Darters dying, need some help!

It started with a banded darter, his color got much darker (actually prettier) and the area between the head and the dorsal fin became skinnier than usual. He acted perfectly fine, he was eating very well, and he just seemed fine. But a few days ago he just died. I also just had a pretty little johnny darter die from the same reason. I have no idea what it is . Ive been extremely careful with trying not to introduce aquarium diseases into the native tank. I now have another johnny darter that is now dark in color and rather skinny in the area I told yall. I need suggestions soon as im afraid im going to lose my other little johnny.

It started with a banded darter, his color got much darker (actually prettier) and the area between the head and the dorsal fin became skinnier than usual. He acted perfectly fine, he was eating very well, and he just seemed fine. But a few days ago he just died. I also just had a pretty little johnny darter die from the same reason. I have no idea what it is . Ive been extremely careful with trying not to introduce aquarium diseases into the native tank. I now have another johnny darter that is now dark in color and rather skinny in the area I told yall. I need suggestions soon as im afraid im going to lose my other little johnny.

well the first step in helping is knowing the water conditions. nitrate, nitrites, and ammonia levels....from there you can move on to diseases

How often and what do you feed and what is the flow and temperature like in the tank?

I find that if I feed my darters on a schedule that works fine for other fish that they tend to get skinny. I've had a couple die off, when trying to scale back feedings for algae issues despite it having no ill effects on the other fish. They also seem to require fairly high dissolved oxygen levels. So high flow, cool temps, lots of aeration are all good ideas.

First thing I'd try would be to start feeding a variety of frozen foods 2 or 3 times a day and adding an air pump or two. If it is just general lack of nutrition they'll pick up. If it is some disease the extra O2 and nutrition will help them fight it, so it's pretty much a win win as long as you keep their water quality high.

Ph-7.4
Ammonia-0
Havent got to the others yet.
My tank is a 30g long with a filter for a 50g (very good filtration, biological, chemical, and mechanical), a maxijet that puts out the amount of current that used for a 60g. So I definantly have good filtration and circulation because I pretty much doubled those.
I feed the fish frozen bloodworms once a day(but I give them a lot) I also sometimes feed them baby earthworms ,and the shiners and topminnows eat flakes sometimes. I feed madtoms when lights off.
The fishs belly isnt skinny its the meat between the dorsal fin and their skull thats skinny
This is why im so confused everything seems fine, even the sick fish act fine.

Edited by Amazon, 31 May 2009 - 02:10 PM.

New update, could be the problem.

Ive been noticing these wierd worms attached to the nozzle of the powerhead and never thought much bout them till now. They are small and brown and they have a longish body with four or five things stcking out of one end of them. Just like anchor worms . About a week ago I also noticed this wierd bug attached to the side of the banded darter that died. It came off after a little while and I just forgot about it after that. My friend also has them on his filter nozzle in his hteranda formosa tank. The wierd thing is my darter tank and his H. formosa tank both have this moss we took from the river in them.
Could this be the problem?
Could they have come from the plant?
Thanks in advance guys

Are they hydra?

Are they hydra?

I think they are
Now im right back in the position I first started in.

You should mail me those. I've been wanting some for a long time. I've never heard of them harming fish aside from very small fry, though they may eat dead ones. I doubt they are the cause of any deaths. They usually eat stuff more on the scale of daphnia and cyclops than darters.

I was just cleaning out my filter and I found out that all these "hydras" are actually old egg sacks. I also found three adults. There were also 2 egg sacks that still had creatures in them, when you would poke the egg it would stick its head out wiggle around. The biggest adult I found was about 2 centimeters and it was one of these things that was attached to the banded darter.
What are they?

Hydra do not live inside any kind of sack, nor do they wiggle. They just contract or lengthen their body and tentacles, like a tiny, skinny sea anemone. They do like to attach on plants, rocks, wood, glass, or filter parts where there is some flow. They cannot eat fish larger than newborn fry, but repeated stings from many hydra can certainly weaken and eventually kill larger fish.

The other things in "egg sacks" sound more like some type of oligochaete worm, maybe Dero, Nais, Stylaria, etc. These are scavengers, which is why you'll find lots of them in your filter, or on dead fish or uneaten food.

The skinny darter syndrome is common, especially in tanks warmer than 75F. If you're sure they are eating well, then it may be some intestinal protozoa or parasite like Hexamita or something causing this "wasting".

I was just cleaning out my filter and I found out that all these "hydras" are actually old egg sacks. I also found three adults. There were also 2 egg sacks that still had creatures in them, when you would poke the egg it would stick its head out wiggle around. The biggest adult I found was about 2 centimeters and it was one of these things that was attached to the banded darter.
What are they?

