With a pinch of salt: metagenomic insights into Namib Desert salt pan microbial mats and halites reveal functionally adapted and competitive communities.

IMPORTANCE: The hyperarid Namib Desert is one of the oldest deserts on Earth. It contains multiple clusters of playas which are saline-rich springs surrounded by halite evaporites. Playas are of great ecological importance, and their indigenous (poly)extremophilic microorganisms are potentially involved in the precipitation of minerals such as carbonates and sulfates and have been of great biotechnological importance. While there has been a considerable amount of microbial ecology research performed on various Namib Desert edaphic microbiomes, little is known about the microbial communities inhabiting its multiple playas. In this work, we provide a comprehensive taxonomic and functional potential characterization of the microbial, including viral, communities of sediment mats and halites from two distant salt pans of the Namib Desert, contributing toward a better understanding of the ecology of this biome.

A field study of the surface disturbance effects of animals and motor vehicles on aeolian sediment emission from a silty playa surface.

Dry playa surfaces can be extremely vulnerable to disturbance which breaks their surface crusts resulting in increased aeolian sand and dust emissions. Trampling by livestock and motor vehicles is an important source of this disturbance. The Hamoun Lakes in the Sistan region of Iran are a major source area of dust storms which are causing damage to infrastructure and communities. This study performed portable wind tunnel tests of controlled surface disturbance by animals (cow, sheep) and motor vehicles (automobile, motorcycle) on a silty playa surface of Hamoun Saberi lake. The aim of this study was to assess the effect of different levels of trampling and disturbed surfaces by both vehicles and livestock on dust emission at wind speeds of 6 and 12 m s-1. A significant increase of sediment emission was found with increased number of passes of vehicles and livestock and the degree of surface disturbance, more so at the high wind speed (12 m s-1). No significant differences were observed between a 10-20% disturbance level and an undisturbed surface, but statistically significant differences became apparent when disturbances reached 50-60% to 90-100% compared to undisturbed surfaces. Greater emission rates were reached by disturbances provided by automobile and cow compared to motorcycle and sheep, indicating greater trampling effects of automobile and cow likely related to greater weight and larger footprint. The automobile was the most surface-destructive of the four anthropogenic disturbances, providing emission in a lower number of passes compared to the motorcycle, cow and sheep. Better management of vehicle and livestock allocation on playas subject to disturbance, such as the Hamoun Lakes, will be a useful strategy to reduce disturbance and the frequency and intensity of dust storms.

The effect of water resources on spatial and temporal change of soil salinity in Izdkhast playa, Fars Province, Iran.

In the south of Fars Province in Iran, there are several closed basins where the salinity of water and soil resources is one of the main problems. Therefore, to manage the water and soil resources of these basins, identifying the source of salinity and its expansion in playa is necessary. Thus, the Izad-Khast pit in the south of Fars Province of Iran was selected as one of these basins for research. To achieve the goal, 16 soil samples were randomly taken from the basin, and their EC was determined. Landsat 8 image was selected according to sampling day, and ten salinity indices were extracted from it. Then, the best index was determined by the relationship between salinity indices and ground EC using linear regression. Using the determined index and linear equation derived from linear regression and Landsat 7 and 8 images, salinity maps were obtained in three periods 2010, 2015, and 2020. Then, using maps of the three mentioned intervals and the CA-Markov method, soil salinity prediction maps were extracted for 2025 and 2030. Based on the research results, salinity index S2 = (Blue - R)/(Blue + R) provided the best results. Salinity maps derived from this index show that the highest level is related to the area with no salinity or low salinity, and high degrees of salinity are concentrated in some parts of the hills and in some areas of the plain, respectively, which determines the origin of salts. The results also showed that the kappa coefficient of CA-Markov is 0.7282, which shows the high ability of the model to predict soil salinity, in which the distance factor from gypsum and salt minerals is the most critical predictor factor. According to the forecasts, from 2020 to 2025, about 1 km2 and then from 2025 to 2030, about 1.6 km2 will be added to the saline lands.

