Biology subjects

Veglia, A. J.

Publications and source records attributed to Veglia, A. J..

7 recordsLinked to original sources

bioRxiv2026

The invasive soft coral Xenia umbellata has been confirmed in Cuban waters

Octocoral colonies with unusual morphology were detected in September 2022 and October 2023 in two coastal areas east of Havana, Cuba, and tentatively identified as Unomia stolonifera. U. stolonifera is an invasive octocoral from the Indo-Pacific that was first reported in the Caribbean off Venezuela in the 2000s, where it has spread rapidly, smothering coral reefs and substantially altering benthic communities. After obtaining tissue samples from a Cuban octocoral colony, we re-examined the specimen using molecular barcoding of three mitochondrial regions (16S/ND2, mtMutS, COI) and the nuclear large ribosomal subunit (28S rRNA), and we unequivocally identified it as Xenia umbellata. X. umbellata, a native of the Red Sea, was first identified in southern Puerto Rico in October 2023 and has since been found in various marine ecosystems along the southern coast of the island. The presence of either invasive octocoral species in Cuba or elsewhere in the Caribbean would be of a serious environmental concern due to their documented tolerance, totipotentiality, propagation capacity and significant negative interactions with local benthic fauna. Attempts to eradicate the invasive soft coral colonies from Cuban waters have been initiated with apparent success, helping to control further expansion. The most likely introduction pathway is the accidental or intentional releases from the aquarium trade but transport via ballast water cannot be ruled out. We cannot discount the possibility of independent invasion events from different routes to Puerto Rico and Cuba occurring within a year of each other. Propagation from Cuba to Puerto Rico, or vice versa, which we consider highly improbable, would likely imply that soft coral populations may also have been established on Hispaniola but have remained undetected in the Dominican Republic and Haiti to date.

ecology↗

bioRxiv2025

Early Invasion Genomic Resources for Xenia umbellata (Native to the Red Sea) and its Associated Dinoflagellate Symbionts in Puerto Rico

The frequency of xeniid soft coral invasions on Caribbean coral reefs is increasing, with three alien species reported so far. Xenia umbellata (Anthozoa, Octocorallia, Malacalcyonacea, Xeniidae), native to the Red Sea, was first reported on Puerto Rico coral reefs in October 2023. Here, we present the first draft genome assembly and early-invasion genomic resources for the rapidly spreading X. umbellata and its dinoflagellate symbiont (Family Symbiodiniaceae) produced from a specimen collected five months after the initial report. Using deep Illumina metagenomic sequencing ([~]243X coverage), we obtained [~]272.4 million high-quality 150 bp reads. The X. umbellata draft genome assembly is 151.14 Mbp in length, composed of 27,739 scaffolds, with an N50 of 6,477,837 bp. GenomeScope2 predicted a haploid genome size of 171.6-171.9 Mbp and calculated a heterozygosity of 1.27-1.29%. This suggests that the assembly captures [~]88% of the X. umbellata genome, and the relatively high heterozygosity may indicate introduction from a genetically diverse wild population. Completeness was further supported by BUSCO analysis (anthozoa_odb12 lineage), which identified 91.4% complete and 3.9% fragmented BUSCOs. Furthermore, 555,596 sequences were identified as belonging to Symbiodiniaceae, of which 99.97% (n= 555,520) aligned to a Durusdinium reference genome, suggesting that the co-invading symbiont belongs to the genus Durusdinium. Establishing these genomic and symbiotic resources at an early stage of invasion provides a critical foundation for monitoring range expansion, investigating host-symbiont evolutionary dynamics, and identifying genomic features that may underlie the invasive potential of X. umbellata as it spreads across Puerto Rico and the wider Caribbean.

genomics↗

bioRxiv2025

First record of a second invasive soft coral species, Latissimia ningalooensis, in southern Puerto Rico

Ever since the discovery of the invasive soft coral species Xenia umbellata (Anthozoa, Octocorallia, Malacalcyonacea, Xeniidae) on the reefs of southwestern Puerto Rico, ongoing surveys have documented its spread and potential impacts on native marine fauna. During benthic surveys conducted by scientific divers from Puerto Ricos DNER and the Department of Marine Sciences at UPRM, colonies of xeniid soft corals were observed with morphological and color characteristics distinct from those of X. umbellata. Morphological and genetic barcoding analyses of four gene regions confirmed the presence of a second invasive xeniid species, Latissimia ningalooensis, in the southern reefs of Puerto Rico. Originally described in Western Australia, L. ningalooensis has recently been reported in southeastern Brazilian waters, marking its expansion into the Atlantic. The discovery of a second xeniid species in Puerto Rico following the recent introduction of X. umbellata, is both surprising and concerning. Highly disturbed reefs, such as those along the southern coast of Puerto Rico and the wider Caribbean, seem highly susceptible to invasive species. Recent reports of invasive soft corals and other marine species in Puerto Rico highlight the potential for some species to become a regional issue, requiring coordinated management actions across the Caribbean.

ecology↗

bioRxiv2024

Shadows over Caribbean reefs: Identification of a new invasive soft coral species, Xenia umbellata, in southwest Puerto Rico

