Could the common bristlenose pleco be Ancistrus martini (A. bodenhameri)?

[racoll]

It's been a while since I first starting this thread back in 2012 after DNA sequencing a common Ancistrus and trying to put a name on it ...

Little has happened since then, but the genetic databases have been slowly filling up with wild caught material. I hoped that, one day, someone in South America would sequence a fish from a native population and we'd get a match. I even wrote some code last year to automate the phylogenetic analysis, called 'ancistr' (@Jools suggested this because it's written in R language). See https://github.com/boopsboops/ancistr.

So, I ran it today, and up pops a match from a newly submitted sequence:

Ancistrus martini

(synonym Ancistrus bodenhameri) caught near Cúcuta, Colombia, in the Maracaibo Basin.

Here is the report (download the html file and open in your browser): https://www.dropbox.com/scl/fi/vk6jixqv ... tm96i&dl=1.

I know @Shane knows a lot about this region, so will be interested to hear his opinion. Looks like he was on the money back in 2007!

It's possible that these are common aquarium trade bristlenose simply released in Colombia, but the collection site while close as the crow flies, appears to be in a separate catchment to Cúcuta, so they would have to be quite wide distribution if they are there.

Remember the usual caveat: mitochondrial DNA (COI) here, so it does not tell us much about hybridisation. However, it is a starting point to investigate further. So far we have common bristlenose samples from New Zealand, South Africa, Germany, South Korea. All of these fall in the same cluster, so looks like these all have the same maternal inheritance.

[Edited to fix missing localities in the report - please download again]

[Catfish-ologist]

Amazing! I'm super excited to here how this progresses. This may have been what was necessary to jump start the confirmation of a proper I.D.
This is a great jump in the right direction!

Cheers,
-- Sean

[bekateen]

That's exciting news! Gone may be the days of A. "cf. cirrhosus." Good luck with the data!

[Jools]

Exciting! I regret not having time to take "Ancistr" further - one day - I think it is / would be useful to get some UK, Czech and particularly US data into the mix.

Cheers,

Jools

[Shane]

I am in Vegas for work this week and will jump on this as soon as I am home. There was also a major paper published on Ancistrus from this region published a couple of years ago that may provide us with some additional clarity.

One very interesting thing was that they described a new Ancistrus from Villavicencio that shares its range with A. triradiatus. It may be possible that we have seen this new sp in the hobby and misidentified it.

-Shane

[Jools]

@racoll, I've shared the doc @shane, @lfinley58 and had worked on. Let me know guys if you have lost access to it. It's been a while......

Jools

[Shane]

To fully cover this, I need to rehash some taxonomy so that we can all be on the same page.

In "Catfishes of Venezuela" (1944) Schultz described Ancistrus brevifilis bodenhameri and Ancistrus triradiatus martini as two new sub species. In 1980 Isbrucker raised both to the species level (and many subsequent authors agreed). In 2013 Taphorn, Armbruster, Villa-Navarro, and Ray in their paper "Trans-Andean Ancistrus" considered A. bodenhameri to be a junior synonym of A. martini. A. martini is thus the only currently valid Ancistrus species from the Lake Maracaibo basin.

As noted above Rupert submitted genetic material from common Ancistrus specimens (AKA Ancistrus sp 3) from New Zealand, South Africa, Germany, and South Korea. A recent submission of a specimen collected in the Maracaibo basin and identified as A. martini was submitted to the same database and came up as a match.

As Rupert also noted,
"Remember the usual caveat: mitochondrial DNA (COI) here, so it does not tell us much about hybridisation. However, it is a starting point to investigate further. So far we have common bristlenose samples from New Zealand, South Africa, Germany, South Korea. All of these fall in the same cluster, so looks like these all have the same maternal inheritance."

If Ancistrus sp. 3 is a "pure" species it is likely identifiable as A. martini. If it is a hybrid, they have maternal inheritance from A. martini. Photos I have seen identified as wild caught A. martini appear to match very well with Ancistrus sp. 3.

I must admit that I am skeptical about the decision to lump A. bodenhameri and A. martini. Both were described in the same paper by the same author as subspecies of two different species. Taphorn et al noted that morphometric analysis failed to detect significance differences. They also noted that pigmentation patterns in A. martini showed great individual variation and thus may encompass the pattern ascribed to A. bodenhameri. If the fish available as A. sp Cucuta is in fact from the Maracaibo drainage it may represent A. bodenhameri. Hopefully, further investigation and collections from the area will answer this question.

-Shane