Hyperactive Moray eel (G. Tile)

[serverustare]

I’ve had a pair of brackish morays for about 2 months now, one colored dark grey (14 inches) and the other is a light brown. (10 inch)
The dark grey eel stays in his hole in the rocks, with his head out and acts like a typical eel would be expected to act.
However the light brown eel is hyperactive. She never hides anymore, and spends all of her time swimming laps around the tank (60 gal) she has been doing this for the last 3 weeks, and although she appears healthy, I have to wonder if something is wrong.
She swims normally, and she does not lean to one side. Every now and then she will stop and look around or swim through some rocks, but she rarely returns to her cave with the other eel.
Every now and then the dark eel will come out and join her for a bit, but he always returns to his rock shelter and she continues swimming.

Any ideas why this would be so? And is it a bad thing?

Diet is live shrimp and feeder guppies. Salinity at 1.008. Ph 7.9. Tank is well oxygenated and filtered.
Tank mates include plecos, a crab, and a pair of large monos.

I'd link a picture, but she won't hold still long enough for me to get one.

 

[davo]

Not sure if it's an unhealthy problem or not. Do you have more than one cave? I would definately recommend taking out the pleco, they do not do well in brackish.

 

[serverustare]

Not sure if it's an unhealthy problem or not. Do you have more than one cave? I would definately recommend taking out the pleco, they do not do well in brackish.

There is only one large rock cave, but the tank is well planted and has a number of decorations to hide in. the eel will swim in and out of these from time to time.
As for the pleco, he’s lived in brackish for about 12 years.

 

[davo]

I am shocked, I've seen them with horrible boil like problems even over a short period... What species is it out of interest? Must be a Pterygoplichthys surely...

 

[serverustare]

I am shocked, I've seen them with horrible boil like problems even over a short period... What species is it out of interest? Must be a Pterygoplichthys surely...

Well if you must see. Here some pics. They are not very good, but eh, they are recent.

 

[davo]

Yes P. pardalis... (chance of disjunctivus I suppose). 12 years you say, amazed it's done so well... How big is it? What you feeding it... looks a tad thin. Do you notice it sucking on the eels at all (may be a reason for your eel to be in distress).

 

[welsher7]

I would suggest adding another cave structure to your tank. eels like tight confinded spaces. Chances are the eel is stressing becuase its not comfortable in the tank.

 

[serverustare]

Yes P. pardalis... (chance of disjunctivus I suppose). 12 years you say, amazed it's done so well... How big is it? What you feeding it... looks a tad thin. Do you notice it sucking on the eels at all (may be a reason for your eel to be in distress).

The pleco gets dried algae wafers, plus whatever is leftover from the other fish, and the picture just makes him look thin. He is about 8 inches. (I got him from a friend 12 years ago at about 1 1/2 inches)
As for the pleco and the eels, they bump into each other every now and then, but nobody has been bitten, sucked on, or injured.

 

[davo]

Ok then, just wondered as they tend to start sucking on the slime coats when they are adults if they are deprived of protein material (they would normally be doing this at night) You should give it some veggie matter too (check out the dietry sticky in the pleco subforum).

I have to say though at 12 years he should have been fully grown long ago and he is only just over half the size it should be. It may be the angle but for a 12 year old pardalis, it does look like it is much smaller and thinner, maybe of one a year(ish) old. I am not calling you a liar about the facts you've given, however suggesting maybe this is from being in a brackish water environment (trying to help).

You are "lucky" as you are using one of the hardiest plecos you'll ever come across, but like I've said, I've seen plecos that have been kept in brackish water and they swell up and can develop boils as they can not pass excess water because their osmosis regulatory organs can not function. These fish are from slightly acidic blackwater areas, not in hard alkaline brackish.

 

[serverustare]

Well, in my own defense, I have had the Pleco since my first fish tank, (Which I got when I was 10, having no idea what I was doing) and that was a 10 gallon where I kept dwarf puffers. He stayed in that tank for the better part of 8 years until I moved him to a 60 gal, and I always suspected it was the size of his original tank that stunted his growth.
Sadly to say, the condition of the pleco in the tank is not something I have thought about much. His only real job was to keep the glass clean.
Maybe I should think about trading him off, but at 12 years old and living in brackish his whole life, I think the shock of going to freshwater would kill him.