Dear arcprolife:
Yes, sir, if your aquarium has been up and running for six months then it should be stable enough for Harlequin shrimp (Hymenocera spp.) or other decorative shrimp. You will be feeding them with starfish that you add to the aquarium every couple of weeks, so as long as you can maintain optimum water quality and stable conditions, they should do fine. When you bring the Harlequins home from your LFS, drip acclimate them over a period of several hours for best results.
As for the starfish, the Harlequin shrimp must be able to overturn the sea star in order to control it and expose their tube feet, which they will normally feed on first in order to immobilize their prey. If the starfish is too large, it may be too heavy or cling to the substrate too tenaciously for the ornate little Harlequins to upend. When that’s the case, the starfish can thwart the Harlequins and evade them. A good-sized chocolate chip starfish may be too big and powerful for them to overcome.
Harlequin shrimp could certainly handle any of the Linkia or Fromia starfish, which are no threat to your seahorses in any case, but you don’t need to serve up the colorful, exotic sea stars for their dinner, which would be a costly waste. I always fed my Harlequins with the common, ordinary, nondescript sea stars from my LFS that were always cheap and readily available. They are just the common brownish to tannish or orangeish seastars that come in to any pet store that keeps marine fish in shipments from Florida or the Caribbean or wherever, often as unwanted add-ins or throw ins. Look for a regular starfish of average size, say with an arm span 3-4 inches across, and they should fill the bill nicely. (Avoid the serpent starfish or brittle stars — you want a common sea star with tubefeet.)
Even though it’s only intended as prey for the Harlequin shrimp, drip acclimate the sea star to your seahorse tank over a period of hours so that it stays lively and healthy. Harlequin shrimp aren’t scavengers. They don’t eat dead, decaying starfish are other decomposing organic matter — they prey only on living starfish, which they consume in such a manner that they remain alive so their food stays fresh.
The Harlequin shrimp will track down and overpower a suitable starfish fairly soon after it it’s added to their tank, but they are cautious and deliberate when they do so. The pair of shrimp work together and pry up one or more of the sea star’s arms, which they use as leverage to overturn their victim. Once the sea star has been upended so they can control it, they will often take it back to a sheltered spot where they can feed on it at their leisure, beginning with the tubefeet on the underside of its arms. If the starfish is crawling on the glass beyond their reach, it is perfectly safe. They can only handle starfish when they are on the bottom of the aquarium.
Best of luck finding a beautiful pair of Harlequin shrimp and inexpensive, suitable starfish for them to feed upon.
Happy Trails!
Pete Giwojna
Ocean Rider, Inc. is an Organic Hawaiian-Based Seahorse Aqua-Farm & Aquarium that Follows Strict Good Farming Practices in Raising Seahorses and Other Aquatic Life.
