National University of Costa Rica

The development of research skills is essential in higher education. Still, it is a challenge for students, so it is necessary to find strategies that support the teaching and learning of research. Therefore, a teaching project was created incorporating peer tutoring to support research training at a public university in the Brunca Region of Costa Rica. This qualitative case study sought to understand how the project has contributed to this work, how teachers and students perceive the support, and what aspects need to be improved. Semi-structured interviews were used with teachers and students who are regular users of the service offered by the project, and thematic analysis was used to analyze the information. The main findings indicated that the search for reliable sources and the ability to express oneself in writing are a challenge for the student population. It is concluded that the support offered through peer tutoring is valued since it complements teacher feedback. Teachers and students suggested that there be more dissemination of the project and the scope of its service.

Brucellosis has therapeutic challenges due to 3%–15% relapses/therapeutic failures (R/TF) after antibiotic treatment. Therefore, determining the antibiotic concentration in tissues, the physiopathological parameters, and the R/TF after treatment is relevant. After exploring different antibiotic quantities, we found that a combined dose of 100 µg/g of doxycycline (for 45 days) and 7.5 µg/g of streptomycin (for 14 days), respectively, achieved therapeutic levels of more than fourfold minimum inhibitory concentrations (MICs) against Brucella abortus in the spleen, liver, bone marrow, and plasma of mice, causing minimal pathophysiological effects. After 30 days of infection, mice received antibiotics, and hematological, histopathological, biochemical, and immunological analyses were performed. After antibiotic therapy, the pathological, hematological, immunological, and physiological profiles paralleled those described in human brucellosis. Treatment lowered antibody titers, reduced proinflammatory cytokines, and reduced inflammation in the target organs for a protracted period. No bacteria were detected in tissues 8 weeks after treatment, suggesting complete recovery. However, despite high doxycycline and streptomycin concentrations in tissues, relapses appeared in 100% of the animals after 182 days post-infection, estimated by the bacterial counts and PCR from organs. This proportion contrasts with the 15% R/TF observed in humans after antibiotic treatments. None of the B. abortus isolated from relapses showed augmented MICs or mutations coding for antibiotic resistance in chromosomal-relevant regions. We discuss whether our findings constitute a general phenomenon or differences in the exhaustive screening method for bacteria detection related to the murine model. Along these lines, we envision likely mechanisms of bacterial persistence in tissues after antibiotic treatment.

This study focuses on the extraction of phenolic compounds from the fermentation of Phanerochaete chrysosporium and Gloeophyllum trabeum. The main goal was to synthesize phenol/chitosan microspheres and PVA films and characterized using FTIR, TGA, DSC, SEM, and mechanical tests to evaluate their physical, chemical, and mechanical properties for antimicrobial packaging applications. Homogeneous chitosan microspheres loaded with lignin-derived phenols were obtained, showing controlled release of antimicrobial compounds. The incorporation of phenolic microspheres into PVA/chitosan films resulted in significant improvements in mechanical properties: the films exhibited an elastic modulus of 36.14 ± 3.73 MPa, tensile strength of 12.01 ± 1.14 MPa, and elongation at break of 65.19 ± 5.96%. Thermal tests revealed that chitosan-containing films had enhanced thermal stability, with decomposition temperatures (T10) reaching 116.77 °C, compared to 89.28 °C for pure PVA. In terms of antimicrobial activity, PVA/chitosan/phenol films effectively reduced Lactobacillus growth and milk acidity, maintaining quality for up to 96 h at room temperature, outperforming controls with acetic acid and H2O2. The films also inhibit yeast growth for one week. In conclusion, phenols can be effective antimicrobial agents in dairy, but their use should be monitored. Additionally, PVA/chitosan-phenol films offer biodegradability, antimicrobial properties, and sustainability for diverse applications.