Vertical Distribution of Soil Free-living Nematode in a Playa Habitat in the North-Western Negev Desert, Israel.

In order to investigate the vertical distribution of soil nematode community under a playa area in the Nizzana inter-sand dune area in the north-western Negev Desert of Israel, soil samples were collected from 0 - 10, 10 - 20, 20 - 30, 30 - 40, and 40 - 50 cm depths in the playa and loessial plain area (as control) during the dry and wet seasons. Each of soil samples was determined for soil moisture, organic matter concentration, electrical conductivity, and nematode community structure and biodiversity. The results revealed that soil moisture, organic matter, electrical conductivity, total nematode abundance and trophic groups were significantly influenced by sampling positions (P < 0.0001) and depths (P < 0.05) and significant interaction effect of position and depth (P < 0.05) was also found. Total number of nematodes in the playa area ranged from 1 to 15 individuals per 100 g dry soil, whereas they ranged from 60 to 631 individuals per 100 g dry soil in the loessial plain area. The greatest nematode number was found in 0 - 10 cm soil depth and the lowest nematode number was found in 40 - 50 cm soil depth. Total number of nematodes, bacterivores, fungivores, plant parasites and omnivores-predators were significantly (P < 0.05) greater in the loessial plain area than that in the playa area in all sampling depths under the dry and wet seasons. Total thirteen genera were found in the playa area, with Acrobeloides as the dominant genus, whereas there were fifty-five genera, with Acrobeles as the dominant genus in the loessial plain area. Nematode ecological indices, such as fungivores/bacterivores ratio (F/B), nematode channel ratio (NCR), trophic diversity (T), Shannon Index (H'), genus dominance (λ), species richness (SR), maturity index (MI), modified maturity index (MMI), Enrichment Index (EI) and Structure Index (SI) were significantly (P < 0.01) differentiated between sampling locations. As conclusion, soil free-living nematode inhabited mostly the upper soil layers (0 - 20 cm) and the number of nematode had gradually decreasing trend with soil depths increasing in the playa area. Moreover, each soil layer had a little nematode abundance and community diversity in the playa area in contrast to loessial plain area during the dry and wet seasons. Sampling sites and depths significantly effected on soil properties, nematode abundance and trophic groups, but nematode ecological indices were affected only by sampling sites.

Exploration, antifungal and antiaflatoxigenic activity of halophilic bacteria communities from saline soils of Howze-Soltan playa in Iran.

In the present study, halophilic bacteria communities were explored in saline soils of Howze-Soltan playa in Iran with special attention to their biological activity against an aflatoxigenic Aspergillus parasiticus NRRL 2999. Halophilic bacteria were isolated from a total of 20 saline soils using specific culture media and identified by 16S rRNA sequencing in neighbor-joining tree analysis. Antifungal and antiaflatoxigenic activities of the bacteria were screened by a nor-mutant A. parasiticus NRRL 2999 using visual agar plate assay and confirmed by high-performance liquid chromatography. Among a total of 177 halophilic bacteria belonging to 11 genera, 121 isolates (68.3%) inhibited A. parasiticus growth and/or aflatoxin production. The most potent inhibitory bacteria of the genera Bacillus, Paenibacillus and Staphylococcus were distributed in three main phylogenetic clusters as evidenced by 16S rRNA sequence analysis. A. parasiticus growth was inhibited by 0.7-92.7%, while AFB1 and AFG1 productions were suppressed by 15.1-98.9 and 57.0-99.6%, respectively. Taken together, halophilic bacteria identified in this study may be considered as potential sources of novel bioactive metabolites as well as promising candidates to develop new biocontrol agents for managing toxigenic fungi growth and subsequent aflatoxin contamination of food and feed in practice.

Influence of incubation temperature, maternal effects, and paternity on quality of olive ridley hatchlings (Lepidochelys olivacea) from a mass-nesting beach in the Mexican Pacific.

