Interactions among Invasive Pacific Red Lionfish, Fish Parasites, and Cleaning Mutualisms Native to Atlantic Coral Reefs

What makes invasive species successful, and how do they affect native populations and communities? I addressed these key questions in the context of the invasion of Atlantic coral reefs by Pacific red lionfish (Pterois volitans). To assess the role of parasites in contributing to the success of this invasion, I compared infection rates of lionfish with syntopic carnivorous fishes at multiple locations in both the invasive and native ranges of lionfish. Invasive Atlantic lionfish had extremely few parasites when compared both to native Pacific lionfish and to ecologically similar native Atlantic reef fishes. Such “enemy release” may help to explain this successful invasion if lionfish consequently allocate more energy to growth and reproduction than to costly immune defenses. With few parasites limiting them, lionfish may consume ecologically important species, including Elacatinus spp. cleaning gobies: ubiquitous, conspicuous fishes that remove ectoparasites from other reef fishes. Although juvenile lionfish ate cleaner goby (E. genie) during laboratory experiments, they quickly learned to avoid them, likely due to a previously undescribed skin toxin in these gobies. Field experiments further revealed no change in the survival and growth rates of newly recruited cohorts of the cleaner goby in the presence vs. absence of lionfish. However, lionfish caused declines in the densities of the most abundant facultative cleaner, juvenile bluehead wrasse (Thalassoma bifasciatum), and of transient fishes that are often cleaned while visiting coral patch reefs. Therefore, lionfish do not have uniformly negative effects on native species; distasteful to potential predators, the cleaner goby is among the remarkably few small fish to escape predation by lionfish. The continued presence of Elacatinus spp. cleaning gobies, the predominant cleaners on invaded reefs, should limit cascading effects of lionfish on other Atlantic coral-reef inhabitants. Nonetheless, given their broad and voracious appetites, invasive lionfish will likely continue to affect native reef communities via predation on other cleaners and ecologically important fishes

A systematic review and meta-analysis of the direct effects of nutrients on corals

Chronic exposure of coral reefs to elevated nutrient conditions can modify the performance of the coral holobiont and shift the competitive interactions of reef organisms. Many studies have nowquantified the links between nutrients and coral performance, but fewhave translated these studies to directly address coastal water quality standards. To address this management need, we conducted a systematic review of peer-reviewed studies, public reports, and gray literature that examined the impacts of dissolved inorganic nitrogen (DIN: nitrate, nitrite, and ammonium) and dissolved inorganic phosphorus (DIP: phosphate) on scleractinian corals. The systematic review resulted in 47 studies with comparable data on coral holobiont responses to nutrients: symbiont density, chlorophyll α (chl-α) concentration, photosynthesis, photosynthetic efficiency, growth, calcification, adult survival, juvenile survival, and fertilization. Mixed-effects meta-regression meta-analyses were used to determine the magnitude of the positive or negative effects of DIN and DIP on coral responses. Zooxanthellae density (DIN & DIP), chl-α concentration (DIN), photosynthetic rate (DIN), and growth (DIP) all exhibited positive responses to nutrient addition; maximum quantum yield (DIP), growth (DIN), larval survival (DIN), and fertilization (DIN) exhibited negative responses. In lieu of developing specific thresholds for the management of nutrients as a stressor on coral reefs, we highlight important inflection points in the magnitude and direction of the effects of inorganic nutrients and identify trends among coral responses. The responses of corals to nutrients are complex, warranting conservative guidelines for elevated nutrient concentrations on coral reefs

Low Susceptibility of Invasive Red Lionfish (Pterois volitans) to a Generalist Ectoparasite in Both Its Introduced and Native Ranges

Escape from parasites in their native range is one of many mechanisms that can contribute to the success of an invasive species. Gnathiid isopods are blood-feeding ectoparasites that infest a wide range of fish hosts, mostly in coral reef habitats. They are ecologically similar to terrestrial ticks, with the ability to transmit blood-borne parasites and cause damage or even death to heavily infected hosts. Therefore, being highly resistant or highly susceptible to gnathiids can have significant fitness consequences for reef-associated fishes. Indo-Pacific red lionfish (Pterois volitans) have invaded coastal habitats of the western tropical and subtropical Atlantic and Caribbean regions. We assessed the susceptibility of red lionfish to parasitic gnathiid isopods in both their native Pacific and introduced Atlantic ranges via experimental field studies during which lionfish and other, ecologically-similar reef fishes were caged and exposed to gnathiid infestation on shallow coral reefs. Lionfish in both ranges had very few gnathiids when compared with other species, suggesting that lionfish are not highly susceptible to infestation by generalist ectoparasitic gnathiids. While this pattern implies that release from gnathiid infestation is unlikely to contribute to the success of lionfish as invaders, it does suggest that in environments with high gnathiid densities, lionfish may have an advantage over species that are more susceptible to gnathiids. Also, because lionfish are not completely resistant to gnathiids, our results suggest that lionfish could possibly have transported blood parasites between their native Pacific and invaded Atlantic ranges

