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18 04 2011

Watch out D. lumholtzi there is a new predator on the rise!

Posted by: Meghan Thomas in Uncategorized, tags: , , , ,

Daphnia lumholtzi most notable characteristics are its pointed helmet and large spines.  2 features that make the D. lumholtzi difficult to feed on allowing it to prosper as an aquatic invasive species. It was first introduced in 1990 in Texas and can now be found throughout southeastern USA.

Philip W. Lienesch and Moshe Gophen of the University of Oklahoma’s department of Zoology and Biological Station, are interested if inland silverside (Menidia beryllina) are size-selective predators of D. lumholtzi. By placing 3 various sizes of  inland silversides in tanks with various sizes of D. lumholtzi, Lienesch and Gophen were able to determine inland silverside’s feeding habits. Smaller inland silversides preferred smaller D. lumholtzi, while the larger fish ate the large D. lumholtzi. Next Lienesch and Moshe tested their results in Lake Texcoma, comparing D. lumholtzi to native Daphnia, results were similar to labratory experiment, suggesting that when zooplankton is scarce, D. lumholtzi could become a food source for juvenile silversides.

Lienesch, P.W., and M. Gopen. 2005. Size-selective predation by inland silversides on an exotic cladoceran, Daphnia lumholtzi. The Southwestern Naturalist 50, 158-165.

This entry was posted on Monday, April 18th, 2011 at 1:38 pm and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.



2 Responses to “Watch out D. lumholtzi there is a new predator on the rise!”

  1.   Jacquelyn Davey Says:
    April 18th, 2011 at 3:34 pm

    I find this very interesting. Do you think it is a possibility for zooplankton to become scarce, thus causing D. lumholtzi to become a more common food source for the silversides? Also, would you ever consider adding more silversides to the environment in order to control the population size of D. lumholtzi?

  2.   Meghan Thomas Says:
    April 19th, 2011 at 11:13 am

    Hi Jacquelyn! I definitely think it is possible for zoo plankton to be scarce. They are like any other organism who has predators and whose population fluctuates. Yet, for them to become scarce it would take a while to happen and a significant cause. Also, according to Lienesch and Gophen it does sound possible. I think adding more silversides would be a great bio-control solution for managing and maybe even eradicating D. lumholtzi. However, a lot goes with that, making sure introducing the silversides won’t upset the balance of the ecosystem or the native silversides. There definitely needs to be more research!