Tuesday, August 11, 2009

An Apparent Explanation For Gill Fluke Pattern

I think I've finally found a reasonable explanation for what we found in telescope shiners, where the peak in breeding condition as measured by gonadosomatic index is very closely correlated with gill fluke infection in the April - July breeding season. I came across a paper by Andrea Simkova and other Czech biologists who work with Dactylogyrus gill fluke infections of European cyprinid fishes like roach. They have found a similar pattern with roach to what we've found with telescope shiners, that the infection of fish with gill flukes goes up in the breeding season. This is attributed to fish putting so much energy into producing eggs and sperm that their immune system is impaired, allowing parasites to increase in number. This basic pattern holds with other parasites such as liver flukes, but apparently is most obvious with the gill flukes. It makes sense to me; I'm still unclear on the exact nature of the fluke life cycle such as life expectancy but I'm working on that, too. I become more fascinated by parasites as time goes on, partially for the creepiness of their life cycles and partially I'm in awe of the influence parasites have on community structure and energy flow through trophic webs.

Our registration numbers are way up at UAH this semester. There are currently 473 students in our BYS 119, Biology I, classes, compared to 440 last year. And the Dean's office is convinced that we could peak at 525 because many students, both transfer and incoming, still haven't registered (school starts next Wednesday). So business is good and we're scrambling to find enough students to teach our lab sections. As of today we have 19 lab sections, compared to 18 a year ago, and we're probably going to add a Saturday morning lab section for the first time in ~25 years. Biology is now a hot major, so away we go! And many of these incoming students are much better prepared than has been the case in the past.

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