Background and Aim: Canine degenerative myelopathy (DM) is an autosomal recessive inherited disease that affects different dog breeds. It has an invariably fatal outcome once the clinical symptoms begin. This study aimed to investigate the population behavior of the mutation superoxide dismutase 1 (SOD1) c.118: G˃A responsible for the high risk of developing DM in two populations of German Shepherd dogs from Uruguay and Paraguay. Materials and Methods: A total of 158 German Shepherd dogs from Uruguay (n = 114) and Paraguay (n = 44) were analyzed. Genomic DNA was extracted from peripheral whole blood. The SOD1 c.118: G˃A mutation was identified by polymerase chain reaction-restriction fragment length polymorphism and subsequently validated using sequencing. Allelic and genotypic frequencies and Hardy–Weinberg equilibrium were calculated for both populations. The rate of clinical progression was evaluated in animals homozygous for the mutation. Results: The frequencies of allele A associated with a higher risk of DM, were 0.15 and 0.23 in Paraguay and Uruguay, respectively. Paraguay’s population was found to be in Hardy–Weinberg equilibrium (p = 1.00), whereas the population of dogs from Uruguay deviated from equilibrium (p = 0.008). When comparing the populations, no significant difference was observed in the distribution of genotypes (p = 0.26). When evaluating the clinical progression rate, all animals aged >10 years showed clinical symptoms compatible with DM. Conclusion: This study demonstrated for the first time the presence of the SOD1:c118 G>A mutation in German Shepherd dogs from Uruguay and Paraguay. The frequency detected in Uruguay was significant. Although the frequency was lower in Paraguay, the allele was present. This demonstrates the need to implement genotyping tests as part of a possible DM control program in both countries studied. Keywords: degenerative myelopathy, genetic disease, German Shepherd dog, superoxide dismutase 1 gene.

Importance There is growing understanding that Social Determinants of Health (SDH) impact on the outcomes of different pediatric conditions. We aimed to determine whether SDH affect the severity of MIS‐C. Design Retrospective cohort study, 2021–2023. Children and adolescents with MIS‐C younger than 18 years of age fulfilling the MIS‐C CDC definition within the REKAMLATINA network were invited to participate. We assessed the i mpact of SDH on the risk of children with MIS‐C to be diagnosed with shock, need of inotropes, respiratory support, transfusion, and death. Results Two hundred and seventy seven patients from 30 centers in 13 countries were included. Of them, 241 children from the four most‐represented countries were included in the final analysis. Food insecurity, higher distance from a health center, not possessing a private vehicle to transport the patient to hospital, and having a home in poor condition, were associated with low LVEF, need of transfusion, shock, and need for respiratory support, when controlling for age, BMI, and ethnicity. The Score of Social Disadvantage was associated with Shock (OR: 1.35, P: 0.011, 95% CI: 1.07–1.71), Respiratory support (OR: 1.39, P: 0.005, 95% CI: 1.1–1.75), Transfusion (OR: 1.63, P0.013, 95% CI 1.1–2.41), but not death (OR: 0.76, P: 0.38, 95% CI: 0.41–1.40). Conclusions Among a large cohort of Latin American children with MIS‐C, SDH negatively affect outcomes. These findings reinforce the need for better investigation of the role of SDH in MIS‐C and other inflammatory conditions and may guide public health interventions.

Objectives Burial space reuse and prolonged interaction with the dead were common practices in the Isthmo-Colombian Area, dating back to at least the Early Ceramic Period in the Greater Coclé region. However, biological and social relationships of individuals interred in collective burial contexts remain unclear. Here, we explore intra-cemetery biological variation through a biological distance analysis of individuals interred in large mortuary features from the first mortuary horizon at the site of Cerro Juan Díaz in Panamá. Materials and Methods Individuals recovered from Features 2, 16, and 94 from Operation 3 at Cerro Juan Díaz were assessed for dental metric and nonmetric traits. Biological distances were calculated through Gower coefficients and subsequently assessed visually with PCoA plots. Differences in phenotypic variability within burial feature (n = 26), age (postpubescent individuals aged 15+ years vs. prepubescent individuals; n = 27), and sex (n = 14) groupings were evaluated statistically via permutational multivariate analysis of variance (PERMANOVA) and PERMDISP tests. Results The estimated distances for each individual showed broad similarities between the three burial features. Significant differences in biological distance were found only when comparing by age. Gower coefficients for prepubescent individuals differed from those of postpubescent individuals in terms of both group centroid location and data point dispersion around centroids. Discussion Our results are largely consistent with previous notions of Cerro Juan Díaz's function as a community burial ground. Prepubescent individuals may have been brought to the site for burial from nearby villages, perhaps following specific mortuary traditions governed by age group.

