Caribbean Species Research Articles

The Clockwork Olive: Perspectives from the “American Shoulder”

The structure and the biological significance of the Olivinae fasciculate ornamentation known as “American Shoulder” (after its presence in the American olives) are investigated for around 20 Western Atlantic / Gulf of Mexico / Caribbean species. The applicability of the “Chevron Paradigm” by Tursch & Greifeneder (2001) to the subchannel area is questioned and contrary evidence is proposed. A robust correlation between lip thinning phases and the generation of the typical American Shoulder features is observed: their coincidence with rapid growth stages as reported by Strano (2017) is plausible but wasn’t established decisively in absence of destructive investigations. The issues of intraspecific and interspecific variability are addressed thanks to an extensive photographic coverage, and a new general description of the peculiar pattern emerges from the investigations. The initial identification of some specimens included in this study is questioned on the basis of their subchannel pattern, hinting at its possible use as an accessory character in species determination, and suggesting to include exhaustive descriptions of American Shoulder patterns in new nomenclatural acts involving the (sub)genus Americoliva.

The genus Kelliella (Bivalvia) in the Atlantic Ocean

ABSTRACT Kelliella M. Sars, 1870 is a genus of small epibenthic bivalves inhabiting muddy bottoms of the outer shelf and slope worldwide, commonly in habitats that are oxygen-poor or enriched in organic carbon. Currently, there are five accepted species of Kelliella with an Atlantic type locality, and six more Atlantic species, including Vesicomya atlantica (Smith, 1885), the type species of Vesicomya Dall, 1886, were at some time placed in Kelliella. In this work, we revise the genus Kelliella from the North Atlantic waters, based on large amounts of new material from both sides, and describe a new species from Martinique (Kelliella madininae n. sp.). We here propose, after revision of the shell morphology, the synonymy of K. biscayensis Allen, 2001 with K. miliaris (Philippi, 1844), and consider a single West European and Mediterranean species of Kelliella. The fossil “Kelliella” barbara is also excluded from the genus Kelliella and reallocated as Coralliophaga barbara (Studencka, 1987) n. comb. In the Atlantic margin of America, we consider that Diplodonta pilula Dall, 1881 remains a nomen dubium. The type material of K. concentrica Allen, 2001 is figured, and this species considered a member of the Vesicomyinae. The new Caribbean species, K. madininae, resemble K. brasuca Passos, Machado & Fantinatti, 2017 from southeastern Brazil. We recorded new localities for Kelliella goesi Odhner, 1960, so far known only from its original description. Diagnostic characters discriminating Vesicomya from Kelliella, stated by Krylova et al. (2018), Journal of Molluscan Studies, 84: 69–91, are discussed, and we consider the hinge architecture as the most robust.

The State of Knowledge of CCA Diversity in the Caribbean Coral Reefs

Crustose coralline algae (CCA) are a diverse and ecologically important species found in most of the world’s oceans. The current lack of taxonomic knowledge and relative abundance compromises our ability to predict species diversity numbers and, thus, their ecological roles and impacts on coral reefs. To gather a better understanding of the state of knowledge of crustose coralline algae taxonomy in the Caribbean, 107 different research papers, and other primary and secondary literature were studied; any source with taxonomical information, species identification, or genetic markers for identification was recorded. All Genebank codes were collected and sorted by supposed species marker and then ran through the National Center of Biotechnology Information. The location these genetic markers were gathered from was compared to the natural habitat range of the species, based on the Algaebank habitat description. Of the supposed 83 described species of crustose algae in the Caribbean, based on morphological characteristics, only 24 total were confirmed by DNA markers. This leaves at least 59 species of CCA to be confirmed in the Caribbean Sea with molecular markers. This indicates the importance of DNA barcode survey studies to assess the accurate diversity of this group in the region. With this limited knowledge apparent, it should be seen that a CCAs phylogenetic and taxonomical review must be done. An in-depth assessment should be conducted on CCA collections to identify the Caribbean species correctly and thus know their biodiversity in local habitats.

