Fireworm Hermodice Carunculata Research Articles

Demographic and population response of the threatened coral Acropora cervicornis (Scleractinia, Acroporidae) to fireworm corallivory

Introduction: The fireworm Hermodice carunculata is a widespread polychaete that can prey upon many coral species. However, few studies have examined the effect of fireworm predation on coral demographics during non-outbreak periods. 
 Objective: To determine whether predation by H. carunculata compromised the growth, survival, and population performance of the threatened coral Acropora cervicornis. 
 Methods: Nursery-reared coral fragments (n = 99) were fixed to the bottom of Punta Melones reef in the Island Municipality of Culebra, Puerto Rico. Predation activity and its demographic consequences on coral outplants were assessed from December 2020 to August 2022. Susceptibility to predation was compared between colonies collected directly from the reef and those originating from outside sources (e.g., coral nurseries). With the demographic data, simple size-based population matrix models were developed to 1) examine whether fireworm predation led to a significant decline in population growth rate (λ), 2) determine the demographic transition(s) that contribute the most to λ, and 3) determining the demographic transition(s) that accounted for differences in λ when comparing scenarios that considered either only predated colonies or both predated and non-predated outplants. 
 Results: Predation increased over time, being more frequently observed in the area with the highest topographic relief and on colonies foreign to the study site. Outplants that were partially consumed grew significantly slower than non-predated colonies; however, predation did not threaten their survival. The likelihood of being attacked by the fireworm increased with branching complexity. The estimated λ for a scenario considering only those predated colonies was 0.99, whereas, for a scenario where both predated and non-predated colonies were considered, λ was 0.91. Population growth, under both scenarios, was mainly influenced by the probability of a large colony surviving and remaining at the largest size. 
 Conclusions: Although predation can negatively impact coral growth, the relatively high survival rate of predated colonies compensates for the adverse effects. Since survival is the demographic transition that contributes most to population growth, it could be concluded that under a non-outbreak scenario, fireworm predation may not be the primary cause of A. cervicornis population decline.

Population structure of the fireworm Hermodice carunculata in the wider Caribbean, Atlantic and Mediterranean Sea

Abstract The bearded fireworm Hermodice carunculata is a conspicuous omnivorous benthic invertebrate distributed in the wider Atlantic Ocean, Mediterranean Sea and the Red Sea. Questions were raised in the past regarding the taxonomic status of amphiatlantic fireworm specimens but subsequent analysis of morphological data with new molecular data reconfirmed the presence of only one species, H. carunculata with amphiatlantic distribution. Hermodice carunculata has been the subject of several taxonomic and genetic studies but there are still questions regarding the genetic diversity and population structure of the species throughout its range. We contributed to the genetic studies of H. carunculata with ~200 new samples from over 20 locations in the Caribbean, Eastern Atlantic Ocean and the Mediterranean Sea. We sequenced the mitochondrial markers Cytochrome c oxidase Subunit I (COI) and Cytochrome b (Cytb) from each polychaete to examine the patterns of genetic diversity of H. carunculata. Our data revealed a significant population structure between the Caribbean H. carunculata including those from Brazil compared with those from the eastern Atlantic (Tenerife, Canary Islands) and eastern Mediterranean (Greece and Malta). We inferred rates of gene flow between eastern and western Atlantic populations by estimating the bidirectional effective migration rate (Nem). We corroborate previous studies indicating the existence of one species with genetically distinct populations. However, the biological significance of the observed population divergence should be evaluated with cross-breeding experiments.

