Diet richness of invasive Indo-Pacific lionfish revealed by DNA barcoding

Abstract

Indo-Pacific lionfish Pterois spp. have recently invaded marine habitats throughout the western Atlantic, Gulf of Mexico, and Caribbean Sea. Their unusual hunting behaviour suggests that they could prey on most fish species within their gape size limits. However, few prey species have been identified so far due to the challenges of identifying partly digested prey. Moreover, it is not clear how well the identifiable diet reflects the unidentified portion. To address these issues, we DNA-barcoded unidentifiable fish items from the stomachs of 130 lionfish captured on Bahamian coral reefs. We identified 37 fish prey species, nearly half of which had not previously been recorded in this region. The total richness of lionfish prey fish recorded so far may represent up to ~54% of potential prey species on the study reefs. The relative importance of prey species in the visually identifiable diet portion, which was limited to 25% of prey items, differed from that in the 'unidentifiable' portion, which was largely resolved here with barcoding, weakening extrapolations from visual identification. The high diet resolution afforded by barcoding can increase our ability to predict the impacts of invasive predators on recipient communities.

Diet of invasive lionfish (Pterois volitans and P. miles) in Bermuda

“…In total, 22 families of teleosts (44 species) and 14 families of crustaceans (17 species) were found in the stomach contents of lionfish in Bermuda. This substantial contribution of both teleosts and crustaceans, with a broad range of families and species in each category, supports the prevailing view that lionfish are generalist and opportunist predators (Muñoz et al 2011, Layman & Allgeier 2012, Côté et al 2013. The contribution of key prey items was fairly consistent across the indices of importance, at the species and family level, and when considering trophic guild (Table 3).…”

“…Taken together, these data suggest that if the lionfish population in Bermuda continues to expand, there will likely be no spatial or temporal refuge for potential lionfish prey, which may eventually include any juvenile or small-bodied fishes or crustaceans. This, in turn, suggests that the impacts of invasive lionfish may eventually be felt across a broad range of species and habitats, as has indeed been suggested by other studies (see for example Muñoz et al 2011, Côté et al 2013). …”

“…This pattern has been previously recognized in lionfish from the Bahamas (Morris & Akins 2009) and could be explained by a number of factors. Since lionfish are a gape-limited predator (Côté et al 2013), the diet shift may reflect an increase in the maximum size of potential prey as lionfish gape increases, and a limit to the minimum size of prey as small items may escape through the gaps between gill rakers (Graham et al 2007). Further, as larger lionfish have greater gross energetic requirements, a switch to teleosts may provide greater mass-specific nutritional benefits compared to crustaceans.…”

Use of DNA metabarcoding for stomach content analysis in the invasive lionfish Pterois volitans in Puerto Rico

“…This technique discards useful information that could be obtained in the digested portion of the stomach contents (the liquids or digested pulp). However, the traditional morphological method is widely applied (Albins & Hixon 2008, Morris & Akins 2009, Alexander & Haynes 2011, Jud et al 2011, Muñoz et al 2011, Green et al 2012, Frazer et al 2012, Layman & Allgeier 2012, Green & Côté 2014, while the more accurate DNA barcoding approach has been less frequently used (Barbour et al 2010, Valdez-Moreno et al 2012, Côté et al 2013. Despite the higher resolution attained with this approach, traditional DNA barcoding also has disadvantages.…”

Habitat and body size effects on the isotopic niche space of invasive lionfish and endangered Nassau grouper

“…The authors also observed individual lionfish consuming up to 20 small fish in a single 30-minute period, and eating prey with body lengths two thirds of their own. Work by Côté et al (2013) indicates that the predator may consume more than half of the potential prey species on invaded reefs, and the impacts on native reef fish populations may yet prove to be severe. Given the intricacies of coral reef trophic interactions, such impacts can rapidly cascade to induce ecosystem-level effects, with Lesser and Slattery (2011) showing that lionfish predation is likely to be the driver of an observed phase shift from coral domination to algal domination on mesophotic reefs that may provide stability and refuge from disturbance for shallower reefs .…”