6 replies to this topic

[catfishcain]

These Mollies where netted from the Arroyo Colorado River in Harlingen, Texas where a canal/creek runs into the river at Hugh Ramsey Nature Park. The river itself was extremely murky and muddy but the water draining into the river from the canal/creek was actually clear. Where the two waters mixed is where I was able to net a good number of tiny mollies in a single swop of the net. At first I was about to dump them all back into the river thinking they were gambusia but noticed they were thicker then the typical gambusia I seen in that area. Now I believe these are Poecilia formosa (Amazon Molly). There are not many photos or good quality photos available online of the Amazon Molly but I did notice that the Amazon Molly does have horizontal rows of spots on its sides fairly similar to the ones shown on these mollies. But then again I could be wrong as this is the first time I have ever dealt with mollies. Below is the location where I netted and released the mollies.

[mattknepley]

More really neat stuff, Levi. I'm hardly convinced, but after consulting Peterson's I might lean more towards shortfin molly, P. mexicana. This is based on the location of the dorsal fin, the spots on the side, and the orange on the anal fin and the orange tinge to the caudal. Dorsal fin location rules out sailfin molly.

That said, you were certainly in range for Amazons, the dorsal fin location matches Amazons, and the habitat and lack of males in the pictures makes P. formosa a very real possibility. Add to this the fact that I had to call in help to verify a sailfin ID in SC, and it's obvious I'm only a half-educated guess at best here.

I still have a hard time wrapping my mind around species like Amazons that only consist of one sex. I can read the explanations as to how such a thing occurs, but still... Thanks for posting!

[don212]

theres a previous strand about orange colored mollies in san marcos river in texas

[Matt DeLaVega]

LOL. Strand=thread. I like it.

[catfishcain]

Neat, I can see the resemblance between shortfin and the ones above. But from the quick search I did I haven't found any info on them being found in the wild in Texas. If they are shortfin then Id say they are definitely reproducing in the wild because even though I netted quite a few in one sweep of the net. There were a lot more that I missed and all of them were around an inch in length.

[gerald]

I dont see any features that scream "not latipinna". Adult male lat's have the dorsal origin far forward, but in female and juvenile lat's the dorsal origin is about the same as in your fish. I counted 12-14 dorsal rays on your pix, which is in the normal range for latipinna.

http://txstate.fishe...a latipinna.htm

http://txstate.fishe...lia formosa.htm

BTW, I wonder how that dorsal-shifting-forward phenomenon in males works. Would be a cool project to x-ray a young male once a week as he grows and track what's happening to his skeleton, Any dentists or radiologists here?

[Matt DeLaVega]

All three species look pretty similar to my untrained eye.