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FAQs on  Tire Track Spiny Eels

Related Articles: Spiny Eels The truth about spiny eels; A closer look at these popular but problematic oddballs by Neale Monks, Husbandry of the Barred Spiny Eel, Macrognathus panacalus by Marco Lichtenberger, 

Related FAQs: Spiny Eel Identification, Spiny Eel Behavior, Spiny Eel Compatibility, Spiny Eel Selection, Spiny Eel Systems, Spiny Eel Feeding, Spiny Eel Disease, Spiny Eel Reproduction,


Tire track eel with what I thought were scrapes     9/28/13
I have a one year old approx foot long tire track eel. He lives in a 125 with a group of rope fish a Senegal and three juvenile pair of Eartheaters.
The tank has two hob filters and two sponge filters due to the eel and the geo's need for clean water. The parameters are all spot on.
<Meaning what, precisely? Tyre-Track eels are best kept in neutral to slightly basic, moderately hard water; some would say slightly brackish conditions are useful too.>
The tank has been running for two years no problems.
My eel takes to pushing rocks around and making a ruckus. So we put bigger rocks we thought he wouldn't be able to move. And even siliconed them together with aquarium safe of course. But he woke me up the other night flinging rocks around and the next morning he had a white patch an the end of his nose and a patch on his side that looked like scuffs. I put him into a 40g hospital tank to be sure I can keep the tank star clean as to prevent infection. Now there is a spot of red in the center of the scrape on his side. Just looks like the scraped skin came off.
He is very active and friendly still not acting weird n any way but that he isn't eating. But I don't know if that is cus of the move or not.
I have treated him with a half dose off furan 2 because I was unsure if he needed or would be sensitive to medication. Any advice would be greatly appreciated.
Thank you,  Timbra
<Antibiotics are generally safe with Spiny Eels (certainly safer than copper and formalin) and should be used promptly where indicated. Spiny Eels often get damaged in tanks with rocks and gravel; they should be kept in tanks with smooth ornaments (ceramic tubes are great) and either very fine gravel or (ideally) sand. Once their skin is damaged, secondary infections are very common -- and often fatal. The addition of tonic salt at about 2 gram/litre seems to be useful and is often recommended. Ropefish and most cichlids will tolerate this just fine. Do read:    http://www.wetwebmedia.com/ca/volume_4/v4i3/Spiny_Eels/Spiny%20Eels.htm
And follow the links. Most problems with Spiny Eels are best avoided rather than treated. Cheers, Neale.>

Tyre track eel     9/30/13
This is my buddy we have been chatting about. As you know the Internet is almost useless when researching these guys to any major extent. He was sold to me as a tire track but I have always been skeptical of whether that is right or no. I have another eel the same size that is the typical dark brown reddish tire track you see and he just isn't the same. Any input?
Thanks a ton.
<Ah yes, it is one of the species sold as "Tyre-Track Eel" but precise species could be difficult to pin down. Often we call this fish Mastacembelus armatus, but another species, Mastacembelus favus, is very similar in size and shape, but with somewhat different markings. There are likely some other similar species, subspecies and/or regional variants. On the plus side, they're all very similar. Big (to 70 cm), predatory (made the mistake of keeping one with Swordtails!), somewhat jumpy (prone to escaping from aquaria), and arguably best kept in very slightly saline conditions (1-2 gram tonic salt/litre of water).>
P.s. that was the first day and he actually is looking much better. Still no appetite though. Well see.
<Indeed. Does seem to be an external bacterial infection. If at all possible remove to an aquarium without any ornaments or sand except for a ceramic pot, but failing that, do medicate appropriately (Maracyn 1 and Maracyn 2 would be a good combination) and keep water quality excellent.
Cheers, Neale.>
Re: Tyre track eel     9/30/13

Thanks for the info. It's much appreciated. That was the morning I woke to find him sick. He had since been moved to a bare bottom hospital tank with his pot. His course of meds is almost done and the spot on his nose is gone and the one on his side is all but gone. And his appetite is back with a vengeance lol. Thank you again for your help. You are a credit to the hobby.
<Thanks for the kind words, and hope this fishy friend gets well soon!

