PlanetCatfish.com

Hi!
Well it is quite well known around that Panaque and Panqolus spp have bacterias to help them digest wood and take nutriments out of it. It is even believe that they could stricly live and make proper grow by eating only wood!
Shane, Jool and other any comment about these bacterias in Panaque/Panaqolus spp? Is it real or just some sort of myth?
Cheers
Yann

Cellulolytic bacteria in wood-eating loricariids is very real. There are scientific studies that show significant cellulolytic activity in the guts of such fish (although the bacteria were not isolated).

Siluris, I've read several times that the lignin in wood somehow helps pleco digestion. Are they able to digest lignin as well as cellulose? Or does it act as roughage? Or are people confusing the two? Lignin is a very inert substance for a microbe to break down. I know the fungi which rot wood can do it, but I don't suppose there are fungi in the gut of a fish.

Apparently not. Lignin is almost impossible to digest. The activity in the gut microflora of loricariids is primarily against cellulose and hemicellulose, which are the main components of wood.
Interestingly, generalized loricariids (e.g. <i>Liposarcus</i>) have a limited wood-digesting ability and may eat wood when no other food is available.
The study quoted is Nelson et al. (1999): Wood-eating catfishes of the genus <i>Panaque</i>: gut microflora and cellulolytic enzyme activities. J. Fish Biol. 54: 1069-1082, and I have a pdf, if anyone is interested.

http://www.towson.edu/users/nelson/Panaque/panaque.html


I can't comment on panaques but my L204s and other Panaqolus eat a lot of drift wood.

The study actually focuses mainly on <i>Panaqolus</i> (that was before it was described).

The reason I ask about lignin is, several forum members have mentioned that large Royal Panaques produce so much sawdust that it clogs filters. But if they don't need lignin, they don't need wood as long as they're fed a largely vegetarian diet rich in cellulose. So why not just leave out the bogwood

Wood is not only a supply of lignin, it has plenty of hemicellulose (and cellulose derivatives) not usually found in softer plant material. The fish presumably need this as a source of energy (not just ordinary cellulose found in green matter).

Is there any news in this area?
According to this thread there's something I missed somehow regarding lignin eating fungi in gut of wood eating loricariids. Can anyone elaborate on this?

You can either read:

Nelson, JA, DA Wubah, ME Whitmer, EA Johnson & DJ Stewart, 1999. Wood-eating catfishes of the genus Panaque: gut microflora and cellulolytic enzyme activities. Journal of Fish Biology 54: 1069â??1082.

Or this

for more info.

HH (and others),
I'll look up the ref when I get home tonight, but I believe recent studies show that Panaque actually utilize a symbiotic gut fungi.
-Shane

Shane,
I believe you actually meant this.

I have always used "driftwood" in my aquariums that contained Panaque nigrolineatus.
African root or "Welaby Wood" is my preference because it sinks even when dry.
Does one of you know what type of wood or tree this actually is?

I was once told that a royal would die without wood so I just always kept some type of wood in with them.
At one time I had collected some local driftwood which was white cedar. Shortly after adding
it to my aquarium, one of my largest and favorite royals died. I submersed the wood in boiling water
for 20 minutes before I put it in my tank so I don't believe I contaminated the tank with
parasites. Could the white cedar have been toxic? What types of wood would these catfish
browse on in the wild?

Silurus thank you for posting those PDF's as I downloaded them and will read them carefully.

Yes, cedar is one of the woods that contains potentially harmful oils & such. There are site out there that warn about using cedar as bedding with certain small animals, too.

Potatoes seem to be a very good idea for Panaque, I wonder if they could fully replace wood? And, indeed, if "processed" potatoes are any less bothersome to filters than sawdust.

Jools

I've been feeding my L190 sweet potatoes. Jools are talking about regular potatoes?

My theory is that the cedar driftwood killed my royal but maybe I'm wrong.
I am still curious about the types of driftwood royals might eat in South America.
Since I'm not a tree expert I'm just guessing that some of the Amazonian trees must
contain phytotoxins. I did read that Cercropia is the most abundant tree in the Amazon
and that sloths eat the leaves because they are not toxic. Since they grow along the river
banks, could this be one of the woods that Panaque species actually eat?
Some of the forum members have probably traveled to this region and could comment.

I have not travelled in the Amazon, but I would expect them to eat (just about) any wood that is in the water. There may be certain types of wood that are poisonous to them, but they probably either know to avoid them (by natural selection). Certainly domestic cows know [inherently] which mushrooms are poisonous and which are not... This, of course, may not work for "foreign" wood.

