No, sir, I think a watchman goby (with or without a symbiont pistol shrimp) would make a fine companion for red banded pipefish (Doryrhamphus dactyliophorus) and/or Ocean Rider seahorses.
I know a number of home hobbyists who have kept seahorses and pipefish successfully with a watchman goby (or a watchman goby/by fish combo) without any serious competition for food. The watchman goby is primarily a bottom feeder whereas the pipefish prefer to take their prey while it is still suspended in the water column and the seahorses will quickly learn to take their meals of frozen Mysis from an elevated feeding station, with no interference from the watchman goby at all.
The key to keeping seahorses and pipefish well fed in a community tank with other fish such as watchman goby is to target feed the ponies and pipes, as explained below in more detail, Don:
For captive-bred seahorses, which eat enriched frozen mysis as their staple diet, it is customary to feed the more active fish and inverts their fill of standard aquarium foods first, and then target feed the seahorses with frozen mysis, using the feeding wand or baster to discourage any fishes that might try to steal a bite while the seahorses are eating (Delbeek, Oct. 2001). This works quite well providing the fishes are suitable tankmates for seahorses.
That’s SOP for many seahorse keepers and is not much different than the situation in a species tank when one of your seahorses is an aggressive eater with an insatiable appetite that tends to monopolize the feeding station, and one of your other seahorses is a deliberate feeder that has to examine every morsel of Mysis forever before he finally eats it. Hardly an insurmountable problem — just hand feed or target feed the seahorses, as described below, and the problem is solved.
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 are 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. And it’s great for tapping on the cover to ringing the dinner bell and summon the diners for their gourmet feast!)
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.
In short, Don, I would not hesitate to add a watchman goby to an aquarium that includes seahorses and/or pipefish. Just make sure to quarantine the watchmen goby beforehand to make sure it is healthy and be prepared to target feed the ponies and pipefish, as explained above, and everything should go smoothly.
Pete Giwojna, Ocean Rider Tech Support