FishBase says "RTC is introduced but not established in Florida." Anyone knows more?

[Viktor Jarikov]

Does anyone know anything about this?

I've not done much digging deeper than what FishBase states in RTC "Biology" Section: Feeds on fish, crabs and fruits (Ref. 6868). The species is introduced but not established in Florida. http://www.fishbase.us/summary/Phractoc ... terus.html

Note lack of reference for the last statement... but I'd not think this would refer to sporadic illegal releases but likely to a controlled state-allowed / sponsored release, no?

[Silurus]

When FishBase uses that term, they mean release into the wild, be it sporadic or large-scale. Here is more information on the status of the RTC in the US.

[bekateen]

Hi Victor,

I can't answer your question from personal knowledge, but I followed up on this and found the following info:

The website http://nas.er.usgs.gov/queries/FactShee ... ciesID=838 lists "non-indigenous occurrences" for the RTC, some of which have citations. The number of confirmed discoveries is "2-5" in Florida for 2015. The website describes its status in Florida as "Failed;" sorry, I don't know what that means. Also, the website lists "Probable aquarium release" as the means of introduction.

After reading your post, I also followed your link and visited the fishbase page, which led me to ponder another question. So as not to hijack your thread, I'm posting my thoughts in a separate thread (viewtopic.php?f=37&t=41845).

Cheers, Eric

EDIT: Oops, ninja'd by Silurus. Oh well.

[Viktor Jarikov]

Thanks much, guys.

Am I imagining it wrong or over-thinking? To establish to me would mean that sexually mature adults of both sexes should be present for a significant time period and enough of them and they should procreate and multiply successfully enough to not diminish the existing population. No?

It appears that the evidence of several, maybe half a dozen dead RTCs in FL should not lead to the "failed to establish" conclusion. The more proper wordage could be "failed to survive". To say they failed to establish, I'd think a large scale experiment needed to be carried out. I do get that failure to survive invariably negates establishment too but we don't know how many perished and how many survived per se.

So IMHO, "apparently(?) failed to survive" describes the findings more rigorously and clearly whilst "failed to establish" confuses. Maybe it's just me but, for illustration, one can say "RTC failed to establish in Africa". This statement would carry little sense as opposed to "RTC does not survive in salt water", which is the reason RTC has not colonized Africa (if that was that simple but it's a start at least).

So, my tangent is: there could have been a "large-scale experimentation". Hence, again, does anyone know more?

[Viktor Jarikov]

IIRC, A Florida Wildlife Commission officer from Miami, who paid me a visit as a part of my getting business licenses said something to that regard - that RTCs have been experimented with in FL by FWC, as in released in numbers but have not formed a self-sustaining population. It's been 3 years since then and I'm getting foggy on my memory.

Hence, I asked the community.

[mcdaphnia]

A USCG map shows it present near some coastal areas in Florida, Louisiana, and Texas. Oddly a fisherman's report of catching one in a Florida lake suggests a reason for the FWC to introduce it. This was a lake populated by snakeheads so introducing the redtail as a predator to reduce the snakehead population sounds like something a government agency would try. And passing the blame to the citizenry for a government sponsored introduction also fits the pattern for numerous government financed introductions of plants and animals that did not go as planned.