Aquarium Fish: A Look at the Gobies
Despite the typically small size of its members, the family Gobiidae is the largest family of marine fishes, being the home of over 2,000 species. Of course, I won't be going over all of these, but I do want to give you an introduction to the family and cover some of the species most commonly seen in the hobby. After all, many (but certainly not all) are quite hardy and easy to care for, and many are attractive and/or have interesting behaviors. This is especially so when it comes to some of my personal favorites, the shrimp gobies.
Before getting into any specifics, I'll say that essentially all gobies live on or very near the bottom. So, you won't likely see one swimming around in the upper parts of your aquarium too often, unless their after some food. The vast majority also stay relatively small, as in less than four inches in length. Thus, many can make great additions to smaller aquariums, but their diminutive size may make them less appealing to some hobbyists, as they can easily be "lost" in large aquariums. Small gobies can also become expensive snacks for any larger predatory fishes in a tank, so they should probably be left out of any aquarium housing any such fishes, too. They're also prone to jumping out of tanks if they are harassed or spooked, so a glass top is a good idea, as well. But, there isn't much else of interest to say here though, as there are so many different types of gobies that it's difficult to make general statements about them. Many are sand sifters, some are cleaners, a few live with burrowing shrimps, etc. So, it's time to take a closer look...
The Sifter Gobies
When it comes to gobies, the sifters (also commonly called sleepers for some reason) can get relatively large, with some species reaching 6 or 7 inches in length. They're generally quite peaceful with other sorts of fishes though, so don't be worried about their size. They're also a hardy bunch and can be quite useful at times, too.
They feed on tiny sand-dwelling invertebrates, and collect them by scooping up mouthfuls of sand, which is also why they're often called sifters. They'll essentially make a shallow nose dive into sandy substrates, fill their mouth with sand, and then quickly sift through it in order to capture any edible organisms within it. The sorted sand is ejected through the gill slits behind the head, and then they'll take another scoop.
This feeding activity can help to keep the upper layer of a sand bed cleaner, but you should note that if you're trying to maintain a thriving deep sand bed, these fishes will indeed eat some of the beneficial organisms living in it. I've found that they don't really deplete a sand bed of critters if kept in a large enough system housing enough sand, but they can literally clean out a relatively shallow sand bed in a smaller aquarium.
Again, they usually get along fine with other types of fishes, but they may not get along so well with other species of sifters or other individuals of the same species, either. So, it's best to keep just one in a tank, or a mated pair, unless the tank is large and has plenty of room for everyone. They'll typically learn to take a variety of fish foods too, although some hobbyists have reported otherwise on occasion. I've had no problems keeping the two most common species Valenciennea puellaris and V. strigata, but can't say much for the others.
The Dragon Goby:
The dragon goby (or brownbarred goby, Amblygobius phalaena) is another one that can get big for a goby, sometimes reaching lengths of about 6 inches. This is another a sifter that also scoops up mouthfuls of sand and consumes the creatures living in it, and can thus help keep a sand bed clean, too.
Like the above, they should be kept one to a tank, although they're more likely to get along okay with other sorts of fishes, including other types of sifters, again as long as there's plenty of room for everyone. But, that's not always the case, as they never get along with other dragon gobies best as I can tell, unless they're kept as a mated pair.
The Rainford's Goby:
The Rainford's goby (or Old Glory goby, Amblygobius rainfordi), is a beautiful little fish, typically staying under 2.5 inches, but they're especially prone to die from starvation. I've also been told that they don't ship well, either. I've never tried keeping one myself due to the fact that everything I've heard/read about them indicates that they need to graze on green filamentous algae (hair algae) in order to thrive, or even survive. Hair algae is usually something that reef aquarists should try to avoid like the plague, so I think it's safe to say that this fish is a no-go for reef aquariums. Admittedly, I have read one report of a hobbyist that through persistence was able to get one to eat a few types of fish food (Michael, 2005). But, that's just one report.
Still, if you're into taking risks with the lives of fishes, note that these should be kept one per tank, or as mated pairs. However, with that said, Michael (2005) also reported that they usually occur singly, not in pairs, in the wild, and that he purchased a supposed mated pair that didn't get along at all. Just pick something else folks…
The Neon Gobies:
These predominantly Caribbean species are some of the smallest, staying under two inches, and are generally quite hardy "cleaners" that help keep other fishes at their best. Like the cleaner wrasses, these gobies will eat any parasites or dead skin they can find on another fish, which is why they're all called cleaners.
