Juan Armando Sanchez

Los Andes University (Colombia) | UNIANDES · Department of Biological Sciences

The degradation of the night sky’s quality due to artificial light sources negatively affects marine environments, because many organisms use natural light as cues for reproductive and dispersal behaviors, find favorable habitats, and for the biochemistry of their symbiotic microorganisms. Despite the tremendous effect on marine life, measuring the...

The euendolithic algae Ostreobium (Bryopsidales: Chlorophyta) is an important microbioeroder responsible for tropical coral reefs dissolution. In the current context of widespread decline of coral reefs in the Caribbean, a better understanding of the associations that exist between bioeroders and corals is needed to accurately anticipate the future...

Ostreobium comprises endolithic algae commonly seen in conjunction with scleractinian corals. In the past, it was solely recognized as a coral skeleton bioeroder. Their relationship with corals is critical because they give photosynthetic byproducts and help the coral when it loses its primary symbionts due to stress. The variety of these algae in...

Coral skeletons provide habitat for a euendolithic community, forming a green band within the skeleton, where Ostreobium spp. is the dominant group. Euendoliths, actively penetrate live coral skeletons, but how they use and modify skeletal structure is not properly understood. This study explores the microstructural characteristics of skeletal micr...

Ostreobium comprise endolithic algae commonly seen in conjunction with scleractinian corals. In the past, it was solely recognized as a coral skeleton bioeroder. Yet, their relationship with corals is critical because they give photosynthetic byproducts and help the coral when it loses its primary symbionts due to stress. The variety of these algae...

The coral microbiome conforms a proxy to study effects of changing environmental conditions. However, scarce information exists regarding microbiome dynamics and host acclimation in response to environmental changes associated to global-scale disturbances. We assessed El Niño Southern Oscillation (ENSO)-derived thermal anomalies shifts in the bacte...

Queremos buscar las formas de establecer estándares que permitan la co�laboración interinstitucional para masificar el buceo científico y reducir los costos para los estudiantes e investigadores. Regular las buenas prácticas, en especial las normas de seguridad en buceo científico, es el primer paso para fortalecer e impulsar esta creciente comu...

Background Mesophotic coral communities are increasingly gaining attention for the unique biological diversity they host, exemplified by the numerous mesophotic fish species that continue to be discovered. In contrast, many of the photosynthetic scleractinian corals observed at mesophotic depths are assumed to be depth-generalists, with very few sp...

During the last 25 years in Colombia, deep-sea corals species have been reported based on several mesophotic and deep-sea expeditions. Although many of these records have been published independently in different journals, there is no clear number of these organisms for Colombian waters despite the usefulness of this information for future research...

Coral reefs are facing significant environmental challenges. Ocean acidification has the potential to induce the dissolution of coral reefs. The community of micro-bioerosion exhibits a heightened level of concern in the context of ocean acidification. Comprehending the close interplay between bioeroders and corals is of utmost importance in predic...

Confronting a sustained coral reef conservation crisis, we need new opportunities to rethink how to protect areas successfully and efficiently in the face of a changing world. We studied the benthic community, including foraminifera, fish community, and genetic connectivity (SSRs and SNPs) of main reef-building corals, Orbicella faveolata and Agari...

Biodiversity on coral reefs depends not only on primary reef-builders, but also on associated taxa that create microhabitats for other species. Hydrocorals of the genus Stylaster, commonly known as lace corals, form small branching colonies that enhance three-dimensional complexity on reefs and are known to support a variety of commensal species. F...

The genus Muricea, a highly speciose gorgonian coral group in the Tropical Eastern Pacific (TEP), is commonly found on shallow rocky reefs including Machalilla National Park (MNP), El Pelado Marine Reserve (REMAPE) and Galápagos Marine Reserve (GMR). Here, we report the presence of M. hebes, M. echinata and M. robusta, which have been not previousl...

Mesophotic coral communities are increasingly gaining attention for the unique and distinct biological species they host, exemplified by the numerous mesophotic fish species that continue to be discovered. In contrast, many of the photosynthetic scleractinian corals observed at mesophotic depths are assumed to be depth-generalists, with very few sp...

The Equatorial Front, in the southern part of the Tropical Eastern Pacific (TEP) region, has been characterized as a hotspot of functional biodiversity due to the mixing of warm and cold waters. Nevertheless, the biogeographic patterns for some organisms, such as octocorals, remain unknown in some coastal regions. Therefore, we aimed to assess the...

Confronting a sustained coral reef conservation crisis, we need new opportunities to rethink how to protect areas successfully and efficiently in the face of a changing world. We studied the benthic community, including foraminifera, fish community, and genetic connectivity (SSRs and SNPs) of main reef-building coral, Orbicella faveolata and Agaric...

Largely understudied, mesophotic coral ecosystems lie below shallow reefs (at >30 m depth) and comprise ecologically distinct communities. Brooding reproductive modes appear to predominate among mesophotic‐specialist corals and may limit genetic connectivity among populations. Using reduced representation genomic sequencing, we assessed spatial pop...

