Six species of exotic molluscs known to be established in Texas are: Asian clam (Corbicula fluminea), applesnail (Pomacea insularum), red-rim melania (Melanoides tuberculatus), quilted melania (Tarebia granifera), giant rams-horn snail (Marisa cornuarietis), and Chinese mysterysnail (Cipangopaludina chinensis). Because the current status of C. fluminea, and P. insularum in Texas was recently reviewed (Karatayev et al., 2005; Howells et al., 2006), in this report we concentrated on the analysis of the history of spread, current distribution and potential impact of other exotic gastropods established in Texas. Over 20 waterbodies, most of them known to have populations of exotic gastropods, were sampled in 2006-2007. We found that M. tuberculatus continue to spread in Texas and are already present in at least 27 waterbodies and 18 counties. In contrast to M. tuberculatus, other exotic gastropods are limited to thermally stable spring-fed ponds and streams and did not expand their distribution during the last 30 years. Tarebia granifera was found in the San Antonio River, San Marcos River, and Comal Springs, M. cornuarietis was found only in San Marcos River and Comal Springs. The single well established population of C. chinensis was found in Kidd Springs (spring-fed city park pond) in Dallas, Tarrant County The main vector of spread of exotic gastropods in Texas is aquarium release. In addition, these snails might be spread with scientific equipment that was not adequately disinfected.
The results of the survey are in preparation for publication.
Sampling in Las Moras Creek, Kinney Co., March 2007.Alexander Karatayev. Photo: Lyubov Burlakova
Melanoides tuberculatus (Red-rim melania) from Las Moras Creek, Kinney Co.,
March 2007. Photo: Lyubov Burlakova.
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Exotic gastropods Melanoides tuberculatus (Red-rim melania).Balmorhea State Park, Reeves County. March 2007. Photo: Alexander Karatayev.
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Melanoides tuberculatus (Red-rim melania) from Devils River, TX
March 2008. Photo: Lyubov Burlakova.