I cleaned the filter, and did a 50% water change. If this doesnt do anything, what do I do about protozoa or parasites? I now only have 1 out of the three johnny darters I had left and this is gettin pretty agravating.
The things that come out the tubular sacks are some kind of crustacean, they almost look like mini mealworms with two things sticking out their tail, they have two eyes and a few of em are slightly green.

I would recommend treating your tank with Parasite Clear by Jungle Labs. That should get rid of those "things". Hopefully, that will solve your problem.

Brian

OK, if the THINGS have eyes then they are not oligochate worms. More likely some kind of midge (fly) larvae, related to bloodworms.
They are NOT parasites and probably have nothing to do with your darters getting thin and dying, but they do suggest you have excess decaying food.
If gut parasites (protozoa or worms) are suspected, then Aquarium Pharm API "General Cure" or other meds containing metronidazole, trichlorophon, praziquantel, or flubendazole MIGHT work. I had some redbelly dace that got bulging-belly, skinny-body symptoms like you describe (during summer, probably too hot), and they started looking better a week after one treatment of Flubendazole.

I cleaned the filter, and did a 50% water change. If this doesnt do anything, what do I do about protozoa or parasites? I now only have 1 out of the three johnny darters I had left and this is gettin pretty agravating. The things that come out the tubular sacks are some kind of crustacean, they almost look like mini mealworms with two things sticking out their tail, they have two eyes and a few of em are slightly green.

The things that come out the tubular sacks are some kind of crustacean, they almost look like mini mealworms with two things sticking out their tail, they have two eyes and a few of em are slightly green.

I think you are describing caddisfly larvae. Odd that they would be in your tank. Is your sediment from the stream? They can come in that way. I don't think they are related to your problems, though.

Hydra do not live inside any kind of sack, nor do they wiggle. They just contract or lengthen their body and tentacles, like a tiny, skinny sea anemone.

I think hydra could be described as wiggling, especially tenticles. Actually, when viewed on a slide they do cartwheels! No joking!

I had that same thought. Try a google image search for "hydropsyche" and see if your critter is a caddisfly. And if not, try "chironomid" (midge).
Caddisflies seem unlikely to colonize a fish tank, but since you did collect moss from the river, it certainly could have caddis, midges, mayflies, etc.
All of these make excellent darter food.

[quote name='nativeplanter' date='Jun 3 2009, 05:10 PM' post='59766']
I think you are describing caddisfly larvae. Odd that they would be in your tank. Is your sediment from the stream? They can come in that way. I don't think they are related to your problems, though.

I find bloodworms don't contain much nutrient. Fish love them but they don't really grow fast on them, and to feed them enough to have the fish growing well, you will go broke in now time. (I mean adult fish, not fry)

Now, I am from New Zealand and have never had darters, but our bullies are amazingly similar, even down to the intricacies of breeding behaviour. Try feeding them ox heart for a while (or beef heart or whatever it gets labeled). Cut off all the fat and misc disturbing bits and freeze it. Then chop it up in little bits and your fish will go nuts. It is an excellent food for putting size on them! Bullies grow pretty slow, but they are in excellent condition with a staple diet of ox heart.

Look up what your natural internal parasites are. I used to wonder about them till I learned about the life cycles of our native parasites.
Unless you are sure they have parasites, you are unlikely to see much difference (even if they do have parasites you probably won't see much difference), but I guess it is one thing to tick off the possibilities list.

Gerald, thanks for the reply. They are caddisfly larvae. My substrate and plants are both from the river. Luckily, I have not had any more fis die in the tank, now my only problem is my speckled darter's tail is gone and the entire back half of the body is yellow. I'm guessing its the speckled madtoms but theyre no bigger than the darter.
I guess its time for him to have a little medicine bath.

.......Alright last nigt I just had 4 flagfin shiners die, my johnny darter has a ragged tail and the area has very quickly (overnight) turned yellow. My speckled darter is almost all the way yellow with no tail and flipped upside down. The rest of the flagfin shiners are swimming wierd. Some of the fish are scraping against the gravel. This has all happened in the matter of 2 days and getting worse.
I cannot id the problem is there anybody who knows what this is?

tail becoming ragged
body on the tail end turning yellow
fish scraping against gravel
fish not acting or swimming normal

Im probably going to start treating wit Melafix and Pimafix.

Scratching is something I see often from parasite infected fish. However, I imagine any sort of wound or infection of the skin could cause itchiness and scratching behavior.

At this point I'm not sure there is a downside to trying the meds.

Could be Flexibacter or Flavobacteria, aka "columnaris". Very common especially on newly caught or otherwise stressed fish. It ofetn eats away the tail and fins first, then moves into the body (especially caudal peduncle), turning the muscle opaque and then quickly killing the fish. Nasty stuff, hard to treat.