Depth Range Extension for the Misty Grouper Hyporthodus mystacinus Documented via Deep-Sea Landers throughout the Greater Caribbean

Misty Groupers (Hyporthodus mystacinus) are one of the largest and most geographically widespread grouper species and one of the few grouper species known to occur at depths greater than 200 m. However, aspects of their basic biology, behavior, and ecology remain poorly understood, leaving significant gaps in our ability to evaluate their functional role throughout the vertical water column, as well as our understanding of their conservation needs in a changing ocean. Through in-situ video observation obtained using deep-sea landers in both The Bahamas and Cayman Islands over multiple years, we documented Misty Grouper occurrence up to 470 m depth in the mesopelagic zone. These observations provide a new depth range extension for the species and illuminate the potential importance of deep-water habitats for large grouper species in the wider Caribbean.

An expanded concept of Ceratocystis manginecans and five new species in the Latin American clade of Ceratocystis

ABSTRACT The genus Ceratocystis contains a number of emerging plant pathogens, mostly members of the Latin American Clade (LAC), in which there are several unresolved taxonomic controversies. Among the most important are Brazilian pathogens in the C. fimbriata complex, C. manginecans and C. eucalypticola. Representatives of C. manginecans and C. eucalypticola from India and China, respectively, were shown to be fully interfertile in laboratory matings, and hybrids between the putative species were identified on Punica in India. An Indian tester strain was sexually compatible with representatives of what has been considered C. fimbriata on numerous hosts across Brazil. In this revision of the LAC, the name C. fimbriata is restricted to the widely dispersed Ipomoea strain, and C. manginecans is recognized as a Brazilian species that is important on Mangifera, Eucalyptus, and many other crops. C. mangivora and C. mangicola are also considered synonyms of C. manginecans. Based on phylogenetics and mating studies, two other Brazilian species are recognized: C. atlantica, sp. nov., and C. alfenasii, sp. nov., each with wide host ranges. Three new Caribbean species are recognized based on phylogenetics and earlier inoculation studies: C. costaricensis, sp. nov., on Coffea, C. cubensis, sp. nov., on Spathodea, and C. xanthosomatis, sp. nov., on the vegetatively propagated aroids Xanthosoma and Syngonium. Some of the other Ceratocystis species were based primarily on unique internal transcribed spacer (ITS) rDNA sequences, but the unreliability of rDNA sequences was demonstrated when intraspecific crossing of isolates with differing ITS sequences generated single-ascospore progeny with intragenomic variation in ITS sequences and others with new ITS sequences. Species recognition in Ceratocystis should use phenotype, including intersterility tests, to help identify which lineages are species. Although some species remain under-studied, we recognize 16 species in the LAC, all believed to be native to Latin America, the Caribbean region, or eastern USA.

New species and record of Dodecaceria (Annelida: Cirratulidae) the Biological Reserve of Rocas Atoll, Brazil, the only atoll in the South Atlantic Ocean.

The polychaete Family Cirratulidae is one of the most abundant and diverse groups of Annelida, although it remains poorly known worldwide. Dodecaceria Ørsted, 1843 is one of the least described genera of Cirratulidae. The present report is the first taxonomic study of the genus Dodecaceria for the Brazilian coast. Cirratulidae were collected at Rocas Atoll, the first Brazilian marine protected area and the only atoll in the South Atlantic Ocean. We described one new species, Dodecaceria zelinhae n. sp., and a new record of D. dibranchiata Blake & Dean, 2019, previously only known from Panama. The new species is distinguished from other Dodecaceria species by having lateral tentacles, a smooth peristomium, 3-5 pairs of branchiae, hooks from chaetiger 11 in notopodia and 9 in neuropodia. Dodecaceria dibranchiata, a Caribbean species, is here recorded for the first time in the South Atlantic Ocean.

