Saltcorner: Article: Goats in My Aquariums

These fish belong in the “Order Perciformes” and “Suborder Percoidei” as members of the “Family Mullidae” (Goatfishes), which consists of 6 genera, containing at least 35 described species. Most hail from the Indo-Pacific or the Eastern Pacific region, however, there are some found in the Atlantic Ocean, in both tropical and semi-temperate waters.

In the wild, these fish mostly live in areas containing soft substrates, and because of that, favor shallow protected bays and lagoons where sand, rubble, and/or mud collects. Most species are difficult to identify using morphological features alone, however, color variations do help, especially for those who are not trained scientists. Their diet consists mainly of benthic invertebrate such as shrimp, worms, small brittle stars, and crabs. They generally have elongated bodies with large scales, a small mouth, and have two strong barbels/whiskers on their chin, which are used for digging and sensing prey in various substrates and crevices. In fact, each barbell can individually be moved, helping to quickly located buried prey in either direction. Their anterior and posterior dorsal fins are set wide apart, with the caudal fin deeply forked.

Since their diet mainly consists of benthic invertebrates, they often overturn small pieces of rubble to expose concealed prey. In aquaria this sometimes causes stress, both to its inhabitants and the aquarist when the target is small corals and clams! Nevertheless, they are generally peaceful, yet some will also feed upon small fish. Most younger/smaller specimens make good sand stirrers. In aquariums they should be offered a meaty diet consisting of various types of chopped/graded fresh and frozen marine fish and crustacean flesh, and if possible, live grass/ghost shrimp.

Even though there are many different species entering the trade, past experience has shown only a few species in two genera make suitable specimens for hobbyist aquariums, i.e., Parupeneus and Pseudupeneus. Therefore, the real useable choices are quite limited in the present aquarium trade. And as to ‘other’ species than those discussed here, care must be taken to identify those newcomers before placing them in your aquaria since most can get far too large for anything but a large aquarium, i.e., over 125 gallon aquarium. Besides, many can or will become ‘fish’ eaters as they grow to maturity, and that could lead to a diminished head count in your aquarium! So be careful when choosing a goatfish specimen for your aquarium and do the necessary research before putting it your aquarium!

In fact, I’ve found only a few suitable for aquariums under 100 gallons! And because of that, have only kept only four species over the past 15 years, Parupeneus barberinoides, P. cyclostomus, P. multifasciatus, and Pseudupeneus maculates. And even though I had good success with them all, that still doesn’t mean I’d recommend keeping Parupeneus cyclostomus, which I’ll explain more about further on in this article.

My favorite is Parupeneus barberinoides, which is usually called the Bicolor Goatfish or Half-and-Half Goatfish. I’ve also seen the name Swarthyheaded Goatfish! It hails from Moluccas and the Philippines, west to Samoa and north to the Ryukyu Islands, and south to New Caledonia and Tonga. In the wild it is usually found in lagoons, seagrass beds or on reef faces and reef fore-slopes. Yet prefers the protected places where sand and rubble collects, and worms and crabs are plentiful. It’s about the smallest of goatfish that show up in aquarium shops, and generally gets no bigger than about 9 inches (22.5 cm) in the wild. Yet most seen in the trade are about half this size. I’ve had this species in several different size aquariums, from 75 gallons to 180 gallons. All were reef systems with either plenums or sandbeds that were no deeper than a few inches (7 cm) directly on their bottoms. Keep in mind that if a goatfish is going to be kept, it should be where there is sufficient substrate, as almost all of these fish constantly search the sand for food.

With the keeping of my first specimen, I found it had a fondness for sinking shrimp pellets. I would drop about a dozen small pellets in the aquarium and within seconds, the fish was turning them over and over, taking in the material as it softened. In fact, it would occasionally swim away for a few minutes, then return to gobble up a little more food. Since they have a high metabolism rate, I tried to feed several times a day. I also grated different types of frozen fish and shrimp flesh so as to obtain the right size morsels, however, other fish usually got most of that before it could reach the bottom. Yet, it did help provide a more varied diet for the fish, which it seemed to enjoy when it could reach the tasty morsels. However, once it came to realize that this type foodstuff was entering the water, it sometimes became a high water feeder, mixing with the other fish when feeding time came about. It also fed on fortified live brine shrimp occasionally, which was nothing more than a special treat for the entire fish population. And even though it would occasionally cruise the different live rock formations in the aquarium and disturb clam mantles causing them to close, it never bothered other fish and basically was a very good tankmate.

I’ve also had P. multifasciatus, the Manybar Goatfish, which hails from Christmas Island to the Hawaiian, Marquesas, and Tuamotus Islands, north to southern Japan and south to Lord Howe and Rapa Islands. In the wild its found in lagoons, seagrass beds, back reefs, reef faces, and fore-reef slopes where sand and rubble collects. It feeds almost entirely on crabs and shrimp. Except for size, as this species gets to about 12 inches (30 cm) in the wild, I did not find much difference in maintaining it than the above-mentioned species. It was kept in a 100-gallon old fashion invertebrate tank with a deep sandbed, much macroalgae, some mushroom corals, and a wide variety of different fish. It really liked digging deeply into the bed, and often caused large swirls of detritus to be swept up into the bulk water, which I really didn’t mind as some was drawn off into the overflow, or fed some of the mushroom corals in the aquarium.

