Is There Such A Thing As A Freshwater Moray?

[Marine/Freshwater?]

I'd really like to post this under the pinned topic section. If somebody could put it there or tell me how to put it there it would be greatly appreciated. Also feel free to make suggestions.


There are many true eels that aren’t restricted to saltwater environments . Some are only tolerant of freshwater. However the commonly offered "spiny eels" are not true eels at all. One of the major red flags that proves you don’t have a true eel is the presence of gill flaps or the absence of protruding nostrils . If you are curious about whether or not your pet eel is tolerant of freshwater check it out on fishbase.org . Fishbase.org is a great site for information about the classification of fish. In this thread I will include information on several commonly encountered eels, and some other eel like fish that occasionally turn up in brackish aquaria.

First of all you need to understand the taxonomy of the order Anguilliformes in order to determine the salinity requirements of the different species of eels you will encounter as an aquarist. Anguilliformes is the order of all true eels . Under the order, classification wise is the family. There are 15 families of true eels. Some that you might be familiar with include Snake eels, Moray eels, Spaghetti eels and of course the Freshwater eels. There is an entire family of eels called freshwater eels that look similar to conger eels that live in freshwater and spawn in saltwater. All of the eels in that family can be found in freshwater. In addition there are many species freshwater and brackish eels in other eel families. For example, Gynothorax Tile (commonly called the Freshwater moray, really brackish though.), Strophidon sathete (Gangentic River Moray.), Pisodonophis boro (Rice Paddy Snake eel, freshwater,brackish,marine).

Below are several species of brackish eels available that I think are worth mentioning:

HARDY,HUNGRY (Gymnothorax tile) Freshwater Moray- Often mislabeled as Gymnothorax polyuradon. This is dusky tan to brown colored eel that is covered with metallic gold flecks. It is the most commonly sold "Freshwater Moray". It in fact requires a salinity of 1.010+ to live a long healthy life. It can live for 15+years and grow to at least 36" or 90cm. when properly cared for.

SUPER RARE (Gymnothorax polyuradon) River Moray- An extremely rare moray Gymnothorax polyuradon is yellow or white with large black spots that resemble a leopard. This species is said to be much less hardy than Gymnothorax tile. This is why it is less likely to survive transport. However hypothetically (if anyone could actually keep it alive) would tolerate freshwater. Being on the safe side the salinity that they could be kept at should be near 1.005 but no higher than 1.018. Only known to reach 24" or 60 cm.

DOESN'T EAT OTHER FISH (Echidna leucotaenia) White Face Moray- I often see pictures of this fish labeled as Echidna rhodochilus. Echidna rhodochilus is known as the Pink Lipped Moray. This eel resembles the marine Snowflake Moray (Echidna nebulosa) in shape and acts similarly. It is an overall burgundy or brown with white marks on its lips. This is not as easy to care for as Gymnothorax tile, but an advantage is it will likely ignore fish. It only eats crustaceans. It needs a salinity of at least 1.010 and appreciates marine conditions. It grows to 18" or 75cm.

VERY FRAGILE (Uropterygius concolor) Ghost Eel, Unicolor Snake Moray, Ghost Ribbon Eel- Rarely encountered as a marine fish. It is a shimmer silver color with a white edged dorsal fin. It also appears to have black dots on its face. This is a very petite slender eel. It is often sold in a saltwater settling, however it can be kept at salinities as low as 1.015. Acclimate it slowly to high end brackish. Warning: it can be easily confused with several saltwater only look alikes. These include: (Gymnothorax albimarginatus) White Margin Moray, (Gymnothorax phasmatodes) Ghost Moray, (Pseudechidna brummeri) White-ribbon Eel.