Herbaceous angiosperms, pteridophytes and shrubs cocktail for rapid ground cover for soil and water bioengineering in the Caribbean

Among the Nature-based Solutions currently spreading worldwide, soil and water bioengineering techniques, are used to stabilize hill slopes, earth embankment, and riverbanks. They consist in the use of living plants, sometimes coupled with dead materials, to control erosion and restore ecosystems.These approaches remain to be adapted to Neotropics and particularly to the Caribbean Islands biodiversity hotspot. The success of soil and water bioengineering designs depends on the selection of suitable native plant species and considering the hydrodynamic and geotechnical processes. In the Caribbean, data are available concerning woody species but are still lacking for the other constitutive components of riparian plant communities. The objective of this study was to identify the riparian forest understory species best suited for use in SWBE at their establishment phase. In a three-month ex situ experiment, we measured the survival rate, biomass production and root growth of propagules (cuttings and bulbils) of eleven native Caribbean species (5 herbs, 4 pteridophytes, 2 shrubs) occurring naturally in a variety of riparian environments. All the herb and shrub species studied displayed growth vigour adequate for a successful inclusion in soil and water bioengineering techniques. Among herbs, Commelina diffusa, Hymenachne amplexicaulis and Sphagneticola trilobata performed the best. Gynerium sagittatum and Dieffenbachia seguine, despite their slower growth and root development, remain suitable. Regarding the two shrubs, Ludwigia octovalvis gave better results than Clidemia hirta. Among the pteridophytes, Adiantum latifolium, Thelypteris reticulata and particularly Lycopodium cernuum appeared poorly suited to soil and water bioengineering. Acrostichum danaeifolium was the best-performing pteridophyte. These first experimental results focusing on the propagation and establishment of native herbs, pteridophytes and shrubs, allowed to identify a diversity of species of interest as cuttings for soil and water bioengineering and practical clues for their use in the Neotropics.

Alacranes reef: A refuge for structurally complex coral species from increasing stressors

Coral reefs worldwide are being exposed to an interconnected myriad of anthropogenic stressors degrading their structure and functions. Therefore, global coral cover and coral reef ecosystem services have declined by half since the 1950s. Yet, remote reefs represent a time capsule to study ecological processes on minimally disturbed reefs, and these findings can steer management decisions and actions to enhance resilience. Combining in situ and satellite-derived data from the remote Alacranes Reef system located in the Gulf of Mexico, we evaluated benthic cover data and coral structural complexity together with physical drivers and direct coral stressors to better understand the current reef conditions of this remote system. Our main results show that 57% of the reef sites have >10% hard coral cover and are dominated by structurally complex species. Moreover, sites with >20% coral cover were associated with significantly shallower depths, smaller wave significant height, fewer bleaching impacts, as well as fewer macroalgae and cyanobacteria cover. Despite cumulative stressors impacting the Alacranes reef system, coral species assemblages and conditions are still driven by natural physical gradients, and the system hosts potential refuges for structurally complex species in the wider Caribbean. However, not all these refuges are fully protected, and strategic local management is key to maintaining and enhancing coral resilience in the context of increasing global stressors.

Building a Teleost Fish Traceability Program Based on Genetic Data from Pacific Panama Fish Markets.

Fish tissue samples from 203 adult individuals were collected in the main ports and markets of the Pacific coast of Panama. Molecular identification based on a cytochrome oxidase I gene segment of all species was verified by GENBANK reference sequences. A total of 34 species from 14 families (Ariidae, Caranjidae, Centropomidae, Gerreidae, Haemulidae, Lobotidae, Lutjanidae, Malacanthidae, Mugilidae, Scianidae, Scombridae, Serranidae, Sphyraenidae, Stromateidae) were identified at the species level from 164 sequences. Additionally, three Caribbean species were molecularly identified among the analyzed samples (Mycteroperca xenarcha, Paralonchurus brasilensis and Lobotes surinamensis). Species diversity was slightly higher in the Gulf of Panama than in the Gulf of Chiriquí. For species with five or more individual sequences, genetic diversity and genetic connectivity parameters such as total number of haplotypes (H), haplotype diversity (Hd), and nucleotide diversity (π) were calculated. Overall, pelagic-migratory species showed higher values of genetic diversity than coastal and estuarine species with some exceptions. Connectivity between Gulf areas was compared using values of genetic distances and genetic differentiation (Fst). The high level of connectivity observed between the Gulf of Chiriqui and the Gulf of Montijo indicates the existence of a single stock in that area for the following species: Scomberomorus sierra, Caranx caninus and Lutjanus guttatus. The demographic history of the most common species was examined using Tajima's D values, suggesting population expansion for two snapper species, L. peru and L. argentiventris, having significant and higher values. Another important contribution from this research was the production of primers and dual-labeled probes for environmental DNA detection using qPCR for the five most abundant species (spotted rose snapper, yellow snapper, green jack, Pacific crevalle jack and the Pacific sierra fish). These markers represent a new set of tools for environmental DNA (eDNA) detection and molecular traceability of three commercially important fish species along the supply chain including landing sites and markets of the main fishery areas.