Abundance of the bearded fireworm Hermodice carunculata (Polychaeta: Amphinomidae) increases across a euphotic-mesophotic depth gradient in the remote St. Peter and St. Paul’s Archipelago

The bearded fireworm Hermodice carunculata is widely distributed across tropical and subtropical Atlantic and Mediterranean Oceans and was previously considered to be mostly associated with shallow reefs. We provide here data on the distribution, abundance and habitat use of H. carunculata across a euphotic-mesophotic gradient (0-90 m) in the Saint Peter and Saint Paul’s Archipelago (SPSPA, Mid Atlantic Ridge, Brazil). Samples were obtained using SCUBA and a Remote Operated Vehicle (ROV). A total of 189 individuals were observed and a sharp increase in abundance with depth was recorded, particularly from 50 m depth onwards. In the mesophotic zone (50-90 m) individuals were closely associated with branching black-corals (Tanacetipathes spp.) and predation over black-corals and the scleractinian Madracis decactis was commonly sighted. A Boosted Regression Tree model indicated black-coral abundance as the main driver of H. carunculata abundance, suggesting that preference for optimal habitats to hide/forage is more important than depth per se on the bathymetric distribution of the fireworm. The high abundances of H. carunculata in the mesophotic zone, and its predation on keystone benthic cnidarians, suggests that this species play important roles in the dynamics of deep reefs.

Development and catch efficiency of an attracting device to collect and monitor the invasive fireworm Hermodice carunculata in the Mediterranean Sea

The fireworm Hermodice carunculata (Annelida) is emerging as a native invader and a neonative species in the Central Mediterranean basins. Its ongoing areal expansion has probably been triggered and pursued by the climate alterations which are affecting the Mediterranean environments and biota. However, increased H. carunculata abundance and distribution may be miscalculated and underestimated due to the lack of effective tools for collection and monitoring. Indeed, fireworms spend most of the daytime in crevices and holes, making it impossible to obtain reliable data in underwater surveys.In this study, traps were developed to provide suitable shelter and food to fireworms, and their effectiveness and specificity were assessed by testing different immersion times, environmental conditions and types of bait. Pierced plastic baskets adapted for fireworm capture proved to be extremely easy to set up, reproducible, cheap, and highly specific. The devices were used in 11 sites located along the Ionian Apulian coast (Italy). They resulted suitable and effective: more than 90% of the traps baited with raw fish succeeded in capturing H. carunculata specimens, with an average of 8-9 fireworms captured per trap. The traps were deployed in a depth range of 1.5-9 m with immersion times of up to 4 h, and even large sized fireworms (> 32 cm in length) were caught. These attracting devices could be successful in different forthcoming challenges, allowing the collection of a great number of fireworms to investigate their impact on rocky bottom communities, distribution and potential for bioprospecting. Besides, the cheapness and ease of use of the traps also make them suitable for Citizen Science studies and sampling campaigns aiming at characterizing the expanding populations. Future applications will be critical to improve deployment success and test user friendliness.

Differential gene expression indicates modulated responses to chronic and intermittent hypoxia in corallivorous fireworms (Hermodice carunculata)

Climate models predict an increase in extent, frequency, and duration of marine hypoxia events in the twenty first century. A better understanding of organismal responses to hypoxia in individual species is a crucial step for predicting ecosystem responses. We experimentally subjected a common invertebrate, the bearded fireworm (Hermodice carunculata) to two levels of chronic hypoxia and, in a separate experiment, to intermittent hypoxia. We found components of the conserved hypoxia-inducible factor (HIF) pathway and show a modulated response to hypoxia depending on the severity of hypoxic stress: under mild hypoxia, only the HIF-1α subunit is upregulated, while expression of the other subunit, aryl hydrocarbon nuclear translator, only increases significantly at more severe hypoxia levels. The chronic trials revealed down-regulation of genes related to cell adhesion, transport, development and heme-binding, and up-regulation of genes related to glycolysis, oxygen binding, cell differentiation, digestive and reproductive function. The intermittent hypoxia trials revealed an upregulation of heme transporter activity during hypoxia, and our time series analysis characterized nine clusters of genes with similar expression patterns. Our findings suggest that H. carunculata is likely to tolerate, and be resilient to, predicted future hypoxia conditions.