Non-eels for brackish aquaria-

(Mastacembelus sp.) Spiny Eels- Very good fishes to keep. No real complaints about spiny eels just don’t trust them with small fish, also get a tight fitting cover. They seem to have a suicidal fixation with the garbage disposal. Apparently likes to jump. One of my friends used to have a Fire eel that would end up in the garbage disposal once a month until he moved his tank off of the kitchen counter. Spiny eels don't really belong in brackish aquaria. They do tolerate a higher P.H., 8.0 and seem to appreciate small amounts of salt but anything over 1.005 would be damaging. Spiny eels do not and will never belong in the same tank as a Freshwater Moray. Totally different water parameters.



NOT AN EEL BUT IS QUITE HARDY (Congrogadus subducens) Green Wolf Eel-really a Pseudochromiod (dottyback). Salinity between 1.010-marine. Good choice for beginners but really bad about eating its neighbors. Good match for medium and large Gymnothorax tile, not babies though.

EVIL, KEEP ISOLATED, WIEGHT DOWN COVER Swamp eel- One fish I really hate, but I would recommend it for those who will keep it alone. They look similar to morays but they have gill flaps. They are often a molted brown color like a really sick Freshwater Moray. They are always getting sold at my LFS as Freshwater Morays. They are Really, Really, Really , Really , Really , Really Mean! It bit me when it was taking it out of the bag and putting it in my fish tank. Then it KILLED all my fish, it was very aggressive it bit anything that moved it did not even eat anything it killed. It bit fish that were twice the size of it head and taste tested anything that moved. I was glad I kept the receipt. Swamp eels would make great pets, but keep them by themselves in a large tank. Most species can’t tolerate saltwater. They are very hardy and strong. They even have auxiliary breathing organs. Be sure to weight down the cover they love to take long walks in the park. Don’t use your Algebra book though. I had to explain to the bookkeeper how my fish knocked my book in the tank. WARNING: some species get huge!

GOOD EATER (Plotosus lineatus )Striped Eel Catfish does not look that much like an eel but I like it. Black with horizontal white stripes. WARNING it has some pretty lethal venom on its dorsal spines so watch out, they really do hurt. It can live in water with a salinity no lower than 1.015. It is able to tolerate freshwater as an adult but a salinity of 1.015 would be good long term. You can find more about this fishes feeding, and habits elsewhere.

In closing I must say don't ever trust what pet shops say! Google or better yet look the fish species up on Fishbase.org. Do not be intimidated into buying a fish that you are not familiar with.

 

[chibi]

If you want it pinned, I suggest giving it a more user-friendly structure, bolding names and important things, and check spelling.

 

[andywg]

And also don't post it in two different forums.

 

[nmonks]

Looks good to me, though I'm personally not wild about animations all over essays. But that's just me...

A few general comments. Firstly, how about breaking this up into Species Index profiles for that section? There's a nice format used there that allows users to quickly locate key bits of information such as diet and water chemistry. The only rule is that you've kept the fish described, but assuming you have, the moderators are pretty good about uploading new index entries.

In terms of formatting, I think it's better to create headings and subheadings rather than to use bold typeface or capital letters, both of which *make stuff harder to read*. So for example, you might do something like this:

Brackish water eels
Moray eels
Some text about moray eels

• Species 1
• Species 2

Spaghetti eels
Some text about spaghetti eels

• Species 1
• Species 2

This way, people can immediately see the structure of the essay, and the easier something is to read, the more information they will extract from it. Capital letters are the single worst way to write anything, and bold letters are only marginally better because they obscure the bits of each letter that make them identifiable.

Always check your grammar. There are meant to be spaces after commas, for example. Grammar isn't about pleasing schoolteachers and pedants. Grammar makes stuff easier to read. And, as said before, the easier something is to read, the more readily the information contained is absorbed. Simple as that.

Also check spellings. If you're giving scientific ("Latin") names, make sure they are spelled correctly. It's "Gymnothorax polyuranodon" for example, not "Gymnothorax polyuradon". If someone visits Fishbase and enters an incorrect name, it doesn't suggest similar names, it just says it can't find the species. So pre-empt this by giving the right spelling.

