobbyist:

MYSIDS (Opossum Shrimp)

Pros:
• Excellent food value.
• A favorite natural food that all large seahorses attack greedily.
• Thrives in saltwater: feed and forget — will survive until eaten.
• Can be easily collected at times.
• Cultured Mysis are available.

Cons:
• Challenging to culture for the home hobbyist.
• Inland hobbyists have no opportunity to collect them.

Collecting Tips:
Mysis shrimp follow a daily rhythm in their movements, regularly forming dense shoals over sandy bottoms or amidst seaweeds, and they can sometimes be collected in vast numbers while shoaling by seining or dragging a large aquarium net through mats of vegetation (Giwojna, Oct. 1996). Look for a shallow, sandy, weedy area at low tide during the day, and you can often see them swimming in the weeds or settling on the sand. If there is a significant current, they will congregate in slack water areas on the down-current side of objects. Once you have spotted a likely location, return at dusk when they are more active and net them as described above (Bentley, 2002).

A large net with very fine mesh works best for collecting mysids. I suggest a net with a mouth at least a foot square and mesh less than 1 mm square (Bentley, 2002).

Likewise, mysids are sometimes concentrated in large numbers in tidal pools on mudflats and grassflats by the falling tide. The stranded Mysis can easily be netted from these pools at low tide.

Culture Instructions (Bentley, 2002):

Specific gravity: 1.016 for estuarine species;
pH: 7.8-8.3 (reproduction stops if the pH falls lower than 7.4);
Photoperiod: 14 hours of daylight provided by two Gro-lux fluorescent tubes.
Temperature: 77 degrees F (25 degrees C)

The following guidelines are based on Maureen Bentley’s methods for culturing Mysis (Bentley, 2002). The main culture tank should be large, well aerated, and heavily filtered. I suggest undergravel filtration in conjunction with external biological filters. Mysids are extremely sensitive to water quality, and a good protein skimmer is vital for this reason (Bentley, 2002). Natural seawater is much preferable to artificial, and if you are using a synthetic mix, it’s best to allow the artificial saltwater to age at least one month before use (Bentley, 2002).

When stocking the main tank, introduce the shrimp gradually until you’ve reached a density of about 20-40 adults per gallon (Bentley, 2002). Overcrowding leads to fighting and dead broodstock. If you notice lots of mysids jumping out of the water, the tank is very likely overstocked (Bentley, 2002).

Small quantities of mysids can be harvested daily using a small glass tank equipped with an air-operated undergravel filter. Place 15 to 20 large gravid females in the small tank, returning them to the main tank as soon as they have released their young (Bentley, 2002). (Mysis are cannibalistic and the young must be separated from the adults.) The young can then be raised in the small tank for a short period.

Feed them newly hatched Artemia nauplii or rotifers twice daily until they are a few days old (Bentley, 2002). After a few days, begin supplementing their feedings with marine flake food on occasion, especially brine shrimp flake food (Bentley, 2002).

A feeding frenzy will follow the introduction of live food, which can help you determine the right amount to feed. When fed the proper amount, this frenzy should last around 15 minutes, during which all the live food should be eaten (Bentley, 2002). You will know you have fed enough when the normally transparent mysids have orange stomachs after feeding on the baby brine shrimp (Bentley, 2002). If the adults — especially the males — start eating numbers of the younger Mysis, that’s a sure sign of underfeeding (Bentley, 2002).

Comments:
Mysidacea, or Opossum Shrimps, are found worldwide. They are small shrimplike crustaceans with a heavy carapace covering their thorax. They are commonly called opossum shrimp because the females carrying their developing young in a bulging pouch or marsupium formed by thoracic plates at the base of their legs (Giwojna, Oct. 1996). The average life span is about 12 months and adult mysids seldom exceed 1 inch in length. At least 460 Mysis species are found around the world (Bentley, 2002), and wherever opossum shrimp occur, they form a large part of the indigenous seahorses’ natural diet. They are snapped up greedily by even the most finicky syngnathids, including the fabulous but delicate Seadragons (Phycodorus and Phyllopteryx sp.). In fact, large seahorses are so fond of these crustaceans that they scarf up frozen Mysids with relish. This is superb food that should form the basis of your seahorses’ diet if you can possibly obtain it–live, fresh, or frozen (Giwojna, Oct. 1996).

So that’s one method of going about it, Sindy. If you search the Net, you’ll find scads of information on culturing Mysis, which should give you a pretty good idea whether or not it’s practical in your case. For example, he sure to check out the following to online articles:

http://www.syngnathid.org/articles/mysisCulturing.html
http://www.seahorse.org/library/articles/mysisCulturing.shtml

Best of luck getting your finicky H. reidi back onto a staple diet of frozen Mysis, Sindy!

Respectfully,
Pete Giwojna