Should I Keep My Shrimp Goby With a Pistol Shrimp?

From yashas to yellow watchmen: the shrimp gobies include some of the best-looking and iconic reef species in the saltwater aquarium hobby. In the wild, these fish maintain symbiotic relationships with pistol shrimp of the family Alphidae. But what about in your aquarium? Should you keep your shrimp goby with one of these snapping shrimp, or will it do just as well on its own?

Below, let’s first find out how this unlikely pairing actually works before going over the pros and cons of keeping your shrimp goby with a pistol shrimp. Hint: these two are definitely better off together!

Why do gobies and pistol shrimp like each other so much?

Sometimes two really are better than one. When predators lurk around every corner like they do on the reef, a solid security system makes the difference between life and death. But what to do when you can’t see very well? Or when you have no real means of defending yourself? The solution is obvious: find someone whose strengths are your weaknesses.

Shrimp or prawn gobies and their pistol shrimp partners may sound like unusual roommates, but they actually make a perfect match. The goby has much better eyesight than the shrimp, but is practically defenseless; the shrimp packs some serious heat but doesn’t really know where to aim without assistance. That means they’re much better off together than alone.

The sentry & the gunslinger

This dynamic duo is incredibly finely tuned to each other, their symbiosis including multiple tasks for each species. Safety is, of course, the priority. Any potential intruders are quickly spotted by the goby. Because the shrimp never strays far — it maintains tactile contact with its fish friend most of the time — a quick flick of the tail fin or raising of an oversized dorsal fin is enough to warn of approaching danger.

When confronted with a possible predator or intruder, both the shrimp and the goby usually first opt for flight. If hiding alone isn’t enough, though, the shrimp can dispatch the enemy (or at least send it fleeing for its life) using its oversized snapping claw.

We could dedicate an entire article to how a pistol shrimp’s fascinating underwater gun works, but the basic gist is that it produces powerful cavitation bubbles. These bubbles form when the pressure of a liquid drops low enough to turn it into a vapor. The vaporization causes the liquid to instantly boil and then implode within milliseconds, generating a shock wave.

Cavitation bubbles are actually a common headache in underwater engineering, but the shrimp produces them on purpose using a special hinge in its oversized claw. As with a real pistol, a hammer joint snaps into place, creating and ejecting the “bullet” with an audible POP!. It can be deadly to small prey and sends larger predators packing with a pounding headache.

Once the coast is clear, the goby pops back out of the burrow to return to its surveillance duties or busy itself foraging. Pistol shrimp are perfectly capable of catching their own meals using their built-in firearms — larger specimens can kill fish as well as crustaceans, using their antennae rather than their eyes to locate prey — but they do also rely on their roommates bringing them part of their daily meals.

The shrimp will quickly scoop up any small scraps of food the goby brings to the burrow. No problem if the meal comes predigested, either: goby feces features prominently on the menu. Pistol shrimp have been observed to be pretty bold about the rules of sharing, taking freshly caught prey right out of their partner’s mouth without any negative reaction from the goby.

The goby has good reason to be generous, as those food scraps are traded for luxury housing most reef inhabitants can only dream of. The pistol shrimp takes care of digging an elaborate burrow for the dream team to inhabit, ensuring their shared abode stays in tiptop shape at all times. It will also occasionally clean the goby of ectoparasites, ridding it of itchiness while catching a free meal for itself.

Did you know? The shared burrow can become pretty crowded if both goby and shrimp bring their partner. And that’s not all: goby-shrimp assemblages can include various additional hangers-on. One recorded combo included a porcellanid crab freeloader, which seemed to benefit from the burrow and its sentinel without actually contributing much itself. This is called a commensal, rather than symbiotic, relationship.

Three way symbiosis between a goby, a shrimp, and a crab (2016)

Does my shrimp goby need a pistol shrimp?

Or does your pistol shrimp need a shrimp goby? Hah!

The short answer? No. Both the goby and the shrimp are capable of surviving on their own. This being said, we highly recommend keeping them as a duo — for your sake as well as theirs.

The most important reason to keep these two together is that they’re visibly happier when paired with their natural partners. Solo shrimp gobies in particular are known to become skittish and reclusive. With no burrow to retreat into and no bodyguard to shoot intruders, they spend most of their time wedged into rudimentary hides like rock cracks and overhangs.

