Gulf Of Mexico Coast Research Articles

Home ranges and Movements of Two Diamondback Terrapins (Malaclemys terrapin macrospilota) in Northwest Florida

The diamondback terrapin (Malaclemys terrapin) is a small estuarine turtle distributed along the Atlantic and Gulf Coasts of the USA that is threatened by drowning in crab pots, road mortality, exploitation in the pet trade, and habitat loss. Little is known about the movement patterns and home ranges of these turtles, particularly along the U.S. Gulf of Mexico coast. Satellite tags were deployed on two adult female terrapins captured at two distinct sites in Northwest Florida. A first-difference correlated random walk approach was used to determine distances traveled and estimate home range for each individual. The two terrapins were tracked for 146 and 147 days, and the total distance traveled for each terrapin was 70.1 km and 723.0 km, respectively. The maximum distance moved from capture location was 11.3 km and 49.6 km. Home ranges here were much larger than those previously reported in other studies. The movements we documented were greater than expected and indicate habitat protection for this species may need to be expanded to incorporate more distant foraging sites.

Gulf of Mexico Coastal County Resilience to Natural Hazards.

Using a Cumulative Resilience Screening Index (CRSI) that was developed to represent resilience to natural hazards at multiple scales for the United States, the U.S. coastal counties of the Gulf of Mexico region of the United States are compared for resilience for these types of natural hazards. The assessment compares the domains, indicators and metrics of CRSI, addressing environmental, economic and societal aspects of resilience to natural hazards at county scales. The index was applied at the county scale and aggregated to represent states and two regions of the U.S. Gulf of Mexico (GOM) coastline. Assessments showed county-level resilience in all GOM counties was low, generally below the U.S. average. Comparisons showed higher levels of resilience in the western GOM region while select counties Louisiana, Mississippi and Alabama exhibited lowest resilience (<2.0) to natural hazards. Some coastal counties in Florida and Texas represented the highest levels of resilience seen along the GOM coast. Much of this increased resilience appears to be due to higher levels of governance and broader levels of social, economic and ecological services.

Complete Genome Sequence of Marinobacterium sp. Strain LSUCC0821, Isolated from the Coastal Gulf of Mexico.

Here, we present the complete genome sequence of Marinobacterium sp. strain LSUCC0821, isolated from the coastal Gulf of Mexico with artificial seawater using high-throughput dilution-to-extinction (DTE) cultivation. The 2.36-Mbp circularized genome sequence has 2,231 predicted genes, a 91.5% coding density, and a GC content of 47.8%.

Effect of farming practices on growth and mortality rates in triploid and diploid eastern oysters Crassostrea virginica

Commercial off-bottom aquaculture of the eastern oyster Crassostrea virginica is challenged by repeated summer mortality events that appear to affect triploid oysters disproportionally. Many farmers believe common farming practices, especially when performed during hot summer months, may increase triploid mortality. The goal of this study was to investigate how diploid and triploid oysters react to common stressors imposed by farmers: tumbling during size grading and desiccation to prevent biofouling. Triploid and diploid oysters were deployed in floating cages at 3 farm sites along the US Gulf of Mexico coast. In May and July, oysters in 7 cages were subjected to 1 of 6 stress treatments: 1 of 3 levels of desiccation (18, 24, or 48 h) mixed with 1 of 2 levels of tumbling (tumbled or not tumbled), along with a never handled, submersed control. The mortality and growth rate of oysters were assessed in June, August, and September. Growth rates of both ploidies were affected by compounding stressors; that is, treatments with both tumbling and the longest desiccation period exhibited slower growth. Triploid oysters exhibited a greater increase in mortality in response to farm stress than diploid oysters, and mortality increased in all oysters subjected to extreme stress treatments when compared to the control. Based on this study, farmers should limit the desiccation time of oysters (particularly triploids) in the summer months to avoid any mortality or reduced growth resulting from compounding stressor effects.

