Could Panaques be brackish spawners?

[Barbelses]

Thread title says it all. I was looking at the occurrence records for Panaque nigrolineatus on fishbase and started thinking about the distance from the ocean. https://fishbase.mnhn.fr/museum/Occurre ... rolineatus

Apologies if this is an obvious question. Many people much more knowledgable than me have spent a long time trying to crack the panaque breeding code.

[bekateen]

Hi @Barbelses,

Welcome to Planetcatfish!

Your question is a fine question.

The answer is most likely no. The MNHN database is very narrow. If you look at other websites (I've chosen GBIF.org as one example), the distribution for this species is pretty clearly freshwater.

More curiously from this data is a single report from northern California, USA. Probably a release of an aquarium fish.

Cheers, Eric

[Barbelses]

Thanks!

I wish we had more data on the parameters/tank setup of the few events of accidental panaque breeding. I believe there's speculation some species may dig a nest in mud, rather than cave spawning.

Stephen Huang has gotten them to produce eggs, but I believe he gave up because the fry kept dying. I wonder if they need to eat the parents' waste to get appropriate gut flora for xylophagy?

[Shane]

I have captured hundreds of P. nigrolineatus new born fry in the Venezuelan llanos, so they definitely hatch there. They are usually found on the submerged branches and leaves of terrestrial trees. They appear to feed in this environment until they reach about 1.5 inches. Beyond that size they are only caught in deeper waters in and around sunken wood.

I think the rarity of captive spawnings has more to do with the fact that few people have a large enough aquarium and a compatible pair. Raising a group of juveniles together and ending up with a compatible pair would be ideal, but that would be a very, very long project.

-Shane

[Barbelses]

I have captured hundreds of P. nigrolineatus new born fry in the Venezuelan llanos, so they definitely hatch there. They are usually found on the submerged branches and leaves of terrestrial trees. They appear to feed in this environment until they reach about 1.5 inches. Beyond that size they are only caught in deeper waters in and around sunken wood.

I think the rarity of captive spawnings has more to do with the fact that few people have a large enough aquarium and a compatible pair. Raising a group of juveniles together and ending up with a compatible pair would be ideal, but that would be a very, very long project.

-Shane

I was hoping to find more knowledge on their natural habitat! Thank you so much for your input. Have you taken photos of the wild fry? How deep are the waters the adults live in?

I won't be building a tank for at least a year or two, so I'm still in the lengthy information-gathering, pre-design phase. How large a tank are we talking? 500 gallons? 2000 gallons? Actual pond?

[Shane]

Yes, look in the Catelog and Shane's World for pictures and further habitat information.

I don't think the tank needs to be gigantic. You could raise a group in a 100-125 gallon tank easily. Once you have an identified pair (or even trio) they could be housed in their own 125. You could sell off any extras for a nice profit or set up a second spawning group. I think its most likely they spawn in the crevices in sunken logs, but proper size spawning caves may serve just as well.

Large adults will stay on or near sunken logs in the deepest channel. Depending on the river this could be 20 feet or more down. Some Amazonian Panaque spp have been found in very, very deep water.

-Shane

[Barbelses]

Yes, look in the Catelog and Shane's World for pictures and further habitat information.

I don't think the tank needs to be gigantic. You could raise a group in a 100-125 gallon tank easily. Once you have an identified pair (or even trio) they could be housed in their own 125. You could sell off any extras for a nice profit or set up a second spawning group. I think its most likely they spawn in the crevices in sunken logs, but proper size spawning caves may serve just as well.

Large adults will stay on or near sunken logs in the deepest channel. Depending on the river this could be 20 feet or more down. Some Amazonian Panaque spp have been found in very, very deep water.

-Shane

The Catelog has been a huge help! This website is such a good resource. How does one identify a pair or trio that has grouped together?

Is a 500+ gal tank or pond-type setup enough space to keep multiple breeding pairs and give everyone enough territory to avoid conflict?

When you say that you've found fry in submerged branches and leaves, do you mean live trees that have been temporary submerged due to seasonal water levels, or leaf litter and dead branches?

[Shane]

Personally, I would not use a pond. Just too difficult to monitor the fish and make sure they are healthy, eating, and getting along.

Yes, submerged leaves from living trees along the banks.

-Shane

[Barbelses]

Personally, I would not use a pond. Just too difficult to monitor the fish and make sure they are healthy, eating, and getting along.

Yes, submerged leaves from living trees along the banks.

-Shane

I've been reading more about the local weather patterns and how much the water level rises during the wet season. I guess I'd have to use marginal and floating plants as a substitute nursery for the fry?

[Kirin]

As a database Fishbase is good but also for information it is a (very large) pinch of salt. Databases can be tricky to create with what you include and exclude. Fishbase I've found also includes information that lacks citations or the citation might not entirely back it up.
The other aspect with localities is particularly with GBIF where the specimens location can be included so you'll see fish listed as from Europe, yet no way was that species fished there, it's just the museum collection. In general localities without coordinates can be related to where the fish was found, so might just be a fish market.
There are always a lot of data biases, particularly where major cities might be largely focused at the coast. Always worth checking scientific papers particularly that type location.
I'm also not convinced Loricariids are migratory fishes? There are possibly exceptions such as I'd say Aspredinidae aren't but then Platystacus seem to travel or be just widespread.

[Barbelses]

As a database Fishbase is good but also for information it is a (very large) pinch of salt. Databases can be tricky to create with what you include and exclude. Fishbase I've found also includes information that lacks citations or the citation might not entirely back it up.
The other aspect with localities is particularly with GBIF where the specimens location can be included so you'll see fish listed as from Europe, yet no way was that species fished there, it's just the museum collection. In general localities without coordinates can be related to where the fish was found, so might just be a fish market.
There are always a lot of data biases, particularly where major cities might be largely focused at the coast. Always worth checking scientific papers particularly that type location.
I'm also not convinced Loricariids are migratory fishes? There are possibly exceptions such as I'd say Aspredinidae aren't but then Platystacus seem to travel or be just widespread.

Scientific papers are a good idea, do you have any resources you'd recommend?

Shane gave me a lot of useful info further up in the thread.