Tropical cyclones (TCs) are one of the major natural hazards to island and coastal communities and ecosystems. However, isotopic compositions of TC‐derived precipitation (P) in surface water (SW) and groundwater (GW) reservoirs are still lacking. We tested the three main assumptions of the isotope storm “spike” hypothesis (sudden spikes in isotopic ratios). Our database covers 40 TCs and is divided into recent (N = 778; 2012–2023) and archived (N = 236; 1984–1995) rainfall isotope observations and SW/GW isotope monitoring (N = 6013; 2014–2023). Seasonal rainfall contribution from TCs ranged from less than 1% to over 54% (4% on average) between 1984 and 2023. Mean δ¹⁸O compositions across TCs domains were significantly lower than the regional (noncyclonic) δ¹⁸O mean (−5.24 ± 4.27‰): maritime (−6.29 ± 3.28‰), coastal (−7.78 ± 4.28‰), and inland (−9.80 ± 5.18‰) values. Coastal and maritime TC convection resulted in large rainfall amounts with high isotope compositions. This could bias past climate reconstructions toward unrealistic drier conditions. Significant δ¹⁸O and d‐excess differences were found between storm intensities. P/SW and P/GW isotope ratios revealed the rapid propagation of TC excursions in freshwater systems. Our findings highlight the potential of TC isotope observations for diagnosing intensity and frequency in paleoproxies beyond idealized TC models.

Isotope hydrological studies to understand groundwater‐surface water interactions in tropical, high‐elevation catchments are limited. These interactions are important in controlling lake water residence time, aqueous biogeochemistry, and water availability for downstream communities and ecosystems. To better comprehend the complexity of spatio‐temporal variations in the aquifer‐lake domain in tropical volcanic regions, a multi‐tracer approach including water and inorganic carbon stable isotopes (δ²H, δ¹⁸O, δ¹³CDIC), hydrochemistry, and ²²²Rn was applied in Lake Hule, northern Costa Rica. Seasonal isotope mass balance calculations using lake, stream, precipitation, and groundwater compositions were supplemented with local hydrometeorological information. Evaporation to inflow ratios (E/I) revealed a small variability between the dry (December–April) and wet seasons (May–November), with relatively low evaporation losses, 2.9 ± 1.0 % and 3.2 ± 1.8 %, respectively. Bayesian end‐member analysis indicated that annual inputs from groundwater, precipitation, and runoff represented 61.3 ± 8.1%, 24.4 ± 8.4, and 14.3 ± 5.9% of total lake inflow, respectively. Temporal variations of δ¹³CDIC confirmed the key role volcanic carbonate buffering plays in this lake and indicated greater CO2 degassing from groundwater sources in the wet season. This tracer‐aided assessment in a volcanic lake maar of northern Costa Rica provides evidence of previously unknown groundwater‐surface water interactions and illustrates the application of isotopic tools for estimating water balances and seasonal variability of groundwater discharge into natural lakes across the volcanic front of Central America.

Beach soccer has gained increasing interest for study in the sports sciences. In this sense, the analysis of activity profiles is important for training design and load individualization. Therefore, the aims of this study were to identify the most important variables to assess the activity profile and to compare them according to the playing position and game periods in international beach soccer matches. A total of 19 matches of the Spanish national beach soccer team were analyzed during their participation in different international competitions during the 2021-2022 season. A Principal Component Analysis (PCA) was applied to objectively select the external load variables that best explain the data. Kaiser-Meyer-Olkin values of 0.705 and Bartlett's Sphericity (p < 0.01) were obtained. Kruskal-Wallis and Friedman tests was performed for playing positions and game period comparisons, respectively. The PCA showed seven components that grouped a total of 20 variables, explaining 66% of the total variance. Only PC1 and PC2 explained more than 15% (23% and 17%, respectively). Differences were found between playing positions (H > 22.73; p < 0.01) and between game periods (X2 > 16.46; p < 0.01). A significant decrease was found throughout the game, with the highest demands in period 1 and the lowest in period 3. The highest workloads were performed by wingers and the lowest by goalkeepers. The differences between positions and game periods were found in the following: Total Distance (m/min), HIBD (m/min), High Acc (m/s), High Dec (m/s), Acc 1-2 m/s 2 (m), Acc 2-3 m/s 2 (m), Imp 4-5G (n), Imp 5-6G (n), Sprint (n), and Dec 10-6 m/s 2 (m) (p < 0.01). In conclusion, physical and tactical demands faced by elite-level beach soccer players will be influenced by playing positions and game periods. Coaches needs to develop position-specific training programs and optimize substitution strategies for enhancing overall team performance.

