One Nasty-ass Aquarium Bug

[Headdy]

Okay…

Deviating slightly from my other post about a new tank setup, unfortunately I’ve lost a few of my fish after just a few days. I’ve gotten used to fish dying somewhat, though it’s still distressing.

I did a partial water change yesterday, and am doing one right now. The nitrate and nitrite levels are low (20 mg/l nitrate, 0 mg/l nitrite), and the pH is slightly acidic. I’ve removed all the dead fish and some dead foliage, as well as some fungus-like stuff that accumulated under a coconut shell.
I also added some medicine to the water before starting the water change; I’m not exactly sure if it’s worked, but my last catfish standing has become more lively again.

Then I came across this nasty thing:

I have no idea what it is, or how it got in there, but I got it out of the tank as soon as I could. I can’t help thinking it had some kind of role to play.

Any ideas?

Attached files

[mickthefish]

it looks very much like some kind of dragonfly nymph, they do predate on fish and suck all the fluids from the fish, destroy it mate.

mick

[Headdy]

QUOTE (mickthefish @ Oct 29 2008, 01:33 AM) <{POST_SNAPBACK}>

it looks very much like some kind of dragonfly nymph, they do predate on fish and suck all the fluids from the fish, destroy it mate.

mick

I flushed that thing down the toilet, only because I don’t have my lighter on me.

I just hope there isn’t any more of them.

[Mark Duffill]

I would agree with Mick, there are two types of dragonfly larvae, the short bodies which you have and the longer bodied larvae that has 3 small spikes/hairs at the tail end.

I have had dragonfly larvae in my tanks before and they can do some real damage, unfortunately they usually come in on plants and where there is one there will usually be a couple more.

Keep an eye on the base area of any plants or edges of any rock work, if they are moving around you will eventually spot them.

[Malti]

yep thats a dragon nymph, they’re dangerous to small fish usually

[Matt]

Evil little buggers. I had one come in on the filamentous algae Manuel gave me actually. I’m on the second floor so must admit I just chucked it straight out the window when I spotted it.

#311328

[Headdy]

I’ll definitely keep an eye out for these things… if I find any more I won’t be nearly as merciful to them. I’ve lost at least eight fish to it in just a few days.

Ironically I searched the net last night for ways of getting rid of them. All I found were message boards with people saying what delightful creatures they were.

[Headdy]

QUOTE (Matt @ Oct 29 2008, 02:53 PM) <{POST_SNAPBACK}>

Sorry to hear about your fish. What were the symptoms?

The first fish I’d lost were in the smaller tank: this was back when I had six rasboras, a betta and two shrimp.
One of the shrimp and my first betta fish went after separate water changes, where they decomposed. (For the betta I’d used RO water.)
My second betta fish and a rasbora probably went because of bad water quality – it was hard to keep a tank of that size clean for long.
Four of the rasboras and a shrimp went “missing”. I suspect the betta fish were responsible for that.

[Headdy]

Update for you fellow aquarists…

I got home and checked on the tank first thing. Everything looked okay, until I spotted a fallen tetra after noticing one was missing.

I’d spent the next few minutes searching the tank for more dragonfly larvae. Initially I was looking for the same kind as I’d found before.
Just when I was about to give up, I’d somehow spotted the other larvae kind (long body, three “spikes” at the back). Immediately I got my gravel cleaner and tried to suck it up, but I’m sure it escaped.

I decided there was only one thing to do…

I stripped out all the [probably egg-ridden] plants and – except for the moss balls – threw them in the bin. It was a good chance to get rid of the dead foliage too! Then I transferred all of the small fish to the spare small tank, only leaving the obedient hatchets.

I used my oversized net to disturb the gravel, and netted any flushed out larvae. They blended right in with the gravel, being a light brown colour and only distinguishable by its long body. The hatchets were very cooperative, moving to the opposite end of the tank as I progressed.

As I began taking out ornaments, bogwood and rocks, as expected, more larvae came out of hiding. Once I got used to their movement they were easy to catch, though one almost escaped.

In total there were five of these long-bodied things, all of which got a dignified send-off (read: cremation with lighter fluid and rubbing alcohol).

I sure hope there’s no room for unexpected surprises, but I don’t know what else to do to be rid of them once and for all.

[dunc]

That’s horrible Drew. Sounds like you did well to get rid – is your tank in the clear now?

[Headdy]

QUOTE (dunc @ Nov 24 2008, 03:45 PM) <{POST_SNAPBACK}>

That’s horrible Drew. Sounds like you did well to get rid – is your tank in the clear now?

There were a few more losses afterwards (one rainbowfish, the last catfish and a tetra), probably due to the water quality in the other tank. Thankfully, though, there hasn’t been any more losses since.

[Author]

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