Wood Digesting Pleco and Sponge filter

phreeflow

Aimara
MFK Member
Nov 19, 2007
726
885
130
ca
I think that is questionable. Old sticky/thread from 2012 posted below, with some more recent papers discussed at the end. IMO wood can be replaced with cleaner alternatives. Up to you.

Some good info in that 2012 thread. I had gotten rid of all panaques since I can’t stand the mess they make rasping on wood. Gonna try again without wood next time
 
  • Like
Reactions: RD. and tlindsey

RD.

Gold Tier VIP
MFK Member
May 9, 2007
12,413
10,613
3,360
62
Northwest Canada
Years ago I had a 9" L014 sunshine pleco , collected in the wilds of Brazil, an absolute she devil of a fish, that could turn a 4ft piece of oak into sawdust almost overnight. lol I'm exaggerating of course, but this species doesn't even fall into one of the "wood-eating" species. Planetcatfish describe this species as omnivorous, but also state: "Sinking pellets and frozen bloodworm are ideal although all prepared foods that reach the bottom are accepted. Larger individuals will tackle whole king prawns and mussels with relish". ------ Mine ate anything, but higher protein/fat pellets/wafers were attacked like this fish hadn't eaten in days. Personally I would consider the adults of this species as omnivores, that lean heavily towards the carnivorous side of the equation. But she still spent many hours of her day rasping/chewing/scraping on anything in her tank. My L014 made such a mess in her tank that had wood, that I couldn't keep up to keeping the filters clean. I eventually moved her into a larger tank, with no wood, but contained some very large boulders. She seemed to "enjoy" that tank, just as much as her previous one.

Over the years I have also kept various fish from the Ancistrus genus, at that time their sole purpose besides my enjoyment of observing them, was to keep my tanks clean of biofilm/algae growth. They did a magnificent job, and some of those tanks contained zero wood. Again, I didn't deprive them of their natural behavior, they simply carried that behavior over to other surfaces in those tanks, such as large boulders, etc.

A wild pleco doesn't care if the biofilm/algae growth is coming off of a piece of dead wood, or a 30 lb boulder. It is a behavior that goes back to the beginning of time, and one that will continue in captivity no matter if wood is present, or not.
 

jjohnwm

Redtail Catfish
MFK Member
Mar 29, 2019
1,196
2,778
154
Manitoba, Canada
Lol, I never stop getting a chuckle out of hearing about "happy" fish...never mind "desperate" ones. I sometimes wonder how many are described as one but are actually the other...:)

I've been a devotee of plywood tanks for a long time, and have noticed that the few different pleco-type catfish I have owned would generally avoid feeding on the tank walls if provided with wood. In the absence of wood, they always appeared to favour rocks over the epoxy-coated plywood walls. Since I always had a nagging concern in the back of my mind about damage to the epoxy, I always provided a fair bit of wood to alleviate my worries. I never clean the sides or back of a tank, so biofilm was certainly present; but they seemed to prefer getting it off wood first.

To my way of thinking, if a fish displays a preference for one thing over another, be it food, substrate, decor, plants, lighting, current, whatever...it is only natural to cater to that preference if doing so is safe and practical. I wouldn't keep single specimens of schooling fish...or borrowers/sand-sifters on coarse gravel or bare bottoms...or lurkers/hiders without suitable cover...or plecos without plenty of wood. Not saying they need it...but lacking it just might cause some low-level stress, so why not provide it?

Vacuuming the surface of a sponge hose with a siphon goes a long way towards keeping the wood debris at bay.

Interesting thread.
 

RD.

Gold Tier VIP
MFK Member
May 9, 2007
12,413
10,613
3,360
62
Northwest Canada
To my way of thinking, if a fish displays a preference for one thing over another, be it food, substrate, decor, plants, lighting, current, whatever...it is only natural to cater to that preference if doing so is safe and practical.
The only comment that I would add to that is this - in captivity IME the vast majority of plecos, including those that are considered "wood-eaters", will choose a meaty/fatty food over wood, 100% of the time. At least IME, I have never owned one that didn't. Once they get a taste for a food with a large nutrient payload, wood is only used to brush their teeth. lol In that case, and this goes with many species of fish, most animals, and even humans, the preference of one thing over the other should not necessarily dictate how we keep them in a glass box. I also don't believe that a pleco (wood eating or not) is stressed from a lack of wood in their tank, if all other parameters are being met. A wild fish, maybe? A captive raised pleco, hmmm, doubt it.