Future climate change scenarios project that the increase in surface temperatures will affect ocean temperatures, inducing shifts in marine biodiversity. Sea turtles are species that are particularly vulnerable to the effects of climate change because temperature is a factor that influences embryonic development. We collected clutches of olive ridley turtles from a mass-nesting beach in the Mexican Pacific, which were incubated in ex situ conditions. When the hatchlings emerged, we measured the body condition index-which evaluates the weight-length relationship-and swim thrust, both were considered traits associated with fitness, termed "fitness proxies," and evaluated the effects of incubation temperature, maternal effects, and paternity on these fitness proxies. The body condition index was correlated positively and significantly with the arribada month and temperature during the last third of the incubation period but showed an inverse relationship with the maternal effect. While swim thrust was positively correlated with the maternal effect and the arribada month, there was an inverse relationship with incubation temperature during the first third of the period. Paternity, whether single or multiple, did not have a significant effect on either fitness proxies; however, it may have effects on the average fitness of a population of hatchlings. These results underscore the need to expand research on the sublethal effects of high incubation temperatures on the adaptation and survival of sea turtles, particularly in scenarios of rapid climate change.

Isotopic and hydrochemical evidence for the source and mechanism of groundwater salinization in Kashan Plain aquifer in Iran.

Groundwater salinization and interaction between Playa Lake and regional groundwater were investigated using multi-chemo-isotopic evidences. Forty groundwater and 26 Kashan Playa Lake (KPL) water samples were collected and analyzed for their geochemical compositions. The evolution of hydrochemical facies in Kashan Plain Aquifer (KPA) to KPL is Ca-HCO3 (19%), Mix Ca-Cl (9%), Ca-Cl (17%), and Mix Na-Cl and Na-Cl (55%). Also, the Hydrochemical Facies Evolution Diagram (HFE-D) proposed cation exchange as the main process of salinization in KPA. Based on the binary hydrogeochemical diagrams of (Na+/Cl-)/Cl-, (Ca2+ + Mg2+)/HCO3- + SO42-, and Cl/Br, dissolution of halite and gypsum in the Miocene marlstone in the KPA is the main source of salinity. The δ18O of water in aquifer and playa water samples varies from -10.03 to 7.03‰ (VSMOW) with an average of -6.95‰ and -60.73 to 25.08‰ with average of -45.82‰ for δ2H. Based on the results, the relation between δ18O and δ2H, and δ18O and Br, approves discharge of saline water from KPA to KPL. Likewise, the isotopic composition of δ34SO4, varies from 5.95 to 22.55‰ CDT in KPA, and 5.95 to 9.99 ‰ CDT in KPL. Also, the relations between δ18O-δ34SSO4 and Cl-δ34S were non-linear, indicating that sulfur concentration in KPA and KPL changed due to sulfide oxidation and sulfate reduction in the freshwater and deep brines in the aquifer and mixed during the over-pumping in the KPA. Oxidation of sulfide minerals in the mineralized region in the western part of the aquifer (recharge zone) may have been the source of sulfur leached by seasonal runoff. Water-rock interaction, ion exchange, and hydraulic gradient have been the dominating factors in changing the water chemistry between aquifer and playa leading to saline groundwater discharged to the playa.

Seasonal deposition of marine debris on an important marine turtle nesting beach in Costa Rica.

Marine debris pollution poses a threat for wildlife and can negatively impact the economy of communities whose livelihoods depend on tourism. Playa Norte, in northeastern Costa Rica, is an important nesting ground for four marine turtle species identified as vulnerable or endangered on the IUCN Red List. It is highly polluted but has low human occupancy. We conducted accumulation rate surveys following a standardized marine debris protocol from March 2016 to January 2018. Macro-debris was categorized by size and material type. Of the 191,030 debris items retrieved during the two-year study period, 96.2% of them were plastic. Debris accumulation was higher during the dry season (January - September). This study contributes towards understanding the drivers of marine debris pollution in critical wildlife nesting habitats; and informs managers and the local community on possible strategies to prevent and reduce marine pollution, thereby aiding in tourism derived economies.

