As for what is wrong with your pleco, it is hard to tell from your pic, better ones would help a lot. However, if the fish has white marks one both sides of its head in similar places, they may be scrapes. Plecos like to squeeze into tight spaces. Sometimes they try to fit into a place that is just too small and they scrape themselves finding out by having first to force their way in and then getting back out.
Sorry, I cannot let go of incorrect information re panaqolus not being "plecos." (I have met Shane and hear him speak at weekend fish events.) The below is from Planetcatfish.
Shane's World
Catfishology
Just Say Pleco
Article © Shane Linder, uploaded January 01, 2002.
First published in Tropical Fish Hobbyist, June 1999 and reproduced here with permission.
What is a Pleco?
The term "pleco" is used, in the aquarium hobby, to describe any member of the family Loricariidae (pronounced, lohr-ih-care-EE-id-dee). The family Loricariidae is by far the largest of the over thirty known catfish families. There are more than 450 species of Loricariids known to science and at least 200 more that have been discovered but not yet scientifically described. Besides being known as the plecos, Loricariids are also called "suckermouth catfishes", "armored catfishes", and "armored suckermouthed catfishes". This is because the combination of their heavy armour and suckermouths easily distinguish the Loricariids from all other catfishes. .........
Why Do We Call Them Plecos?
Here is the somewhat convoluted story, as near as we can reconstruct, of why we generically call Loricariids plecos. The first Loricariid imported was, most likely, what we now call Hypostomus plecostomus (Hypo= underneath; stomus=mouth and pleco=plated, in case you were wondering) from eastern Venezuela and Trinidad. This does seem quite likely as, in addition to H. plecostomus, many of the earliest aquarium fishes, such as Guppies and Corydoras aeneus, were also imported from this area. However, we can never say for sure that the fish imported was H. plecostomus. We can only say that whatever the Loricariid imported was, people thought it was H. plecostomus.
The name Plecostomus plecostomus was applied to Hypostomus plecostomus for many years. It was probably the genus name Plecostomus that was shortened to pleco. Let's face it, Plecostomus is a mouth full! A study of the name Plecostomus in the scientific literature was done in 1968 by M. Boseman. Boseman found that the name Plecostomus had been used before Hypostomus. Normally in taxonomy the first name suggested has priority and becomes the official name. However, for various reasons, the International Commission on Zoological Nomenclature (ICZN) decided Plecostomus should not be used and Hypostomus should. The ICZN decides which scientific names are valid, so the genus Plecostomus has not been valid for over thirty years. To add to the confusion, many hobby books published after 1968 kept using the old Plecostomus name.
from https://www.planetcatfish.com/shanesworld/shanesworld.php?article_id=175&title=Just+Say+Pleco
Next, Plecostomus was never a family. The fish in question is:
Family: Loricariidae
Sub-Family: Hypostominae
Genus: Panaqolus
Species: maccus
Finally,
Even more important is this (I have posted this on this site before in another thread re panaqolus diet.
https://www.planetcatfish.com/forum/viewtopic.php?f=14&t=49153&p=324889&hilit=wood+eat#p324889
And the simple conclusion from the scientists in this thread about the "wood eating" panaqolus
" This is where it gets interesting. Rotten wood may be the way to go. "
"Putting it in my own words, these fishes live from the rotting bacteria, not from the wood itself.
Or would this be to bold to state? "
" No, I think that is right."
Basically, the wood is useful but not as the direct source of nutrition for the panaqolus. In a tank they can be fed many things not wood and they will be fine.
" These fish really like to have something to chew on. Squash, cucumber, and other vegetables should be readily available to them (yams are a favourite). Supplement two to three times weekly with frozen foods. "
However, if we put wood in our tank it rots over time. This requires bacteria. So eating the rotted (soft) wood means eating the bacteria. The wood may still contain some fiber as do the veggies mentioned above.
Sorry, I cannot let go of incorrect information re panaqolus not being "plecos." (I have met Shane and hear him speak at weekend fish events.) The below is from Planetcatfish.
Shane's World
Article © Shane Linder, uploaded January 01, 2002.
First published in Tropical Fish Hobbyist, June 1999 and reproduced here with permission.
What is a Pleco?
The term "pleco" is used, in the aquarium hobby, to describe any member of the family Loricariidae (pronounced, lohr-ih-care-EE-id-dee). The family Loricariidae is by far the largest of the over thirty known catfish families. There are more than 450 species of Loricariids known to science and at least 200 more that have been discovered but not yet scientifically described. Besides being known as the plecos, Loricariids are also called "suckermouth catfishes", "armored catfishes", and "armored suckermouthed catfishes". This is because the combination of their heavy armour and suckermouths easily distinguish the Loricariids from all other catfishes. .........
Why Do We Call Them Plecos?
Here is the somewhat convoluted story, as near as we can reconstruct, of why we generically call Loricariids plecos. The first Loricariid imported was, most likely, what we now call Hypostomus plecostomus (Hypo= underneath; stomus=mouth and pleco=plated, in case you were wondering) from eastern Venezuela and Trinidad. This does seem quite likely as, in addition to H. plecostomus, many of the earliest aquarium fishes, such as Guppies and Corydoras aeneus, were also imported from this area. However, we can never say for sure that the fish imported was H. plecostomus. We can only say that whatever the Loricariid imported was, people thought it was H. plecostomus.
The name Plecostomus plecostomus was applied to Hypostomus plecostomus for many years. It was probably the genus name Plecostomus that was shortened to pleco. Let's face it, Plecostomus is a mouth full! A study of the name Plecostomus in the scientific literature was done in 1968 by M. Boseman. Boseman found that the name Plecostomus had been used before Hypostomus. Normally in taxonomy the first name suggested has priority and becomes the official name. However, for various reasons, the International Commission on Zoological Nomenclature (ICZN) decided Plecostomus should not be used and Hypostomus should. The ICZN decides which scientific names are valid, so the genus Plecostomus has not been valid for over thirty years. To add to the confusion, many hobby books published after 1968 kept using the old Plecostomus name.
from https://www.planetcatfish.com/shanesworld/shanesworld.php?article_id=175&title=Just+Say+Pleco
Next, Plecostomus was never a family. The fish in question is:
Family: Loricariidae
Sub-Family: Hypostominae
Genus: Panaqolus
Species: maccus
Finally,
Even more important is this (I have posted this on this site before in another thread re panaqolus diet.
https://www.planetcatfish.com/forum/viewtopic.php?f=14&t=49153&p=324889&hilit=wood+eat#p324889
And the simple conclusion from the scientists in this thread about the "wood eating" panaqolus
" This is where it gets interesting. Rotten wood may be the way to go. "
"Putting it in my own words, these fishes live from the rotting bacteria, not from the wood itself.
Or would this be to bold to state? "
" No, I think that is right."
Basically, the wood is useful but not as the direct source of nutrition for the panaqolus. In a tank they can be fed many things not wood and they will be fine.
" These fish really like to have something to chew on. Squash, cucumber, and other vegetables should be readily available to them (yams are a favourite). Supplement two to three times weekly with frozen foods. "
However, if we put wood in our tank it rots over time. This requires bacteria. So eating the rotted (soft) wood means eating the bacteria. The wood may still contain some fiber as do the veggies mentioned above.