Effects of herbivory by the urchin Diadema antillarum on early restoration success of the coral Acropora cervicornis in the central Caribbean

In an era of coral reef decline, coral restoration is receiving increasing attention, with many recent developments in culture and transplant techniques. However, how the ecological processes operating on coral reefs influence the success of restoration efforts remains largely unexplored, particularly during the first months after outplanting which are considered crucial for colony survival. Herbivory is a key process well-known to maintain a coral-dominated state, and in the Caribbean Sea, the long-spine urchin Diadema antillarum is thought to aid coral success by removing algae from seafloor substrate that might otherwise outcompete coral outplants. In this study, we conducted a three-month manipulative experiment in southeastern Dominican Republic to test the effect of Diadema antillarum density on percent living tissue and growth rate of outplanted fragments of the critically endangered coral species Acropora cervicornis. Increasing herbivore density had no significant effect on coral survival or growth but did increase the percent of living tissue when urchin abundance was 3× ambient levels. The greatest growth and survival outcomes were instead related to the initial size of the outplanted coral and were reduced through predation by the fireworm Hermodice carunculata. Our results highlight the potential importance of considering ecological processes like herbivory and predation to maximize the success of ecological restoration.

Commentary on: “Unravelling the ultrastructure and mineralogical composition of fireworm stinging bristles” by Righi et al. 2020

In a recent paper published in Zoology, Righi et al. (2020) investigated the chaetae of the venomous fireworm Hermodice carunculata (Amphinomida, Annelida) and revived the hypothesis of venom injection by hollow chaetae. This conclusion reached by Rigihi et al. (2020) contradicts previously published results, and in our opinion, it is also not supported by their data. We propose the idea that broken chaetae cause lesions and unprotected exposure to venomous epidermal mucous. Herein we also provide further data that show the artificial nature of the empty core of the calcareous bristles. We further emphasise that there is no evidence for venom storage within the chaetae. The idea that fireworm’s chaetae are equipped with a venom delivery mechanism, analogous to hypodermic needles, must be considered as refuted. We hope our commentary may help future clarification of venom delivery in fireworms.

Enhancing Diversity Knowledge through Marine Citizen Science and Social Platforms: The Case of Hermodice carunculata (Annelida, Polychaeta)

The aim of this research is to set a successful strategy for engaging citizen marine scientists and to obtain reliable data on marine species. The case study of this work is the bearded fireworm Hermodice carunculata, a charismatic species spreading from the southern Mediterranean probably in relation to global warming. To achieve research objectives, some emerging technologies (mainly social platforms) were combined with web ecological knowledge (i.e., data, pictures and videos about the target species published on the WWW for non-scientific purposes) and questionnaires, in order to invite people to collect ecological data on the amphinomid worm from the Adriatic Sea and to interact with involved people. In order to address future fruitful citizen science campaigns, strengths and weakness of each used method were illustrated; for example, the importance of informing and thanking involved people by customizing interactions with citizens was highlighted. Moreover, a decisive boost in people engagement may be obtained through sharing the information about citizen science project in online newspapers. Finally, the work provides novel scientific information on the polychete’s distribution, the northernmost occurrence record of H. carunculata in the Mediterranean Sea and new insights on predatory behavior on other living benthic species.

Ecology, distribution and expansion of a Mediterranean native invader, the fireworm Hermodice carunculata (Annelida)

Global change and the overall raise of seawater temperature are causing a poleward shift in species distribution, increasing the occurrence of warm-water biota in many ecosystems worldwide. In the Mediterranean, the ongoing sea warming is promoting native subtropical species to invader status. The bearded fireworm Hermodice carunculata (Amphinomida) is a thermophilic generalist predator spreading in the Central Mediterranean Sea. Although it is a typical inhabitant of Ionian coasts, several sightings have occurred at more northerly localities along the Tyrrhenian and Adriatic Seas, suggesting that density increases and range expansion are underway. These distributional records are in contrast with historical literature and museum collections, which provide poor sporadic information.The present study aimed at investigating the spatiotemporal changes that have occurred in H. carunculata abundances and distribution in the Mediterranean basins surrounding the Italian peninsula so far. We examined an exhaustive collection of existing information. A total of 857 reports of H. carunculata were collected from 368 localities. These data significantly expand knowledge on the life and feeding habit of H. carunculata. The integration of different data sources allowed the reconstruction of the shifts that have happened over the last 50 years, which are coherent with the consistent warming trend of Mediterranean Sea surface temperatures. Recent colonization events have occurred both along the Adriatic and Western Mediterranean coasts. The present findings provide unique insights into the expansion of H. carunculata, supporting future spreading throughout the Northern and Western Mediterranean. Tracking these changes is critical to assess potential impacts on coastal rocky-benthic communities, public health and commercial fisheries.