Cloudy eyes in my tire track eel, no data       9/5/12
I Just purchased a medium sized tire track eel about three days ago. The second day I noticed that her eyes were very cloudy then today I noticed they were puffy.
<Mmm, water quality? Often Mastacembelids have their sensitive eyes scraped in being netted, moved...>
 She is still swimming around, and she actually ate half a night crawler yesterday which surprised me because I know they are hard to get to eat.
<Actually; not this species>
I took my water to be tested at three different places and each one told me the same thing, "your water is perfect, nothing is wrong with the ammonia, nitrates, or the PH." I called the store where I got her and told them the situation and they told me, and I quote,  "that it is probably a change in PH and her eyes were burned".
<Need values, not subjective statements>
 I told them that I had my water tested three times and that nothing was wrong and they said "Well bring the water here and we will test it for you." What that tells me is that they are just trying to cover themselves, so now since I can obviously rule out help from them, I am turning to you guys for advise on what to do. She is a beautiful girl and I would hate to lose her so I'll do anything. The place I got her from kept her in a tiny ten gallon tank with two other tire track eels and a catfish of some sort, and yes they actually had them on gravel! I have a non abrasive sand in my tank so she can't hurt herself, but I know that she had some abrasions on her nose when I got her home. I am at a loss for what to do at this point, any advise you can give me will be extremely helpful and appreciated. I have attached some photo's of her below just so that you can see what she looks like.
<.... Please read here:
and the linked files above. Bob Fenner>
Re: Cloudy eyes in my tire track eel    9/5/12

I have already read all of these, and none of that is happening to her. Its just her eyes.
<I see>
 I was told today that it could be a fungus
<Not likely a true fungus... much more likely a bacterial infection...>
 so I started treatment, but I'm not so sure because she has no other areas that concern me. What would you do?
<Nothing treatment wise. IF this were a wholesale/producer operation w/ many animals involved I might treat w/ soluble Oxytetracycline and a bit of aquarium salt. BobF>

add Figure 8 Puffer to tank? 11/10/10
Hi, Crew,
I have a 90 gallon low-end brackish tank, sg fluctuates between 1.003 and 1.005. I inherited a disparate group of fish about a year ago that I've been trying to accommodate. In this particular tank, I have one archer (Toxotes jaculatrix), a tire track eel and a fire eel. The eels are both 8" long. The eels seem to tolerate the salinity--do you think this will be OK long-term? Conversely, do you think the archer will be happy in this level of salinity? The archer seems very happy at the moment (it's probably about 1 year old). I realize I'm compromising a bit from either side of the salinity scale with these fish. Next, I have a scourge of Malaysian trumpet snails in this tank. I am toying with getting a figure 8 puffer for the tank because 1) I love puffers and I understand figure 8's are low-end brackish and less aggressive than other puffers; 2) I don't see much in the tank at any given moment except for the archer because the eels hide; 3) I would like to control the snail population.
Is this a bad idea?
Thanks for your help in advance. I appreciate your time.
<Hello Laura. Tyre-track Eels will certainly do okay at up to SG 1.005 at 25 C, but Fire Eels I'm less certain on, and I'd tend to nudge the salinity down to about 1.003 at 25 C. The Archer shouldn't mind, and that'll still be salty enough for a wide range of species, both true brackish water fish and salt-tolerant freshwater fish such as Brown Hoplo Catfish, Horseface Loaches and virtually all of the livebearers. Now, as for Figure-8 puffers, while this might work, I think you'll be disappointed at the impact they'll have on Melanoides snails. You'd be much better off with Assassin Snails, Clea helena, which should acclimate to SG 1.003 without problems given they're members of a marine snail family, though I've never tried it
myself. They're cheap enough that trying them out won't be expensive. Allow 3-4 Assassin Snails per 10 gallons if you want them to exist in sufficient strength to depress Melanoides snail numbers. The thing with puffers in general is that they won't eat snails if softer, easier food is on offer -- and that can sometimes mean the fins of other fish. Plus, the small size of Figure-8 puffers makes them easy prey for adult Archer Fish, Tyre-track Eels and Fire Eels. Obviously an adult Fire Eel will need a tank bigger tan ninety gallons, so you may be planning to rehome him as/when he gets above a certain size. But an adult Archer fish could swallow a Figure-8 puffer in one gulp! Do not underestimate how predatory Archer fish -- sure, they enjoy eating insects, but they are dedicated fish-eaters as well. Finally, do understand that Melanoides snails are not in themselves harmful, but they are indicators of aquarium conditions rich in organic matter. It may well be that your tank is less clean than you think, and you're overfeeding your fish far more than you suppose, and if you have a lot of algae, then adding fast-growing plant species might make a difference. Treat snails as a symptom, not a problem, and it's much easier to effect a long term
solution. Cheers, Neale.>
Re: add Figure 8 Puffer to tank? 11/10/10

