Seaward Migration and Larval Release Coincide with Lunar and Light-dark Cycles in Supratidal Land Crabs Cardisoma carnifex and Epigrapsus notatus.

Herein we investigated the synchronous breeding migration and larval release of ovigerous females in two dominant supratidal land crabs Cardisoma carnifex and Epigrapsus notatus in the mixed semidiurnal tidal regime in Taijiang National Park (Tainan, Taiwan). We mainly focused on the monthly and daily rhythms during the breeding season of migration and larval release for these two crabs. We also sought to understand what the main environmental cues were for these monthly and diel rhythms. Both lunar and tidal amplitude cycles are potential proximate causes for the monthly lunar/semilunar reproductive rhythm in crabs. Likewise, either the 24-hour (diel) light cycle or tidal cycle can act as the proximate cause for diel reproduction rhythm, and we investigated which one was the main factor that entrains the diel rhythm for these two species. We found that the season of migration and larval release in C. carnifex occured mainly between June and September during the rainy season while those of E. notatus occurred mainly between September and October, near the end of the rainy season. Regarding the rhythm of migration and larval release in monthly time scale, C. carnifex exhibited a semilunar rhythm following the syzygies and E. notatus exhibited a lunar rhythm following the full moon. However, these rhythms did not occur with the maximum amplitude nocturnal and diurnal high tides. This implies that the lunar cycle is a more important environmental cue than the tidal amplitude in the entrainment of the synchronous monthly breeding rhythm for these two species. This pattern is different from other intertidal crabs, most of which use the tidal amplitude cycle as the main environmental cue for larval release. In addition to Chiromantes haematocheir (a supratidal crab), our study provided two more species that live in the supratidal zone time their reproduction with respect to the lunar light cycle and independent of the tide amplitude cycles. For the diel rhythm, both species migrated to the shore and released larvae in the first half of the night during the flood tide. This suggests that the diel light cycle is a dominant cue for the determination of larval release timing for these two species. Larval release does not track the high slack tides, since larvae are only released during the first half of the night and these high slack tides occur only after midnight (0000-0600H) during the days of larval release for these two crab species.

Increasing salinity stress decreases the thermal tolerance of amphibian tadpoles in coastal areas of Taiwan.

Global warming is the main cause for the rise of both global temperatures and sea-level, both major variables threatening biodiversity. Rising temperatures threaten to breach the thermal limits of organisms while rising sea-level threatens the osmotic balance of coastal animals through habitat salinization. However, variations in thermal tolerance under different salinity stresses have not yet been thoroughly studied. In this study, we assessed the critical thermal maxima (CTmax) of amphibian tadpoles in different salinity conditions. We collected tadpoles of Duttaphrynus melanostictus, Fejervarya limnocharis and Microhyla fissipes from coastal areas and housed them in freshwater, low, and high salinity treatments for 7 days of acclimation. The CTmax, survival rate, and development rate of tadpoles in high salinity treatments were significantly lower than that of the two other treatments. Our results indicate that physiological performances and heat tolerances of tadpoles are negatively affected by salinization. Maximum entropy models showed that CTmax and sea-level rise are predicted to negatively affect the distribution of the three focal species. The present results suggest that global warming can lead to negative dual-impacts on coastal animals because of reduced thermal tolerances at elevated salinity. The impacts of global warming on anurans in coastal areas and other habitats impacted by salinization may be more severe than predicted and it is likely to cause similar dual-impacts on other ectotherms.

An authentic inquiry-based laboratory module for introducing concepts about volatile-mediated communication resulted in stronger students' self-efficacy.

Volatile-mediated impacts of microbes on plants have aroused interest among scientists in the life science field. This study describes an inquiry-based laboratory module named "Microbial Talk", which related to microbial volatile-mediated communication, including the process of design, implementation, and assessment. First-year biology students in this course were allowed to complete authentic microbiology research using both typical experimental techniques and knowledge related to interspecies communication. The instructor provides continued guidance and support to ensure that students are aware of their knowledge and of the choices they encountered. Pretests and posttests were implemented to evaluate the efficacy of the "Microbial Talk" and the students' experimental design ability. Assessment of the module showed that students gained self-efficacy in executing experiments and interpreting data. In conclusion, this module is cost-effective and it can be used to help guide students in their future when they encounter situations that need these scientific skills.

Roosting Site Usage, Gregarious Roosting and Behavioral Interactions During Roost-assembly of Two Lycaenidae Butterflies.

Lycaenidae is one of the larger of the world's butterfly families, based on number and diversity of species, but knowledge of roosting in this group is sparse. Zizina otis riukuensis and Zizeeria maha okinawana are two small lycaenids that are commonly found in urban settings and widely distributed across much of Asia. We conducted experiments on a university campus to determine the plant species and plant structures commonly used by these two blues when roosting. We also tested the hypothesis that gregarious roosting exists in these two blues by demonstrating the non-random distribution of roosting blues and the tight mapping of their roosts to the spatial distribution of specific plant species and/or specific plant structures, as well as by demonstrating behavioral interactions among individuals during roosting-assembly. We found that both Z. otis and Z. maha roosted primarily on flowers and fruits of Tridax procumbens and Vernonia cinerea. We also found that these blues formed conspicuous roosting aggregations with significant positive associations between the flowers and fruits of both T. procumbens and V. cinerea and the blues. Moreover, our behavioral observations showed that these blues expressed various levels of interaction during roosting gatherings. Based on these findings, we conclude that gregarious roosting exists in both Z. otis and Z. maha. To our knowledge, this paper represents one of the first demonstration of nocturnal gregarious roosting in lycaenids. This study also highlights the importance of institutional estates in providing roosting resources for butterflies in urban ecosystems.