First description of early developmental stages of the native invasive fireworm Hermodice carunculata (Annelida, Amphinomidae): a cue to the warming of the Mediterranean Sea

Observations on the reproductive behavior and larval development of the bristled fireworm Hermodice carunculata, a common inhabitant of shallow marine rocky bottoms in the Southern Mediterranean Sea, are reported here. In recent years, an increase in abundance and a northward expansion of the populations along the Southern Italian coast were jointly detected, presumably linked to rising water temperature in the Mediterranean Sea. After making in situ observations on two consecutive spawning events, live worms and fresh spawn were brought into the lab, kept at either 27 ºC or 22 ºC and followed through development. Complete and normal development was observed only at 27°C. By contrast, embryonic and larval development appeared to be slowed down at 22°C, stopping at the protrochophora stage. Early development of H. carunculata suggests the existence of a long pre-metamorphic, planktotrophic period in the water column that can explain the genetic cohesion of this species and the low genetic divergence found among populations across the Atlantic Ocean. The observed increase in abundance, invasiveness potential, and geographical northern distribution of the bearded fireworms is probably determined by a progressive northward latitudinal shift of the sea surface temperature coincident with the temperature threshold required for the developmental and reproductive success of the worm.

New Evidence of Marine Fauna Tropicalization off the Southwestern Iberian Peninsula (Southwest Europe)

Climate change and the overall increase of seawater temperature are causing a poleward shift in species distribution, which includes a phenomenon described as the tropicalization of temperate regions. This work aims to report the first records of four species off the southwestern Iberian Peninsula, namely, the oceanic puffer Lagocephalus lagocephalus (Linnaeus, 1758), the Madeira rockfish Scorpaena maderensis Valenciennes, 1833, the ornate wrasse Thalassoma pavo (Linnaeus, 1758), and the bearded fireworm Hermodice carunculata (Pallas, 1766). These last three species, along with other occurrences of aquatic fauna and flora along the Portuguese coast, reveal an ongoing process of poleward expansion of several species, which urgently necessitates a comprehensive survey along the entire Iberian Peninsula. The putative origins of these subtropical and tropical species off continental Portugal are discussed, as well as the potential public health problems that two of the four reported species may cause.

Laboratory observations on predator–prey interactions between the bearded fireworm (Hermodice carunculata) and Mediterranean benthic invertebrates

ABSTRACTThe bearded fireworm (Hermodice carunculata) is an amphinomid polychaete with a circumtropical Atlantic-Mediterranean distribution. In the Mediterranean Sea, very little information is available on its feeding habits and ecological functions. Here, its increasing abundance and the ability to actively prey on a keystone sea urchin species suggest potential repercussions for the structure and functioning of benthic communities. We performed laboratory feeding experiments to investigate interactions between Mediterranean H. carunculata and 12 species of sessile or sedentary invertebrates. H. carunculata preyed efficiently on 9 of the species offered. In particular, active predation of a polychaete upon nudibranchs, colonial ascidians and chitons was reported for the first time. Fireworms’ predatory ability may be due to a combination of several ‘weapons’ (large size, motility, stinging chaetae and eversible, sucking pharynx) which seems to be unique among marine worms, and could enable H. carunculata to persist also after radical changes in prey community composition and withstand selective pressures associated with ongoing environmental changes.

