An invasive predatory fish that has been rapidly expanding its presence in the Caribbean Basin and the Western Atlantic originated from multiple locations, not just one as previously believed, according to research published in a recent edition of the journal Marine Biology.
The venomous, coral reef-dwelling red lionfish had long been thought to have been introduced in Florida. In the new study, however, a team of US Geological Survey scientists propose that there were multiple points of origin, including some further south in the Caribbean Basin range.
Two genetically distinct populations discovered
Using new genetic data to help unravel the mystery, the study authors collected lionfish samples from 14 countries and territories in the Greater Caribbean and Western Atlantic. They discovered unique regional patterns that separated the area into distinct northern and southern regions.
The split occurred in the vicinity of the Bahamas, and given the regional genetic differences they found in the course of their investigation, the study authors now believe that there were multiple introductions of the species. One rare genetic strain was detected in only a few southern samples, but was found to be pervasive in the northern ones, the researchers explained.
“Studying the genetic strains across regions gives us insight into how these fish are spreading,” said lead author John Butterfield, a USGS contract biologist. “Dispersal against the flow of ocean currents may explain why we see this rare strain in the south, but even if that is the case, additional support for multiple introductions exists.”
“The genetic patterns found in this study support the idea of multiple introductions, and could be due to additional releases in the south,” Butterfield added. He and his fellow investigators noted that continued releases could make it more likely that genetically diverse red lionfish could join the existing population, hampering attempts to remove the species or limit its spread.
Using the findings to address the lionfish problem
Conversely, conducting genetic analysis of the invasive red lionfish and determining if there are still introductions occurring could give a boost to response and control efforts, the USGS experts said. The creature, which is native to the Indo-Pacific, can have a significant negative impact on its environment by disrupting marine food webs and preying on fish and invertebrates.
“The red lionfish can be used to help us understand other non-native populations and their invasion dynamics,” USGS geneticist Margaret Hunter said. “The more we know about this species and its progression, the more we can help resource managers and others fighting the invasion be prepared to help control lionfish colonization in new locations.”
“Ultimately, any information gleaned from this species could be applied to managing and assisting with eliminating future invasive species,” she continued. State and federal officials in the US are currently in the process of finalizing a national plan to prevent the spread of the lionfish and assess its impact on native species and habitats, the USGS added.