Impact of Measuring Techniques on Study of Pomacea - 2007

[Zardeenah]

Here is an interesting abstract from a paper presented as part of a symposium at Southwestern University (TX). The papers were written and presented by students in 2007, and covered a wide variety of interesting subjects. It discusses how measurement standards need to be adopted in order to accurately describe which exotic species are invading an area and in which proportion. I found it interesting anyway.

I'll quote the relevant abstract:

Comparing Applesnails to Oranges: the Impact of Different Measuring Techniques on the Study of Pomacea

Abigail Youens, Dept. of Biology, Southwestern University
Sponsor: Romi Burks, Dept. of Biology, Southwestern University

Exotic invasive species threaten native species, especially in freshwater ecosystems. Applesnails (genus Pomacea) -- large aquatic gastropods that can reach the size of an apple -- have historically been global exotic invaders. These macrophagous snails cause considerable damage to plants, which raises both ecological and economic concern. P canaliculata exhibits an extensive invasive history in Asia and recently established populations in California and Arizona. A much less well-known exotic species, P. insularum, has invaded freshwater and brackish systems in the Houston, Texas area. Very little ecological information exists about P. insularum. However, this larger applesnail may pose similar threats to those posed by P. canaliculata, thus warranting concern. In the present study, we analyzed body size relationships of P. insularum and the use of different body measurements within literature on P. canaliculata to explore methods to study this new exotic invasive species. Shell height, operculum width, and eight exhibited highly predictive relationships. We also tested the inter-measurer reliability of shell height and operculum width and argue that operculum width constitutes a more reliable measure. P. canaliculata researchers most often measure shell height, but operculum width may be better suited for study of the potential new invader P. insularum. When providing new information on a novel invasive species, establishing methodology may aid in later comparisons between studies.

http://www.southwestern.edu/fromeveryvo ... gram07.pdf

Houstonians, hang on to your snails! Don't make the problem worse. : )