I'm 100% sure, however, that Jools is referring to "regular" or "common" potatos. Sweet potato is certainly another good food for these fish, as are many other vegetable varieties.

--
mats

Their microbs partially break down cellulose/hemicellose,
so fish have to scrape off alot of wood all the time.
I feed 75% cellulose pellet (25% are binders) for my P. nigro. They produce alot of feces but grow fine.
No evidences that fish secrete cellulase directly, but I assume
they don't (no vertabrates known to do that yet).
Individual bacteria does not break down cellulose but a community
of several bacterium does. Yes, there are a few fungus in their GI tracts.

Followings are extention of my study with Jay A. Nelson.
In field study, they exclusively found around one type
of palm tree submerged in the river, Bakuri palm (Scheelea phalerata). According to carbon stable isotope
analyses on field collected otoliths of P. nigro, they do
not likely change their diet through their life (those of
Hypostomus regani were varied, so they may change according
to what available in the field). Of course, whole GI tract
content from P. nigro was wood shavings in my field study.
Dietary controlled experiments with H. sp. showed they are
not capable to wood only diet (only lived in a few months).
Carbon stable isotope analyses on otoliths of H. sp. that
were given different diets for a certain period showed
d13C values associated to their dietary d13C. So, diet d13C
reflect d13C in fish otoliths.

Bakuri tree is commonly seen in South Brazil. Different
population of P. nigro may consume different tree spp. in
their habitat.
In N. America, I feed alot of different types of trees.
They are likely attracted to soft trees such as pine or poplar,
or any decaying trees. Strong 'earthy smell' which some
actinomycetes produce in soil/decaying wood is the best
attractant to these fish. Supplying freshly brought wood
pieces from forested area is the best food for Panaque
spp. Fish start produce alot of feces out of these woods.
If fish start reducing their feces production, you should
add more woods or replace old wood pieces to new ones.

Some scientists including Jay are now writing a research grant
for more microbe studies in MD. I am looking for a good
fish supplyer who has licence/permission to ship fish to the
US and does not use any drags to fish during transportation
for our study (just avoiding kill of microbes in their GI
tracts by drags).
If any of you guys know someone I can contact, please let me know.
You can contact to me if you are interested in my previous
experiments on P. nigro.
Thanks.

Interresting thread!

Would the commonly available mangrove wood be sufficient for all the woodeating plecos?

Is it likely that these species need a certain type of wood to become ready for breeding?

Is the lack of correct nutrition possibly one of the most significant reasons why these species appear to be difficult to spawn?

I own PAEX exports in Peru and I do transship here in the states. I can set aside some sp for scientific study with arrangements made.

Andre' J. Rowe
Manager/Owner
AquariumPAEX.com
Xoticaquatix.com
509-251-4309
USA/PERU

Thank you, Waldo. I will contact to you for realistic
fish transaction from Peru to the lab.

H.N/Panaqs

Waldo wrote:I own PAEX exports in Peru and I do transship here in the states. I can set aside some sp for scientific study with arrangements made.

Andre' J. Rowe
Manager/Owner
AquariumPAEX.com
Xoticaquatix.com
509-251-4309
USA/PERU

Despite the dangers of speculating on the subject of "key innovations" in the evolutionary sense, I feel it is worth pointing out that phytophagy is often considered to be a key innovation. The ability to consume cellulose as a carbon source could be what is behind the success (in # of species) of the family Loricariidae.

Can we assume that a panaque, like many other wood-eating organisms, actually gains most of its nutrition by digesting the gut flora?

Have these specific bacteria been found in any other Loricariidae? Could it be in lesser amounts? Or is this a "you have it or you don't" type of thing?

>menschenjaeger
It may be true that fish digest microbes, but not known
how much. One thing I know is their d13C value is a little
different to other herbivorous fish. It may be due to
methane production during digestion or gut flora effects...
My question is where they get N source from wood. I agree
with digestiong microbes theory but also interested in if
they have N fixing bacterium or not.... Hope more results
come near future.


>bronzefry
Yes for Cochliodon spp. but not well known other genus yet.
Even Cochliodon spp. do not have all spp. of microbes found
in Panaque. A lot of those microbes can be found in
termites or other inverts that consume cellulose.

Thanks for the info. I've noticed when the L-147 goes through a "growth spurt", he tends to eat more wood than anything else.

H.N wrote:I feed 75% cellulose pellet (25% are binders) for

Who do you buy these from?