I believe it was 2013 or 14.
And I didn't bring any back, collecting, keeping alive in transit on flights, and trying to go thru customs is not so easy. The paperwork to do it legitimately is quite complicated and grueling, not to mention expensive. I give a bow to those who get the proper permits and go thru the trouble.
You'll notice in the vdeo, they are not densely populated. I circumvented the entire cenote at least twice, and saw maybe 1 every 20 ft or so, maybe only 10 individuals in all. The video is edited down from an hour of shooting, in most of it there weren't any, just Astyaax tetras, and live bearers. It may have been different if I used hook and line, and fished it in a deep area.
Where I live in Panama at the moment, no animals can leave the country unless a research permit is acquired.