Novel inspection of sugar residue and origin in honey based on the 13C/12C isotopic ratio and protein content.

Regarding the honey industry, market prices are strongly affected by the origin and composition of products. In particular, the adulteration of honey can be divided into cases of honey being mixed with artificial syrup, the different origin of the adulteration and the presence of cane sugar residue. Unfortunately, recent studies mentioned that most honey is mixed with artificial syrups. Thus, determining such unnaturally present sugar is necessary to maintain the trust of the consuming populations. To investigate the possibility of syrup augmentation, this study first clarifies two points of great importance. First, long-term feeding of cane sugar to honey bee colonies in winter and the continuous harvest of honey were investigated to evaluate the C4 sugar ratio in spring through inspection of the 13C/12C isotopic ratio. As the results indicated, C4 sugar was detected as "sugar residue" in honey samples when the honey bee colonies were fed with cane sugar in winter and when the honey was collected in the first and second harvests in March. As indicated from the samples of 89 Taiwanese longan honeys, 54 Thai longan honeys, and 20 Taiwanese non-longan honeys for analysis, such "sugar residues" were in 40% (8/20) of the Taiwanese non-longan honeys, 15% (3/20) of 2017 Taiwanese longan honeys and 20% (4/20) of 2017 Thai longan honeys; these samples were classified as adulterated honey (C4% > 7). Second, as revealed in the honeys' protein contents, statistically significant differences were found between Taiwanese (>1.00 mg/g) and Thai longan honeys (<1.00 mg/g). Apparently, this significant difference could be used to classify the difference in origins of longan honeys. This novel inspection of "sugar residue" and "origin" in honey could represent the first attempt for a protocol to guarantee both the quality and quantity assurance of honey in the marketplace.

Regional scale high resolution δ18O prediction in precipitation using MODIS EVI.

The natural variation in stable water isotope ratio data, also known as water isoscape, is a spatiotemporal fingerprint and a powerful natural tracer that has been widely applied in disciplines as diverse as hydrology, paleoclimatology, ecology and forensic investigation. Although much effort has been devoted to developing a predictive water isoscape model, it remains a central challenge for scientists to generate high accuracy, fine scale spatiotemporal water isoscape prediction. Here we develop a novel approach of using the MODIS-EVI (the Moderate Resolution Imagining Spectroradiometer-Enhanced Vegetation Index), to predict δ(18)O in precipitation at the regional scale. Using a structural equation model, we show that the EVI and precipitated δ(18)O are highly correlated and thus the EVI is a good predictor of precipitated δ(18)O. We then test the predictability of our EVI-δ(18)O model and demonstrate that our approach can provide high accuracy with fine spatial (250×250 m) and temporal (16 days) scale δ(18)O predictions (annual and monthly predictabilities [r] are 0.96 and 0.80, respectively). We conclude the merging of the EVI and δ(18)O in precipitation can greatly extend the spatial and temporal data availability and thus enhance the applicability for both the EVI and water isoscape.

Using stable isotopes to unravel and predict the origins of great cormorants (Phalacrocorax carbo sinensis) overwintering at Kinmen.

The Food and Agricultural Organization of the United Nations and the World Organization for Animal Health have called for a better understanding of the role that migrating birds may play in spreading H5N1 highly pathogenic avian influenza (HPAI). Bird banding, traditionally used in studies of migration, is limited by low recapture rates. Telemetry can only be applied to larger species and a limited number of birds. We show that analyses of multiple stable isotopes (delta(13)C, delta(15)N, delta(18)O and deltaD) can provide an understanding of the number of breeding populations represented at large congregations of wintering birds, probable locations of these breeding populations, and which breeding populations do not contribute migrants to a wintering site. As Asia is thought to be the origin of many HPAI strains and the center of their evolution, and as bird migration is poorly understood in this part of the world, we recommend that, in addition to banding, satellite, and VHF telemetry, the stable isotope analysis of migration patterns should become a part of long-term surveillance studies.

Thermal acclimation of metabolic rate may be seasonally dependent in the subtropical anuran Latouche's frog (Rana latouchii, Boulenger).

We tested the hypothesis that the lack of metabolic thermal acclimation ability in tropical and subtropical amphibians is dependent on season and investigated the effects of body size, sex, time of day, and season on metabolic rates in Rana latouchii. The males were acclimated at 15 degrees, 20 degrees, and 25 degrees C, and their oxygen consumption was measured at 15 degrees, 20 degrees, 25 degrees, and 30 degrees C in all four seasons, with the exception that we did not measure oxygen consumption at 30 degrees C in winter frogs. We also acclimated the males at 30 degrees C in summer for investigating diel variation of metabolic rate. The females were acclimated at 20 degrees and 25 degrees C, and their oxygen consumption was measured at 15 degrees , 20 degrees , 25 degrees , and 30 degrees C in summer. Our results showed that metabolic rates of R. latouchii differed by time of day, season, and acclimation temperature but did not differ by sex if the results were adjusted for differences in body mass. Summer males exhibited a 26%-48% increase in metabolic rates from the lowest values in the seasons. There was a trend of increased oxygen consumption in cold-acclimated males, but it was significant only at 15 degrees and 25 degrees C in summer, autumn, and winter. These results support the hypothesis that thermal acclimation of metabolism is seasonally dependent, which has not been reported in other tropical and subtropical amphibians.