As for its diet, I did try something different in feeding it, as I occasionally fed it a small earthworm. I use to have a small bait shop near that home where that tank was set up and would stop by once and while to a pick out a ‘single,’ small earthworm. The shop owner would just laugh when I walked in, and say ‘help yourself!’ If there were other customers in the store, they gave me odd looks when I walked out with one worm! And as a side note, neither the owner nor I would tell anybody what I was doing with only one small worm. We just enjoyed mystifying everybody! I would then clean the worm by rolling a wooden pencil over its entire length, thereby forcing out its gut contents, which were mostly dirt, then place it near the fish. After I did this a few times, I could swear I saw a smile on the face of that fish after it gobbled up that worm. I should note this was an “occasional” treat, usually once a month, as I preferred to feed marine flesh since it’s a healthier foodstuff. I found this species to also be easy to care for and a good tankmate.

Probably the only goatfish I didn’t have great success with was P. cyclostomus, the Yellowsaddle or Yellow Goatfish, which I purchased about ten years ago. This species hails from the Red Sea to the Hawaniian, Marquesan and Tuamotu Islands, north to the Ryukyu Islands, and south to New Caledonia and Rapa Islands. In the wild it’s found in lagoons, and on reef faces and reef fore slopes where sand and coral rubble collect. What I didn’t know about the species when I bought it was that in the wild, besides ‘occasionally’ consuming worms, shrimp, and crabs, it eats small fish! I purchased a small specimen, about 4 inches (10 cm). In the wild, it can get to 20 inches (50 cm). Actually, I wanted a different species, but this was the only ‘goatfish’ species available when I went shopping. Anyway, it went into 125-gallon fish only tank with a shallow, about two inches (5 cm) deep, sandbed. This was a somewhat crowded tank and its sandbed required vacuuming at least monthly to keep in clean looking. So I thought I’d try a goatfish to continuously stir the shallow bed in the hope some of its detritus would enter the water column and get carried off to the systems overflow and get filtered out. Well, that’s not the way it went, as this goatfish thinks it’s a regular fish and mostly liked to swim with the other fish in the aquarium, not search through the sand for a meal. In fact, it would generally feed no different than the other fish in the aquarium and paid little or no attention to the sandbed. Even though it turned out to be a good tankmate, probably because it was too small at that time to eat any of my other small fish, it didn’t behave like other goatfish, which was a disappointment. About a year later, it was returned to the shop where I purchased it and was given credit towards another purchase.

Another somewhat small, about 11 inches (28 cm), is the Spotted Goatfish Pseudupeneus maculatus. Its an Atlantic Ocean species, and hails from areas as far north as New Jersey and south to Bermuda, and then further south to Brazil. In the wild it tends to inhabit lagoons, reef faces and reef fore-slopes where it feeds mainly on crabs, shrimp, and worms. Juveniles are usually found in seagrass beds. I tried one in a 180-gallon reef system along with a Bicolor Goatfish. Even though all its food and environmental requirements were the same, it did not like its goatfish tankmate. Not that they fought, they just chased each other sometimes, but it never resulted in any damage to either fish. It could have simply been defense of its own feeding territory, but was quite annoying for its tankmates and me, as they would zip around and dive through crevices disturbing some corals. Otherwise, it was a peaceful fish and did not bother its other tankmates and also enjoyed sinking shrimp pellets.

Well, if you’re looking for a fish to stir the bottom sand, three out of the above four are a good choice! They were easy to maintain, yet did require frequent feedings as they all have a high metabolism rate. In addition, they all did well in average water quality conditions and were peaceful fish. Yet keep in mind, they are mostly bottom fish and should not be kept with aggressive fish such as moray ells, most triggerfish, and anything else that might pick on a slower moving species. Furthermore, they may feed upon prized tubeworms, small ornamental shrimp, small sea stars/brittle stars and small bottom dwelling fish such as dragonets and/or gobies. In addition, they cannot be trusted in aquariums containing clams, as they might just get a taste for clam meat someday!

Otherwise, they are good sand stirrers, helping to keep sandbeds looking somewhat clean. The only overall minor drawback is that I’ve found them to reduce some of the more valuable infauna in my sandbeds. To overcome that I tried feeding them as often as feasible, which met with a variable degree of success. But I think the good far out weighed the downside and was happy with three of four above-mentioned species. I’ve also found, if possible, it’s better to attain most as juveniles, as there is a greater possibility they will adapt to available aquarium foods. As for Parupeneus cyclostomus, it would be a species that I would ‘not’ try again as it did not fit in with what I expected from a goatfish species.

References and recommended sources:

Kuiter, Rudie H. 1993. Coastal Fishes of South-Eastern Australia. University of Hawaii Press, Honolulu, Hawaii.

Debelius, Helmut & Kuiter, Rudie H. 1994. Southeast Asia Tropical Fish Guide. Tetra-Press, Melle, Germany.

Michael, Scott W. 1999. Marine Fishes, A PocketExpert Guide, Microcosm, Shelburne, VT.

Michael, Scott W. 2004. Angelfishes & Butterflyfishes, Vol. 3., Microcosm, Shelburne, VT.

Goats in My Aquariums

Authored by: Bob Goemans