Pterygoplichthys pardalis maximun size

[hfjacinto]

Hello all,

I have a question regarding the maximum size of Pterygoplichthys pardalis. I read in the cat-a-log that its maximum size is 13.8 (inches –SL). I currently have one that is around 8 inches (it’s hard the measure the sucker when he is moving). I have had him for over 3 years and the last year the growth has slowed in that he grew only around ½ inch. The first year he went from 2 inches to 5 inches, second year he went from 5 to over 7 and this year he went from over 7 to around 8 inches. Is the slowdown of this much growth normal? When do they attain maximum size? How long do they live? Do all grow to around the same size?

The tank he is now is a 45 gallon tall (36 x 12 x 20), I know the tank is small for a fish this size and I was planning on getting a 90 gallon in the future to house him/her. I do large weekly water changes of 50%.

The parameters are as follows:

PH 7.4 to 7.6
Nitrates 30 to 40 PPM
Nitrite 0
Ammonia 0

I don’t change the tap water parameters, so the water supply we have is hard and alkaline with some nitrates already present in the water.

The tank is densely planted with 2 filters running all the time.

The pleco’s get algae wafers, sinking pellets, frozen brine shrimp and some zucchini. There bellies always look full

[MatsP]

It's natural for most fish to slow down in growth, but I would expect your fish to grow a little bit more than that.

However, a 45g tank is on the small side for an 8" fish, so you shouldn't really "wish it grows faster".

--
Mats

[Bas Pels]

I have 2, I got them some 3 years back. Than the were around 25 cm (10 inches) I would guess them to be around 40 cm (16 inches) by now

I've seen more fishes trying to cope with a wrong environment, and if they get released into a better one (their tank measures 270 cm, that is 9 feet) they can restart growing

I have a relative (P gibbiceps (if it is really this species) for over 15 years. I would assume pardalis, being slightly smaller, will not life as long as gibbiceps, but this gibbiceps is not ancient yet.

I might have it for another 15 years, so expect pardalis to reach 25 years or more.......

[hfjacinto]

Even though I think it is a Pardalis I am not sure and several species are listed as common Pleco's. The LFS that I purchased from stated that these "common pleco's" tend to get around 9 inches and he hasn't seen any larger of these type. He has several gibbiceps that are over 1 foot long.

From the pictures it looks like a Pardalis (belly wise) but from the top it looks like a gibbiceps.

I would love a 3 meter long tank but the wife would never allow it. They will have move to a 90 gallon sometime next year. Until I get the tank the large water changes will keep on happening.

[MatsP]

Most "commons" are P. pardalis/P. disjunctivus - both grow to almost identical size, but of course, if they are kept in small tanks, they tend to not get enough excercise as well as hing nitrate levels, either which doesn't exactly make them grow quickly.

--
Mats

[bruiser]

I find the maximum size posted here hard to believe. I have one that's 15 inches and still growing. In the wild, they can get up to 24 inches and I see no reason the same can't be true in a 75+ gallon aquarium. Also, as far as I now, every animal naturally slows growth after some time. If we grew at the same rate as we did when we were babies, we'd be 25-30 feet by the time we're 20-years-old. Everything's probably fine.

[Silurus]

In the wild, they can get up to 24 inches

Where is this source of information from? In briefly perusing the scientific literature, I find no reference to fish bigger than 320 mm (12.5") SL (the length of the fish minus the caudal fin), so the Cat-eLog is about right.

[minipol]

I bought a P. pardalis that was 28cm when I bought it.
I has grown 2 cm in 3 years. Tank where it was originally housed was 270cmx90cmx70cm.
Now it's in my 3m tank.

From the growth rate, I guess it was already 5 to 7 years old when we bought it.
He's now 30cm, and if I look at the growth rate of the last 3 years, it grows about 0,5 cm a year
but I don't expect him/her to grow much larger.

[Corycory]

I am a bit late answering this thread but anyway...
I have a common pleco, possibly pardalis or a cross with disjunctivus. I've had him for over 5 years. He's now 12" but that's including his tail. He tends to grow steadily each year, rather than having a growth outburst and then slow down.
I'd say based on my experience at 3 years 8" is normal and they tend to grow about 2" a year. But I measure this from nose to tail so mine has more growing to do and it doesn't seem it's stopping yet.
Food amount and quality of food plays as an important role as the water quality and tank size.
A lot of people keep these in aggressive tanks where the pleco doesn't get much food despite the size of the tanks.
However, I think P.Pardalis don't grow as large as some other types of "common" plecos. P.Gibbiceps grows way larger and faster...so it depends what you have...

The good part is, mine is a very docile fish these days, comes to my hand for food, tolerates and is gentle amongst small fish as he grew up with them(a bunch of corydoras), and still cleans the glass daily and even make upside down attempts on plant leaves without damaging them.