Antimicrobial resistance poses a growing threat to human health, yet its implications for wildlife remain a subject of ongoing research. River otters inhabiting the Peñas Blancas River face exposure to various anthropogenic activities in their habitat, potentially leading to the accumulation of antibiotic-resistant genes (ARGs) with unknown consequences for their health. This study aimed to identify specific ARGs in otter feces from this river basin, employing quantitative polymerase chain reaction (qPCR), DNA sequencing of ARGs, and phylogenetic analysis techniques. Over the period from 2019 to 2022, we collected 102 fecal samples from otters through the Peñas Blancas River watershed, spanning its upper and middle basins. We assessed the bacterial presence via the 16S rRNA gene through qPCR analysis and screened for 12 ARGs. Sequences of 16 ARG-positive samples were subsequently analyzed using Maximum-likelihood-base taxonomic placement. In total, 56 samples tested positive for the 16S rRNA gene, with 24 exhibiting at least one ARG. Notably, three samples showcased a “multi-resistance microbiome”. qPCR analyses identified seven distinct ARGs: tetB (in 26.8 % of the samples), sulI (21.4 %), sulII (21.4 %), qnrS (10.7 %), tetQ (8.9 %), tetW (7.1 %), and tetA (3.6 %). Phylogenetic analysis confirmed the taxonomic association of all detected ARGs, which were compared with The Comprehensive Antibiotic Resistance Database. Our findings underscore the importance of comprehending the spread of ARGs in wildlife populations, with river otters serving as potential sentinels for ARG dissemination. Moreover, they highlight the potential impact of anthropogenic activities on the health of aquatic ecosystems, emphasizing the need for proactive measures to mitigate antimicrobial resistance in natural environments.

This article examines the results of two qualitative research studies undertaken in Costa Rica on transformations linked to the experience of belief and gender in family and community environments featuring religious diversity. Actions and discourses are identified as forms of belief management that are tributary to non-hegemonic values, which are transferable from the private to the public sphere. In making a critical reading of the local context, the analysis is inscribed in the decolonial turn in Latin America (Quijano, 1992; Castro Gómez and Grosfoguel, 2007; Fornet-Betancourt, 2009; Walsh, 2010; Escobar, 2012). The construction of social agency is seen to arise from the colonial wound and the questioning of family and community universality in interreligious coexistence. The conceptual approach taken up is presented, discussion is made of the characteristics of interreligious coexistence in mixed families and of the particularities of the minority religious groups studied, and analysis is made in the conclusions of the decolonizing transformations of their narratives.

Spirocerca lupi is a parasitic nematode of domestic and wild canids of the world. This nematode induces esophageal spirocercosis and may eventually lead to carcinomas, aortic aneurisms, and death of the animal. Two genotypes of S. lupi have been described based on specimens from Europe, Asia, Africa, and Oceania, but no profound analysis has been conducted with S. lupi from the Americas. To study this, S. lupi specimens isolated from domestic dogs from Mexico, Costa Rica, and the United States, were molecularly characterized using 18S rDNA and cox1 fragments. Bayesian inference (BI) phylogenetic trees, Templeton- Crandall-Sing (TCS) haplotype networks and Principal coordinate analysis on nucleotide distances were constructed for each locus separately. In addition, a phylogeographic study using a fragment of the cox1 gene was used to infer the evolutionary history of the genus. BI cox1 trees grouped S. lupi from the Americas in genotype 1, together with Israeli specimens, and showed a high nucleotide identity with those worms. In the TCS network, American specimens clustered next to Israeli S. lupi. Furthermore, the 18S rDNA gene fragment separated Costa Rican worms from African, Asian, and European specimens and other species of the family Spiruridae. Interestingly, the phylogeographic analysis suggested that the origin of S. vulpis was in Europe, and it later diverged into S. lupi that spread first to Africa, then to Asia and finally to the Americas. Therefore, we suggest that the worms from the American continent might have originated from Asia by dispersion of infected intermediate, paratenic or definitive hosts.

