Congratulations on the new seahorses!
It’s a good idea to target feed your seahorses, just as you have been doing, JE, since that will minimize wastage and help keep the conditions in the tank sanitary, while allowing you to see for yourself how much each of the seahorses is getting to eat.
But it’s difficult to quantify how much of the smaller Hikari Mysis they should be eating each meal, since that depends on a number of different factors, including how big the seahorses are and whether or not they are juveniles that need all the calories they can get to sustain growth, or if they are sexually mature seahorses that are actively breeding and churning out brood after brood of babies. Seahorses that are breeding regularly also need all the calories they can get because the female devotes so many of her bodily resources to produce each clutch of eggs and the male expends so much energy nourishing and supporting the brood of fetal fry and embryonic young developing within his marsupium.
We will discuss some of these factors in more detail later in this message, JE, but, for now, I would just say to give each of your seahorses its fill of the Hikari Mysis twice a day. When you are target feeding them or handfeeding seahorses, it’s easy to see when they start taking the Mysis you offer them less greedily and enthusiastically, and start to become a little halfhearted about it. That’s a good indication that they’ve had their fill and you should discontinue the feeding session.
I’ve found that a seahorse’s appetite is a pretty good gauge of how much they need to eat. When they are really hungry, their actions make it known, and they can be capable of incredible feats of gluttony and sheer piggery. When they’ve had enough, they will be much more lackadaisical about how they pursue and slurp up the frozen Mysis when it drifts past their snouts.
Here are some general guidelines to keep in mind when feeding your seahorses, JE:
As you know, the feeding regimen that generally works best for most captive-bred seahorses is to provide each of them with 2-7 frozen Mysis relicta twice a day and then to fast your seahorses entirely once a week. In other words, your seahorses should each be eating a total of around 4-14 frozen Mysis each day, depending on the size of the seahorse and the size of the Mysis. But those are just rough guidelines and there is a lot of variation in how much Mysis healthy seahorses eat each day. (In your case, JE, the Hikari frozen Mysis are much smaller than the jumbo Mysis relicta, so you should multiply those figures by 2-3, depending on whether your ponies are still juveniles in the calories to grow, or if they are mature seahorses, whether or not they are actively breeding at the moment.)
A large seahorse naturally eats more than a smaller pony. And jumbo-sized Mysis will fill up a hungry seahorse faster than smaller shrimp. So a seahorse that’s scarfing up king-sized Piscine Energetics Mysis relicta does indeed need to eat fewer shrimp than a pony that’s dining on the tiny Hikari Mysis. (You’ll see what I mean when you get your PE frozen Mysis — it will probably be quite considerably larger than the Mysis you are using now. The feeding guidelines are based on the jumbo PE Mysis, so you can increase the number of Mysis you feed daily accordingly if you are using another brand of Mysis.)
Aside from size, some of the other factors that determine how much a seahorse eats are water temperature, the age of the seahorse, and whether or not it is actively breeding at the moment. The warmer the water temperature (within the seahorse’s comfort zone), the higher its metabolism, and the more calories it needs to eat as a result. Young seahorses that are still growing rapidly typically eat more than mature seahorses that have reached their full growth. As you might expect, breeding pairs that are producing brood after brood every few weeks need to eat a lot because so much of their bodily resources go towards producing clutches of eggs or nourishing a pouch full of developing young.
So don’t get hung up trying to count every morsel every seahorse in your tank scarfs down, JE. Just make sure all your seahorses have full bellies at the end of the day, as indicated by their well-rounded abdomens. After a good feeding, the seahorses belly rings should be flush or even slightly convex in cross section when viewed from head on.
Another good way to tell whether or not your seahorses are getting enough to eat is to check their fecal production. Seahorses that are producing well-formed fecal pellets throughout the day are getting good nourishment. (Seahorses that are not getting enough to eat will not be doing much pooping, and when they do, they will tend to produce white stringy feces rather than well-formed fecal pellets.)
I will send you an e-mail off list, JE, with an attached document for you to download and save on your computer so that you can read through it at your leisure. It’s a well illustrated article that discusses feeding seahorses with frozen Mysis in much detail, including all of the most helpful techniques (handfeeding, target feeding, and training the ponies to use a feeding station). You’ll find it to be useful and it should help answer any remaining questions you may have about feeding your new seahorses.
Best wishes with all your fishes, JE!
Pete Giwojna, Ocean Rider Tech Support