Akysis vespa

[kruseman]

I went to Germany this morning and got myself 5 little "wasps":







Although the pictures aren't that great; the fish are!

[Silurus]

I think these are

Akysis longifilis

.

[kruseman]

You're right, Silurus.
Checking the cat e-log yesterdaynight I actually had the same notion. They were labelled as A. vespa.

[Martin S]

Are they all the same?
The fish bottom right in the second picture has different colour and shape markings than the others.
Or is the colour variable?
Martin

[Silurus]

They all look the same to me.

[Bijn]

They all look the same to me.

Not to me. I'm not saying they are not all the same species but there is one with obvious different markings and colors.


Cool fishes Arjan Your only acquisition's that day?

[Bas Pels]

Obviously, one has a darker body thant others, but from Silurus opinion I tend to conclude this is not a significant difference

That is always the problem: does a little dot in the fin, or so mean anything? Sometimes it does, sometimes it doesn't. Only an expert can tell

[Bijn]

I's more then a little dot in a fin.


the one that looks different to me has:

- a more yellowish coloration
- more pigmented pelvic fins
- more pigmented barbels
- a broader black area behind the head
- a black spot in the first lighter spot on his back


really, these are a lot off differences if you ask me.

[Silurus]

The only way to be sure would be to examine the belly. If it's generally dark, then it's

Akysis prashadi

which can easily be mixed with shipments of

Akysis longifilis

(which has a pale belly).

[kruseman]

I am going to catch the different looking one and have a closer look at the belly tonight.
I forgot to ask the guy who sold them at the fair in Duisburg if he bred the fish himself. In that case it will be almost impossible that I have to do with 2 sp. of Akysis. Anyhow: He labelled them wronlgy.
Pretty active fish. Nicely coloured as well.

Why is it that a lot of catfish in different continents have the samelooking "wasppattern". Convergent evolution probably, but why?

@Bijn: These are the only fishes I bought. Ivanocara was way too expensive. Bought a bunch of "hardware": Cheap filterfloss, food, filter and a LED nightlight for watching Centromochlus and Brachyrhamdia at night ;) Had a chat with Heiko Bleher and Wolfgang Staeck.
Missed the stand of Tanganyika.de.

[sidguppy]

the wasp-like pattern becomes clear if you see a sandy or finely gravelled stream with leaves and sticks lying on the substrate


in such a biotope a fish with a wasp-like pattern can lie in plain view on the substrate between the sticks and the leaves and the silouette breaks up; making it really hard to spot.
especially with sunlight shining on the surface.

i can think of several unrelated fish that have the same pattern and likely encounter leaves, sticks and shadows in very shallow streams;
Mochokiella, Microglanis, Akysis, Chiloglanis, Amphilius, some small Synodontis, Rineloricaria, Lampiella, Bunocephalus etc.

[kruseman]

I see. That is a good clarification. I almost could have thought of that myself. Almost.
There's plenty of knowledge on PC.

I caught the different looking Akysis yesterdaynight: Looked at the belly and sure enough:
It was dark. The other ones have greyish bellies. I did not make a picture : I didn't want to stress the little fellow too much.

So I have 2 species of Akysis. Pretty weird. Maybe 2 species are living sympatric in the same stream somewhere in Birma. Have to check that out.

[MatsP]

More likely, the two came from different places and got mixed by the exporter that just think they all look the same...

--
Mats