Two new alkali-sink specialist species of Paruroctonus Werner 1934 (Scorpiones, Vaejovidae) from central California.

Herein we describe two new species of Paruroctonus (Werner 1934) from California: Paruroctonussoda sp. nov. from the Soda Lake playa at the center of the Carrizo Plain in San Luis Obispo county and Paruroctonusconclusus sp. nov. from the Koehn Lake playa in the Mojave Desert of Kern County. They can be differentiated from other Paruroctonus by a combination of morphological features including deeply scalloped pedipalp fingers in males, specific patterns of fuscous pigmentation, unique setal counts, and unique morphometric ratios. They can also be separated from one another by the latter three characters. Photographs of a large selection of live scorpions are provided, including detailed images and figures of many morphological features. Their distributions, habitats, and ecologies are discussed; and important steps towards their conservation are described.

Genomic Characterization of a Prophage, Smhb1, That Infects Salinivibrio kushneri BNH Isolated from a Namib Desert Saline Spring.

Recent years have seen the classification and reclassification of many viruses related to the model enterobacterial phage P2. Here, we report the identification of a prophage (Smhb1) that infects Salinivibrio kushneri BNH isolated from a Namib Desert salt pan (playa). Analysis of the genome revealed that it showed the greatest similarity to P2-like phages that infect Vibrio species and showed no relation to any of the previously described Salinivibrio-infecting phages. Despite being distantly related to these Vibrio infecting phages and sharing the same modular gene arrangement as seen in most P2-like viruses, the nucleotide identity to its closest relatives suggest that, for now, Smhb1 is the lone member of the Peduovirus genus Playavirus. Although host range testing was not extensive and no secondary host could be identified for Smhb1, genomic evidence suggests that the phage is capable of infecting other Salinivibrio species, including Salinivibrio proteolyticus DV isolated from the same playa. Taken together, the analysis presented here demonstrates how adaptable the P2 phage model can be.

Urban Areas Create Refugia for Odonates in a Semi-Arid Region.

In western Texas, most wetlands are fed from precipitation runoff, making them sensitive to drought regimes, anthropogenic land-use activities in their surrounding watersheds, and the interactive effect between these two factors. We surveyed adult odonates in 133 wetlands (49 in grassland settings, 56 in cropland, and 28 in urban areas) in western Texas from 2003-2020; 33 species were recorded. Most species were widespread generalists, but urban wetlands had the highest species richness, as well as the most unique species of any of the three wetland types. Non-metric, multidimensional scaling ordination revealed that the odonate community in urban wetlands was distinctly different in composition than the odonates in non-urban wetlands. Urban wetlands were smaller in surface area than the other wetland types, but because they were fed from more consistently available urban runoff rather than seasonal precipitation, they had longer hydroperiods, particularly during a multi-year drought when wetlands in other land-cover contexts were dry. This anthropogenically enhanced water supply was associated with higher odonate richness despite presumably impaired water quality, indicating that consistent and prolonged presence of water in this semi-arid region was more important than the presence of native land cover within which the wetland existed. Compared to wetlands in the regional grassland landscape matrix, wetlands in agricultural and urban areas differed in hydroperiod, and presumably also in water quality; these effects translated to differences in the regional odonate assemblage by surrounding land-use type, with the highest richness at urban playas. Odonates in human environments may thus benefit through the creation of a more reliably available wetland habitat in an otherwise dry region.

The protection of Salicornia rubra from ultraviolet radiation by betacyanins and phenolic compounds.