Determinants of Tubastraea coccinea invasion and likelihood of further expansion in the northern Gulf of Mexico

Invasive species have large economic and ecological impacts and are the leading driver of extinction for both plants and animals worldwide. In the USA, coral reefs, which provide $3.4 billion per year in ecosystem services, are impacted by invasive marine species. One such species is Tubastraea coccinea, which was the first scleractinia to invade the western Atlantic and recently has spread to natural reefs within the northern Gulf of Mexico (GoM). We document this recent invasion by compiling occurrence records, develop a species distribution model identifying important determinants of invasion, and project potential range expansion. Our results indicate T. coccinea currently is distributed along the GoM coast from the Florida Keys to southern Texas, with documented localities clustered ≈ 100 km off the Louisiana coast and ≈ 200 km off the Texas coast, and sparsely distributed elsewhere. Our species distribution model identified five environmental factors that together contribute > 99% to the overall model. These factors include two surface variables (mean pH and mean calcite, contributing ≈ 40%) and three benthic variables (maximum current velocity, minimum iron, and minimum dissolved oxygen, contributing ≈ 60%). Our model suggests potential habitat for range expansion is distributed mainly within the western portion of the northern GoM, with the highest probabilities of occurrence (0.8 < P < 1.0) clustered along the Texas and Louisiana coasts between 88 and 97° W (near the border between states).

Germination potential of baldcypress (Taxodium distichum) swamp soil seed bank along geographical gradients

Changing environments of temperature, precipitation and moisture availability can affect vegetation in ecosystems, by affecting regeneration from the seed bank. Our objective was to explore the responses of soil seed bank germination to climate-related environments along geographic gradients. We collected seed banks in baldcypress (Taxodium distichum) swamps along the Mississippi River and the Gulf of Mexico Coast in the United States, which have distinct temperature and/or precipitation gradients, and germinated them in a greenhouse. The frequency, richness and seed density of species germinated from the seed bank were compared between various geographic locations, experimental water regimes (saturated, flooded) and wetland types (tidal, non-tidal and inland swamps). We also analyzed the relationship of seed density to the environment by using a Non-metric Multi-dimensional Scaling (NMDS) model. Sixty-one species germinated from the seed bank, differing in pattern by geographic location, experimental water regime and wetland type. The foundation species (i.e., T. distichum and Cephalanthus occidentalis) germinated with a niche affinity for the northern part of the latitudinal gradient (Tennessee and Illinois) and these species may shift northward with climate change. Some species had higher seed density in the locations that were subject to more persistent drought conditions (e.g., Texas) including Cyperus rotundus and Gratiola virginiana, indicating that these species may be better adapted to sites with high temperature and low precipitation. In contrast, certain species including Saururus cernuus and Ludwigia palustris were present throughout the range of these gradients, and so may be more resilient to any future climate shifts. We found that the regeneration potential of baldcypress swamps might be altered by changes in local and climate environment because of nuances of responses of seed banks to climates along latitudinal and longitudinal gradients. Our study can help predict vegetation regeneration potential to climate change environments depending on the ability of these species to disperse and maintain seed banks.

Applying cumulative effects to strategically advance large-scale ecosystem restoration.

International efforts to restore degraded ecosystems will continue to expand over the coming decades, yet the factors contributing to the effectiveness of long-term restoration across large areas remain largely unexplored. At large scales, outcomes are more complex and synergistic than the additive impacts of individual restoration projects. Here, we propose a cumulative-effects conceptual framework to inform restoration design and implementation and to comprehensively measure ecological outcomes. To evaluate and illustrate this approach, we reviewed long-term restoration in several large coastal and riverine areas across the US: the greater Florida Everglades; Gulf of Mexico coast; lower Columbia River and estuary; Puget Sound; San Francisco Bay and Sacramento–San Joaquin Delta; Missouri River; and northeastern coastal states. Evidence supported eight modes of cumulative effects of interacting restoration projects, which improved outcomes for species and ecosystems at landscape and regional scales. We conclude that cumulative effects, usually measured for ecosystem degradation, are also measurable for ecosystem restoration. The consideration of evidence-based cumulative effects will help managers of large-scale restoration capitalize on positive feedback and reduce countervailing effects.