Mesophotic Coral Ecosystems (MCEs) develop on a unique environment, where abrupt environmental changes take place. Using a time-calibrated molecular phylogeny (mtDNA: mtMutS), we examined the lineage membership of mesophotic gorgonian corals (Octocorallia: Cnidaria) in comparison to shallow and deep-sea lineages of the wider Caribbean-Gulf of Mexic...

The current knowledge on the diversity of the genus Plexaurella is based on a series of dated revisions, often with no examination of types. Although being common octocorals in western Atlantic reefs, there is no consensus on an exact number of valid species. Furthermore, phylogenetic reconstructions do not support the current classification of Ple...

Vastly understudied, mesophotic coral ecosystems lie below shallow reefs (> 30 m depth) and comprise ecologically distinct communities. Brooding reproductive modes appear to predominate among mesophotic-specialist species and may limit genetic connectivity among populations. Using reduced representation genomic sequencing, we assessed spatial popul...

Nonindigenous species are increasingly transported around the world through multiple pathways by a diversity of vectors. Invasive species are a subset of those that are introduced into the receptor community, where they establish and increase their population to a size where they impact the native system. Marine invasive species can therefore inter...

1. Summary Mesophotic Coral Ecosystems (MCEs) develop on a unique environment, where abrupt environmental changes take place. Using a time-calibrated molecular phylogeny (mtDNA: mtMutS), we examined the lineage membership of mesophotic gorgonian corals (Octocorallia: Cnidaria) in comparison to shallow and deep-sea lineages of the wider Caribbean-G...

Parrotfish are a keystone group that reduces competition between algae and corals while shaping the dynamics and resilience of coral reefs. We investigated the structure of disseminated coral-associated bacteria and the extent to which the cell integrity of dinoflagellate photosymbionts (family Symbiodiniaceae) is maintained in the faeces. Similar...

En este volumen se presenta un resumen del diagnóstico realizado en el foco temático Océanos y Recursos Hidrobiológicos y se incluyen lineamientos para diseñar políticas públicas, estrategias, misiones emblemáticas y proyectos, encaminados a mejorar el desarrollo humano sostenible y a generar oportunidades socioeconómicas basadas en conocimiento ci...

https://www.frontiersin.org/articles/10.3389/fmars.2020.00646/full .... Queen conch Aliger gigas (Linnaeus, 1758), formerly known as Strombus gigas, constitute a valuable commercial and cultural resource for native communities since pre-Hispanic times (Baisre 2010). Populations of this marine gastropod are registered for 36 countries in the Caribbe...

Corals are some of the conspicuous taxa in deep-sea ecosystems. Yet, characterizing coral diversity is difficult and requires a combination of both morphological and genetic data. Many leading coral taxonomy experts are close-to retirement or have already retired. It is now imperative that the hands-on expertise that these taxonomists have – much o...

La Misión Internacional de Sabios 2019 fue convocada por el Gobierno de Colombia en el mes de febrero de 2019. Estuvo conformada por un grupo de expertos independientes y ad honorem en diferentes campos y de diferentes nacionalidades. La Misión recibió el encargo de trazar una hoja de ruta para el desarrollo de la ciencia, la tecnología y la innova...

Gorgonian corals occurring in shallow waters are vulnerable to changing environmental conditions and human-related pressures such as pollution, overfishing, and diseases. However, anthropogenic effects on coral systems are difficult to quantify due to the lack of base-line data of unaffected populations. In order to assess the impact of global and...

The octopus fauna from the southern Caribbean is an understudied field. However, recent taxonomic work in the Colombian Caribbean has led to the discovery of several new species in the family Octopodidae. To provide molecular evidence for recent descriptions in the area (i.e., Octopus taganga, O. tayrona and Macrotritopus beatrixi ) and contribute...

Xestospongia muta is among the most emblematic sponge species inhabiting coral reefs of the Caribbean Sea. Besides being the largest sponge species growing in the Caribbean, it is also known to produce secondary metabolites. This study aimed to assess the effect of depth and season on the symbiotic bacterial dynamics and major metabolite profiles o...

Mesophotic gorgonian corals comprise a polyphyletic group of octocorals mostly with a proteinaceous branching axial skeleton. Dense assemblages of gorgonian corals usually dominate the seascape in mesophotic coral ecosystems (MCEs). In this chapter, we review the mesophotic gorgonian coral biodiversity, followed by a synthesis of the ecological imp...

Background Attention to the deep-sea environment has increased dramatically in the last decade due to the rising interest in natural resource exploitation. Although Colombia holds a large submerged territory, knowledge of the seabed and its biodiversity beyond 1,000 m depth is very limited. During 2015–2017, Anadarko Colombia Company (ACC) carried...

Coral reef decline persists as a global issue with ties to climate change and human footprint. The SeaFlower Biosphere reserve includes some of the most isolated oceanic coral reefs in the Southwestern Caribbean, which provide natural experiments to test global and/or basin-wide factors affecting coral reefs. In this study, we compared coral and ot...

DNA barcoding is a useful tool for documenting the diversity of metazoans. The most commonly used barcode markers, 16S and COI, are not considered suitable for species identification within some "basal" phyla of metazoans. Nevertheless metabarcoding studies of bulk mixed samples commonly use these markers and may obtain sequences for "basal" phyla....

