The term alien species is synonym of introduced, exotic, non-indigenous, or non-native species. Refers to a species living outside its native distributional range, which has arrived there by human activity, either deliberate or accidental. Non-native species can have various effects on the local ecosystem. Introduced species that become established and spread beyond the place of introduction are called invasive species.

The term alien species is synonym of introduced, exotic, non-indigenous, or non-native species. Refers to a species living outside its native distributional range, which has arrived there by human activity, either deliberate or accidental. Non-native species can have various effects on the local ecosystem. Introduced species that become established and spread beyond the place of introduction are called invasive species.

You could try " human mediated or extra-limital range expansion/ or just range exapansion" see Davies et al. 2013 - Farm dams facilitate amphibian invasion: Extra‐limital range expansion of the painted reed frog in South Africa, Austral Ecology 28

Ecological fitting

I agree with Dr. Luis Miguel Constantino, An alien species is a species introduced outside its normal distribution.

Alien species or non-indigenous are the most commonly used terms

Alien species is wider than adventive species. E.g., I described from the Carpathians a species of Parastenocaridae harpacticoid copepode that belongs to the Ethiopian fauna – it is alien for the region of Central Europe. Alien can be even appeared accidentally in small amount or one specimen but adventive (lat. adventicius) is an immigrant population that appears in the area after some expansion caused by different reasons – both natural and man-caused.  An example can be appearance in Europe some eastern Asian fish species. Sometimes first action can be man-caused by after that works nature! The most sencitive into adventive species are the ruderal habitats. Adventive can be even endemial species – named in this case neo-endemial (!) – e.g., steppe pole-cat (Mustela eversmanii) in Germany.  It penetrates from South steppe zone into previously wooden area after devastating of forests.So, you can use for such species term NEO-ENDEMIAL species (compare with PALEO-ENDEMIAL).

A.

What about "Translocated"

Try "translocated species" in google schoolar for several examples; just the first one:

"Although species translocated within the United States can also have significant impacts, this assessment is limited to non-indigenous species that did not originate within the United States or its territories"

from:

https://www.researchgate.net/profile/Lori_Lach/publication/259640053_Environmental_and_Economic_Costs_of_Nonindigenous_Species_in_the_United_States/links/543fa0e40cf27832ae8bab50.pdf

Article Environmental and Economic Costs of Nonindigenous Species in...

Hi Dario,

I think that Dr. Luis Miguel Constantino's answer it's not only correct but prudent. Many of these terms are synonyms and/or they not exclude each other, a non-native species can be invasive, introduced species may have different invasive potentials, some exotic species might not be invasive, and so on.

There are many other concepts that may be related to these terms but if used, can drive into confusion. As I said, many don't exclude each other and some should be applied for specific cases. Scale and the stage of the invasion play an important role in defining how to call the species of interest, as suggested in attached papers.

Hope it helps!

Article A proposed unified framework for biological invasions

Article A neutral terminology to define ‘invasive’ species

The original question stats that the species under question is one that has been found in a different area of the known distribution within the political boundaries of a country. The questions are: how well known is the current distribution of that species in that country? How well known are the basins in that country? How well known are the canals uniting basins in that country? Probably the species in question has always inhabited such area that is only now been studied. Thus, I suppose, that before we can discuss about a name for a species, either exotic, native, etc., the researcher needs to knows about the natural history of the place versus the anthropogenic actions in the place. There are many places, in different continents that still remain largely unknown. There are many places, in every country, that are almost unknown because of the geography of the place and or its isolation, etc.  An interesting problem!

Thanks to all your interesting answers. The term I'm searching was "translocated" as Carles Alcaraz suggests. Also knowing the our interests species distribution is crucial as Gloria Arratia says.

If could be usefull, I report here the definitions framework I'm using for my PhD thesis about alien species.

The references are taken (in addition to those suggested by Juan Felipe Albarracin-Caro ) from Kolar, C.S. and Lodge, D.M. (2001). Progress in invasion biology: predicting invaders. Trends Ecol. Evol. 16, 199-204 and from Walther, G.R., et al. (2009). Alien species in a warmer world: risks and opportunities. Trends Ecol. Evol. 24, 686-693.

Alien species (or allochthonous, introduced, exotics, non-indigenous): a species occuring outside both its natural past or present range and dispersal potential, whose presence and dispersal is due to intentional or unintentional human action.

Invasive alien species (or pests. Although with this definition researchers refers to noxious species for agriculture and in general field crops): an established alien species that are rapidly extending their range in new regions. Usually associated with an organism that cause significant harm to biological diversity, ecosystem functioning, socio-economic values and human health in invaded regions.

Established: an alien species (invasive or not) with a self-sustaining population outside of its native range.

Naturalized: an alien species without a self-sustaining population in the introduced area. Due to ecological conditions, the adult individuals living in the new habitat did not breed.

Native species (autochthonous): a taxon that has originated in a given area without human involvement or that has arrived there without intentional or unintentional intervention of humans.

I can not recall where I have seen that term years ago, but I remember that they called a species under the circumstances you describe as 'transplanted' or 'translocated'. But I am not sure if these terms are really the correct ones and in use today.