The key to a successful invasion may lie in living fast and dying young. University of Iowa biologists studying a species of freshwater snail found that lineages that were the most successful invaders matured and reproduced more quickly than noninvasive counterparts within the species. Credit: Carina Donne, Colorado State University
Key Points:
- Asexual snails have been successful invasive species, despite having low genetic diversity.
- For invasive species, there is a major advantage to the combination of slow growth rate and early reproductive maturity.
- The measure of a species’ reproductive success could possibly be used to predict which species would make good invaders, thereby enabling early prevention measures.
Researchers at the University of Iowa have discovered “live fast and die young” may not just be rap lyrics. For invasive species, the motto is actually a successful way of life.
In a new study, published in Oecologia, the research team examined why a type of freshwater snail that has invaded ecosystems worldwide has been so successful. The freshwater mud snails studied are native to New Zealand and have spread—likely beginning on commercial ships—to dominate numerous lake and river ecosystems in Asia, North America, Europe, and elsewhere. The species are interesting to biologists because they reproduce both sexually and asexually.
The asexual snails have been the more successful invaders, despite having much lower genetic diversity than the sexual snails. Additionally, the asexual snails have slower growth rates—and are smaller in size—than the sexual snails. While that combination would generally sink a species’ ability to compete in a new setting, the opposite has played out.
To figure out why, the researcher team grew populations of snails originally collected in Belgium and in six locations across the United States in their lab. They examined the progeny for “life history traits,” meaning the characteristics related to an organism’s fitness or reproductive success that would allow them to thrive in a new environment.
“They grow up substantially faster than their New Zealand counterparts,” said Carina Donne, the study’s corresponding author and a doctoral student at Colorado State University. “That just shortens the whole life cycle. If you can make babies at a younger age, then all things being equal, your populations will grow faster.”
“I think the data suggest there seems to be a real advantage to this combination of slow growth rate and early reproductive maturity,” said Maurine Neiman, the study’s senior author and professor at University of Iowa. “Their generation times are faster, and they are likely to outcompete other snail lineages that mature more slowly.”
Beyond a successful strategy for one invasive species, the researchers say the study results shine a light on the importance of life history traits. They think life history traits could be fundamental to whether and how other species root themselves in new settings.
“A lot of invasive species research focuses on prevention measures. We have so many invasive species, once they’re there and established, it’s harder to get rid of them,” said Neiman. “If we can find some way to predict what would be good invasive species, we could implement prevention measures.”
Data provided by University of Iowa.