First record of the fireworm Hermodice carunculata preying on colonies of the threatened staghorn coral Acropora Cervicornis in the southeastern outplanting sites of the Dominican Republic

Several fireworms Hermodice carunculata (Pallas, 1766) were observed feeding on coral colonies or transplanted fragments of the threatened staghorn coral Acropora cervicornis (Lamarck, 1816), in outplanting sites at Bayahibe, Dominican Republic. The fireworm H. carunculata has a highly negative impact on A. cervicornis populations, causing several lesions on the living tissue of branches and partial or complete mortality at the outplanting sites. This is the first report of predation on transplanted colonies in a coral restoration program in the Dominican Republic.

Celomic cells of the marine fireworm Hermodice carunculata (Annelida, Polychaeta)

Department of Life Sciences, University of Modena and Reggio Emilia, Modena, ItalyWe have examined the morphological and functional characteristics of the celomic cells in the marine fireworm Hermodice carunculata. The cells differ in morphology, in relation to the presence of cytoplasmic granules, adhere to the glass, phagocytize zymosan A particles and contain ACTH-like molecules. We suggest the presence of only one cell type in the worm celomic fluid, i.e., the immunocyte described in other invertebrates.

Prevalence, consequences, and mitigation of fireworm predation on endangered staghorn coral

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 516:187-194 (2014) - DOI: https://doi.org/10.3354/meps10996 Prevalence, consequences, and mitigation of fireworm predation on endangered staghorn coral M. W. Miller1,*, C. Marmet2, C. M. Cameron1,2, D. E. Williams1,2 1National Marine Fisheries Service, Southeast Fisheries Science Center, 75 Virginia Beach Drive, Miami, FL 33149, USA 2Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA *Corresponding author: margaret.w.miller@noaa.gov ABSTRACT: In the current era of reduced coral populations, the effects of predation are likely to compromise the growing investment in restocking of imperiled coral populations and may be a strong, chronic deterrent of natural population recovery. A 2 yr surveillance study documented highly variable prevalence of predation by the fireworm Hermodice carunculata on both wild (0 to 51%) and restocked (0 to 53%) populations of the Caribbean staghorn coral Acropora cervicornis, but significantly higher prevalence overall in 2012 than 2011. In addition, individual predation scars (branch tips) were tagged to determine the costs of predation both in terms of healing time (i.e. to recover positive rates of branch growth) and in terms of likelihood of progressive disease-like tissue loss on preyed branch tips. The risk of preyed branches showing progressive tissue loss at the subsequent survey was 10 times higher than for non-preyed branches. A survival analysis indicated an estimated mean time to healing for preyed branch tips of 110 ± 6 d (95% confidence). Finally, an experiment conducted in 2013 tested whether removing the dead skeleton from preyed branch tips could accelerate recovery. Indeed, this intervention shortened the mean time to formation of a new apical tip to 46 d (range: 22 to 92 d). Thus, fireworm predation imposes significant costs on both remnant wild and restocked staghorn colonies, but removing dead tips, rather than leaving them to bioerode, is a useful strategy to accelerate recovery from predation. KEY WORDS: Hermodice carunculata · Acropora cervicornis · Corallivory · Florida Keys · Restoration Full text in pdf format PreviousNextCite this article as: Miller MW, Marmet C, Cameron CM, Williams DE (2014) Prevalence, consequences, and mitigation of fireworm predation on endangered staghorn coral. Mar Ecol Prog Ser 516:187-194. https://doi.org/10.3354/meps10996 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 516. Online publication date: December 03, 2014 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2014 Inter-Research.

