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1. Checklist and distribution of Collembola from Greater Puerto Rico

   https://doi.org/10.3897/BDJ.8.e52054  

   Ospina-Sánchez, Claudia; Soto-Adames, Felipe; González, Grizelle (July 2020, Biodiversity Data Journal)

   null (Ed.)

   Springtails (Arthropoda, Hexapoda, Collembola) are small arthropods commonly found in soil, litter and other habitats all around the Globe. More than 9,000 species have been described worldwide, but knowledge about their diversity and distribution remains far from complete. Reports of springtail diversity in the Antilles are uneven, some islands are relatively well known, whereas others have not been explored at all. The fauna of Puerto Rico is reasonably well known, but many recent reports are scattered in published literature and unpublished theses. Here, we present a summary of all springtail species identified from the Bank of Puerto Rico, including unpublished records. As a result, we list 146 species including 43 unnamed, included in 65 genera and 17 families. Most species, 33, belong to Entomobryidae, but this possibly reflects the taxonomic expertise of specialists working in Puerto Rico rather than a real bias in the distribution of higher taxa in the islands. In addition to the new records, the database provides information on the world and local distribution of species listed. The dataset, presented here, is work in progress and will be updated as ongoing taxonomic inventories are completed. 

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2. Directional takeoff, aerial righting, and adhesion landing of semiaquatic springtails

   https://doi.org/10.1073/pnas.2211283119  

   Ortega-Jimenez, Victor M.; Challita, Elio J.; Kim, Baekgyeom; Ko, Hungtang; Gwon, Minseok; Koh, Je-Sung; Bhamla, M. Saad (November 2022, Proceedings of the National Academy of Sciences)

   Springtails (Collembola) have been traditionally portrayed as explosive jumpers with incipient directional takeoff and uncontrolled landing. However, for these collembolans that live near the water, such skills are crucial for evading a host of voracious aquatic and terrestrial predators. We discover that semiaquatic springtails, Isotomurus retardatus , can perform directional jumps, rapid aerial righting, and near-perfect landing on the water surface. They achieve these locomotive controls by adjusting their body attitude and impulse during takeoff, deforming their body in midair, and exploiting the hydrophilicity of their ventral tube, known as the collophore. Experiments and mathematical modeling indicate that directional-impulse control during takeoff is driven by the collophore’s adhesion force, the body angle, and the stroke duration produced by their jumping organ, the furcula. In midair, springtails curve their bodies to form a U-shape pose, which leverages aerodynamic forces to right themselves in less than ~20 ms, the fastest ever measured in animals. A stable equilibrium is facilitated by the water adhered to the collophore. Aerial righting was confirmed by placing springtails in a vertical wind tunnel and through physical models. Due to these aerial responses, springtails land on their ventral side ~85% of the time while anchoring via the collophore on the water surface to avoid bouncing. We validated the springtail biophysical principles in a bioinspired jumping robot that reduces in-flight rotation and lands upright ~75% of the time. Thus, contrary to common belief, these wingless hexapods can jump, skydive, and land with outstanding control that can be fundamental for survival. 

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3. Most soil and litter arthropods are unidentifiable based on current DNA barcode reference libraries

   https://doi.org/10.1093/cz/zoad051  

   Recuero, Ernesto; Etzler, Frank E.; Caterino, Michael S.; Jia, ed., Zhi-Yun (November 2023, Current Zoology)

   Abstract We are far from knowing all species living on the planet. Understanding biodiversity is demanding and requires time and expertise. Most groups are understudied given problems of identifying and delimiting species. DNA barcoding emerged to overcome some of the difficulties in identifying species. Its limitations derive from incomplete taxonomic knowledge and the lack of comprehensive DNA barcode libraries for so many taxonomic groups. Here, we evaluate how useful barcoding is for identifying arthropods from highly diverse leaf litter communities in the southern Appalachian Mountains (USA). We used 3 reference databases and several automated classification methods on a data set including several arthropod groups. Acari, Araneae, Collembola, Coleoptera, Diptera, and Hymenoptera were well represented, showing different performances across methods and databases. Spiders performed the best, with correct identification rates to species and genus levels of ~50% across databases. Springtails performed poorly, no barcodes were identified to species or genus. Other groups showed poor to mediocre performance, from around 3% (mites) to 20% (beetles) correctly identified barcodes to species, but also with some false identifications. In general, BOLD-based identification offered the best identification results but, in all cases except spiders, performance is poor, with less than a fifth of specimens correctly identified to genus or species. Our results indicate that the soil arthropod fauna is still insufficiently documented, with many species unrepresented in DNA barcode libraries. More effort toward integrative taxonomic characterization is needed to complete our reference libraries before we can rely on DNA barcoding as a universally applicable identification method. 

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4. The effects of intraspecific and interspecific diversity on food web stability

   https://doi.org/10.1007/s12080-020-00460-z  

   Noto, Akana E.; Gouhier, Tarik C. (May 2020, Theoretical Ecology)

   Although the effects of species diversity on food web stability have long been recognized, relatively little is known about the influence of intraspecific diversity. Empirical work has found that intraspecific diversity can increase community resilience and resistance, but few theoretical studies have attempted to use modeling approaches to determine how intraspecific diversity will affect food web stability. To begin to address this knowledge gap, we added intraspecific diversity to May’s classic random food web model. We found that, like species diversity, intraspecific diversity decreased stability. These effects on stability were not simply attributable to changes in interaction strengths, suggesting that intraspecific diversity can have its own independent effects on stability. Its effect depends on the relationship between inter- and intra-genotype interactions; when competition within genotypes was stronger than among them, food webs were generally more stable than when the converse was true. Overall, our model suggests that determining the direction and the magnitude of intraspecific diversity’s effects on stability in natural systems will require more empirical information about how its inclusion alters patterns of interaction strength and food web topology. 

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5. Geographical patterns of intraspecific genetic diversity reflect the adaptive potential of the coral Pocillopora damicornis species complex

   https://doi.org/10.1371/journal.pone.0316380  

   Carr, M; Kratochwill, C; Daly-Engel, T; Crombie, T; van_Woesik, R (January 2025, PLOS ONE)

   Tavakoli-Kolour, Parviz (Ed.)

   Marine heatwaves are increasing in intensity and frequency however, responses and survival of reef corals vary geographically. Geographical differences in thermal tolerance may be in part a consequence of intraspecific diversity, where high-diversity localities are more likely to support heat-tolerant alleles that promote survival through thermal stress. Here, we assessed geographical patterns of intraspecific genetic diversity in the ubiquitous coralPocillopora damicornisspecies complex using 428 sequences of the Internal Transcribed Spacer 2 (ITS2) region across 44 sites in the Pacific and Indian Oceans. We focused on detecting genetic diversity hotspots, wherein some individuals are likely to possess gene variants that tolerate marine heatwaves. A deep-learning, multi-layer neural-network model showed that geographical location played a major role in intraspecific diversity, with mean sea-surface temperature and oceanic regions being the most influential predictor variables differentiating diversity. The highest estimate of intraspecific variation was recorded in French Polynesia and Southeast Asia. The corals on these reefs are more likely than corals elsewhere to harbor alleles with adaptive potential to survive climate change, so managers should prioritize high-diversity regions when forming conservation goals. 

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