Using Coral Color to Indicate Coral Health in Five Caribbean Species

Coral reefs are one of the most biodiverse and productive ecosystems on Earth, and color has been shown to indicate coral health in Australian and Hawaiian reef systems. However, no standardized method exists to quantify coral health for Caribbean corals. Therefore, a health assessment card using coral color was developed for five species of Caribbean corals to monitor coral health non-invasively. To quantify coral health, individual corals of each species were photographed in a controlled environment to develop color profiles. Simultaneously, nondestructive measurements of “health” were quantified by measuring photosynthetic efficiency (Fv/Fm) using pulse amplitude modulation (PAM) fluorometry, which determines how efficiently the symbiotic algae provides energy to the coral host. The results of this work successfully corresponded photosynthetic efficiency to coral color for five dominant species of Caribbean corals to develop a Coral Health Assessment Card for Caribbean reefs. Implementing a standardized assessment of symbiont performance can assist in monitoring changes in coral health, which can consequently be implemented into long-term and widespread monitoring projects to track overall Caribbean reef health. KEYWORDS: Photosynthetic Efficiency, Symbiodinium spp., Coral Bleaching, Pulse-amplitude Modulated Fluorometry, Health Assessment

Species assemblages of insular Caribbean Sticta (lichenized Ascomycota: Peltigerales) over ecological and evolutionary time scales

Phylogenetic approaches to macroevolution have provided unique insight into evolutionary relationships, ancestral ranges, and diversification patterns for many taxa. Similar frameworks have also been developed to assess how environmental and/or spatial variables shape species diversity and distribution patterns at different spatial/temporal scales, but studies implementing these are still scarce for many groups, including lichens. Here, we combine phylogeny-based ancestral range reconstruction and diversification analysis with community phylogenetics to reconstruct evolutionary origins and assess patterns of taxonomic and phylogenetic relatedness between island communities of the lichenized fungal genus Sticta in the Caribbean. Sampling was carried out in the Greater Antilles (Cuba, Jamaica, Dominican Republic, and Puerto Rico) and Lesser Antilles (Dominica, Guadeloupe, and Martinique). Data for six molecular loci were obtained for 64 candidate Caribbean species and used to perform both macroevolutionary phylogenetics, which also included worldwide taxa, and phylobetadiversity analyses, which emphasized island-level communities. Our work uncovered high levels of island endemism (∼59%) in Caribbean Sticta. We estimate initial colonization of the region occurred about 19 Mya from a South American ancestor. Reverse migration events by Caribbean lineages to South America were also inferred. We found no evidence for increased diversification rates associated with range expansion into the Caribbean. Taxonomic and phylogenetic turnover between island-level communities was most strongly correlated with environmental variation rather than with geographic distance. We observed less dissimilarity among communities from the Dominican Republic and Jamaica than between these islands and the Lesser Antilles/Puerto Rico. High levels of hidden diversity and endemism in Caribbean Sticta reaffirm that islands are crucial for the maintenance of global biodiversity of lichenized fungi. Altogether, our findings suggest that strong evolutionary links exist between Caribbean and South American biotas but at regional scales, species assemblages exhibit complex taxonomic and phylogenetic relationships that are determined by local environments and shared evolutionary histories.