Thanks, Neale!
I sure wasn't thinking about the Archer going after the Puffer, so thanks for that! (I actually saw the Archer eat one of the snails the other day, but I figured that was an anomaly.)
I'll check out Assassin Snails. Luckily I don't have algae in this tank, but I am trying to find the right amount of food/feeding times for the eels.
I've probably been overfeeding the eels. They seem so temperamental and unpredictable. I understand they shouldn't eat every day and will sometimes go for a couple of weeks without eating, but this makes me nervous! I don't want them to starve. I probably just need to calm down about it!
By the way, I searched but couldn't find how long it takes for a fire eel to reach full size--do you know?
Thanks again,
<Hello Laura. Fire Eels growth rate varies with age, but specimens under a year old can add about an inch in length per month. Growth slows down a bit after that, but you can expect yours to be at least a couple of feet long within 18 months, and nearer three feet by the end of the second year. If the Fire Eel was stunted for whatever reason while it was younger, it will grow quite slowly, and may never reach its full size, fish growth rate being determined by age, not the need to reach a certain size. This is why some people find their Fire Eels get really big, really fast while others find their Fire Eels quite slow growing fish. A bigger problem will be aggression: all the Mastacembelus species are territorial, and Fire Eels and Tyre-track Eels are unlikely to coexist in a relatively small tank, Fire Eels in particular being notoriously grumpy fish. Look out for unusual white marks on their bodies indicative of fighting. Sometimes juveniles get along well, even sharing caves, but do be aware than this situation may not persist. When feeding predators, the "art" is providing enough that their bellies are gently rounded, but not obviously swollen; if the latter is the case, you fed too much in one sitting! Earthworms are the best food for Spiny Eels, but they sometimes escape into the sand, and when they die there, you'll get lots of nitrate and phosphate in the water you don't want, as well as food for Melanoides snails. Best to feed little but often, rather than gorging the fish a few times per week. Cheers, Neale.>
Re: add Figure 8 Puffer to tank?  11/11/10

Thanks, Neale, this is very helpful indeed. I think I may start looking to re-home the fire eel now.
<Glad to help. Cheers, Neale.>

Questions about tire-track eels 10/10/08
I have a tire track eel who loves his bloodworms. His tank mates also enjoy those instead of the brine shrimp and other goodies I feed them. Yesterday, I decided that hand feeding the eel would be a better idea and he readily took the frozen cube. What I'm worried about - when I look at him closely, the end of his long nose has what looks like a stinger or curved needle (sort of like a fine thorn) at the end. Can or will it hurt my fingers/hand should he accidentally stab me with it when I hand feed him.
<This will not hurt, its quite soft tissue. Ive never been bitten by a larger spiny eel and guess it will not hurt much, either. In contrast to some African members, the Asian spiny eels dont have teeth on their palatines and the vomer is toothless, too.>
I had previously written about tank mate compatibility, asking about your thoughts on adding tiger barbs. The fish I had concerned over eating them didn't really care. The eel ate 5 out of the six over a two day time period. He had never eaten live food, but eating tiger barbs whole and alive were apparently a great meal to him. There is one lone barb who he eyes, but leaves alone. It strikes me as odd that he, or his tank mates, haven't finished the final barb off.
<Yes, they can easily swallow fish of the size of a tiger barb and larger ones once they are grown. Tiger barbs like all minnows and carps are no good food fish for your eel. To fatty and containing a vitamin destroying enzyme. Earthworms are loved by spiny eels in general.>
Is there a way to tell the gender on an eel? I'm just curious on how an eel reproduces.
<Yes, but its difficult. Adult females exhibit a larger protruding anal tube, called urinogenital papilla, used to lay eggs. Youll need some experience an a very calm specimen to determine sex this way for sure. Females are generally larger (greater girth) than the males. If you got two adults of equal age next to each other it is possible to tell if they are of opposite sex and who is who. For breeding also see http://www.wetwebmedia.com/ca/volume_4/v4i3/Spiny_Eels/Spiny%20Eels.htm and the FAQs, at least for smaller spiny eels its possible.>
One of my Plecos, who is rather large seems like sucking on the eel once in a while, and the eel lets him. Is this normal?
<Yes, their skin mucous seems to taste well. Too much sucking theoretically can harm the eel, so he needs to have the possibility to bury or hide himself if he wants, too. Also, if you see any sores or discolorations Id separate them.>
Thanks and have a great weekend. Skye.
<Will try, have a great weekend, too. Marco.>