Salicornia rubra is a commonly occurring annual species of the salt playas of the Great Basin Desert of the western United States. In such habitats, plants experience high levels of ultraviolet radiation, which could potentially damage DNA. As a member of the Amaranthaceae (Caryophyllales), S. rubra shoots typically contain high concentrations of the red-violet pigments called betacyanins, which are ultraviolet-absorbing compounds. Nevertheless, some specimens of S. rubra are green even when growing with full exposure to the sun. We, therefore, tested several hypotheses regarding the causes of variation among S. rubra plants in betacyanin concentration and the role of betacyanins in the absorption of ultraviolet radiation. We measured ultraviolet radiation absorption and the concentrations of betacyanins and phenolic compounds of the cell sap expressed from red and green plants growing in full sun, as well as plants grown under various levels of shade. We found that while betacyanin concentrations were predictable from plant color (red plants contained more betacyanins than green plants), the ability to absorb ultraviolet radiation was determined primarily by the concentration of phenolic compounds, which was determined by the level of exposure to the sun. Therefore, the DNA of green plants growing in full sun appears to be at no greater risk than the DNA of red plants.

Subsurface Microbial Ecology at Sediment-Groundwater Interface in Sulfate-Rich Playa; White Sands National Monument, New Mexico.

The hypersaline sediment and groundwater of playa lake, Lake Lucero, at the White Sands National Monument in New Mexico were examined for microbial community composition, geochemical gradients, and mineralogy during the dry season along a meter and a half depth profile of the sediment vs. the groundwater interface. Lake Lucero is a highly dynamic environment, strongly characterized by the capillary action of the groundwater, the extreme seasonality of the climate, and the hypersalinity. Sediments are predominantly composed of gypsum with minor quartz, thenardite, halite, quartz, epsomite, celestine, and clays. Geochemical analysis has revealed the predominance of nitrates over ammonium in all of the analyzed samples, indicating oxygenated conditions throughout the sediment column and in groundwater. Conversely, the microbial communities are primarily aerobic, gram-negative, and are largely characterized by their survival adaptations. Halophiles and oligotrophs are ubiquitous for all the samples. The very diverse communities contain methanogens, phototrophs, heterotrophs, saprophytes, ammonia-oxidizers, sulfur-oxidizers, sulfate-reducers, iron-reducers, and nitrifiers. The microbial diversity varied significantly between groundwater and sediment samples as their temperature adaptation inferences that revealed potential psychrophiles inhabiting the groundwater and thermophiles and mesophiles being present in the sediment. The dynamism of this environment manifests in the relatively even character of the sediment hosted microbial communities, where significant taxonomic distinctions were observed. Therefore, sediment and groundwater substrates are considered as separate ecological entities. We hope that the variety of the discussed playa environments and the microorganisms may be considered a useful terrestrial analog providing valuable information to aid future astrobiological explorations.

Water quality variation with storm runoff and evaporation in playa wetlands.

Playas are the often most noticeable surface water feature in the Southern High Plains. The purpose of our study is to provide local and timely reference data on playa water quality and quantity in drier and wetter weather conditions. Water quality parameters of three playas in Texas, in the summer of 2016, were monitored via weekly environmental sampling. Annual water volume-depth dynamics within the study playas were also estimated by water balance informed by climate and geospatial data. The results showed that both direct rainfall and runoff affect the volume of water within the playa where the volume of runoff entering into a playa is contingent upon the surrounding drainage area. In addition, water quality does vary substantially from playa to playa (conductivity 180-850 µS/cm, TOC 13-81 mg/L) and between playa and non-playa surface water. Differences were related to local soils, drainage area size/slope, and land use. It was also found from the water quality analysis that playas are capable of containing a quality of water that would make them an attractive habitat for wildlife. The greatest economic value of playas may be their ability to contain high quantities of biodiversity though the future of their capacity to do so is uncertain.

Tracking neonicotinoids following their use as cotton seed treatments.

