I am crossing another item off my BYU wish list as I get a chance to work as a TA for my boss over the summer. The class he wants me to help with is BIO 557, Stream Ecology. Now since it is a 500 level class that means I’ve never taken it. He was pretty desperate for some help. 500 level classes are for graduate students so true to form the class has nine students, seven of which are studying for masters degrees. The other two are PhD candidates. I’m in deep water. How do you TA a class which you have never taken filled with people older, better educated, and more experienced than you are? Well, I guess you just do it.
The main reason I am there is for the field trips. They have a major project that involves doing stream measurements, the same measurements that I took in my work in the Uintas over the summer. Yesterday we had our first fieldtrip. I haven’t been so intimidated for… okay, for a little while. We went to the mouth of Hobble creek, a place I’ve worked before although the water has dropped significantly. The area was built a few years ago in an attempt to restore June Sucker habitat and ten ponds were excavated in the flood plain. Back in July when we sampled the area all the ponds and river were connected by the runoff. Now the river has dropped considerably and the ponds are separate from the river, little aquatic islands of treasure.
Walking in we noticed a strange red algae on the first pond. It almost looked like motor oil had spread across the top. I waded in and filled a test tube with the stuff. As the students (graduates) practiced taking slope and measuring the flow of the stream I had a minute to peak into our second pond. I had to dodge a few snakes to get over to it but failed to dodge the mosquitos which are remarkably bad in this swamp. Although they are nearly invisible the welts last for days.
Approaching the pond I first saw the bugs coating the water surface. Nasty welt-producers. Then I saw the mosquito fish and minnows coating the pond surface. Finally I saw something that made me pause a minute. I could see two fish at the bottom of the pond, maybe two feet deep. They were around 8 inches and had catfish whiskers. They were swimming very close together, head to tail, and were circling a dark spot like the two halfs of yin and yang. They were staying very close to that dark spot and it took me a minute to figure out why. I thought it was just a shadow and they were staying there to avoid the sun or hide but then I realized there was nothing to cast a shadow. As I looked closer I realized that the spot was moving. It was made up of hundreds or thousands of small black larval fish.
They weren’t avoiding the sun, they were feasting on some newly hatched eggs. I could only imagine the terror of the little fish as the big fish circled again and again. Surely they were getting mowed down by the dozens with each pass. Then I saw something interesting, a small 2 inch fish approached the swarming mass and one of the large fish attacked it and chased it around the pond. It appeared that it didn’t want to share the fishy feast.
Then it dawned on me that perhaps this wasn’t a feast but a family outing. The more I watched the more it looked like the two large fish were parents. They stayed close to their 2000 twins and kept them corralled together in safety. When enemies or predators approached the parents would do their best to chase them away and lead the young to safety in clumps of cattails. I chided myself for my sentimental musings. Fish don’t protect their offspring, and they certainly don’t pair bond. They’re fish, they barely have brains.
I returned to the students and as they worked on figuring out the various tools of the trade I mentioned it to the professor who said it was likely a feeding frenzy just as I had first thought. He walked over to take a look and went through the same stages of thought that I did. Minus the last minute doubt about there being any fish that would behave in such a way. This was a family outing and he had a name for the fish.
Black Bullheads are a type of catfish very common throughout America. I haven’t found a lot of information on them but they do pair bond for a while to protect the eggs and the fry for the first couple weeks. I’m not sure how long these marriages last but they are listed as a monogamous species and quite dedicated parents.
So there you go. The graduate students got to play with slope and flow instruments and I got to see a rare natural example of a working marriage trapped in a shrinking pond in a man made flood plain along a small Utah creek.