panaque nigro spawning ??

[Acanthicus, posts: 439]

heard about this version too... and about another saying that Panaque could possibly have migration spawning behaviour... based on the fact that most little Panaque are found far away from the places of the big ones...

a lot of theories, but nothing really checked...

I investigated several months of field operation in my theory that Cochliodon migrate in the upper riverpart to spawn. I also wrote about it in DATZ, and the answer is: Yes, they do migrate. So, I am quite sure Panaque do as well.

The idea with elongated containers is really a good one, but unfortunately not practicable here.


cheers,

[matthewfaulkner, posts: 290]

Here's a picture showing some sexual characteristics. You can sort of see the chubby pelvic/ventral fins and the odontodes along the body. Do you think this points to a male fish?

[Jools]

I'm not sure body odontodes point to gender in Panaque (by which I mean Panaque not Panaqolus and Scobinancistrus). The genital papillae seems blunt and that points to a female... I think with these guys a picture of that is the best way to tell. I am not sure of the rest.

Jools

[MatsP]

Yes, they do migrate. So, I am quite sure Panaque do as well.

Does this also mean that they spawn in the middle/late part of the rainy season when water levels are at their highest? One could expect so...

The idea with elongated containers is really a good one, but unfortunately not practicable here.

Unless you can make a very large, and quite long "river" running into the tank?

--
Mats

[matthewfaulkner, posts: 290]

I'm not sure body odontodes point to gender in Panaque (by which I mean Panaque not Panaqolus and Scobinancistrus). The genital papillae seems blunt and that points to a female... I think with these guys a picture of that is the best way to tell. I am not sure of the rest.

Jools

I agree that the body odontodes are probably inconclusive, as it seems that these fish tend to have them as a prominent feature anyway. What do you think about the pelvic/ventral fins? It's my understanding that enlarged fins point towards a male. The genital papillae is blunt and seems to pulsate a lot with a peristalsis like movement. I don't know whether that's normal or just because the fish was pooing at the time.

I hope more people can post similar pictures so we can see any similarities/differences.





And although not related to the topic, I thought I'd share his/her wood gnashers.

[ElTofi, posts: 500]

And although not related to the topic, I thought I'd share his/her wood gnashers.

Awesome ! really awesome ! Thanks for sharing...

[pleco_breeder, posts: 803]

Enlarged pelvic fins does point to male in a lot of species. I don't know if this holds true in Panaque.

Likewise, the peristaltic contractions tends to point to male. This is only an observation I've made, but it seems the genitalia of females is usually too bulbous to be able to note if any movement is taking place. I see it in males of most plecos rather often, but don't recall ever noting it on a known female. I don't think it's sexually related, but something that seems to happen quite a bit.

Larry

[Scleropages, posts: 425]

Unless you can make a very large, and quite long "river" running into the tank?

Or, unless you live in southern Florida and are designing your own pond. Sounds like a project for Viktor!

[MatsP]

Or, unless you live in southern Florida and are designing your own pond. Sounds like a project for Viktor!

Yes, of course in (sub-)tropical regions, you could do this as well.

--
Mats

[Jools]

Pectoral fins enlarging in Panaque I am not sure about, I come to that from my experience with Scobinancistrus which have the most spiny thick rayed females I have seen.

However, those ventral fins look really interesting. Crazy notion - what if these guys spawn like Chaetostoma...

Jools

[rob rensen, posts: 271]

There's is still a lot to discover about the large panaque's.....I'll hope to contribute to that issue

[rob rensen, posts: 271]

This is my 35cm female

[ElTofi, posts: 500]

[Acanthicus, posts: 439]

Hi Mats,

Does this also mean that they spawn in the middle/late part of the rainy season when water levels are at their highest? One could expect so...

Unless you can make a very large, and quite long "river" running into the tank?

exactly. The adults wait for the rainy season and then swim in the upper river part where they start spawning. I have lots of data about this behaviour. I observed one species in a special river for months.

I don´t think a really strong "river like" waterflow will be sufficient to stimulate some species. They need the distance which is between the upper and the lower river. Comparable to Rhinelepis.

[Jake Adams, posts: 42]

The size and thickness of the odondotes has a lot to do with the hardness of the water in which the fish has been grown. After noticing my blue eyes failing to develop the kind of bristles and spines they once had in my softwater aquarium, I have recently begun adding calcium and carbonate to the water.\

The rate at which new spiny tissue has grown is quite impressive, the pectoral odondotes are way thicker and the opercular whiskers are growing faster than they are falling out. So the size and shape of the odondotes is irrelevant for sexing unless you can verify the hardness of the water where the fish came from.

[rob rensen, posts: 271]

That's sounds very strang to me. I've never heard this before. I have several panaque's L190 (7) in one tank....the females have hardly or small odontes and the males bigger ones. The males have also odontes on their pectoral fins

They all swim in the same water

[jac, posts: 743]

Jake, how long have you had your Panaque's? Have you had them since small fish? Very interesting story about the odonthal growth!! Since the odonthodes are the same as the bony plates on the body of a fish, could they contain calcium? That would make your story very believable.

Rob, I don't think you have kept your Panaque's long enough to see such differences The bigger ones you have, have had a very long growing up time somewhere else. You don't know how they've been kept, in what kind of waters. As your Panaque's come from many different sources I do think that waterparameters could have a certain effect on (ondonthode) growth on the fish.

[rob rensen, posts: 271]

Then you should see also difference between the growth of their spoon shaped teeth. they also contain calcium.

I don't reallly believe that odontes story, i never heard it before.

[ElTofi, posts: 500]

what I know for sure is that the Panaque cf armbrusteri "Xingu" I had during 6 years in swiss tap water (GH around 8-12) had odontodes, depending on water conditions, stress or even food...

What I still hold for males had grown (and lost) interopercular and pectoral odontodes several times

the signal for loosing their odontodes was most of the time a too much high nitrates level... Or not enough oxygen... any major change in water parameters was sufficient for the panaque to loose their odontodes...

I had 3 specimen (no idea of the sexing) but only one developped very strong odontodes, by cycles, depending on the above mentionned criterias.

it's believable that GH could have an impact on odontodes grow, but I must refer that stressing conditions (water quality, poor feeding, temperature fluctuations, other inhabitants) do have an effect on odontodal growth...

another note I can add, based on more than 8 years observations (on Panaque xingu and the actual Panaque L191) :

Panaque only use terracota cave when there's nothing else to hide... if they find roots, sunken woods or even driftwoods, they always will prefer it as a hiding place...

I have project, as we all have, with my panaques, but I'm still navigating "in the mist", no idea of what's wrong or what could be right...

[rob rensen, posts: 271]

Poor feeding, bad water has influence on every fish or pleco