In the wild they tend to sit around at a "cleaning station", which may be operated by a single neon goby, but more often they're seen hanging around in pairs or in small groups where other fishes know to come for a good going over. These fishes looking for a cleaning recognize the neon gobies for what they are and refrain from harassing or eating them, and the gobies can get a meal out of the deal, of course.
These are far better choices than the cleaner wrasses though, because the wrasses oftentimes will not take any sort of fish foods offered and often end up starving to death in aquariums. To the contrary, the neon gobies will typically eat a variety of fish foods and can be kept with or without other fishes. So, they'll clean if they can, but won't starve if they can't.
The Clown Gobies
The clown gobies (or coral gobies) are also quite small, staying under 2.5 inches in length. In fact, the most common species (Gobiodon okinawae) doesn't even reach 1.5 inches, making them well-suited for life in very small tanks. They're brightly colored too, and typically won't bother anyone with the exception of other clown gobies.
Even though they don't get along well with other clown gobies when kept in confined quarters, if a number of them are kept in a large enough tank with plenty of rock and corals, they'll often pair up into male-female couples and will get along well from there. They also have an odd hangout, as they like to perch in the branches of stony corals like Acropora, but they don't do any harm to them.
About the only other thing to throw in is that they tend to be quite hardy and will eat a wide variety of fish foods, as long as the size is small enough. However, due to their smallness, it's obviously best to keep them with other small, peaceful fishes. Otherwise, they may be harassed by larger tankmates, and more aggressive fishes also tend to get all the food.
The Catalina Goby
Next is the Catalina goby (or blue-banded goby, Lythrypnus dalli) that hails from the waters off California and Baja Mexico, which is a problem for most of us. This is because these waters are much cooler than our reef aquariums, and even many non-reef marine aquariums. So, our tanks tend to be too warm for these gobies to live in, as they should be kept in the 50's to 60's Fahrenheit and shouldn't be kept at temperatures above the low 70's. I have heard reports of some hobbyists being able to keep them alive at higher temperatures, but I can't help but think they cannot be as healthy or live as long under such conditions. Sorry, but these are unsuitable choices for most us, despite their appearance and availability.
Still, if you have a relatively cool tank, this is another particularly small species (also typically less than two inches length), and several can be kept in one tank. They're actually territorial, but due to their diminutive size, even a 30 gallon tank can be considered plenty big enough to keep a few of them. Of course, you do have think about the other fishes in the tank, which will certainly be larger, and make sure that there's nothing that will harass these gobies. Oh, and they're typically easy to care for, as they'll take a variety of regular fish foods without issue.
The Shrimp Gobies:
The shrimp gobies (which belong to the genus Amblyeleotris, Cryptocentrus, or Stonogobiops) are also rather small in size, and they all live in close relationships with a number of pistol shrimps. These different animals help each other stay alive and well though, as the gobies have great eyesight, while the shrimps have very poor eyesight, but are excellent diggers. In fact, the shrimps can build and maintain burrows in sandy bottoms that are big enough for themselves and for one or more gobies, too. So, the basis of the relationship is that the goby watches out for any potential predators that come too close to the burrow or the shrimp, and will warn the shrimp that trouble is near, while the shrimp makes a home for both of them. I'll tell you more about this below, but for now I do need to point out that these fishes can be kept without shrimps, too.
Anyway, when they're kept with a shrimp, what you'll see is that the goby is usually out of the burrow, at least partially, but near its entrance, with the shrimp behind it. Sometimes the shrimp will venture out from the goby a few inches at the most while it's working on the burrow, but most of the time it stays close by and maintains physical contact with the goby by touching it with one of its antennae. In the event that the goby feels the need to warn the shrimp of any impending trouble, it'll wiggle its tail or body in a way that alerts the shrimp, and off it goes into the burrow with the goby typically following right behind.
They'll do this if a potential predator comes too close, but they'll oftentimes scram even when harmless fishes get too close at feeding time, or the goby will do just the opposite depending on the competition. I've got a goby/shrimp pair in my 125 gallon, and another in my 55 gallon, and neither of the gobies is a chicken. I've had others that were, though. I'll explain…
The gobies will both eat anything I put in the tank for fishes, but I've been feeding the shrimps with sinking food pellets for over a year now by using a long piece of rigid airline tubing to drop the pellets right into the burrows opening. Still, when my other fishes smell the pellets they go after them, too. Of course, they aren't after the gobies or the shrimps, but the gobies still send the shrimps scurrying away into the burrow. Then, in both tanks, the gobies will chase off the other fishes in an effort to protect the food pellets. They'll open their mouth as wide as possible and charge at the other fishes to fend them off.