Comparing public perceptions of sea level rise with scientific projections across five states of the U.S. Gulf Coast region

Sea level rise (SLR) in the twenty-first century poses fundamental risks to coastal residents. The US Gulf of Mexico Coast (Gulf Coast) is among the regions experiencing the most rapid relative SLR. Beyond its increasing exposure to SLR and related coastal flooding, the Gulf Coast is home to a large population and displays high social vulnerability. How the coastal population in this vulnerable region perceives the impending risks posed by SLR warrants further examination. Do coastal residents’ perceptions of SLR conform to the scientific projections? We adopt an integrative approach based on a 2019 survey merged with contextual data including percentage of population living within the Special Flood Hazard Area (SFHA) and social vulnerability at the county level, both of which are extracted from the Centers for Disease Control and Prevention. We find that public risk perceptions of sea level change are influenced by political predisposition, with Republicans being less likely than Democrats to expect SLR in the future. Moreover, SLR remains a temporally distant issue among coastal residents. We then directly compare public expectations and scientific estimations of SLR in five states of the US Gulf Coast region and find that coastal residents in states that have experienced faster SLR in the past are more optimistic about future SLR by underestimating its magnitude compared to those experiencing slower SLR. Moreover, we find that people likely conflate the severity with likelihood of SLR risk. The contextual force represented by percentage of population living within the SFHA designated by the Federal Emergency Management Agency (FEMA) can significantly influence individuals’ estimations of future SLR, with higher percentages leading to higher estimates. We suspect that the SFHA has become a powerful risk communication tool that influences coastal residents’ judgments about future risk.

Using Public Participation Geographic Information Systems (PPGIS) to Identify Valued Landscapes Vulnerable to Sea Level Rise

The U.S. Gulf of Mexico coast has a long history of intense and varied development, from energy infrastructure and seaports to vacation homes and tourism. Coastal populations and development are growing. Concurrently, global climate change will influence sea level rise, resulting in increased flooding, storm surge, and coastal erosion. Regional planners must prepare for sea level rise and develop adaptive solutions to maximize resiliency. Comprehensive coastal vulnerability mapping assessments (CVMA) can integrate social, economic, and physical vulnerability with spatial analysis of natural hazards for local place-based investigations. Public Participation Geographic Information Systems (PPGIS) are a potentially important tool for the spatial collection of stakeholder knowledge for CVMA. The objective of this study was to assess the locations of a range of landscape values, ecosystem services, and development preferences held and identified by the general public using PPGIS to determine if those valued locations are vulnerable to sea level rise. We found that PPGIS can be used to map a wide variety of landscape values and that they can be used to assess vulnerability to sea level rise. We conclude with a discussion on how to integrate PPGIS into participatory CVMA for sea level rise planning.

Evolución de la especialización y competitividad de la producción de limón en México

El objetivo de esta investigación fue estudiar la especialización y competitividad de la producción de limón en México. Los métodos de análisis fueron el cociente de localización, el Shift and Share y se integró un análisis de especialización y competitividad. Los resultados muestran una reconfiguración en la estructura productiva. Destacan a nivel nacional nueve estados especializados y competitivos. Los estados con mayores perspectivas de crecimiento de esta actividad son los que integran la costa del Golfo de México. La especialización y competitividad se relaciona con las condiciones naturales de las regiones productoras, la demanda del mercado y el cambio tecnológico.