Site fidelity and population parameters of pantropical spotted dolphins in the Eastern Caribbean through photographic identification

The Agoa protected marine area, located in the French West Indies, eastern Caribbean, holds several cetacean species, of which the pantropical spotted dolphinStenella attenuatais the most commonly observed. This species is the focus of whale-watching activities off the leeward coasts of Guadeloupe and Martinique, which has allowed the development of a citizen science program to characterize individuals through the collection of photographic data. Here, we conducted a photo-identification study with a sample of 115,705 photos collected between 2014 and 2019, in which 290 marked individuals (179 in Guadeloupe and 111 in Martinique) were identified. Based on an Agglomerative Hierarchical Classification (AHC) analysis, dolphins from each island were separated into two residency clusters. The Catch–Mark–Release (CMR) POPAN statistical model for open populations estimated the pantropical spotted dolphin populations in Guadeloupe and Martinique at 657 (95% CI: 525–821) and 336 (95% CI: 253–446) individuals for frequent users, respectively, while occasional visitors were estimated at 3,063 (95% CI: 2,133–4,398) and 1,443 (95% CI: 1,024–2,033), respectively. The Martinique population tended to use a reduced coastal area and appeared to be smaller and stable, while the Guadeloupe population showed a slight decline in abundance throughout the study period. These results showed that the leeward coasts of Guadeloupe and Martinique are of particular importance for pantropical spotted dolphin populations, highlighting the need for continued monitoring through both scientific and citizen science programs to fill information gaps on this species in the eastern Caribbean.

Unique horizontal gaze control in the box jellyfish, Tripedalia cystophora

All known cubozoans, box jellyfish, have a similar visual system. They possess four sensory structures called rhopalia, which carry-six eyes each. Two of these six eyes are true image-forming camera type eyes in several ways similar to vertebrate eyes. The rhopalia hang by a thin flexible stalk and in the distal end, there is a high-density crystal. In an earlier study of the Caribbean species Tripedalia cystophora, we showed that the crystals act as weights ensuring that the rhopalia are always upright no matter the orientation of the medusa and the vertical part of the visual field of the eyes thus kept relatively constant. Here we have examined the horizontal part of the visual field under different experimental conditions including different visual environments. We find that the horizontal gaze direction is largely controlled by the anatomy of the rhopalium and rhopalial stalk, similar to what has previously been shown for the vertical gaze direction. In a vertically oriented medusa, the rhopalia are kept with a 90° angle between them with the lower lens eyes (LLE) pointing inwards. This 90° shift is kept in horizontally swimming medusa, resulting in the left LLE gazing right, the right gazing left, the bottom gazing orally (backwards compared to swimming direction), and the top LLE gazing aborally (forwards compared to swimming direction). The light environment was manipulated to test if the visual input influences this seemingly strict horizontal gaze direction but even in complete darkness there is tight mechanistic control.

New Echinoderes (Kinorhyncha: Cyclorhagida) from Mexico: Molecular barcoding demonstrate species delimitation between highly similar morphospecies

Two new species of Echinoderes are described from Mexico. Echinoderes abeli sp. nov. is described from the archipelago Islas Marias in the Mexican Pacific Ocean west coast. The species is characterized by very short and stout lateral terminal spines, middorsal spines on segments 4 to 8 and lateroventral spines on segments 6 to 9, lateroventral tubes on segment 2 and 5, midlateral tubes on segment 4, and sublateral ones on segment 8, and in laterodorsal positions on segment 10, as well as glandular cell outlets type 2 in subdorsal positions segment 2. The second new species, Echinoderes wilberti sp. nov. is described from the Caribbean coast in Yucatan. The new species show great resemblance with another species, Echinoderes horni, that occurred at the same locality. The only notable difference is a pair of subdorsal tubes on segment 2, present in E. wilberti sp. nov. only. However, barcoding of COI demonstrated the two morphospecies differed genetically more than 8%. This result shows that small morphological differences might be supported by much more conspicuous molecular differences. Based on the high level of morphological similarity between E. wilberti sp. nov. and E. horni, as well as a third Caribbean species, Echinoderes parahorni, a species group, the E. horni group, is proposed to accommodate this potentially monophyletic group of species.This article is registered at www.zoobank.org under urn: lsid: zoobank.org:pub: 5AE5C820-C922-492B-83F3-66C957E53453.

