Vanmanenia Observation.

[Martin Thoene]

I noticed the other day that one of my Vanmanenia hainanensis had developed white areas on the dorsal and pectoral fins. I was alarmed at first because I thought it was some sort of fungus or something.

However, closer observation reveals it's more than just whiteness. Note groups of raised dots on dorsal on top of the white areas.



Head on, the dorsal is obviously thickened and symmetrical side to side.





You can see that it is the areas inbetween the rays that are white on the pectoral fins..



Judging by long-term observation of behaviour this fish is a male.

Martin.

[Blue]

Nice pics.

[Jim Powers]

Very interesting. Nice close up too.
Do you suppose this is some kind of sexual trait such as the "fences" on Sewellia?

[Martin Thoene]

That's what I'm thinking. Weird though, because Sewellia (and some Gastromyzon remember) have modified rays. Certainly on the pectorals this is on the fin membrane. I'll see if I can get a picture with the dorsal properly raised.

Martin.

[Emma Turner]

Some of this would fit with what Les and I have observed with the similar looking Annamia normani. Although the raised areas in the centre of my fish's pectoral fins are not as pronounced as that. Not noticed any 'dorsal stuff' though.

Fab pics.

Emma

[Jim Powers]

I have never noticed anything like this on my L. disparis, have you?

[Martin Thoene]

No never.

Martin.

[shari2]

Few questions:
When did you first notice this?
How long has it been present?
Did it develop over time or overnight?
Is the fish behaving normally in all respects?
Any other fish affected?
Is this in the tank with the limpets?
Do you have any white growths on the wood in this tank?
Does this fish hang out on the wood?

in other words, it doesn't look to me like a 'normal' sexual characteristic.
sorry...

[Martin Thoene]

Few questions:
When did you first notice this? - Two days ago.
How long has it been present? - I guess around two days.
Did it develop over time or overnight? - Not sure.
Is the fish behaving normally in all respects? - Absolutely, plus it's been following the female around.
Any other fish affected? - No. The other two Vannies look the same as normal.
Is this in the tank with the limpets? - The limpets were on a piece of bogwood that has not even been in a tank since Pablo gave it to me ages ago.
Do you have any white growths on the wood in this tank? - No.
Does this fish hang out on the wood? - The fish is everywhere in the tank.

in other words, it doesn't look to me like a 'normal' sexual characteristic.
sorry... Well that was my initial thought upon the discovery but who knows? We keep constantly discovering things about these fish.

Martin.

[shari2]

We keep constantly discovering things about these fish.

True.

Don't mean to be alarmist here.
The fact that it developed in about 2 days is a red flag for me.
It appears to be more similar to a growth that came out of nowhere than a normal sexual development type thing.

I'd keep an eye on it to see if it continues to develop or spreads.

really hoping it's nothing more than a previously undocumented normal thing...

[zmo63]

that looks just like the white spots I'm seeing on the tail fins of my white skirt tetras. I started a thread - http://forums.loaches.com/viewtopic.php?t=7922 but didn't discover anything definite.

Totally unrelated types of fish, but those spots sure do look familiar. If it matters, the two affected tetras are also believed to be male - something about the size/shape of the anal fin, according to the LFS - not sure if that's true or not.

[Martin Thoene]

Today, this fish has some white in the upper caudal lobe. It's still behaving perfectly normally and in fact was the first to the food this morning.







One of the others.



Closer..........



Weird.

Martin.

[shari2]

Different fish?
If so, you may have a problem...not sure what, tho...

[Martin Thoene]

No, that last pic is the original fish. It's the only one of the 3 showing this. I caught it with the largest one (that I think is female) doing the pushing/shoving, rubbing the chin on the nape thing we've seen with these fish types before this morning.
Can't be feeling too bad I would say

Martin.

[shari2]

Is good.