Earthworms 'N' Eels - 03/07/2006 This is just a note for those eel lovers or those wanting to embrace the eel so to speak.   <.... I might pet one, but hugging is maybe not quite in my plans.> A couple of years ago I bought 4 eels for my hundred gallon aquarium.  Two fire eels and two tire track.  Sadly someone left the lid on the tank askew and I lost one a couple of weeks ago.   <Aww!  So sorry to hear this!> It was about 18 inches long.  I still have three left that are about that size, one is a good 23 inches long.  They share the aquarium with a sun catfish, a drift wood cat, a tiny (but extremely swift) zebra loach, a very fat clown loach which I bought at the same time (he's a good 10 inches long) a spotted perch, a dojo and a pair of spotted catfish that act like they're on crack.  I love my eels but let future eel owners be warned, they'll eat you out of house and home.  They pick at flake food in the morning, ah but at night they go through 3 of the large cubes of frozen blood worms  and whine for more.  I'm thinking that someday in the future I will find just one very enormous eel in that tank, all other fish having become snacks.  Do you know if eels might eat fishing worms?   <Yep.  Especially at that size.  I recommend culturing your own, to be sure they are in good health and nutrition.  Google "vermiculture".  You can start with worms in your own yard, provided you haven't used any pesticides, herbicides, etc.> I'm curious but haven't tried offering any.   <I'm sure they'd love 'em.  Try small worms, not big fat Nightcrawlers.> I was kind of hoping that the larger worms might just fill the tanks up a bit quicker.  Luckily I can say that none of them have had an ailment in the years I've had them. (knock on wood) and I don't want to encourage anything a live food might bring in.   <Agreed.> So if you have any information on earthworms for eels please let me know.  It would be much appreciated.    <I say give it a try - I've seen even smallish (<8" or so) spiny eels take small worms.> Thanks Jo <All the best to you,  -Sabrina>

Purchasing some spiny eels I was thinking about purchasing some spiny eels from an online store. Is it wise to have a striped peacock, a Zig Zag, and a fire eel all in the same tank? <Not problematical in terms of them getting along, feeding/foods, having different habitats if this is what you mean> Also, the site I was planning on ordering from said that spiny eels eventually needed 29 gallon tanks... but I read about people having to put them in 100 gallon tanks, what's the minimum size I can have for one and does it affect what size of tank I need if I have one of each of the aforementioned spiny eels? <Mmm, at least a hundred for the Fire Eel... gets quite large over time, in good health... the others could live in 29 gallon systems (well-covered!). Please read here: http://www.wetwebmedia.com/FWSubWebIndex/matacembelids.htm and the Related FAQs (linked, in blue, at top)>   I read that the eels will eat crustaceans, so I assume a blue crayfish would be a bad tank mate...  Is it wise to order online?  Or would you suggest going to a local breeder or distributor?  Thanks in advance. <Both sources could work... or be trouble. The spiny eels are quite tough if cared for well, and doomed if not... Seeing them ahead of purchase is definitely a bonus, better start if you can find, order them locally. Bob Fenner>

Ghosts, Knives and something else So how many of each Corys and/or loaches? <Say four to six Corys or three or four loaches. But as I said the loaches will get too big in time. You may have to trade them in at some point. And what are your thoughts on a tire track eel? <A tire track eel will get over 2 feet. Recommend min tank size is over 100 gallons. Don> Nicole

Boiled Eel.. >Hi, >>Hello. >Wow incredible site. >>Thank you. >My sister has a tire track eel and it's sick, it has boils (?) on its back. That's how she described it to me. >>Sounds like ulcers, an open sore is my take on it.  This isn't good, though. >What might it be and how can we fix it? >>We see ulcers of this type most commonly on goldfish.  It's called septicemia (see here: http://www.fishbase.org/Diseases/DiseasesSummary2.cfm?discode=809 ) >Do you have any good references for info on curing disease/sick tire track eels? >>Not specific to tire track eels, but you can also search for treatments for SCALELESS fishes. >I read on your site that if it has sores it's likely to die soon? >>Maybe not so soon, but these afflictions can be very difficult to deal with.  It should NOT be treated in the main display, however. >She's very found of this eel as she says it has a lot of personality! >>I'm sure it does, and if you can, search further on http://www.fishdisease.net/ as well as looking for freshwater fish forums and sites.  Because these infections can by caused by many bacteria, treatment is rather like "blasting" with antibiotics.  Marina >Thanks, Cindy