Seasonal and spatial patterns of mudblister worm Polydora websteri infestation of farmed oysters in the northern Gulf of Mexico

Mudblister worms Polydora websteri bore holes into oyster shells, and oysters respond by secreting extra layers of shell, creating a mudblister. When shucked, mudblisters can burst and release anoxic mud. Thus, infestation devalues oysters, particularly on the half-shell market. This study quantified oyster condition index and worm abundances over 2 full growing seasons at commercial oyster farms on the US Gulf of Mexico coast, and our results indicate that oyster growth rate, manipulated through ploidy and stocking densities, had little effect on worm infestation. Larval spionid worms were found year-round. Larval abundances were slightly higher within than away from farms, and larval size distributions were skewed toward smaller larvae within the farms, suggesting that farms may be a source of larvae. Triploid oysters had higher or comparable condition index values to diploids, but during summer months, when worm infestation was high, worm infestation was not correlated with condition index. Previously infested shells deployed at farms became more infested than uninfested shells at moderate infestation levels, but re-infestation was influenced more by farm location than by previous infestation condition. Higher infestation at a farm with more variable salinity as well as higher infestation in 2017 when salinity was lower suggest that salinity may be a potential driver of mudblister worm infestation. Results indicate that oyster farmers on this coast should use desiccation to treat oysters for mudblister worms frequently during the summer, but that manipulating stocking density or ploidy is unlikely to be effective in preventing mudblister worm infestation.

Surface textures of quartz and ilmenite grains from dune and beach sands of the Gulf of Mexico Coast, Mexico: Implications for fluvial, aeolian and marine transport

Surface textures of quartz and ilmenite grains provide an insight in assessing current mechanical, chemical and mechanical-chemical processes in dune and beach sands of the Gulf of Mexico Coast (GMC) Mexico. The GMC area produces hybrid sands enriched in monocrystalline quartz and ilmenite-free grains. Quartz grains are observed in all dunes and beach localities of the central GMC close to the Trans-Mexican Volcanic Belt characterized by large conchoidal fractures (>100 μm), angular to subangular outlines, arcuate steps, high relief, and sharp edges associated with fluvial transport. Aeolian quartz features like meandering ridges, upturned plates, bulbous edges and adhering particles on quartz are only present in some GMC sites, whereas marine surface textures like straight and curved grooves are sparse. Chemical surface textures on quartz and ilmenite are a consequence of silica saturated low-energy subaqueous conditions and subaerial exposure, diagenesis and intermediate weathering processes in the dunes and beach sands. Ilmenite grains are common in all studied localities of the GMC, characterized by large conchoidal fractures (>100 μm), angular to subangular outlines, flat cleavage surfaces, arcuate steps and high relief. In some ilmenite grains, upturned plates, meandering ridges, bulbous edges and abrasion fatigue characterize aeolian surface features. Straight and curved grooves only characterize marine surface textures. To assess the prevailing transport mechanisms along the GMC, quartz and ilmenite grains from dunes and beach sands were selected based on surface texture observations. Our findings suggest that quartz and ilmenite grains are primarily transported and deposited along the coast by riverine input, a second-cycle of aeolian transport onshore, and recycling by marine longshore currents and waves.

INFLUENCES OF UPPER FLORIDAN AQUIFER WATERS ON RADIOCARBON IN THE OTOLITHS OF GRAY SNAPPER (Lutjanus griseus) IN THE GULF OF MEXICO

ABSTRACTThe otoliths (ear stones) of fishes are commonly used to describe the age and growth of marine and freshwater fishes. These non-skeletal structures are fortuitous in their utility by being composed of mostly inorganic carbonate that is inert through the life of the fish. This conserved record functions like an environmental chronometer and bomb-produced radiocarbon (14C)—a 14C signal created by atmospheric testing of thermonuclear devices—can be used as a time-specific marker in validating fish age. However, complications from the hydrogeology of nearshore marine environments can complicate 14C levels, as was the case with gray snapper (Lutjanus griseus) along the Gulf of Mexico coast of Florida. Radiocarbon of these nearshore waters is influenced by freshwater input from the karst topography of the Upper Floridan Aquifer—estuarine waters that are 14C-depleted from surface and groundwater inputs. Some gray snapper likely recruited to this kind of environment where 14C levels were depleted in the earliest otolith growth, although age was validated for individuals that were not exposed to 14C-depleted waters to an age of at least 25 years with support for a 30-year lifespan.