As for the science. I'm not convinced Gymnothorax polyuranodon cannot tolerate higher salt concentrations than SG 1.018. According to Fishbase, the species is found in marine habitats. It is also said to be catadromous, that is, spawns in the sea. As for Echidna spp. not attacking other fish, that's the theory, but in reality even if they are predators on crustaceans and molluscs in the wild, in aquaria they can and will eat small fish given the chance. So I'd tend to moderate any statements as to its community tank credentials with the proviso that it should be kept with fast, robust tankmates of similar size. Monos and scats would be good, guppies and gobies would not.

It's also worth using scientific language if you're aiming for a scientific analysis. Saying that spiny eels have a "suicidal fixation with the garbage disposal" is meaningless. I get the joke, but it isn't a statement of fact. All it means is that oftentimes people end up with dead spiny eels because they keep them wrong. Spiny eels jump out of tanks, they wiggle out of cracks, they are difficult to feed, and they are very sensitive to poor water quality and skin infections, all of which adds up to a shockingly high mortality in captivity. Highlight the specific problems and offer solutions. In this case, Macrognathus spp. especially should be given a tank with no gaps or escape routes; floating plants for comfort; soft substrate for digging (not gravel, ever); live foods on import and wet frozen foods once settled in; and no benthic tankmates likely to steal their food. Spiny eels have their place is the brackish water aquarium, but only the low-end ones suited to things like BBGs, glassfish, halfbeaks, brackish water barbs, etc.

Likewise, swamp eels really don't "love to take long walks in the park" and the venom on eel-catfish isn't "lethal".

Hope this helps,

Neale

 

[poopsydrew]

Neale,
Just wanted to say I just read your article in the 55th edition of tropical fish hobbyist: "Mission Impossible? The Search for the Community Tank Oddball" The article was great and fun and informative. I like how you mixed it up a little and did your article in a different styles than the others. I had great fun telling my gf that I occasionally talk with the same person who wrote this article for TFH. Again, great article. Are you going to be in TFH next month?

Drew

 

[nmonks]

Thanks for the kind words!

It was definitely a fun article to write, and soon as I'd finished it I felt positive about it, something that doesn't always happen. I'm looking forward to seeing how the article was laid out. It's a shame the magazine can't have a soundtrack... I keep hearing that Mission Impossible tune in my head! (Old school M:I though, not that Tom Cruise nonsense.)

I have no idea what months I'm included in TFH. I send stuff off, and sometimes it runs the next month, sometimes two years later...

Cheers, Neale

Just wanted to say I just read your article in the 55th edition of tropical fish hobbyist: "Mission Impossible? The Search for the Community Tank Oddball" The article was great and fun and informative. I like how you mixed it up a little and did your article in a different styles than the others. I had great fun telling my gf that I occasionally talk with the same person who wrote this article for TFH. Again, great article. Are you going to be in TFH next month?

 

[poopsydrew]

Thanks for the kind words!

It was definitely a fun article to write, and soon as I'd finished it I felt positive about it, something that doesn't always happen. I'm looking forward to seeing how the article was laid out. It's a shame the magazine can't have a soundtrack... I keep hearing that Mission Impossible tune in my head! (Old school M:I though, not that Tom Cruise nonsense.)

I have no idea what months I'm included in TFH. I send stuff off, and sometimes it runs the next month, sometimes two years later...

Cheers, Neale

Just wanted to say I just read your article in the 55th edition of tropical fish hobbyist: "Mission Impossible? The Search for the Community Tank Oddball" The article was great and fun and informative. I like how you mixed it up a little and did your article in a different styles than the others. I had great fun telling my gf that I occasionally talk with the same person who wrote this article for TFH. Again, great article. Are you going to be in TFH next month?

Your welcome Now you got the song stuck in my head everytime I read the magazine lol. I had no idea thats how articles were put into magazines...Well, I will continue to look for your articles and books....keep up the themed articles, its way more enjoyable than much of the articles I read.

Drew

 

[Straydum]

including links to pictures would help.