Identity of Pterygoplichthys spp. invading India

[racoll]

Bijukumar, A., R. Smrithy, U. Sureshkumar & S. George (2015). Invasion of South American suckermouth armoured catfishes

Pterygoplichthys

spp. (Loricariidae) in Kerala, India - a case study. Journal of Threatened Taxa 7(3): 6987–6995; http://dx.doi.org/10.11609/JoTT.o4133.6987-95.

[Shane]

Nicely done paper.
-Shane

[bekateen]

Interesting note in the M&M:

Out of the 1,023 specimens collected, 102 specimens were separated at random and transported live to the laboratory and the remaining fishes were released back into the water body, for ethical reasons.

I appreciate why the investigators did not want to harm the 921 animals which were not used for the study. But I am surprised that the fish would simply be returned back into the waterways, given the negative impacts these plecos have on native ecosystems. I suppose two reasonable justifications for their action are (1) the challenge of finding new homes for 900 big plecos is probably insurmountable, and (2) since the plecos are reportedly breeding year round in this environment, then 900 individuals, while it sounds like a lot, is probably a "drop in the bucket" in terms of total pleco population number; and therefore, removing 900 fish would likely have little impact on the total population or on the damage the population is causing to the ecosystem.

[Bas Pels]

Good find, Bekateen.

I think these ethical reasons might have to do with religion - in Hinduism and Buddhism people look rather different towards the killing of animals then in other religions.

To us the matter is rather strange - one collects a thousand unwanted fish, and returns 900 - but when one sees killing as wrong, I think this becomes is different.

Perhaps someone from India could explain?

[Shovelnose]

I think these ethical reasons might have to do with religion - in Hinduism and Buddhism people look rather different towards the killing of animals then in other religions.

Indeed, a significant number of Hindus are vegetarian and hence, refrain from killing animals of all kinds. In fact, some Jains (from Jainism, another Indian religion), even wear masks so as to not kill even the smallest living creature (http://en.wikipedia.org/wiki/Vitalism_%28Jainism%29).


Edit : Religion not withstanding, the most sensible thing to do in this case would have been to cull them all.

[biju]

Thank you for the comments on the Peterygoplichthys spp invasion in India. The release of large number of fish back to the system is purely based on ethical reasons. This issue was commented by one of the reviewers of the paper as well. The release of course will not impact help eradication of species, as the system is fully chocked with the species, each cast net operating yielding 30-50 individuals of more than 30 cm in size weighing up to 50 kg!

Regards

Biju
University of Kerala

[bekateen]

Thank you, Biju, for that info.
Cheers, Eric