In October 2023, several colonies of an alien soft coral species were reported on shallow reefs in southwest Puerto Rico. The soft coral was identified as a xeniid octocoral (species undetermined), resembling the octocoral Unomia stolonifera, which has invaded and overgrown reefs in Venezuela in recent years. To conclusively characterize the species of the invading xeniid, we employed multilocus barcoding targeting four genes (ND2, mtMutS, COI, and 28S) of three separate colonies across three locations in southwest Puerto Rico. Sequence comparisons with xeniid sequences from GenBank, including those from the genera Xenia and Unomia, indicated a 100% sequence identity (>3,000 bp combined) with the species Xenia umbellata (Octocorallia : Malacalcyonacea : Xeniidae). Xenia umbellata is native to the Red Sea and to our knowledge, this represents the first confirmed case of this species as an invader on Caribbean reefs. Similar to U. stolonifera, X. umbellata is well known for its ability to rapidly overgrow substrate as well as tolerate environmental extremes. In addition, X. umbellata has recently been proposed as a model system for tissue regeneration having the ability to regenerate completely from a single tentacle. These characteristics greatly amplify X. umbellatas potential to adversely affect any reef it invades. Our findings necessitate continued collaborative action between local management agencies and stakeholders in Puerto Rico, as well as neighboring islands, to monitor and control this invasion prior to significant ecological perturbation.

genetics↗

bioRxiv2022

Consumer feces impact coral health in guild-specific ways

Microbiota from consumer feces can impact resource species in guild-specific ways. We tested the effect of fresh and heat-killed feces from corallivorous (coral-eating) and grazer/detritivorous fish on coral health and found that fresh grazer/detritivore feces, but not fresh corallivore feces, affected coral health in detrimental ways compared to heat-killed feces, suggesting that microbiota in grazer/detritivore feces were harmful. Bacterial diversity across 10 fish species suggests our experimental findings are generalizable to consumer guild: corallivore feces contained more coral-associated bacteria, and lower abundances of the coral pathogen, Vibrio coralliilyticus. These findings recontextualize the ecological roles of consumers on coral reefs: although herbivores support coral dominance through removal of algal competitors, they also disperse coral pathogens. Corallivore predation can wound corals, yet their feces contain potentially beneficial coral-associated bacteria, supporting the hypothesized role of corallivores in coral symbiont dispersal. Such consumer-mediated microbial dispersal as demonstrated here has broad implications for environmental management.

ecology↗

bioRxiv2022

Endogenous viral elements reveal associations between a non-retroviral RNA virus and symbiotic dinoflagellate genomes

Endogenous viral elements (EVEs) offer insight into the evolutionary histories and hosts of contemporary viruses. This study leveraged DNA metagenomics and genomics to detect and infer the host of a non-retroviral dinoflagellate-infecting +ssRNA virus (dinoRNAV) common in coral reefs. As part of the Tara Pacific Expedition, this study surveyed 269 newly sequenced cnidarians and their resident symbiotic dinoflagellates (Symbiodiniaceae), associated metabarcodes, and publicly available metagenomes, revealing 178 dinoRNAV EVEs, predominantly among hydrocoral-dinoflagellate metagenomes. Putative associations between Symbiodiniaceae and dinoRNAV EVEs were corroborated by the characterization of dinoRNAV-like sequences in 17 of 18 scaffold-scale and one chromosome-scale dinoflagellate genome assembly, flanked by characteristically cellular sequences and in proximity to retroelements, suggesting potential mechanisms of integration. EVEs were not detected in dinoflagellate-free (aposymbiotic) cnidarian genome assemblies, including stony corals, hydrocorals, jellyfish, or seawater. The pervasive nature of dinoRNAV EVEs within dinoflagellate genomes (especially Symbiodinium), as well as their inconsistent within-genome distribution and fragmented nature, suggest ancestral or recurrent integration of this virus with variable conservation. Broadly, these findings illustrate how +ssRNA viruses may obscure their genomes as members of nested symbioses, with implications for host evolution, exaptation, and immunity in the context of reef health and disease.

microbiology↗

bioRxiv2021

Thermal stress triggers productive viral infection of a key coral reef symbiont

Climate change-driven ocean warming is increasing the frequency and severity of bleaching events, in which corals appear whitened after losing their dinoflagellate endosymbionts (family Symbiodiniaceae). Viral infections of Symbiodiniaceae may contribute to some bleaching signs, but little empirical evidence exists to support this hypothesis. We present the first temporal analysis of a lineage of Symbiodiniaceae-infecting positive-sense single-stranded RNA viruses ( dinoRNAVs) in coral colonies, which were exposed to a 5-day heat treatment (+2.1{degrees}C). A total of 124 dinoRNAV major capsid protein gene aminotypes (unique amino acid sequences) were detected from five colonies of two closely related Pocillopora-Cladocopium (coral-symbiont) combinations in the experiment; most dinoRNAV aminotypes were shared between the two coral-symbiont combinations (64%) and among multiple colonies (82%). Throughout the experiment, seventeen dinoRNAV aminotypes were found only in heat-treated fragments, and 22 aminotypes were detected at higher relative abundances in heat-treated fragments. DinoRNAVs in fragments of some colonies exhibited higher alpha diversity and dispersion under heat stress. Together, these findings provide the first empirical evidence that exposure to high temperatures triggers some dinoRNAVs to switch from a persistent to a productive infection mode within heat-stressed corals. Over extended time frames, we hypothesize that cumulative dinoRNAV production in the Pocillopora-Cladocopium system could affect colony symbiotic status, for example, by decreasing Symbiodiniaceae densities within corals. This study sets the stage for reef-scale investigations of dinoRNAV dynamics during bleaching events.

ecology↗