Neonicotinoids are a leading class of insecticides on the global market, accounting for nearly 25%. They are widely used in both agricultural and residential settings. Causing neuron failure by irreversibly binding to the insect nicotinic acetylcholine receptor, neonicotinoids offer broad spectrum efficacy against a variety of pests. However, because they are non-selective with regard to insect species, there has been some concern with neonicotinoid use over threats to pollinators such as honeybees, and potential indirect effects to migratory waterfowl as a result of invertebrate prey population depletion. In order to study occurrence and fate of neonicotinoids (thiamethoxam and imidacloprid), we analyzed cotton leaves on plants grown from neonicotinoid-treated seeds and corresponding soil samples between cotton rows. Neonicotinoid concentration data from cotton leaves appears to be consistent with the claim that seed treatments protect plants for 3-4 weeks; by 30 days post-planting, neonicotinoid concentrations fell, in general, to 200 ng/g or lower. This represents about a 10-fold decrease from plant concentrations at approximately 2 weeks post-planting. It was found that neonicotinoids used as seed treatments remained present in the soil for months post planting and could be available for runoff. To that end, 21 playa wetlands were sampled; 10 had at least one quantifiable neonicotinoid present, three of which were classified as grassland or rangeland playas, two were urban, and the remaining five were cropland playas. In several instances, neonicotinoid concentrations in playas exceeded EPA chronic benchmarks for aquatic invertebrates.

Prokaryotic Community Structure and Metabolisms in Shallow Subsurface of Atacama Desert Playas and Alluvial Fans After Heavy Rains: Repairing and Preparing for Next Dry Period.

The Atacama Desert, the oldest and driest desert on Earth, displays significant rains only once per decade. To investigate how microbial communities take advantage of these sporadic wet events, we carried out a geomicrobiological study a few days after a heavy rain event in 2015. Different physicochemical and microbial community analyses were conducted on samples collected from playas and an alluvial fan from surface, 10, 20, 50, and 80 cm depth. Gravimetric moisture content peaks were measured in 10 and 20 cm depth samples (from 1.65 to 4.1% w/w maximum values) while, in general, main anions such as chloride, nitrate, and sulfate concentrations increased with depth, with maximum values of 13-1,125; 168-10,109; and 9,904-30,952 ppm, respectively. Small organic anions such as formate and acetate had maximum concentrations from 2.61 to 3.44 ppm and 6.73 to 28.75 ppm, respectively. Microbial diversity inferred from DNA analysis showed Actinobacteria and Alphaproteobacteria as the most abundant and widespread bacterial taxa among the samples, followed by Chloroflexi and Firmicutes at specific sites. Archaea were mainly dominated by Nitrososphaerales, Methanobacteria, with the detection of other groups such as Halobacteria. Metaproteomics showed a high and even distribution of proteins involved in primary metabolic processes such as energy production and biosynthetic pathways, and a limited but remarkable presence of proteins related to resistance to environmental stressors such as radiation, oxidation, or desiccation. The results indicated that extra humidity in the system allows the microbial community to repair, and prepare for the upcoming hyperarid period. Additionally, it supplies biomarkers to the medium whose preservation potential could be high under strong desiccation conditions and relevant for planetary exploration.

Dalangtan Saline Playa in a Hyperarid Region on Tibet Plateau: I. Evolution and Environments.

Since 2008, we have been studying a saline lake, Dalangtan (DLT) Playa, and its surroundings in a hyperarid region of the Qaidam Basin on the Tibetan Plateau as a potential Mars analog site. We describe the evolution of saline deposits in the Qaidam Basin (including DLT), based on investigative findings accumulated over the course of 60 years of geological surveys. In addition, we report regional meteorological patterns recorded for the past 32 years along with meteorological station recorded data at DLT since 2012. Overall, the DLT area on the Tibetan Plateau has low atmospheric pressure, high ultraviolet radiation, low annual mean temperatures (T) but large seasonal and diurnal T cycles, and extremely low relative humidity, all of which bear some similarities with the equatorial region on Mars. In addition, salt types similar to those found on Mars, such as magnesium-sulfates, chlorides, and perchlorates, are found at the surface and subsurface in the DLT area (and the other two playas in the Qaidam Basin), thus supporting DLT as a Mars analog in terms of mineralogy and geochemistry.

