The Wolf of Water Street

Let's all take a vote on what fish is the most commonly misidentified and/or misnamed fish in aquarium keeping. While you mull over your answer, the correct one is Congrogadus subducens. Looks like an Eel, acts like a Blenny, and it gets called either and sometimes both and at least one common name calls it a Perch (Green Eel Perch). Spoiler alert, it's a Pseudochromis, the one thing it is pretty much never called. Depending on where you live you might call this fish any number of names like Carpet Conger, Mud Blenny, Daggerfish, Eared Eel, Launce, Mud Blenny, Ocellated Eel Blenny and the most popular two: Carpet Eel Blenny and Green Wolf Eel, though a staff favorite around here is Lurking Machete, how cool is that? Danny Trejo needs one of these.

Beyond its plethora of common misnomers, this is a very cool fish. They do look very eel like, and if you haven't seen one before, check these pictures out and maybe hit YouTube to watch a couple videos about them, they are one of the coolest and hardiest oddball fish around. In regard to other Pseudochromis or Blennies, The Green Wolf Eel/Blenny gets huge; there is no IGFA record for a hook and line capture, but the largest specimen ever collected was 18 inches tip to tail (much bigger than you are ever likely to achieve in your home aquarium). However, when compared to most commonly available Eels for the home aquarium, it is positively petite! They are usually some shades of green with brown camouflage, or vice versa, though nearly white ones have been recorded, and they are capable of a moderate level of color change to better hide in their environment.

If we take all this info and start designing an aquarium for them, the first box we need to check is one of size. Smaller individuals could be kept for quite a while in a 90-gallon tank, but 125 or 150 would be more suitable at full grow out, which is likely to be in the 12-to-15-inch range (bigger never hurts). The next portion is aquascape, the more places you make for your Green Wolf Eel/Blenny to hide, the more you'll see them, especially initially. I know it seems counter intuitive, but the more secure they feel, the bolder they are. They are great candidates for dark sand and rocks, which makes their colors really pop. They don't need sand and do just fine in bare bottom tanks as well. This tank should be covered, while these fish are not the escape artiste (chef's kiss) that most Eels are, they can find their way onto the floor if you don't cover that glass box.

Food wise, the Green Wolf Eel/Blenny has an appetite that lives up the expectations of the name. In the wild, this fish would be an ambush hunter, eating pretty much anything that moves as long as it fits in its mouth. This makes it pretty easy to feed in the home aquarium and they'll usually house down most thawed meaty food. When they are smaller, they'll do well on foods like Gamma Krill (Superba and Pacifica); Gamma also offers Whole Mussel, Whole Cockle and Whole Fish, and these are all perfect for Congrogadus subducens well into adulthood but may have to be cut down for younger individuals. Variety is important in their diet, and timing is infrequent. Until they are four or five inches long, you should feed them once a day, but after they hit six inches or so, these feedings should decrease. Monitor your fish's behavior and body. If they're getting plus sized and aren't that interested in meals, decrease frequency. If they're looking a bit skinny and their belly is more sunk in than usual, either increase the size of the meal, or the frequency of foods. If your fish aren't that interested in your offerings, try using a feeding stick to give some life to it. It's very rare that you'll need to offer live food, but for those of you with a clean source for live feeders like saltwater guppies, mollies or shrimp, this is always fun to watch! Once these fish associate you with food, they're going to be very excited to see you walk up to the tank!

Congrogadus subducens is the largest pseudochromis available and are excellent and resourceful hunters. This is a fish that can actually remove hermit crabs and snails from their shells and shrimp (yes, even cleaner shrimp) are a preferred food source. Small, slow or incautious fish that are housed with the Green Wolf Eel/Blenny have a high likelihood of ending up as dinner. In general, this is a fish that is going to get along fine with everything it doesn't see as food, and so can be kept with pretty much anything that is big enough or fast enough to stay away from it. They are low risk with corals, but as far as other invertebrates, plan on regularly restocking your cleanup crew.

We'd love to see a commercial aquacultured source for these but as of the writing of this, it hasn't happened for one reason or another. There are reports of them being bred in captivity by hobbyists in Germany, and many other aquacultured Pseudochromis are regularly available, so maybe here is your opportunity to break into commercial aquaculture! The Green Wolf Eel Blenny is an amazing Oddball fish. They're easy (and fun) to feed, they look cool, they're as hardy as a 90's Tacoma and are an “Eel” that you'll actually see swimming around the tank! (Once they're comfortable). Sound like a good match for your aquarium? Head over to your LFS and ask them about getting you a Congrogadus subducens from Quality Marine today!