Distribution, food preference, and trophic position of the corallivorous fireworm Hermodice carunculata in a Caribbean coral reef

The fireworm Hermodice carunculata is a facultative corallivore on coral reefs. It can interact with algal overgrowth to cause coral mortality. However, because of its cryptic nature, little is known about its ecology. We used micropredator attracting devices (MADs) and stable isotope analyses to provide insights into the distribution and diet of H. carunculata in a coral reef on Curacao, southern Caribbean. MADs consisted of algal clumps inside accessible mesh nets which H. carunculata could use as refuge. To obtain indications on its distribution pattern, MADs filled with Halimeda opuntia were deployed in different reef habitats ranging from 0 to 16 m water depth. Fireworms were found inside MADs in all reef habitats, indicating that they have a widespread horizontal and vertical distribution, ranging from the shoreline to the deeper reef slope. On the reef crest, MADs were filled using different algal species and deployed on dead or live scleractinian corals. MADs hosted more fireworms when placed on live corals, regardless of algal species used, suggesting that algal-induced corallivory may be widespread. To test for food preferences, different food sources were added inside the MADs. Fireworms detected potential prey within 6 h and were significantly more attracted by decaying corals and raw fish than by live corals, hydrozoans, or gorgonians. Stable isotope analyses indicated detritus, macroalgae, and scleractinian corals as potential food sources and revealed an ontogenetic dietary shift toward enriched δ 13C and δ 15N values with increasing fireworm size, suggesting that large-sized individuals feed on food sources of higher trophic levels. Our findings highlight H. carunculata as a widespread, and omnivorous scavenger that has the potential to switch feeding toward weakened or stressed corals, thereby likely acting as a harmful corallivore on degraded reefs.

Culturable Heterotrophic Bacteria Associated with Healthy and Bleached Scleractinian Madracis decactis and the Fireworm Hermodice carunculata from the Remote St. Peter and St. Paul Archipelago, Brazil

We report on the first characterization of the culturable heterotrophic bacteria of the scleractinian Madracis decactis. In addition, we characterized the culturable bacteria associated with the fireworm Hermodice carunculata, observed predating partially bleached coral colonies. Our study was carried out in the remote St. Peter and St. Paul Archipelago (SPSPA), Mid-Atlantic Ridge, Brazil. We constituted a 403 isolates collection and subsequently characterized it by means of pyrH and 16S rRNA partial sequences. We identified Photobacterium, Bacillus, and Vibrio species as members of the culturable microbiota of healthy M. decactis. V. campbellii, V. harveyi, V. communis, and V. maritimus were the most commonly found Vibrio species in healthy corals, representing more than 60% of all vibrio isolates. Most of the vibrios isolated from the fireworm's tissues (n=143;>90%) were identified as V. shiloi. However, we did not recover V. shiloi from bleached M. decactis. Instead, we isolated V. communis, a novel Photobacterium species, Bacillus, Kocuria, and Pseudovibrio, suggesting a possible role of other facultative anaerobic bacteria and/or environmental features (such as water quality) in the onset of bleaching in SPSPA's M. decactis.

Predation on coral settlers by the corallivorous fireworm Hermodice carunculata

Coral predation by the fireworm Hermodice carunculata was investigated by presenting settlers ( 90 %) in the presence of small-, mid- and large-sized fireworms, respectively. In contrast, fireworms hardly preyed on adult corals, irrespective of their sizes. Our results suggest an ontogenic shift in the diet of H. carunculata and in the susceptibility of corals to predation by fireworms. H. carunculata, in particular small-sized individuals, could be an important cause for early post-settlement mortality in corals. The corallivore could reinforce recruitment bottlenecks and reduce coral recovery after disturbances.

The Vibrio shiloi/Oculina patagonica model system of coral bleaching.

The scleractinian coral Oculina patagonica undergoes bleaching (loss of its endosymbiotic zooxanthellae) every summer in the eastern Mediterranean Sea when seawater temperatures rise. The causative agent of the disease is Vibrio shiloi. The pathogen adheres to a beta-galactoside-containing receptor in the coral mucus, penetrates into epithelial cells, differentiates into a viable-but-not-culturable form, multiplies, and produces a proline-rich peptide toxin that inhibits photosynthesis of the zooxanthellae in the presence of ammonia. Several of the virulence factors, such as adhesin, toxin, and superoxide dismutase, are produced only at the elevated summer seawater temperatures. The fireworm Hermodice carunculata is a winter reservoir and spring/summer vector for V. shiloi. The generality of the bacterial hypothesis of coral bleaching is discussed.