Predicting predatory impact of juvenile invasive lionfish (Pterois volitans) on a crustacean prey using functional response analysis: effects of temperature, habitat complexity and light regimes

Abstract

The ecological implications of biotic interactions, such as predator-prey relationships, are often context-dependent. Comparative functional responses analysis can be used under different abiotic contexts to improve understanding and prediction of the ecological impact of invasive species. Pterois volitans (Lionfish) [Linnaeus 1758] is an established invasive species in the Caribbean and Gulf of Mexico, with a more recent invasion into the Mediterranean. Lionfish are generalist predators that impact a wide range of commercial and non-commercial species. Functional response analysis was employed to quantify interaction strength between lionfish and a generic prey species, the shrimp (Paleomonetes varians) [Leach 1814], under the contexts of differing temperature, habitat complexity and light wavelength. Lionfish have prey population destabilising Type II functional responses under all contexts examined. Significantly more prey were consumed at 26°C than at 22°C. Habitat complexity did not significantly alter the functional response parameters. Significantly more prey were consumed under white light and blue light than under red light. Attack rate was significantly higher under white light than under blue or red light. Light wavelength did not significantly change handling times. The impacts on prey populations through feeding rates may increase with concomitant temperature increase. As attack rates are very high at low habitat complexity this may elucidate the cause of high impact upon degraded reef ecosystems with lowdensity prey populations, although there was little protection conferred through habitat complexity. Only red light (i.e. dark) afforded any reduction in predation pressure. Management initiatives should account for these environmental factors when planning mitigation and prevention strategies.

Global ecological impacts of marine exotic species

“…However, it is important to consider not only the mean but also the variability of the effects. For instance, exotic species that inflict strong disparate impacts depending on geographical locations or habitat types 58,59 will have large error bars around the mean, which was the case for some exotic species on our list. Therefore, many of the exotic species on our list could qualify as invasive in some locations but not others, although their global effect might not be significant.…”

Ecological effects of non‐native species in marine ecosystems relate to co‐occurring anthropogenic pressures

“…Our findings have a number of limitations, as they derive from statistical relationships where specific mechanisms are not explicit. However, the patterns uncovered and the associated predictions have value, as the context‐dependent nature of introductions and ecological effects of non‐native species (e.g., the successful establishment and effects of the exotic species may vary depending on location or environmental conditions; (Green & Crowe, ; South, Dick, McCard, Barrios‐O'Neill, & Anton, ) imply that large‐scale predictors for the effects of non‐native species are almost nonexistent. Context dependency was likely a driving factor for why the effect of non‐native species on abundance of natives was not related to any human footprint proxy.…”

An appetite for invasion: digestive physiology, thermal performance, and food intake in lionfish (Pterois spp.)

“…When prey are more scarce, lionfish with a high AMR and high scope for activity may be better competitors and more able to secure access to prey that would offset their more costly SDA and longer SDA dur , which we found to be up to 46% higher and almost 24 h longer than in individuals with low scope for activity, respectively. As such, metabolic phenotypes may confer resilience to the lionfish invasion, particularly in light of past research showing they can cause local collapses in their prey populations and, therefore, variability in food availability (Green et al, 2012;Benkwitt, 2015;Ingeman, 2016;South et al, 2017).…”

“…Their invasion is driven mainly by a lack of natural predators, prey naivety, and unique hunting traits not found in native predators, which allows lionfish to spread and forage with few, if any, limits (Valdivia et al, 2014;McCormick and Allan, 2016;Green et al, 2019). Lionfish threaten western Atlantic marine ecosystems by consuming small-bodied fish and crustaceans, significantly lowering their populations and even extirpating them locally (Benkwitt, 2015;Palmer et al, 2016;Ingeman, 2016;South et al, 2017), facilitating coral-smothering algal growth by removing grazers (Kindinger and Albins, 2017), and outcompeting native mesopredators (Raymond et al, 2015;Curtis et al, 2017). Green et al (2011) estimated that an adult lionfish could consume 8.9% of its body mass per day based on field observations in The Bahamas, which was more than twice their required daily energy intake for maintenance (i.e.…”