Anthropometric profile and body composition of the Mexican olympic beach volleyball team / Perfil antropométrico y composición corporal de la selección olímpica mexicana de voleibol de playa

SUMMARY: The present research corresponds to a cross-sectional descriptive study in the anthropometric field, which allows coaches to develop standards to identify talent and optimize training in the discipline of beach volleyball. Its objective was to define the anthropometric profile and body composition of the Mexican Olympic beach volleyball teams in both sexes. The participants were couples one and two of Mexico in both sexes (defined by FIVB ranking), 4 women and 4 men with average age of 30.25±6.85 and 27.25±7.36 years. The technique used was Heath-Carter´s somatotype method and the anthropometric profile restricted ISAK protocol. Among the findings resulting from the research, unification can be observed in the male morphological characteristics (triceps skinfold, front thigh skinfold, calf skinfold, circumference of relaxed and contracted arm, waist, hip, femur diameter and BMI), as for the somatotype, both sexes of Mexican couples are positioned in mesomorphs-balanced. In relation to other studies consulted, balance in somatotype and muscular development is observed with high performance teams. Weight and height, as well as age, are important variables for the selection of talent and future optimal performance in world and professional volleyball.

La presente investigación corresponde a un estudio descriptivo transversal en el campo antropométrico, que permite a los entrenadores desarrollar estándares para identificar talentos y optimizar el entrenamiento en la disciplina de voleibol de playa. Su objetivo fue definir el perfil antropométrico y la composición corporal de las selecciones olímpicas mexicanas de voleibol de playa en ambos géneros. Los participantes fueron las parejas uno y dos de México en ambos géneros (definidos por ranking Fédération Internationale de Volleyball), 4 mujeres y 4 hombres con edad promedio de 30.25±6.85 y 27.25±7.36 años. La técnica utilizada fue el método del somatotipo de Heath-Carter y el protoolo ISAK del perfil antropométrico restringido. Entre los hallazgos resultantes de la investigación, se puede observar una unificación en las carácteristicas morfológicas masculinas (pliegue cuatáneotricipital, pliegue cutáneo anterior del muslo, pliegue citáneo de la pantorrila, circunferencia del brazo relajado y contraído, cintura, cadera, diámetro del fémur e IMC), en cuanto al somatotipo, ambos sexos de las parejas mexicanas se posicionan en mesomorfos-equilibrados. En relación a otros estudios consultados, se observa equilibrio en somatotipo y desarrollo muscular con equipos de alto rendimiento. El peso y la altura, así como la edad, son variables importantes para la selección del talento y en el futuro desempeño óptimo en el voleibol mundial y profesional.

Anidación de la tortuga marina Lepidochelys olivacea (Testudinata: Cheloniidae) en Campamento Tortuguero Cedeño, Honduras (2011-2021) / Nesting of olive ridley sea turtle Lepidochelys olivacea (Testudinata: Cheloniidae) in Campamento Tortuguero Cedeño, Honduras (2011-2021)

Introducción: El Campamento Tortuguero de Cedeño ha sido el sitio menos investigado del Golfo de Fonseca, donde se protege a la tortuga golfina en Honduras desde 1975. Objetivo: Evaluar la anidación de la tortuga Golfina (Lepidochelys olivacea) durante la temporada de veda entre el 2011 y 2021 en Campamento Tortuguero Cedeño, Choluteca, Honduras. Métodos: Entre 2011 a 2021, se llevó a cabo el monitoreo diario de las actividades de anidación durante la veda del 1 al 25 de septiembre. Los patrullajes se realizaron entre las 6:00-18:00 h, y las 18:00-5:00 h. Se registró el número total de tortugas que anidaban y se recogieron sus huevos, que se transportaron al criadero, donde se tabularon los resultados de las puestas y las crías. Resultados: Se registró un total 1 065 tortugas de L. olivacea, 95 051 huevos recolectados, 1 065 nidos marcados en tres playas que fueron reubicados en viveros artificiales y una eclosión exitosa de 62 747 neonatos. La playa Las Doradas fue el sitio con el mayor número de tortugas anidadoras, seguido de Los Delgaditos y por último Cedeño. El promedio de la frecuencia de anidación fue de 96 nidos. Del 2011 al 2021 el esfuerzo de recolección de los nidos aumentó en un 91.6 %, pasando de 84 a 161 nidos. El número de personas patrullando se asoció con la cantidad de nidos detectados en las playas. Conclusión: Los esfuerzos de monitoreo y conservación para la especie han indicado que ha habido un incremento en la anidación de L. olivacea en las tres playas, con un mayor incremento en Playa Las Doradas. Este escenario comprueba la funcionalidad de la veda en esta zona.