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

TuttleLillianJ2016_FigC1.mp4

What makes invasive species successful, and how do they affect native populations and communities? I addressed these key questions in the context of the invasion of Atlantic coral reefs by Pacific red lionfish (Pterois volitans). To assess the role of parasites in contributing to the success of this invasion, I compared infection rates of lionfish with syntopic carnivorous fishes at multiple locations in both the invasive and native ranges of lionfish. Invasive Atlantic lionfish had extremely few parasites when compared both to native Pacific lionfish and to ecologically similar native Atlantic reef fishes. Such “enemy release” may help to explain this successful invasion if lionfish consequently allocate more energy to growth and reproduction than to costly immune defenses. With few parasites limiting them, lionfish may consume ecologically important species, including Elacatinus spp. cleaning gobies: ubiquitous, conspicuous fishes that remove ectoparasites from other reef fishes. Although juvenile lionfish ate cleaner goby (E. genie) during laboratory experiments, they quickly learned to avoid them, likely due to a previously undescribed skin toxin in these gobies. Field experiments further revealed no change in the survival and growth rates of newly recruited cohorts of the cleaner goby in the presence vs. absence of lionfish. However, lionfish caused declines in the densities of the most abundant facultative cleaner, juvenile bluehead wrasse (Thalassoma bifasciatum), and of transient fishes that are often cleaned while visiting coral patch reefs. Therefore, lionfish do not have uniformly negative effects on native species; distasteful to potential predators, the cleaner goby is among the remarkably few small fish to escape predation by lionfish. The continued presence of Elacatinus spp. cleaning gobies, the predominant cleaners on invaded reefs, should limit cascading effects of lionfish on other Atlantic coral-reef inhabitants. Nonetheless, given their broad and voracious appetites, invasive lionfish will likely continue to affect native reef communities via predation on other cleaners and ecologically important fishes

TuttleLillianJ2016.pdf

What makes invasive species successful, and how do they affect native populations and communities? I addressed these key questions in the context of the invasion of Atlantic coral reefs by Pacific red lionfish (Pterois volitans). To assess the role of parasites in contributing to the success of this invasion, I compared infection rates of lionfish with syntopic carnivorous fishes at multiple locations in both the invasive and native ranges of lionfish. Invasive Atlantic lionfish had extremely few parasites when compared both to native Pacific lionfish and to ecologically similar native Atlantic reef fishes. Such “enemy release” may help to explain this successful invasion if lionfish consequently allocate more energy to growth and reproduction than to costly immune defenses. With few parasites limiting them, lionfish may consume ecologically important species, including Elacatinus spp. cleaning gobies: ubiquitous, conspicuous fishes that remove ectoparasites from other reef fishes. Although juvenile lionfish ate cleaner goby (E. genie) during laboratory experiments, they quickly learned to avoid them, likely due to a previously undescribed skin toxin in these gobies. Field experiments further revealed no change in the survival and growth rates of newly recruited cohorts of the cleaner goby in the presence vs. absence of lionfish. However, lionfish caused declines in the densities of the most abundant facultative cleaner, juvenile bluehead wrasse (Thalassoma bifasciatum), and of transient fishes that are often cleaned while visiting coral patch reefs. Therefore, lionfish do not have uniformly negative effects on native species; distasteful to potential predators, the cleaner goby is among the remarkably few small fish to escape predation by lionfish. The continued presence of Elacatinus spp. cleaning gobies, the predominant cleaners on invaded reefs, should limit cascading effects of lionfish on other Atlantic coral-reef inhabitants. Nonetheless, given their broad and voracious appetites, invasive lionfish will likely continue to affect native reef communities via predation on other cleaners and ecologically important fishes

Counts of Elacatinus gobies on Bahamian reefs with controlled lionfish densities from reef surveys conducted in Eleuthera, Bahamas in 2012 (Lionfish Invasion project)

Dataset: lionfish and goby countsThis dataset includes counts of Elacatinus gobies on Bahamian reefs with controlled lionfish densities from reef surveys conducted in Eleuthera, Bahamas in 2012. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/3886NSF Division of Ocean Sciences (NSF OCE) OCE-085116

Cleaner and host species observed on Bahamian reefs under varying experimental conditions in Eleuthera, Bahamas in 2012 (Lionfish Invasion project)

Dataset: lionfish cleaner bottle exptCleaner and host species observed on Bahamian reefs under varying experimental conditions in Eleuthera, Bahamas in 2012 (Lionfish Invasion project). For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/3907NSF Division of Ocean Sciences (NSF OCE) OCE-085116

Results of experimental field studies, in the Bahamas, Cayman Islands, and Philippines, assessing susceptibility of red lionfish (Pterois volitans) to parasitic gnathiid isopods in both native and introduced ranges in 2009-2011

Dataset: lionfish gnathiid experimentsResults of experimental field studies, in the Bahamas, Cayman Islands, and Philippines, assessing susceptibility of red lionfish (Pterois volitans) to parasitic gnathiid isopods in both native and introduced ranges in 2009-2011. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/3889NSF Division of Ocean Sciences (NSF OCE) OCE-085116

Results of an investigation of parasite communities infecting lionfish (Pterois volitans) in their native range, Guam and the Philippines, and in their invaded range, the Bahamas and the Cayman Islands

Dataset: lionfish parasitesResults of an investigation of parasite communities infecting lionfish (Pterois volitans) in their native range, Guam and the Philippines, and in their invaded range, the Bahamas and the Cayman Islands. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/3894NSF Division of Ocean Sciences (NSF OCE) OCE-085116