The photo shows the Poecilia latipinna, Mustang Island collection site.
This post is about the saga of Poecilia latipinna and Siegen University in Germany.
Years ago we got an order from Siegen University for Poecilia latipinna (our native green sailfin molly) from Comal Springs in New Braunfels, Texas. The fish were wanted for research into female sexual preferences. They University wanted that particular P. latipinna population because they had used it before and they wanted 125 pairs. It was in January. In the winter you’d have to collect thousands of fish to get 125 males. Why? Because this species ceases reproduction in October and doesn’t resume until March. While females produce roughly the same number of males and females per brood, males, once they color up, are exposed to a much higher predation rate than females. As a result, by January there are only one or two mature males to 100 females. Now, some of the “females” are probably young males who will color up in the Spring, so the sex ratio isn’t quite that bad. I advised the University of this, and they agreed to take 250 fish, with as many males as possible and the rest females. Once in Germany, the fish were to be placed under 14 hours per day lighting and kept above 70ºF. This would trick the fish into thinking it was spring and they’d begin to reproduce and any undeveloped males would mature.
Cara (my daughter and at that time employee) and I went to Comal Springs in a New Braunfels city park and found a knee deep pool with thousands of mollies. We seined up at least a thousand and got only a handful of males. The fish were shipped to the University.
Fast forward to Fall 2013. Siegen University wanted 60 pairs of wild Poecilia latipinna again. So, I went to scout out Comal Springs. Unfortunately, the City of New Braunfels had in the interim banned wading in the pool in which the mollies congregate during the winter. I surveyed the lake fed by the springs and found the mollies too dispersed to economically capture 60 pairs. I advised the University and it was decided that another P. latipinna population could be substituted.
My first attempt to find them was Coleto Creek where we had collected hundreds of fish in the past. Ashley (our hatchery technician) and I gathered up seines, buckets, bags, boxes, etc. and headed out to Coleto Creek. Alas, the site we usually collect was a victim of Texas’ extended drought. There was no surface water. The creek was now running underground.
The next try was Coleto Creek reservoir, which is downstream of my preferred collection site. This lake is used as a cooling lake for a coal-fired power plant and as such is maintained full by pumping water, when necessary, from the Guadalupe River. I surveyed it and once again found the mollies too dispersed.
Thinking of other potential sites, I remembered collecting some very nice P. latipinna from the Guadalupe River at Victoria probably 30 years ago. I scheduled a collecting trip. Unfortunately, before we could make the trip, it rained hard and the river was flooding. I know, Texas is in drought, but I’ve heard a meteorologist describe Texas climate as “persistent drought with occasional flooding.” We’d found the flooding stage. In a few weeks the river had returned to drought conditions and we set off on a collecting trip. We found not a single molly after trying multiple sites. The population I’d collected decades ago no longer existed. I reported this to the University. They despaired of ever getting any mollies and implored me to continue looking.
By this time it was May 2014. My wife, Susie, had planned a family long weekend outing to Port Aransas, Texas on Mustang Island. I blogged about this trip before (see Poecilia latipinna Mustang Island). On that trip I planned to search for mollies and so advised the University. During the trip Susie, four of our children, and five grandchildren did some collecting in the bay where I hoped to find some fish for the University. No luck in the bays. So, we tried a freshwater drainage ditch and hit pay dirt. Lots of mollies including a decent ratio of males to females. None of the fish were large, but they were sexable. I advised the University and in late July Ashley and I collected the fish.
That proved to be the easy part. It turned out we had to coordinate with the University’s trans-shipper, the US Department of Agriculture, our vet, and American Airlines. I won’t give the blow-by-blow, but it took until until late August before Siegen University got their fish.
As a result of collecting extra fish, we now have Poecilia latipinna, Mustang Island and will soon be offering them.