Re:Worried new mama

Dear Laurie:

It sounds like the decrease in appetite began when you switched from the smaller frozen Mysis to the jumbo PE Mysis relicta. If that’s the case, try switching back to the smaller frozen Mysis that they had been eating so well previously, and see if that makes a difference. (Some seahorses have very definite preferences regarding the size of the shrimp that they eat best. So if your new pair of seahorses seem to prefer the smaller Mysis, stick with that for the time being. Later, as they grow, the size preferences of your seahorses may change, and I expect that you will find they will eat the large PE frozen Mysis equally well once they mature. Just keep your PE Mysis frozen and it will last indefinitely.)

If the red feeder shrimp are proving to be too elusive and too adept at hiding to make easy prey, you might also consider crippling or disabling the live shrimp to slow it down and make it easier to target before you offer it to your seahorses. The most humane way to do this is to cool the live shrimp down so that it’s barely moving when you put it in the aquarium. Put several of the red feeder shrimp 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 a feeding response, but the red 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 accomplish the same thing by removing most of the shrimp’s legs to cripple it and slow it down. 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.

I agree with Loveless then it would also be a good idea to double check your water quality and it would be helpful if you can update me on your current aquarium parameters:

Ammonia (NH3/NH4+) =
Nitrite (N02) =
Nitrate (N03) =
pH =
specific gravity =
water temperature =

it might also be a good idea for you to check the dissolved oxygen levels in your aquarium, Laurie. Seahorses will become increasingly sluggish and lethargic when they are not getting enough oxygen. So low O2 and/or high CO2 levels could be one reason that they have become less active, and inadequate oxygen is also commonly associated with a loss of appetite.

If you would like to monitor the dissolved oxygen levels in your seahorse tank, which I recommend, the Tetra Oxygen Test Kit (TetraTest 02) is a good liquid reagent test kit for fresh or saltwater with simple color scales for comparing readings that tests for 02 in the range of 2-14 PPM. It will cost you between $8.50 to $14 depending on where you shop and should be available at any well-stocked LFS. Salifert also makes a nice 02 Test Kit (their 02 Profi-Test) that will run you about $20.

Either of those test kits fit the bill very well and are worthwhile investments for the seahorse keeper.

Dissolved Oxygen (02): Optimum level = 6 – 7 ppm

High levels of dissolved oxygen are vital to the well being of both fish and invertebrates. The key to maintaining high O2 levels in the aquarium is good circulation combined with surface agitation (Webber, 2004). Wet/dry trickle filters and protein skimmers facilitate efficient gas exchange and oxygenation. It is important for the hobbyist to monitor the dissolved oxygen levels in the aquarium because a drop in O2 levels is often an early indicator of impending trouble — a precursor of problems ahead. A drop in O2 levels will tip off the alert aquarist and allow corrective measures to be taken, nipping the problem in the bud before it adversely affects his seahorses. For example, a drop in O2 levels could be an early indicator of overcrowding — a signal that your system has reached its carrying capacity. Or it may merely signal a rise in the water temperature due to a summertime heat wave or indicate that the tank is overdue for a water change and/or a thorough cleaning to remove excess organics and accumulated detritus. Or it could be telling you that your tank is under circulated and you need to increase the surface agitation and water movement.

The point is that checking the O2 levels in your aquarium can alert you to impending problems and allow you to do something about them before they have dire consequences. A drop in O2 levels is often the first sign of a water quality problem and it can tip off the alert aquarist that trouble is brewing before his seahorses are gasping for air in obvious respiratory distress. Checking the dissolved oxygen levels regularly is the next best thing to continuously monitoring the Oxidation-Reduction Potential (ORP) or redox of the water, which is a luxury few hobbyists can afford.

So I would suggest that you purchase an inexpensive test kit for dissolved oxygen, Laurie. In the meantime, to be on the safe side, you can increase the surface agitation and aeration and in the aquarium in order to promote efficient gas exchange at the air/water interface and to provide better oxygenation. A simple airstone anchored just below the surface of the water is a quick, easy way to accomplish this.

It doesn’t sound like your new acquisitions are in dire straits, Laurie. As long as their abdomens are not sunken or pinched in, they are getting enough nourishment and are in no danger of starvation.

And it isn’t unusual for seahorse stallions to be a bit more sedentary than their mates. It is SOP for male seahorses to be somewhat less active than the females. Males tend to be real homebodies that will often choose one particular hitching post as their home base and spend much of there time perched right there (think of your Dad hunkered down in his favorite easy chair in the den). Researchers studying seahorses in the field therefore refer to males as "site-specific" because they can be found at the same tiny patch of reef or seagrass day after day, rarely straying from their chosen spot. Mature males are often naturally more shy and retiring than females, which can be quite brazen at times. I suspect this is due to their parental duties — during the breeding season, pair-bonded males are ordinarily ALWAYS pregnant, and they can’t risk exposing their precious cargo to any more risk than absolutely necessary.) The unfettered females tend to be far more footloose and fancy free, and in the wild they typically roam over a home territory of up to 100 square meters. So I wouldn’t worry if your male only tends to wander around the tank on occasion, whereas your female is more active and explores more.

In summation, I would suggest switching back to the smaller frozen Mysis to see if that makes a difference in the eating habits of your ponies. If that doesn’t work, try crippling some of the red feeder shrimp so they will be easy to catch and your stallion can get a good meal. And increase the surface agitation and aeration to make sure that your dissolved oxygen levels are nice and high.

Best of luck getting your newcomers eating like horses again, Laurie! Please let me know your current aquarium parameters at your earliest convenience.

Respectfully,
Pete Giwojna