Aside from the welfare aspect, getting to observe fascinating ocean symbioses in your own home is one of the main reasons reef keeping became popular in the first place. Just ask Nemo and his anemone! It really is a treat to see how well these two drastically different creatures understand each other. We’ve even observed little domestic squabbles, with the goby seemingly getting tired of the shrimp’s constant touching.

If you’re worried about a pistol-carrying shrimp potentially causing damage, rest assured. Unlike mantis shrimp, those other underwater gunslingers, pistol shrimp are very polite and not known to break aquarium glass or cause mayhem. They’re also hardy and beginner-proof, which actually makes them one of the better shrimp species for new reef keepers.

We can only think of two potential disadvantages of keeping your prawn goby with a shrimp. The first is that larger pistol shrimp can pose a danger to small crustaceans, particularly shrimp and especially those that might roam the substrate at night. This problem can be mostly prevented by getting a shrimp on the smaller end of the Alpheus spectrum, like A. randalli.

The second potential issue is the pistol shrimp’s incessant tunneling, which is fascinating to watch but can also become problematic when hardscape starts shifting. Gluing live rock directly to the bottom of the tank is an excellent idea. So is growing out small coral frags well away from the substrate, because pistol shrimp really aren’t picky about what they drag into their burrows to reinforce those tunnel walls.

How to pair a shrimp goby and pistol shrimp

If this is your first time keeping one of these dynamic duos, your best bet is to get one goby and one shrimp. This prevents any risk of intra-goby territorial squabbles (the males of most shrimp goby species can’t stand the sight of each other). A mated goby pair also works, but given the males and females are almost identical, there’s always a risk of running into trouble later on.

Keep in mind that not all pistol shrimp available in the hobby will pair with gobies. Some Alpheus, like the stunning bullseye shrimp (A. soror), prefer ridin’ solo. Others, like the hefty bigclaw snapping shrimp (A. heterochaelis), are actually more likely to eat a goby than settle into domestic life with it!

Of the pistol shrimp to be found in your local aquarium store, your best bets are:

• Randall’s pistol shrimp (A. randalli). It’s small, polite, and has candy cane stripes. 10/10 on the shrimp scale and the exclusive choice of yasha gobies in the wild.
• Tiger pistol shrimp (A. bellulus). Larger and sporting a beautiful marbled white-and-brown pattern, these commonly accompany yellow watchman gobies — but they’re far from picky.

In the same vein, not all gobies in the hobby will pair with shrimp. Diamond gobies and other sand-sifters don’t need a bodyguard, thank you very much, nor do tiny coral dwellers like yellow clown gobies. Even names can be deceiving: the spectacular flaming prawn goby was originally assumed to partake in this symbiosis, but actually lives alone.

Your best bet for a true shrimp goby is a fish in the genus Cryptocentrus, Amblyeleotris, or Stonogobiops. If you don’t want to go for the standard pairings mentioned above, make sure you get the right shrimp for the right goby — some are more specific about their partners than others.

If your goby already has a buddy when you buy it, you can simply bring the shrimp home as well. If it doesn’t, no problem either: compatible species are highly aware they belong together and rarely have trouble finding each other. Shrimp added at a later stage will often scurry straight into the goby’s hide as soon as they’re released.

Don’t panic if the duo you just brought home instantly disappears into a hide and doesn’t come out again for a while. They’re known to need a few days or even weeks to settle in, sometimes emerging well after they’ve already been declared dead. You can drop their meals at the front door!

Tip: Nothing in the aquarium hobby has a 100% success rate, not even goby-shrimp pairings. Sometimes they temporarily break up and get back together later, and we’ve seen gobies straight-up throwing newly introduced pistol shrimp from their hides. Things usually settle down after a few days or weeks, though. True violence between compatible species is very rare.

Conclusion

Although keeping shrimp gobies and pistol shrimp together isn’t essential to their survival, it’s highly recommended. You’ll love seeing these two vastly different creatures work, eat, rest, and squabble together.

Like the idea of displaying a fascinating reef symbiosis in your home or office, but lack the time or expertise to set up a goby-shrimp biotope? That’s where we come in. Contact FantaSEA Aquariums and we’ll make your wildest aquarium dreams come true.