Despite their going after other fishes trying for their companions' food, none of these gobies really cause any problems with other types of fishes. For the most part they ignore everyone else and mind their own business. Besides, most of these species get no bigger than three to five inches, and are rather skinny. So, they wouldn't pose much of a threat to anything but the smallest of fishes, anyway.
Unfortunately, the exception here is that some species don't care for other gobies, or other individuals of the same species in particular. While there are some that will actually share a burrow with other gobies of the same or other species, there are some that simply will not tolerate having another shrimp goby in the tank with them. These unsocial species will often go after each other relentlessly, until one is finally convinced to hide all time, or is literally run to death. However, there is an exception to the exception, as you may be lucky enough to come across a mated pair for sale, which should get along fine regardless of the species.
Anyway, back to burrows. While you may only see one or two small entrances to a burrow, they're actually much larger than you might expect. At first I wondered how they managed to keep such structures open in a bed of fine sand, but quickly realized that they're quite good at using little bits and pieces of coral rubble, shell, rock, etc. to reinforce the roof and sides of the burrow. They can stack and arrange all sorts of things in ways that give some permanence to the burrows, and constantly work to keep them in good shape.
With this in mind, it's essential to supply some rubble for a shrimp by placing a pile of such stuff near a burrow's entrance. I've provided them with the shells of deceased snails, a good amount of manually broken up pieces of clam shell from the beach, some small pieces (an inch or two) of coral skeleton of various shapes, and similarly sized bits of rock, and they sort through everything for use like a contractor building a stone fence would. Usually, surprisingly quickly, anything I put near a burrow is used somewhere out of sight never to be seen again, and I've provided a heck of a lot of material for them.
Still, at night the burrows' entrances usually cave in or are closed with the goby and shrimp safely inside. Then, when the lights come on, the shrimps quickly get back to work. They'll dig tirelessly during the day, moving sand around from place to place to clean out and re-open the entrances, and will usually keep it open until the lights go off again. In fact, they stay so busy that it seems as if they actually enjoy the work. They're fun to watch for sure, and I'd say that out of all the things in my aquariums, I spend more time watching the activities of my gobies and shrimps than anything else in the tanks.
If this sounds like something you'd enjoy too, do keep in mind that the gobies typically pair with only certain species of shrimp. So, you'll need to do some further homework before buying anything to make sure you get the right kinds together. If you look around enough, you may be able to buy them together though, which is what I had the good fortune to do in both cases. I'll also throw in that as far as marine fishes go, many gobies are being reared in captivity, and there are numerous such specimens available to us. So, if possible, shop for these in particular.
And that's your look at the gobies.
A bit about the shrimps:
These shrimps all belong the genus Alpheus, and are called pistol or snapping shrimps because they have a specially modified claw that they can use to make a little popping sound with. Not all of these associate with shrimp gobies, though. Some live alone and can get relatively large, and can make a pop that sounds pretty loud. In fact, I used to have one in a non-reef tank that was so loud I could hear it at night in my bedroom, even though the tank was in the den. It had to go. To the contrary, the species that pair up with gobies are all relatively small, and aren't so loud. In fact, I never hear my own shrimp making any noise at all. Why do they do it at all? Well, for the species that can really pop, this is a means of defense, as they try to scare away anything that gets too close by repeatedly popping their claw.
- Aquacultured Gobies: http://www.orafarm.com/gobies.html
- Gobiidae.com: http://www.gobiidae.com/
- Karplus, I. 1987. The association between gobiid fishes and burrowing alpheid shrimps. Oceanography and Marine Biology, Annual Revue, 25: 507-562.
- Michael, S. 2005. Aquarium Fish: Gobies of the Genus Amblygobius. Advanced Aquarist's Online Magazine: http://www.advancedaquarist.com/2005/3/fish
- Michael, S.W. 2001. Marine Fishes: 500+ Essential-to-Know Aquarium Species. T.F.H. Publications, Neptune City, NJ. 448pp.
- Schultz, H.C. 2004. You May Call Me 'Yasha', King of the Stonogobiops. Reefkeeping, 2(12): http://www.reefkeeping.com/issues/2004-01/hcs3/index.php
- The Shrimp Goby Chronicles: http://www.explorebiodiversity.com/Hawaii/Shrimp-goby/general/index.htm
- WetWebMedia: http://www.wetwebmedia.com/gobies.htm
- Wikipedia: http://en.wikipedia.org/wiki/Gobiidae