Parasites and Pesticides: An Uncomfortable Truth

Yesterday, I found a rather odd tree frog on the side of our house. It appeared to have two sets of front limbs, which is quite rare and indicative of a potential parasite, the trematode.

See anything strange here?

Just for comparison...

I further investigated causes for deformed limbs in frogs and found an interesting article from Earth Observatory discussing Dr. Joseph Kiesecker's experiments on pesticide and parasite exposure to tadpoles (so, yes, this does fall into the category of aquatic ecology).

http://earthobservatory.nasa.gov/Newsroom/view.php?id=22544

From this article I learned that agricultural pesticides that are washed into aquatic systems (ag runoff) may negatively impact tadpole immune systems. The weakened tadpoles are thus more susceptible to infection from trematodes and are more likely to form cysts that may result in limb deformities. The scary part is, the concentration of pesticide necessary to initiate this effect is equal to or less than the acceptable amount present in drinking water, aka, if you live in an agricultural area you may be consuming these types of pesticides.

 So, how do these trematodes get to the tadpoles, and why do they cause these deformities? Well, the trematode utilizes several hosts in order to reach its definitive host, a wading bird. The infected frogs have deformities so that they are easier for these birds (herons for example), to catch and consume.

Trematode Life Cycle

So, I bet you're wondering just how precise these trematodes are at finding their hosts? Unfortunately, if you've ever had swimmer's itch, you've been infected by this trematode. Trust me, I got it a time or two while collecting snails, it's not the end of the world. If you were in a tropical system though, you might run the risk of getting Schistosomiasis, a potentially fatal infection that kills millions each year. And that's why I prefer waders to bare skin in stagnant waters.

Meet the New House Guest!

After about a week, I decided that enough chemicals had evaporated out of the tank for me to introduce an organism. Unfortunately, the only day I had enough time to get a goldfish from my mom's pond was one of the hottest days this season (upper 90's). This presented some problems, first off, my mom doesn't live that far away, but I have to take curvy back roads. This meant that on the way back I would need to drive slowly, thus making the hot car ride even longer and potentially stressing the fish out too much.

When I arrived, my mom asked if I would prefer to take some pond water or well water. I hadn't considered what type of water I would be taking the fish home in, so I was stumped. I didn't want to put pond water in my tank for fear of adding parasites, but I also didn't want to add well water because of the high levels of metal. In the end I took some pond water for the fish's sake and only added a little bit with him during introduction.

Speaking of introductions, my youngest cat, Mojo, has taken an interest in the fish, to the point that I was afraid to head to work that day. I was relieved to come home and find everyone where they should be.

Mojo checking out our house guest.

I'm planning on acquiring my divider tomorrow and should be getting some mosquito netting in the mail Tuesday. At this rate, I'll be able to get some plants and substrate and then finally insects!

Research Shows...

While my water is aging, I decided to do some more research on keeping aquatic insects. Most of what I found were forums discussing what species work well together, but I was pleased to find a website from the University of Kentucky giving more set up details that I need.

http://www.uky.edu/Ag/CritterFiles/casefile/bugconnection/petbugs/Kentucky/aquatic.htm

It noted that before adding insects to the tank, a filter should be ran and a fish should be introduced for a few days. The purpose of this is to introduce certain microorganisms along with algae to help maintain homeostasis later on. I'm thinking of borrowing a goldfish from my mom's pond for this purpose. I believe this to be a better plan than buying a pet store goldfish because one raised in a pond will have already coexisted with the type of microorganisms that would be present in a naturally occurring body of water and not to mention I would be able to return it to the pond after a couple days.

The utilization of plants within the tank was also listed at the website. This is still an issue for me because I would like to acquire plants directly from the habitat, but I am leery of introducing parasites, pathogens, and dipterans (fly larvae). I am planning on scoping out the plant selection at a few pet and garden stores for something close to what I need that hopefully won't cost too much. Ideally the plants I choose will provide both food and cover without introducing any kind of chemicals that might harm my insects.

Before I start any of this I still need to acquire some necessary pieces to the tank like the divider, aerator, and mesh to go over the top. My hopes are to have all of these and a fish in the tank by this time next week.

Let's Get Tanked!

My latest project is creating an aquatic insect tank. It seemed simple enough, I mean, I've had fish before and no problem, but after doing some research I found that creating a tank suitable for aquatic insects requires a bit more work. Firstly, since the insects I'll be collecting are from stream habitats a constant current and high level of oxygen is necessary. Secondly, I want to collect both predator and prey species, but if put together there would be obvious problems, so a barrier would be necessary. Thirdly, the temperature needs to stay rather cool to maintain oxygen levels, but my apartment doesn't exactly have central air. Finally, most aquatic insects are naiads, or aquatic larvae of flying adults, so there will be an emergence or two to deal with.

So, I decided to just take it one step at a time, and try to come up with solutions along the way. As of now, I have a 20 gallon tank inherited from my mom's storage, along with a filtration system, cover, and a means to change water. Today, I'm going to fill the tank with water and let all the chemicals evaporate out over the next week or so. I'm hoping to get a few more pieces to the tank during this time, such as an aerator, thermometer, some sort of mosquito netting or cheese cloth, and a plastic divider.

The tank's current state.

Hopefully, I'll be able to get the ball rolling and have some awesome insects to show off in the next week or two!