Microbiome disruptions triggering disease outbreaks are increasingly threatening corals worldwide. In the Tropical Eastern Pacific, a necrotic-patch disease affecting gorgonian corals (sea fans, Pacifigorgia spp.) has been observed in recent years. However, the composition of the microbiome and its disease-related disruptions remain unknown in thes...

Understanding how corals and their symbionts specialize across depth gradients allows us to understand biodiversity in shallow and mesophotic coral ecosystems. Here we determined the prevalence of endolithic algal in Agaricia undata (17–83 m) and examined community changes within (shallow, upper and lower zones) and among sites (oceanic vs. contine...

Mesophotic reef-building coral communities (~30–120 m depth) remain largely unexplored, despite representing roughly three-quarters of the overall depth range at which tropical coral reef ecosystems occur. Although many coral species are restricted to shallow depths, several species occur across large depth ranges, including lower mesophotic depths...

Background Phenotypic plasticity, as a phenotypic response induced by the environment, has been proposed as a key factor in the evolutionary history of corals. A significant number of octocoral species show high phenotypic variation, exhibiting a strong overlap in intra- and inter-specific morphologic variation. This is the case of the gorgonian oc...

Los arrecifes coralinos mesofóticos constituyen comunidades arrecifales de profundidad ubicadas entre 30 y 200 m de la zona fótica. Se caracterizan por ser una extensión directa de los ecosistemas arrecifales de aguas someras y están constituidos por corales escleractínios zooxantelados, corales azooxantelados, octocorales, macroalgas, esponjas y u...

Anthozoans (e.g., corals, anemones) are an ecologically important and diverse group of marine metazoans that occur from shallow to deep waters worldwide. However, our understanding of the evolutionary relationships among the ~7500 species within this class is hindered by the lack of phylogenetically informative markers that can be reliably sequence...

Fire corals are the only branching corals in the South Atlantic and provide an important ecological role as habitat-builders in the region. With three endemic species (Millepora brazilensis, M. nitida and M. laboreli) and one amphi-Atlantic species (M. alcicornis), fire coral diversity in the Brazilian Province rivals that of the Caribbean Province...

The tropical snowflake octocoral Carijoa riisei, which is thought to be native to the Indo-Pacific biogeographical region, has been increasingly reported from the Colombian Tropical Eastern Pacific (TEP) over the past two decades. Massive mortalities of native octocorals, particularly in Pacifigorgia spp. and Muricea spp., were observed due to C. r...

Octocoral animal forests (Gorgoniidae and Plexauridae: Octocorallia) at both sides of tropical America provide a unique and characteristic seascape. They can reach over 2 m in height and even form a closed “canopy” in the densest communities. As a functional forest, gorgonian corals provide feeding substrate and habitat for diverse associated biota...

Anthozoans (e.g., corals, anemones) are an ecologically important and diverse group of marine metazoans that occur from shallow to deep waters worldwide. However, our understanding of the evolutionary relationships among the ∼7500 species within this class is hindered by the lack of phylogenetically informative markers that can be reliably sequence...

Xestospongia muta is one of the most abundant sponge species of the coral reef communities at the Caribbean Sea. Its high ecological significance makes this species a suitable holobiont model for further understanding of the relationships between its symbiotic bacteria and the secondary metabolism it produces. The aim of our study was to identify t...

Background: Antarctica is surrounded by the Antarctic Circumpolar Current (ACC), the largest and strongest current in the world. Despite its potential importance for shaping biogeographical patterns, the distribution and connectivity of deep-sea populations across the ACC remain poorly understood. In this study we conducted the first assessment of...

Octocoral animal forests (Gorgoniidae and Plexauridae: Octocorallia) at both sides of tropical America provide a unique and characteristic seascape. They can reach over 2 m in height and even form a closed “canopy” in the densest communities. As a functional forest, gorgonian corals provide feeding substrate and habitat for diverse associated biota...

Background. Background matching, as a camouflage strategy, is one of the most outstanding examples of adaptation, where little error or mismatch means high vulnerability to predation. It is assumed that the interplay of natural selection and adaptation are the main evolutionary forces shaping the great diversity of phenotypes observed in mimicry; h...

The Masquerade game Development of a board game for teaching, playing and outreach (includes tables, figures and a game kit).

Research on coral reef community structure suggests that fine spatial-temporal stochasticity drives biodiversity patterns in this tropical marine ecosystem. The combination of a coral colony and its zooxanthella, or holobiont, should therefore be used as the community indivisible units to better understand this structure. Research in zooxanthellae...

Background. Background matching, as a camouflage strategy, is one of the most outstanding examples of adaptation, where little error or mismatch means high vulnerability to predation. It is assumed that the interplay of natural selection and adaptation are the main evolutionary forces shaping the great diversity of phenotypes observed in mimicry, h...

Background. Background matching, as a camouflage strategy, is one of the most outstanding examples of adaptation, where little error or mismatch means high vulnerability to predation. It is assumed that the interplay of natural selection and adaptation are the main evolutionary forces shaping the great diversity of phenotypes observed in mimicry, h...