I have nothing against wood in a tank, one of my set ups has had wood as part of the natural decor for many years, I just don't feel as strongly about it being a requirement in keeping a healthy & thriving fish, wood-eater, or not.
 

jjohnwm

Redtail Catfish
MFK Member
Mar 29, 2019
1,196
2,778
154
Manitoba, Canada
I have nothing against wood in a tank, one of my set ups has had wood as part of the natural decor for many years, I just don't feel as strongly about it being a requirement in keeping a healthy & thriving fish, wood-eater, or not.
Yes, but...are they happy? Despondent? Spiritually fulfilled? Are their lives fraught with quiet desperation? Are they given the chance to rise to and overcome intellectual challenges? Are they forced to periodically question and examine their own beliefs and morals? Are they burdened with crippling existential angst?

Sorry, ever since I was accused recently of "humanizing" fish I go off on these tangents...:)
 

Fishman Dave

Potamotrygon
MFK Member
Nov 14, 2015
1,110
2,268
164
50
West Yorkshire
Surely a fish that has evolved over thousands of years to rasp on and eat wood has done so for a reason, and I cannot see how the reason has been a lack of meatier substitute.
My royal is in a tank with plenty of wood and is continually demolishing it. All my tanks get meaty feed and pellets and the royal actively ignores the meaty substitute for the wood.
I personally disagree that a fish designed to eat wood would prefer a different diet or would fare exactly the same or better on a different diet, or that being tank raised would have a difference over being wild caught for one or two generations, although having never been shown or brought up with wood would of course force them to feed on something else which in turn would make us think they were perfectly ok (I won’t us the term happy) eating other foods other than wood.
I am with jjohnwm jjohnwm on this one, if a fish eats wood in the wild then why wouldn’t we provide that at least as an option in our aquariums.

As for happy and unhappy. I’ve been doing this for over forty years now and I can certainly spot an unhappy fish or a happy fish, so yes fish have the capacity to be happy, albeit that is most probably not in the same way humans do.
 
Last edited:

RD.

Gold Tier VIP
MFK Member
May 9, 2007
12,413
10,613
3,360
62
Northwest Canada
As for happy and unhappy. I’ve been doing this for over forty years now and I can certainly spot an unhappy fish or a happy fish, so yes fish have the capacity to be happy, albeit that is most probably not in the same way humans do.
I've been observing fish in the wild, and in glass boxes, for 50+ years, and one thing that I have observed over that timespan is that there have been many myths & misconceptions repeated by the masses over those years. Such as protein causing bloat, something that I wrote about in great detail many years ago, one of those old posts was later made a sticky here on MFK. Bloat - Causes - Cures - and BIG Myths | MonsterFishKeepers.com
Yet this was the belief for decades, with many "experts" stating the same.

Many members here believed, and no doubt some still do, that eating wood is part of a nutritional requirement of plecos that rasp on wood in the wild, as though they would die without it. lol They don't. Which is why I posted the following close to a decade ago, and it too was made into a sticky.
Can Plecos Digest Wood? | MonsterFishKeepers.com


I also wrote the following many years ago, and IMO the exact same thing applies to "wood eating" plecos.

In the wild, the cichlids found in the Rift Lakes have evolved & adapted to living in certain niches of the lake, which over time has forced them to become specialized feeders. (as per Ad Konings) Yet all of these specialized feeders will readily eat anything that's available. (as per Ad Konings) While a fish classified as a strict herbivore (such as a Tropheus moorii) may indeed spend its entire day scraping the aufwuchs, I can assure you that they would much rather eat a handful of worms if given the opportunity. In the wild they eat low quality foods because that's the only foods available, not because they choose to!

And while Tropheus and various Mbuna species may in fact be classified by the scientific community as strict herbivores, the reality is that even though algae dominates the stomach contents, the actual foods that make them grow are insect nymphs and larvae, crustaceans, snails, mites, micro-organisms, and zoo plankton, not vegetable matter. (as per Ad Konings)

Their long digestive tracts are designed as such so that in nature they can break down the complex plant matter that they consume, which doesn't mean that they can't properly assimilate more easily digestible forms of protein. Apparently this is a concept that some hobbyists fail to grasp.


Keep in mind that the vast majority of fish are opportunistic feeders, and are all omnivorous to a certain extent. Cichlids classified as carnivores don't just eat meat, any more than a herbivorous cichlid just consumes vegetable matter.



