Pterygoplichthys is everywhere

[Silurus]

Two additional reports on alien Pterygoplichthys:

Levin, BA, PH Phuong & DS Pavlov, 2008. Discovery of the Amazon sailfin catfish Pterygoplichthys pardalis (Castelnau, 1855) (Teleostei: Loricariidae) in Vietnam. Journal of Applied Ichthyology 24: 715–717.

Hossain, MY, MM Rahman, ZF Ahmed, J Ohtomi & ABMS Islam, 2008. First record of the South American sailfin catfish Pterygoplichthys multiradiatus in Bangladesh. Journal of Applied Ichthyology 24: 718–720.

[Richard B]

Blimey!

Are these introduced as a readily available food source? or released by irresponsible fishkeepers? Are there actions underway to eradicate them?

[Silurus]

Nobody eats these things outside of S America, AFAIK.

[Bas Pels]

In NL a warning goes around against giving large Pteroboblichthys away for free - as they are said to be eaten

I can't say whther this is true or not, it does sound too much like an urban legend to me

[MatsP]

In NL a warning goes around against giving large Pteroboblichthys away for free - as they are said to be eaten

I can't say whther this is true or not, it does sound too much like an urban legend to me

That is of course less of an issue than them being released into a river where they may survive - probably not too much risk this far north, but...

--
Mats

[Shane]

released by irresponsible fishkeepers?

Bangladesh... Vietnam, Not exactly bastions of the tropical fish keeping hobby...
-Shane

[Janne]

Vietnam is growing quite fast as a breeding country for ornamental fishes and India have also many breeders around Kolkata which is close to Bangladesh...but I dont think (dont know) if Bangladesh either have any breeders or culture for ornamental fishes.
India is a very large country in the "aquarium hobby" and maybe they should investigate some rivers in India too if they not have done that already, Brahmaputra flows through both these countrys.

Janne

[Jools]

HH will confirm if my memory serves me correctly, but I am sure at one of the fish breeders we visited in Jalpaiguri (North East India) was breeding plecos.

Jools

[sidguppy]

Bangladesh... Vietnam, Not exactly bastions of the tropical fish keeping hobby...
-Shane

your probably right, but as it is one of those countries with low wages, I'll bet some entrepeneur might see a huge oppertunity of fishBREEDING there....

low wages, low costs to buy swamps of land, no need for heating, water comes for free when monsoon comes around etc.

I'll bet it costs next to nothin g to set up a huge tropical fishfarm up there.

unfortunately when the monsoon is a big bigger than average and the place floods, the exotics get everywhere.

another scenario might be that the pleco's originate upstream. China has a rapidly growing upperclass and fishkeeping is going through a boom in China.
some Chinese might dump their outgrown pleco's and these simply have to swim downstream to end up in Vietnam.

[lfinley58]

Hi all,

Regarding the comment on where Pterygoplichthys are (or not) eaten: It has been reported that these catfish(es) first came to the attention of fisheries people in Hawaii via finding locals, mainly of Asian extraction as I recall, collecting the egg masses from the caves created by the guarding males. While the catfish themselves were apparently not favored, the eggs were considered to be a stir fried delicacy.

Lee

[Birger]

I seem to remember there also was something awhile ago about about people catching and barbecuing some from a river in Florida where it caused a stir with fisheries because it is considered a non-game fish.

[Shane]

The eggs are a delicacy throughout the Amazon and there is certainly no reason not to eat them. I have seen them mostly "cooked in the shell" directly over a fire in the Amazon. Further north they are cooked and the meat is used in soup, "Sancocho de Corroncho." Many Venezuelans swear by it as a remedy for the common cold. Sort of their version of chicken soup.

-Shane

[sidguppy]

I seem to remember there also was something awhile ago about about people catching and barbecuing some from a river in Florida where it caused a stir with fisheries because it is considered a non-game fish.

odd.
my thought is that the best way to cope with an exotic pest is to make it a favorite dinner
soon everybody fires up the barbie when there's pleco's to be caught, maybe even commercialize em and mass-catch them; end of problem

now, if only cane toads were edible or made great soup, Australia would be short of 1 problem......can we foist those off on the Chinese as a rare medicin against colds or so?
1.5 billion Chinese can make a fair dent in the cane toad plague....

[apistomaster]

Blimey!