Introduction: The Cedeño Turtle Camp has been the least researched site in the Fonseca Gulf, where Olive Ridley Turtles in Honduras have been protected since 1975. Objective: To evaluate the nesting of Olive Ridley turtles (Lepidochelys olivacea) during the closed season from 2011 to 2021 in Campamento Tortuguero Cedeño, Choluteca, Honduras. Methods: From 2011 to 2021, daily monitoring of nesting activities was conducted during the closed season from the 1st to 25th of September. Patrols were conducted between 6:00-18:00 h, and 18:00-5:00 h. The total number of nesting turtles was recorded, and their eggs were collected and transported to the hatchery, where clutch and hatchling performance were tabulated. Results: A total of 1 065 L. olivacea turtles were recorded, 95 051 eggs collected, 1 065 nests marked on three beaches that were relocated in artificial hatcheries and a successful hatching of 62 747 hatchlings. Las Doradas beach was the site with the highest number of nesting turtles, followed by Los Delgaditos and lastly Cedeño. The average nesting frequency was 96 nests. From 2011 to 2021 the nest collection effort increased by 91.6 %, from 84 to 161 nests. The number of people patrolling was associated with the number of nests detected on the beaches. Conclusion: Monitoring and conservation efforts for L. olivacea in the Campamento Tortuguero Cedeño show a positive trend in nesting with a greater increase in Playa Las Doradas. This scenario proves the functionality of the closed season in this area.

Pachyoliva columellaris G.B. Sowerby I, 1825 (Olividae, Caenogastropoda) in Peru: tidal migrations and population density

The gastropod Pachyoliva columellaris (formerly Olivella columellaris) is particularly common on many sandy beaches in North Peru. In the studied region north of Paita, Piura province, the species reaches densities of over 80,000 individuals per beach meter. The snails perform tidal migrations throughout the lunar cycle although tidal amplitudes differ four-fold between neap and spring tide. Not all animals complete their tidal migrations, and significant numbers remain above the water line at low tide. Throughout the tidal cycle, the proportion of small individuals is increased near the water line whereas large animals dominate in lower beach zones. I conclude that the sandy beaches north of Paita are well-suited for further studies of P. columellaris and the mechanisms underlying tidal migrations in invertebrates.

El gasterópodo Pachyoliva columellaris (antes Olivella columellaris) es particularmente común en las playas arenosas del norte de Perú. En la región estudiada al norte de Paita, provincia de Piura, la especie alcanza densidades de más de 80.000 individuos por metro de playa. Los caracoles realizan migraciones mareales durante todo el ciclo lunar, aunque las amplitudes de marea difieren cuatro veces entre la marea muerta y la marea viva. No todos los animales completan sus migraciones mareales y un número significativo permanece por encima del nivel del agua en marea baja. Durante todo el ciclo de marea, la proporción de individuos pequeños aumenta cerca del nivel del agua, mientras que los animales grandes dominan en las zonas bajas de la playa. Concluyo que las playas arenosas al norte de Paita son apropiadas para estudios adicionales de P. columellaris y los mecanismos de las migraciones de marea en invertebrados.