Bionanotechnology research has surged to the forefront of scientific innovation, propelling the exploration of cutting-edge technologies and interdisciplinary collaboration. Biomimicry, which harnesses nature's ingenuity, drives the development of novel research-based solutions in diverse fields such as vaccines, medicine, and biomedical devices. Nature's role is becoming increasingly pivotal in addressing complex challenges related to environmental conservation, human health, and pandemic preparedness, including those posed by SARS-CoV-2 and other emerging pathogens. Progress in this domain encompasses understanding nature´s mechanisms to develop advanced materials inspired by biological structures. Biomimetic innovations have the potential to revolutionize industries, reduce environmental impacts, and facilitate a more harmonious relationship between humans and nature while considering bioethics, underlining the necessity of conducting responsible research and implementing biomimetic advancements conscientiously. As biomimicry continues to grow, integrating ethical guidelines and policies will ensure these nature-inspired technologies' sustainable development and application, ultimately contributing to a more resilient and adaptive society. This mini-review article broadly overviews bionanotechnology applications based on natural examples. Graphical Abstract

Remaining immobile for an unpredictable period after being touched by a potential predator (post-contact immobility, PCI) may favor survival. However, the factors that determine variation in PCI duration are poorly understood. We tested whether PCI duration depends on the surrounding conspecific density (the selfish prey hypothesis) in the tropical antlion larvae Myrmeleon crudelis. These insects avoid predation by being immobile or burying themselves. The selfish prey hypothesis predicts a reduction in the PCI duration as conspecific density increases because this high density of conspecifics around can stimulate the redirection of the predator's interest in other nearby potential prey. In the field, we measured PCI and found that its duration was independent of the conspecific density. In the lab, we also measured the PCI of a subset of the same larvae in the absence of neighbors. Using a paired design, we found that PCI duration was lower in the lab in the absence of neighbors than in the field. Our results suggest that the antlion larvae did not follow the selfish prey hypothesis. We propose two alternative explanations. First, the larvae have a limited ability to detect neighbors in the field and keep up with the changing number of surrounding active pits. Second, burying may be more important than PCI as an antipredator strategy. In our lab experiment, larvae had a more accurate idea of the conspecific density around their pit because they explored the area. We propose that knowing the absence of conspecifics triggered a shorter PCI duration. Under a high predation risk (i.e., no other prey to which the predator would redirect its attention), the larvae select the unequivocal antipredator behavior of burying. This work illustrates the relevance of accurate information in deciding how to avoid predation, especially when prey can prioritize between alternative behaviors, with success varying between the contexts.

Background: The exposure of environmental bacteria to contaminants in aquatic ecosystems accelerates the dissemination of antibiotic-resistance genes (ARGs) through horizontal gene transfer (HGT). Methods: In this study, we sampled three locations along a contamination gradient of a polluted river, focusing on isolating Enterobacteria from the surface waters to investigate the relationship between urban pollution and antibiotic resistance. The genomes of 15 isolates (5 per site) were sequenced to identify plasmid-borne ARGs and their association with resistance phenotypes. Results: Isolates from the site with the highest contamination (Site 3) showeda larger number of ARGs, plasmids, and resistance phenotypes. Notably, one of the isolates analyzed, E. coli A231-12, exhibited phenotypic resistance to seven antibiotics, presumably conferred by a single plasmid carrying 12 ARGs. Comparative analysis of this plasmid revealed its close evolutionary relationship with another IncH plasmid hosted by Salmonella enterica, underscoring its high ARG burden in the aquatic environment. Other plasmids identified in our isolates carried sul and dfrA genes, conferring resistance to trimethoprim/sulfamethoxazole, a commonly prescribed antibiotic combination in clinical settings. Conclusions: These results highlight the critical need to expand research on the link between pollution and plasmid-mediated antimicrobial resistance in aquatic ecosystems, which can act as reservoirs of ARGs.

Subduction of the Cocos and Nazca oceanic plates beneath the Caribbean plate drives the upward movement of deep fluids enriched in carbon, nitrogen, sulfur, and iron along the Central American Volcanic Arc (CAVA). These compounds fuel diverse subsurface microbial communities that in turn alter the distribution, redox state, and isotopic composition of these compounds. Microbial community structure and functions vary according to deep fluid delivery across the arc, but less is known about how microbial communities differ along the axis of a convergent margin as geological features (e.g., extent of volcanism and subduction geometry) shift. Here, we investigate changes in bacterial 16S rRNA gene amplicons and geochemical analysis of deeply-sourced seeps along the southern CAVA, where subduction of the Cocos Ridge alters the geological setting. We find shifts in community composition along the convergent margin, with communities in similar geological settings clustering together independently of the proximity of sample sites. Microbial community composition correlates with geological variables such as host rock type, maturity of hydrothermal fluid and slab depth along different segments of the CAVA. This reveals tight coupling between deep Earth processes and subsurface microbial activity, controlling community distribution, structure and composition along a convergent margin.