A New Miniature Melocactus (Cactaceae) from Puerto Rico

A new species of Melocactus is described from Puerto Rico. This miniature species, with a stem no more than 70 mm in diameter, is of uncertain affiliation but is unlikely to be a close relative of M. intortus, the only other Melocactus known from Puerto Rico, due to the lack of a pink-coloured stigma, smaller stem dimensions and distinct seed structure. There are morphological similarities with some other Caribbean species: M. lemairei and M. praerupticola of Hispaniola, and M. guitartii (= M. curvispinus) from Cuba.

Evaluating the suitability of neotropical trees and shrubs for soil and water bioengineering: Survival and growth of cuttings from ten Caribbean species

Soil and water bioengineering techniques are now increasingly adopted worldwide for controlling riverbank erosion but have not yet been implemented in the Caribbean Islands biodiversity hotspot. The selection of suitable native plant species is critical for successful soil bioengineering designs on riverbanks, but few data are available regarding Caribbean species. This study aimed to characterize the performance and biotechnical traits of native Caribbean species potentially compatible with soil and water bioengineering. In a six-month shadehouse experiment, we measured the survival rate, biomass production and root growth of cuttings of ten native Caribbean shrub and tree species occurring naturally in a variety of riparian environments. All species appeared suitable for soil and water bioengineering but differed as to the specific bioengineering techniques they seemed particularly suited for, depending on their respective survival rates, growth performances and root system structures. Five tree species, Citharexylum spinosum, Cedrela odorata, Ficus citrifolia, Chimarrhis cymosa, Homalium racemosum, and three shrubs, Piper dussii, Piper dilatatum and Phyllanthus mimosoides, exhibited survival, growth and root characteristics compatible with a broad range of techniques, whereas Tabebuia heterophylla and Cordia sulcata may only be compatible with a few. We also propose using of the DEXi decision-support software for assessing species suitability to a series of widespread soil and water bioengineering techniques. Our results provide practical guidance for the integration of native species in soil and water bioengineering in the Caribbean and the Neotropics at large.

Taxonomic applications of the esophageal flapper valve in Bairdoppilata and Glyptobairdia (Bairdiidae, Ostracoda), with comments on anatomy, ontogeny, and geography.

The esophageal valve follows a uniform design in species of Bairdoppilata and Glyptobairdia, having a thin, wedge-shaped plate with 1016 small teeth along the posterior edge. This structure may be added to the list of diagnostic anatomical traits, including the scissors-like antennal claws and complex distal appendages of the hemipenis, for identification of living species of these genera. These soft anatomical characters are invariably associated with bairdoppilatan supplemental dentition on the carapace, which supports the reliability of that trait for identification of fossils. This report evaluates the consistency of the esophageal plate in nine living species of Bairdoppilata. Photographs of the Oligocene type species, B. martyni, are provided for the first time. Geographic populations of the common Caribbean species, B. cushmani, display some heterogeneity in carapace size and proportions. B. hirsutella, n. sp., is proposed for a population previously misidentified as B. hirsuta. Supplemental information and illustrations are provided for Glyptobairdia coronata and G. trinodosa.

Expression of Opsins of the Box Jellyfish Tripedalia cystophora Reveals the First Photopigment in Cnidarian Ocelli and Supports the Presence of Photoisomerases.

