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The identity, distribution, and impacts of non-native apple snails in the continental United States.

Rawlings TA, Hayes KA, Cowie RH, Collins TM - BMC Evol. Biol. (2007)

Bottom Line: Based on sampling to date, we conclude there are five species of non-native apple snails in the continental U.S. Most significantly, we recognize three species within what has been called the channeled apple snail: Pomacea canaliculata (California and Arizona), Pomacea insularum, (Florida, Texas, and Georgia) and Pomacea haustrum (Florida).The term "channeled apple snail" is descriptive of a morphology found in many apple snail species.It does not identify a single species or a monophyletic group.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biological Sciences, Florida International University, University Park, Miami, Florida 33199, USA. Timothy_Rawlings@capebretonu.ca <Timothy_Rawlings@capebretonu.ca>

ABSTRACT

Background: Since the mid 1990s populations of non-native apple snails (Ampullariidae) have been discovered with increasing frequency in the continental United States. Given the dramatic effects that introduced apple snails have had on both natural habitats and agricultural areas in Southeast Asia, their introduction to the mainland U.S. is cause for concern. We combine phylogenetic analyses of mtDNA sequences with examination of introduced populations and museum collections to clarify the identities, introduced distributions, geographical origins, and introduction histories of apple snails.

Results: Based on sampling to date, we conclude there are five species of non-native apple snails in the continental U.S. Most significantly, we recognize three species within what has been called the channeled apple snail: Pomacea canaliculata (California and Arizona), Pomacea insularum, (Florida, Texas, and Georgia) and Pomacea haustrum (Florida). The first established populations of P. haustrum were discovered in the late 1970s in Palm Beach County Florida, and have not spread appreciably in 30 years. In contrast, populations of P. insularum were established in Texas by 1989, in Florida by the mid to late 1990s, and in Georgia by 2005, and this species continues to spread rapidly. Most introduced P. insularum haplotypes are a close match to haplotypes from the Río Uruguay near Buenos Aires, indicating cold tolerance, with the potential to spread from Florida, Georgia, and Texas through Louisiana, Alabama, Mississippi, and South Carolina. Pomacea canaliculata populations were first discovered in California in 1997. Haplotypes of introduced P. canaliculata match native-range haplotypes from near Buenos Aires, Argentina, also indicating cold tolerance and the potential to establish farther north.

Conclusion: The term "channeled apple snail" is descriptive of a morphology found in many apple snail species. It does not identify a single species or a monophyletic group. Clarifying species identifications permits a more accurate assessment of introduction histories and distributions, and provides a very different picture of the tempo and pattern of invasions than was inferred when the three species with channeled sutures were considered one. Matching introduced and native-range haplotypes suggests the potential for range expansion, with implications for native aquatic ecosystems and species, agriculture, and human health.

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Shells of Pomacea insularum and Pomacea canaliculata collected within the continental U.S. Apertural and abapertural views of two specimens of: a. Pomacea insularum from Lake Tohopekaliga, Florida; b. Pomacea canaliculata from Mecca, California. Scale Bar: 5 cm.
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Figure 6: Shells of Pomacea insularum and Pomacea canaliculata collected within the continental U.S. Apertural and abapertural views of two specimens of: a. Pomacea insularum from Lake Tohopekaliga, Florida; b. Pomacea canaliculata from Mecca, California. Scale Bar: 5 cm.

Mentions: Introduced populations of Pomacea canaliculata are genetically distinct from those of P. insularum, based on mtDNA sequences (Fig. 1), but these species have similar shell morphologies (Fig. 6). The egg masses of P. canaliculata, although bright reddish pink, like those of P. insularum, contain fewer but larger eggs (Fig. 3c) [27]. Clutches of Pomacea insularum often exceed 1,000 eggs (Fig. 3e). The variability in clutch size reported for P. canaliculata [4,30] may reflect inclusion of data for other species, particularly P. insularum. There is some preliminary evidence that these species are reproductively isolated [31].