Encapsulation within a polymeric matrix facilitates targeted drug delivery and release under controlled conditions. This study employed a customized electrospraying system to fabricate zein and poly(vinyl alcohol) particles, optimizing operational parameters to achieve minimized particle size and optimal distribution. Characterization revealed that poly(vinyl alcohol) particles averaged 156 nm, with a peak count at 160 nm, while zein particles averaged approximately 148 nm, with a peak count at 205 nm. These particle sizes fall within the range of optimal potential uptake into the tissue, leading to a better absorption of bioactive agents. Fourier-transform infrared spectroscopy confirmed interactions between poly(vinyl alcohol), zein, and bovine serum albumin forming complex structures, suggesting that bovine serum albumin can be effectively encapsulated with these biopolymers. Our results confirmed that the system is suitable as a potential protein encapsulation method in the development of protein-based therapies.

Climate change, inter‐annual precipitation variability, recurrent droughts and flash flooding, coupled with increasing water needs, are shaping the co‐evolution of socioeconomic and cultural assemblages, water laws and regulations, and equitable drinking water access and allocation worldwide. Recognising the need for mitigation strategies for drinking water availability in urban areas, the Isotope Hydrology Section of the International Atomic Energy Agency (IAEA) coordinated a state‐of‐the‐art global assessment to evaluate water sources and distribution of drinking water supply in urban centres, an initiative entitled ‘Use of Isotope Techniques for the Evaluation of Water Sources for Domestic Supply in Urban Areas (2018–2023)’. Here, we report on (a) current research trends for studying urban drinking water systems during the last two decades and (b) the development, testing and integration of new methodologies, aiming for a better assessment, mapping and management of water resources used for drinking water supply in urban settings. Selected examples of water isotope applications (Canada, USA, Costa Rica, Ecuador, Morocco, Botswana, Romania, Slovenia, India and Nepal) provide context to the insights and recommendations reported and highlight the versatility of water isotopes to underpin seasonal and temporal variations across various environmental and climate scenarios. The study revealed that urban areas depend on a large spectrum of water recharge across mountain ranges, extensive local groundwater extraction and water transfer from nearby or distant river basins. The latter is reflected in the spatial isotope snapshot variability. High‐resolution monitoring (hourly and sub‐hourly) isotope sampling revealed large diurnal variations in the wet tropics (Costa Rica) (up to 1.5‰ in δ ¹⁸ O) and more uniform diurnal variations in urban centres fed by groundwater sources (0.08‰ in δ ¹⁸ O) (Ljubljana, Slovenia). Similarly, while d ‐excess was fairly close to the global mean value (+10‰) across all urban centres (10‰–15‰), reservoir‐based drinking water systems show lower values (up to ~ −20‰) (Arlington, TX, USA and Gaborone, Botswana), as a result of strong evapoconcentration processes. δ ¹⁸ O time series and depth‐integrated sampling highlighted the influence of the catchment damping ratio in the ultimate intake water composition. By introducing new, traceable spatial and temporal tools that span from the water source to the end‐user and are linked to the engineered and socio‐economic structure of the water distribution system, governmental, regional or community‐based water operators and practitioners could enhance drinking water treatment strategies (including more accurate surface water blending estimations) and improve urban water management and conservation plans in the light of global warming.

This contribution is a histological and scanning electron microscopy study of major flagellar setae of antennules from the most cultured crustacean species, Penaeus vannamei. Antennule samples were collected from females and males of selected species and processed for histological as well as scanning electron microscopy (SEM) evaluation. The histological and SEM description of major setae from antennules, namely aesthetascs, plumose setae, and male spines are presented in detail. A unique sexually dimorphic structure, male spines on the inner (medial) flagella, is reported for the first time in a penaeid shrimp. These spines are robust structures, short and thick with non-permeable cuticle and no terminal pore, innervated by receptor neuron clusters. This histological organization suggests the spines are sensilla for mechanoreception, possibly involved in courtship mechanoreception, complementing chemosensory information from aesthetascs. Additionally, SEM observations of other antennule setae are presented, including asymmetric setae associated with aesthetascs.