Cubomedusae, or box jellyfish, have a complex visual system comprising 24 eyes of four types. Like other cnidarians, their photoreceptor cells are ciliary in morphology, and a range of different techniques together show that at least two of the eye types—the image-forming upper and lower lens eyes—express opsin as the photopigment. The photoreceptors of these two eye types express the same opsin (Tc LEO), which belongs to the cnidarian-specific clade cnidops. Interestingly, molecular work has found a high number of opsin genes in box jellyfish, especially in the Caribbean species Tripedalia cystophora, most of which are of unknown function. In the current study, we raised antibodies against three out of five opsins identified from transcriptomic data from T. cystophora and used them to map the expression patterns. These expression patterns suggest one opsin as the photopigment in the slit eyes and another as a putative photoisomerase found in photoreceptors of all four eyes types. The last antibody stained nerve-like cells in the tentacles, in connection with nematocytes, and the radial nerve, in connection with the gonads. This is the first time photopigment expression has been localized to the outer segments of the photoreceptors in a cnidarian ocellus (simple eye). The potential presence of a photoisomerase could be another interesting convergence between box jellyfish and vertebrate photoreceptors, but it awaits final experimental proof.

Phylogenomics of the Caribbean melocacti: Cryptic species and multiple invasions

AbstractThe widespread Neotropical genus Melocactus of approximately 42 currently recognized species, is most diverse in eastern Brazil and the Greater Antilles, especially Cuba. Species delimitation is notoriously problematic in the group, although this is due in part to a lack of detailed systematic studies, as well as a severely cluttered nomenclatural history. To date, no comprehensive phylogenetic hypotheses have been generated for the clade, although some population genetic and morphological studies exist. We generated the largest phylogenetic dataset of Melocactus to date based on plastome data derived from a genome‐skimming approach for 26 taxa, which provided a framework for understanding species limits and relationships among Caribbean species. Our time‐calibrated phylogeny revealed a mid‐Pleistocene origin for Melocactus, and we resolved three major clades, a Cuban clade, a mostly South American clade, and a widespread Caribbean clade, which also included some South American taxa. Our topology recovered the Cuban clade as sister to the rest of the species, although this placement was poorly supported, and several other Cuban species are scattered throughout the rest of the tree. Biogeographic analyses suggested multiple dispersal events from South America leading to the current diversity on Cuba, as well as other parts of the Antilles. Based on our phylogenetic results, previous hypotheses of species numbers and relationships in the Caribbean generated solely on morphology have, in some cases, been greatly underestimated. Our study shows that plastome data are effective for resolving clades and species limits in Melocactus, although future work will need to include broader sampling and larger datasets to fully resolve relationships in this complicated group of cacti. We describe one new cryptic species for Cuba, Melocactus santiagoensis sp. nov., and provide a new combination (Melocactus lagunaensis comb. & stat. nov.), based on our phylogenetic results and morphological data and typify numerous names in the genus. The genus Melocactus is another striking example of the exceptional diversity that has been generated in the poorly studied, seasonally dry tropical forest of the Greater Antilles.

Skeletal growth capacity as a measure of coral species and community resilience

Accretion and erosion of scleractinian (stony coral) carbonate skeletons determine whether a colony will increase or decrease in size with potential consequences for ecosystem processes, functions and services. The capacity for skeletal growth can be estimated by comparing a colony’s rate of calcification with its rate of erosion. Calcification depends on the species-specific metabolic activity of living tissue, and erosion depends primarily on the availability and density of barren skeleton, those areas on the colony where polyps have died. Assessment of skeletal growth capacity requires data on calcification rates, erosion rates and both live and barren colony surface area. Rates of calcification and erosion are documented for many Caribbean species and others can be estimated from existing data. Three-dimensional surface area of colonies can be determined from data collected during demographic surveys, which identify species, measure dimensions, and estimate the proportion of live tissue on a colony. Data from demographic surveys conducted in the U.S. Virgin Islands are used to calculate the skeletal growth capacity (GC) as an indicator of coral species and community resilience. Scleractinia are the primary architects of coral reefs, and the gain or loss of skeletal framework is vitally important to reef ecosystem processes that lead to valued goods and services. Estimates of GC reflect stony coral resilience, which is the capacity to recover from disturbances by returning to previous physical and functional levels. GC can also provide insight to the effects of stressors such as ocean acidification, and can inform several management decisions, including restoration site selection and threatened species designation.