Tiretrack Eels 10/14/03 They have not had an appetite for 3 weeks and I am getting worried so please can any one that is an expert on them please help me. <I really could use more info.  These are Tiretrack eels?  How long have you had them?  What kind of food have you offered  them?  How big is their tank?  What are their tankmates?  Have you tested the water?  How often do you change the water?  After you answer all of these questions I'll be much better equipped to help your fish.  Just to let you know, the only food I have ever seen my eels eat is live Tubifex/black/bloodworms.> and if there is a phone #  I could call to give more detail please tell me. <I'm sorry, we have no phone service.  Emails to this address is the best we can do.> thanks Jeff  <Your Welcome, Pufferpunk>

My zigzag eels mated, babies? >I just received a call at the office from my wife and my 7 year old daughter, informing me that we have at least a couple of 1/2" long zigzags in the 90 community tank. Hopefully I can catch 1 or 2 before they get sucked into the filter or eaten by the local residents.   >>Fish you *didn't* know were in the system? >Any advice? Should I try and locate/relocate the nest if the rest of the eggs have not hatched? I don't see too much advice.   >>Boy, you're not kidding!  I'm having a devil of a time finding info, too. >If anyone is trying to breed these eels, here is the environment: 90 Gallon AGA 40W Daylight Tube Smooth small river rock type gravel Artificial plants, tall and short Several caves made from slate, as well as many other nooks and crannies. Light on from 6:30AM to 8:30PM PH 6.6 Temperature:  77F Hardness: I forget the number, but it is VERY low. (long island, NY soft, acidic water) Nitrites: 0 Ammonia:  0 Nitrates: < 5ppm Tank Location:  Den where 7 and 9 yr old kids fight and play Nintendo. :-) Besides the 2 zigzags (about 6"), the tank has: 1 Black Ghost Knife (6-7") 1 Fire Eel    9" 5 Congo Barbs 2" 4 Pearl Gouramis 3.5" 5 Red Serpae 1.25" 1 Fat 6" brown (turning yellow) Oranda (don't ask) 1 Male Golden Gourami >>This is a toughie, to get the little ones out (who have survived being eggs and larvae thus far) you'd probably have to tear apart the tank.  Truthfully, I think that if Mom and Dad have gotten down already, they're going to go at it again.  I, personally, would wait and see.  Maybe provide some tubes long enough and thin enough that only *they* can get into, to help along their chances of survival.  Otherwise, I'd leave them be, unless you wish to remove Mom and Dad to their own breeding tank.  If you do that, this may upset their readiness to breed, but if you carefully recreate same conditions, and add the benefits of no food competition and start offering live foods (try to remember if you had done any large water changes, any changing tank parameters, etc. to help figure out what induced spawning) chances are you'll get lucky again with these fish. >Thanks for your help and keep up the great work! >>Quite welcome, and best of luck!  Marina

My zigzag eels mated, babies? >Hi Marina, >>Good morning, Bruce. Thank you for your advice. I only saw one of the little guys, less than an inch long and very wispy. About all I could find on their breeding is that they lay about 800-1000 eggs.  Based on the size, I would hazard to guess that maybe he was a month old. >>Well, my thoughts are these: first, if *any* of the larvae have survived those initial stages, that's a great sign.  One thing you don't want is to end up with a tank full of eels that you can't house or find homes for. >Looking back, I cannot think of anything out of the ordinary. I have an eclipse 25 with 2 blue diamonds and 20 or so Neons that get a 50% water change twice per week, so while I have the hose out, I give the 90 gallon a 25% change. Filtration is a pair of Eheim 2217's. I also have two air pumps, one on a wand, the other on a stone as I keep the tank pretty well sealed due to having eels. ;-) All of this is on a battery backup. As far as food goes, I feed flake (Tetra Color) in the AM and late PM. After lights out, I feed Hikari frozen bloodworms (the only ones that they and the fire eel will eat) and beef heart. I will keep a log now of water stats, water changes, and feeding. >>It can only help.  And, if there's someone else out there with the eels breeding, or a breeder even, hopefully they'll pipe up and offer some more information.  In any event, I say if it ain't broke, don't fix it. >BTW, your site is great and I have found it a great resource. I am 44 now. When I was a kid I had a few  tanks. I got back into it when it was our turn to take home the kindergarten goldfish about 5 years ago. Went out and bought the eclipse, and then this February, the 90 AGA. My wife isn't a fish fan, but my kids (both with special needs) love it, so she will on occasion put some flake in! Once again, thank you for all of your help and advice. I will continue to be a daily visitor to your site. >>Very good to hear/know.  Glad the site is of such service, too.  Again, best of luck, Bruce.  Marina

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