Response of Storm-Related Extreme Sea Level along the U.S. Atlantic Coast to Combined Weather and Climate Forcing

AbstractStorm surge and coastal flooding caused by tropical cyclones (hurricanes) and extratropical cyclones (nor’easters) pose a threat to communities along the Atlantic coast of the United States. Climate change and sea level rise are altering the statistics of these extreme events in a rather complex fashion. Here we use a fully coupled global weather/climate modeling system (GFDL CM4) to study characteristics of extreme daily sea level (ESL) along the U.S. Atlantic coast and their response to global warming. We find that under natural weather processes, the Gulf of Mexico coast is most vulnerable to storm surge and related ESL. New Orleans is a striking hotspot with the highest surge efficiency in response to storm winds. Under a 1% per year atmospheric CO2 increase on centennial time scales, the anthropogenic signal in ESL is robust along the U.S. East Coast. It can emerge from the background variability as soon as in 20 years, or even before global sea level rise is taken into account. The regional dynamic sea level rise induced by the weakening of the Atlantic meridional overturning circulation facilitates this early emergence, especially during wintertime coastal flooding associated with nor’easters. Along the Gulf Coast, ESL is sensitive to the modification of hurricane characteristics under the CO2 forcing.

Characteristics of Insect Damage in Propagules of Red Mangrove (Rhizophora mangle) from the Gulf of Mexico Coast

Several species of insects have been found in propagules of species of mangrove forest, but Coccotrypes rhizophorae (Hopkins) (Coleoptera: Curculionidae) has been recorded as one of the main pest of Rhizophora mangle (L.) (Malpighiales: Rhizophoraceae). While the species of mangrove is common in the Gulf of Mexico, the insect fauna associated with its propagules and characteristics of the damage they cause are unknown. This study evaluated the relationship between the presence of insects and damage characteristics in R. mangle propagules. Eleven mangrove forest sites in seven municipalities of the state of Veracruz (Mexico) were sampled, and 10 R. mangle propagules were collected from each site (110 in total). We found 192 individual insects of Coleoptera, Diptera, Hymenoptera, and Lepidoptera at different stages of development in the propagules; Coleoptera was the most abundant order (64.3%). Qualitative characteristics such as perforations and galleries were not always associated with the presence of insects. However, other damage characteristics such as perforation size and gallery volume were significantly related to insect presence. Gallery volume, estimated as a measure of the intensity of tissue removal, was significantly greater when C. rhizophorae shared the gallery with other species of insects than when the beetle or other insects were found alone in the propagule. The results showed that R. mangle propagules could maintain colonization dynamics in insects of different orders, consuming tissue that jeopardized the survival and establishment of propagules. The damage can increase under stress in R. mangle, caused by environmental factor generating potential damage to tropical sentinel ecosystems that can eventually become irreversible.

Morphological differentiation among populations of Quercus elliptica Neé (Fagaceae) along an environmental gradient in Mexico and Central America