The identity, distribution, and impacts of non-native apple snails in the continental United States.

Rawlings TA, Hayes KA, Cowie RH, Collins TM - BMC Evol. Biol. (2007)

Shells of Pomacea insularum and Pomacea canaliculata collected within the continental U.S. Apertural and abapertural views of two specimens of: a. Pomacea insularum from Lake Tohopekaliga, Florida; b. Pomacea canaliculata from Mecca, California. Scale Bar: 5 cm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1919357&req=5

Figure 6: Shells of Pomacea insularum and Pomacea canaliculata collected within the continental U.S. Apertural and abapertural views of two specimens of: a. Pomacea insularum from Lake Tohopekaliga, Florida; b. Pomacea canaliculata from Mecca, California. Scale Bar: 5 cm.
Mentions: Introduced populations of Pomacea canaliculata are genetically distinct from those of P. insularum, based on mtDNA sequences (Fig. 1), but these species have similar shell morphologies (Fig. 6). The egg masses of P. canaliculata, although bright reddish pink, like those of P. insularum, contain fewer but larger eggs (Fig. 3c) [27]. Clutches of Pomacea insularum often exceed 1,000 eggs (Fig. 3e). The variability in clutch size reported for P. canaliculata [4,30] may reflect inclusion of data for other species, particularly P. insularum. There is some preliminary evidence that these species are reproductively isolated [31].

Bottom Line: Based on sampling to date, we conclude there are five species of non-native apple snails in the continental U.S. Most significantly, we recognize three species within what has been called the channeled apple snail: Pomacea canaliculata (California and Arizona), Pomacea insularum, (Florida, Texas, and Georgia) and Pomacea haustrum (Florida).The term "channeled apple snail" is descriptive of a morphology found in many apple snail species.It does not identify a single species or a monophyletic group.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biological Sciences, Florida International University, University Park, Miami, Florida 33199, USA. Timothy_Rawlings@capebretonu.ca <Timothy_Rawlings@capebretonu.ca>

ABSTRACT

Background: Since the mid 1990s populations of non-native apple snails (Ampullariidae) have been discovered with increasing frequency in the continental United States. Given the dramatic effects that introduced apple snails have had on both natural habitats and agricultural areas in Southeast Asia, their introduction to the mainland U.S. is cause for concern. We combine phylogenetic analyses of mtDNA sequences with examination of introduced populations and museum collections to clarify the identities, introduced distributions, geographical origins, and introduction histories of apple snails.

Results: Based on sampling to date, we conclude there are five species of non-native apple snails in the continental U.S. Most significantly, we recognize three species within what has been called the channeled apple snail: Pomacea canaliculata (California and Arizona), Pomacea insularum, (Florida, Texas, and Georgia) and Pomacea haustrum (Florida). The first established populations of P. haustrum were discovered in the late 1970s in Palm Beach County Florida, and have not spread appreciably in 30 years. In contrast, populations of P. insularum were established in Texas by 1989, in Florida by the mid to late 1990s, and in Georgia by 2005, and this species continues to spread rapidly. Most introduced P. insularum haplotypes are a close match to haplotypes from the Río Uruguay near Buenos Aires, indicating cold tolerance, with the potential to spread from Florida, Georgia, and Texas through Louisiana, Alabama, Mississippi, and South Carolina. Pomacea canaliculata populations were first discovered in California in 1997. Haplotypes of introduced P. canaliculata match native-range haplotypes from near Buenos Aires, Argentina, also indicating cold tolerance and the potential to establish farther north.

Conclusion: The term "channeled apple snail" is descriptive of a morphology found in many apple snail species. It does not identify a single species or a monophyletic group. Clarifying species identifications permits a more accurate assessment of introduction histories and distributions, and provides a very different picture of the tempo and pattern of invasions than was inferred when the three species with channeled sutures were considered one. Matching introduced and native-range haplotypes suggests the potential for range expansion, with implications for native aquatic ecosystems and species, agriculture, and human health.

Show MeSH
Related in: MedlinePlus