Plecos in the wild don't eat wood because they "enjoy" eating a **** sandwich all day, every day. They do so to survive. This feeding behavior was not created out of a need for enjoyment, or pleasure, or because it makes plecos happy, it was part of an evolutionary trait that was the result of the natural feast or famine cycle that nature forced this genus/species in to. Wood eating plecos have evolved and adapted to survive under conditions where most fish would perish. And if you read the previous scientific papers that were linked to in the other thread on this topic, you will understand that the wood eating behavior is out of the need (in the wild) to utilize & promote certain bacteria in their gut. We cannot assume that this is the same requirement in a glass box, or that the same microbiome is being created in a captive fishes gut, vs those same species in the wild. Sorry, not so simple. I welcome future research on this subject.

BTW - when I used the term "meaty foods", I was referring to higher protein/fat pellets, not market prawns etc. And I can state that I have seen many "wood eating" species of plecos, with LOTS of wood in their tank, go straight for the pellets when they had the opportunity. I have observed that exact behavior, over several decades, and numerous "wood eating" plecos. Gee, I wonder why? Might it be that in captivity, just as in nature, these fish have learned to adapt, to a diet that is nutritionally speaking far superior to gnawing on a chunk of Malaysian bogwood? Hmmmm. Stupid fish?


Seeing as some folks like to anthropomorphize their pet fish, allow me to add this. A fish that has survived the cruelty of feast or famine for thousands of years, and has learned to be happy with eating a **** sandwich daily, has more than likely also adapted enough over those thousands of years that when a steak dinner falls in their lap, they can very happy eating that as well. Maybe even more happy than when eating the former? Stupid fish?

And again, there are safe substitutes to wood for a pleco to rasp on - if one chooses to keep this group of fish without wood. I am in no way attempting to tell anyone that one way is better, just sharing an alternative way to also successfully keep this genus of fish in captivity. Sans wood, they won't starve to death, and they won't die from being unhappy.
 
Last edited:

jjohnwm

Redtail Catfish
MFK Member
Mar 29, 2019
1,196
2,778
154
Manitoba, Canada
Looking at this from the standpoint of nutrition, it seems obvious that the wood isn't strictly necessary. Plecos, like other animals, have evolved...not learned...to utilize food sources that are available to them, and have developed behaviours and structural modifications to further that goal. The occasional windfall of animal protein that comes their way...whether in nature or in the aquarium...will be welcomed, of course, but the structure of their mouths developed over millennia to allow the rasping of wood. Obviously the behavioural instinct to do so is equally ancient. After generations of evolution gifted them with those amazing mouth structures, plecos didn't suddenly wake up one morning and realize "Hey, holy crap! I CAN EAT WOOD!" I would think that as the mouthparts and the behaviour developed, it began as a way of simply removing the biofilm form the surface of the wood as a food source, and as time progressed the wood itself became an additional resource. But however it happened...it happened. Now they can do it, and feeding them pellets will not cause them to lose that instinct to rasp on wood.

African cichlids pick away all day at rocks, scarfing up quantities of aufwuchs in the hope that they will also glean some small bits of animal protein in there along the way...but, of course, what other choice do they have? And, a nice juicy worm or crustacean will always be a welcome treat, not to be turned down. But they still instinctively "want", for lack of a better term, to pick and rasp at rocky structures. The biggest difference, from the aquarists viewpoint, is that most Africans will be too aggressive to keep without rocks or other structure, so few people will deprive them of it.

I'm sure we will eventually see a study hinting that piranhas roam the waterways in packs, singlemindedly searching for a Massivore pellet somewhere but being forced to skeletonize the occasional cow just to keep up their strength for the quest.

Why is it that civilization is so overpopulated with so many obese individuals? People and their pets...dogs, cats, reptiles, fish, you name it...are often morbidly overweight and out of shape. Surely at least part of the explanation is that all organisms crave and desire and seek the richer foodstuffs, loaded with fat and protein, that would be lacking in their diets if they were forced to live in a natural uncivilized way. Skinny hominids traipsing across the veldt, dodging megapredators and scrounging food, ate what they could find, and that was likely to be mostly vegetable matter with the occasional leftover carcass thrown in...so that's what their bodies evolved to utilize, but of course they were always looking for that next protein/fat "fix". They could never get enough of those items, let alone too much, so they always "wanted" them. We lucky civilized humans have relatively easy access to those coveted goodies, and so we overindulge ourselves and our pets with the good stuff. The age-old desire for fat/protein has outlasted the actual shortage of these items in our diets, and so we tend to eat way more of both than our bodies are equipped to handle.

I want healthy fish...and I also want "happy" fish, in this case meaning that if I can satisfy the natural instincts they have developed over time, without detrimental side-effects, I will do so.

It makes me happy! :)
 
zoomed.com
hikariusa.com
aqaimports.com
Store