Are these introduced as a readily available food source? or released by irresponsible fishkeepers? Are there actions underway to eradicate them?

Once Pterygoplichthys are established in a drainage system they are next to impossible to eradicate. Eradication works best in still waters like lakes. Even when fish killing chemicals like rotenone are used there are always survivors of the pest species while the natives are more likely to be the species eradicated.
Then just as there will always be arsonists, there will always be environmental terrorists. Whenever a species is targeted for eradication and the work is carried out, almost always someone reintroduces them.

[Mike_Noren]

Although Pterygopichthys seems to have caused some river bank erosion issues in the US and there is some speculation they might cause changes in the aquatic vegetation, they seem a lesser problem worldwide than the four horsemen of the aquatic biodiversity apocalypse: Tilapia, Gambusia, Goldfish, and Trout.

[racoll]

Although Pterygopichthys seems to have caused some river bank erosion issues in the US and there is some speculation they might cause changes in the aquatic vegetation, they seem a lesser problem worldwide than the four horsemen of the aquatic biodiversity apocalypse: Tilapia, Gambusia, Goldfish, and Trout.

While presenting no direct evidence of ecosystem effects, Hoover et al. (2004) present many likely risks. I would bet if someone quantitatively studied this, they would be significant, especially in locations like this one in Mexico:



So,

Pterygoplichthys

are now established in:

Vietnam
Indonesia (Java & Sumatra)
Malaysia
Singapore
Philippines
Taiwan
Florida
Hawaii
Puerto Rico
Texas
Bangladesh
Mexico

Here are some references for those records:

Chavez et al., 2006
Nico & Martin, 2001
Wakida-Kusunoki et al., 2007
Sabaj, 1999
Hoover et al., 2004
Bunkley-Williams et al., 1994
Gibbs et al., 2008
Page & Robins, 2006
Hossain et al., 2008
Levin et al., 2008

I would be most interested if anyone had any more records/references, and if anyone wants any of these, let me know.



[edit: thanks jools]

[racoll]

Hmmm, the YouTube tags don't seem to be working for me.

Here is the url: http://www.youtube.com/watch?v=5bK5wg2tZ0U

[Silurus]

You left out Thailand.

ftp://ftp.fao.org/docrep/fao/008/a0113e/a0113e11.pdf

[Jools]

Hmmm, the YouTube tags don't seem to be working for me.

They're working fine, you just need to use...

Code: Select all

[youtube]5bK5wg2tZ0U[/youtube]

Jools

[Silurus]

Time to add South Africa to the list.

http://www.witness.co.za/index.php?show ... d%5D=17047

[Richard B]

This is becoming more alarming every day

[Mike_Noren]

That youtube video was interesting. Do Pterygoplichthys normally form dense schools like the one seen in the video? I thought they were pretty much solitary or even territorial?

[racoll]

Can we add the UK to this list?

Was this fish dumped in a canal and died immediately, or did it die of other causes after a long life in the canal?

I suspect the former, but if lots of little baby gibbiceps turn up.....

Link: http://www.telegraph.co.uk/news/newstop ... shire.html

[Silurus]

We already know it’s in Poland.

Now it’s in Serbia.

[Shovelnose]

I think India can be added to the list too. Collected fry of a Pterygoplichthys Sp very close to the city of Madras. I remember reading a checklist which reported the existence of the Plecos here but it is eluding me at the moment.

[bronzefry]

It will be interesting to see what has happened to the Florida population of this species after the extremely cold winter they had. The non-native snake population has been reduced drastically. To the point where they couldn't find ANY in the Everglades. They usually find tons. Fish farms also had massive die-offs. I haven't seen anything about the non-native fish populations further north. (i.e. the group seen attached to Manatees.)
Amanda

[Suckermouth]

A friend of mine is studying cane toads and was successful in collecting some, so not all tropical animals are gone. I imagine the Pterygoplichthys live with the manatees are okay as they use that area as a winter refuge because there is a warm spring there.

[Shovelnose]

Is this Pterygoplichthys disjunctivitis???? Was spotted as part of fisherman's catch near Madras last Saturday.

[Suckermouth]

It's either a pardalis or disjunctivus. I'd guess pardalis on this one...

[Birger]

: P. pardalis has a spotted pattern, where P. disjunctivus has a vermiculated pattern