Background: Variation in leaf morphology is an important indicator of how plants respond to different environmental conditions. Leaf trait variation is associated with physiological responses of plants to gradients of humidity and temperature. &#x0D; Objective: We analyzed the variation in the leaf morphological and functional traits of Quercus elliptica and its relationships with environmental and geographic variables across the distribution of this species to evaluate population differentiation using ecological niche models.&#x0D; Study species: Quercus elliptica Neé (Fagaceae).&#x0D; Study sites and dates: Plants were collected in diverse forest types between 350 and 2,400 m in elevation in Mexico and Central America during 2016 and 2017.&#x0D; Methods: We measured and analyzed the differentiation in morphological and functional traits of 4,017 leaves from 402 trees from 41 populations using univariate and multivariate analyses.&#x0D; Results: The leaf length and thickness and specific leaf area (SLA) of Q. elliptica were significantly correlated with the seasonality of temperature, precipitation, elevation and aridity. We identified two divergent morphological groups: (1) populations distributed along the Pacific coast with broad and thin elliptical leaves with high SLA values and inhabited humid forests at more than 1,200 m elevation, and (2) populations located along the Gulf of Mexico coast, and in southern Mexico and Central America with thicker, narrower leaves and lower SLA values and inhabited seasonal tropical forests in less than 1,200 m in elevation. &#x0D; Conclusions: Climate and geographic barriers and the ecological niche models supported the population differentiation of Q. elliptica .

Insights on Bloom Forming Jellyfish (Class: Scyphozoa) in the Gulf of Mexico: Environmental Tolerance Ranges and Limits Suggest Differences in Habitat Preference and Resistance to Climate Change Among Congeners

Jellyfish are important components of marine foodwebs and form problematic blooms that negatively impact human enterprise. Jellyfish of the genus Aurelia (Class Scyphozoa) are common bloom-formers in the Gulf of Mexico (GoM). Aurelia have a multi-modal lifecycle where the perennial polyp produces seasonal medusae. Abiotic tolerance ranges and limits strongly influence the distribution of marine species but are unknown for most jellyfish species. Tolerance limits for survival are crucial to understanding present polyp distribution and how distribution may change in climate change scenarios. We sampled and barcoded two Aurelia species from the GoM, namely Aurelia sp. 9 and a possible new species found offshore (Aurelia sp. new). Planulae obtained from one medusa of Aurelia sp. new, and five medusae of Aurelia sp. 9 were used to establish laboratory cultures. Polyps of Aurelia coerulea, a species native to Japan but introduced in North America, Australia, and Europe, were obtained from a local aquarium, barcoded, and used to establish laboratory cultures. Using controlled laboratory experiments, we determined the temperature and salinity limits for polyp survival of the two GoM species and A. coerulea. We find that A. sp. 9 and A. coerulea were tolerant of a broad range of temperatures and salinities, but differed in tolerance limits, suggesting potential differences in habitat and resistance to climate change. A. sp. 9 was most tolerant of high temperatures and low salinities, such as those found in the estuaries of the GoM. Summer high temperatures in the coastal GoM exceed the upper thermal tolerance limit of A. sp. new and A. coerulea, suggesting that A. sp. new is an offshore species and that the coastal GoM waters may not be a suitable environment for A. coerulea. Based on the upper thermal limits identified in this study, the 4°C ocean temperature increase projected for the GoM by the next century may negatively impact Aurelia sp. 9 and Aurelia sp. new populations and is expected to deter Aurelia coerulea from invading the GoM. This is the first account of Aurelia sp. new and the first report of temperature and salinity ranges and tolerance limits for Aurelia species.

Implications of different nitrogen input sources for potential production and carbon flux estimates in the coastal Gulf of Mexico (GOM) and Korean Peninsula coastal waters

