Practice lab

Before we go to the Cibolo Creek for our actual study, we are all learning to carry out the proper protocol. Today we started learning the protocol using feeder fish from Wal Mart.

From Dr. Bonner's grad student:
While your proposed project is very interesting and ambitious, my main concern would be about the feasibility of undertaking such a project. Though your future teacher probably has some of the materials required, it is very unlikely that he has the equipment and supplies adequate for this project. Studies such as this require labs that are dedicated to this type of work (This is why CNC sends their samples to TPWD) and the process is much more complicated than it sounds in the paper. Another way to identify potential hybrids is by counting fin rays and scales. I have attached a paper that discusses this method of identifying potential hybrids. This would be much more feasible but it would require keeping and preserving or freezing the fish.

To answer your questions, we typically use lures that look like either minnows or crawfish to catch Guadalupe bass. If you want to use live bait, minnows would work best but then you run the risk of introducing non-native species into the stream if you don’t know where the baitfish came from (I would strongly recommend lures). You can catch them pretty much any time of the day and they are usually found along the edge of where fast moving water meets slow moving water or around tree roots sticking into the water. The most distinguishing features of a Guadalupe bass are the tall, diamond-shaped bars on the side of the fish and a tooth patch on its tongue (some largemouth bass will have a tooth patch too, but they won’t have the diamond-shaped bars). If you do clip the fin of the bass, you only need to take one 1 cm clip and you can divide that in half later (also, you have to sterilize your scissors and tweezers between fish to avoid cross contamination). Non-denatured alcohol is the best way to store the fin clips (your science teacher would probably have to order it from a scientific supply company to get it) and you can just throw the vials away when you are done with them. Their fins will regenerate within a couple of weeks depending on the size and health of the fish. A minimum of 15 to 20 fish would be needed to have anything informative (for either genetics or counting fin rays/scales). Catching the same fish twice could be a problem given a long enough time for the fin to regenerate; however, you would be lucky to catch the same fish twice if you only collect 15 to 20. As far as my samples, I will be doing the lab work myself but I have not started my lab work yet so I can’t give you an estimate on how long it takes.

Overall, I think that the project that you are proposing is probably too ambitious as the resources your teacher has available are probably not adequate to accomplish the project. I don’t want to discourage your enthusiasm for biology, but this is my honest assessment. On the other hand, using the fin ray and scale counts to identify potential hybrids is very feasible provided you can preserve or freeze the fish and would probably be your best option (also be aware of any fishing regulations such as length limits or bag limits if you are going to keep any fish). I hope I have answered all of your questions.