Abstract. The coastal Gulf of Mexico (GOM) and coastal sea off the Korean Peninsula (CSK) both suffer from human-induced eutrophication. We used a nitrogen (N) mass balance model in two different regions with different nitrogen input sources to estimate organic carbon fluxes and predict future carbon fluxes under different model scenarios. The coastal GOM receives nitrogen predominantly from the Mississippi and Atchafalaya rivers and atmospheric nitrogen deposition is only a minor component in this region. In the CSK, groundwater and atmospheric nitrogen deposition are more important controlling factors. Our model includes the fluxes of nitrogen to the ocean from the atmosphere, groundwater and rivers, based on observational and literature data, and identifies three zones (brown, green and blue waters) in the coastal GOM and CSK with different productivity and carbon fluxes. Based on our model results, the potential primary production rate in the inner (brown water) zone are over 2 gC m−2 d−1 (GOM) and 1.5 gC m−2 d−1 (CSK). In the middle (green water) zone, potential production is from 0.1 to 2 (GOM) and 0.3 to 1.5 gC m−2 d−1 (CSK). In the offshore (blue water) zone, productivity is less than 0.1 (GOM) and 0.3 (CSK) gC m−2 d−1. Through our model scenario results, overall oxygen demand in the GOM will increase approximately 21 % if we fail to reduce riverine N input, likely increasing considerably the area affected by hypoxia. Comparing the results from the USA with those from the Korean Peninsula shows the importance of considering both riverine and atmospheric inputs of nitrogen. This has direct implications for investigating how changes in energy technologies can lead to changes in the production of various atmospheric contaminants that affect air quality, climate and the health of local populations.

Predicting multi-species foraging hotspots for marine turtles in the Gulf of Mexico

Quantifying the distribution of animals and identifying underlying characteristics that define suitable habitat are essential for effective conservation of free-ranging species. Prioritizing areas for conservation is important in managing a geographic extent that has a high level of disturbance and limited conservation resources. We examined the potential use of a species distribution model ensemble for multi-species conservation in marine habitats. Using satellite telemetry locations during foraging as input data, and ensemble ecological niche models, we predicted foraging areas for 2 nesting marine turtle species within the Gulf of Mexico (GoM): Kemp’s ridley Lepidochelys kempii (n = 63) and loggerhead Caretta caretta (n = 63). We considered 7 geophysical, biological, and climatic variables and compared contributing factors for each species’ foraging habitat selection. For both species, predicted suitable foraging habitats encompassed large areas along the GoM coast, but only intersected with each other in relatively small areas. Highly parameterized models resulted in overall greater fits, suggesting that multiple factors influence habitat selection by these species. Model validation results were mixed: cross-validation resulted in high prediction accuracy for both species, but an evaluation against independent data resulted in a low omission rate (5%) for Kemp’s ridleys and a high omission rate (72%) for loggerheads. The relatively small intersection of model-predicted foraging areas for these 2 species within the study area may indicate possible niche differentiations. The high omission rate for loggerheads indicates our samples likely underrepresent the population and illustrates the challenges in predicting suitable foraging extents for species that make dynamic movements and have greater individual variability.

Geographic Distribution of Strumigenys epinotalis (Hymenoptera: Formicidae)

Strumigenys epinotalis (former Pyramica epinotalis) is a tiny arboreal ant (Hymenoptera, Formicidae) first found in Costa Rica in 1924. The earliest known US specimens were collected in Florida and Louisiana in 2009. I compiled 33 site records of S. epinotalis from nine countries: Brazil (4 sites), Colombia (1), Costa rica (3), Ecuador (1), Mexico (9), Nicaragua (1), Panama (1), Paraguay (1), and the US (12). the US sites come from four states: Alabama (1), Florida (6), Louisiana (4), and Mississippi (1). Strumigenys epinotalis has been recorded from widely scattered Neotropical sites in ranging from Paraguay (24.1°S) to central Mexico (20.1°N). records of S. epinotalis in Louisiana and Florida are from considerably higher latitudes (27.2–30.6°N). the US populations may be non-native, or they could be at the northern end of the ant's native range. Most S. epinotalis records apparently come from relatively intact forests, often in swampy areas, and all known nests have been found up in trees, either inside epiphytes or in cavities within trees. I have sampled ants at hundreds of sites in South and Central Florida through vegetation beating and I have only found this species twice. Given the extreme scarcity of S. epinotalis records across its enormous known range, it seems possible that native populations of S. epinotalis occur all along the Gulf coast of Mexico and the US, but have been overlooked.