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Prolonged marine heat waves are a major manifestation of climate change, threatening marine biodiversity. Using the Mytilus galloprovincialis mussel as a sentinel organism, we investigated the impact of experimental, prolonged high temperatures as expected in 2050 on byssus-producing organ. We demonstrated that 30 days exposure at 28 °C, alters molecular and functional properties of mussel foot. Results revealed severe downregulation in the synthesis of the proximal, distal and non-gradient pre-collagen byssus components. The stressed mussels produced less than half the number of byssus filaments compared to the control. Byssus threads showed reduced mechanical resistance to traction, with a 55% decrease in maximum force. At the organism’s health status level, a long-term collapse in heat shock protein 70 subspecies expression suggests energy depletion. This is confirmed by a reduction of the hepatosomatic index during exposure and by the physiological impairment with clearance rate reduction and loss of air exposure tolerance. These effects compromise the mussel’s substrate adhesion, increasing the risk of detachment but also threaten bivalve survival. The potential consequences at the ecological level could be severe, including a reduction in coastal biodiversity, in the ecosystem services provided by these animals, as well as risks to the sustainability of Mediterranean mussel farming.

Seagrasses inhabiting the intertidal zone experience periodically repeated cycles of air exposure and rehydration. However, little is known about the photoprotective mechanisms in photosystem (PS)II and PSI, as well as changes in carbon utilization upon air exposure. The photoprotective processes upon air exposure in Halophila beccarii Asch., an endangered seagrass species, were examined using the Dual-PAM-100 and non-invasive micro-test technology. The results showed that air exposure enhanced non-photochemical quenching (NPQ) in both PSII and PSI, with a maximum increase in NPQ and Y(ND) (which represents the fraction of overall P700 that is oxidized in a given state) of 23 and 57%, respectively, resulting in intensive thermal energy dissipation of excess optical energy. Moreover, cyclic electron transport driven by PSI (CEF) was upregulated, reflected by a 50 and 22% increase in CEF and maximum electron transport rate in PSI to compensate for the abolished linear electron transport with significant decreases in pmf LEF (the proton motive force [pmf]) attributable solely to proton translocation by linear electron flow [LEF]). Additionally, H + fluxes in mesophyll cells decreased steadily with increased air exposure time, exhibiting a maximum decrease of six-fold, indicating air exposure modified carbon utilization by decreasing the proton pump influxes. These findings indicate that efficient heat dissipation and CEF confer daily air exposure tolerance to the intertidal seagrass H. beccarii and provide new insights into the photoprotective mechanisms of intertidal seagrasses. This study also helps explain the extensive distribution of H. beccarii in intertidal zones.

Transposable elements (TEs) are mobile genetic elements that exist in the host genome and exert considerable influence on the evolution of the host genome. Since crustaceans, including decapoda, are considered ideal models for studying the relationship between adaptive evolution and TEs, TEs were identified and classified in the genomes of eight decapoda species and one diplostraca species (as the outgroup) using two strategies, namely homology-based annotation and de novo annotation. The statistics and classification of TEs showed that their proportion in the genome and their taxonomic composition in decapoda were different. Moreover, correlation analysis and transcriptome data demonstrated that there were more PIF-Harbinger TEs in the genomes of Eriocheir sinensis and Scylla paramamosain, and the expression patterns of PIF-Harbingers were significantly altered under air exposure stress conditions. These results signaled that PIF-Harbingers expanded in the genome of E. sinensis and S. paramamosain and might be related to their air exposure tolerance levels. Meanwhile, sequence alignment revealed that some Jockey-like sequences (JLSs) with high similarity to specific regions of the White spot syndrome virus (WSSV) genome existed in all eight decapod species. At the same time, phylogenetic comparison exposed that the phylogenetic tree constructed by JLSs was not in agreement with that of the species tree, and the distribution of each branch was significantly different. The abovementioned results signaled that these WSSV-specific JLSs might transfer horizontally and contribute to the emergence of WSSV. This study accumulated data for expanding research on TEs in decapod species and also provided new insights and future direction for the breeding of stress-resistant and disease-resistant crab breeds.

The original objective was to explore the potential benefiting effects of three prebiotics in hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀). Therefore, three experimental diets (basal diet + 1% fructooligosaccharide, Diet F; basal diet + 1% inulin, Diet I; basal diet + 0.3% mannan-oligosaccharide, Diet M) and one basal diet (Diet C) were prepared and a feeding trial was conducted. However, at the end of the fourth week into the feeding experiment, a water-leaking accident occurred and fishes of all groups went through an unexpected air exposure event. Surprisingly, different prebiotic-supplemented groups showed significantly different air exposure tolerance: the mortality of M group was significantly lower (P ≤ 0.05) than all the other groups. Examination of antioxidant, non-specific immunity, and stress parameters revealed that comparing to control group, M group showed significantly increased catalase (CAT), acid phosphatase (ACP), and alkaline phosphatase (AKP) activities, decreased superoxide dismutase (SOD) activity, and similar cortisol level (P ≤ 0.05). Real-time PCR experiment revealed that M group significantly increased the expression of CAT, glutathione peroxidase (GPx), and manganese superoxide dismutase (MnSOD) genes in head kidney (P ≤ 0.05). Overall, M exhibited the best anti-air exposure/antioxidative stress effects among the three prebiotics and could be considered a promising feed additive to relieve air exposure/oxidative stress in hybrid grouper culture.

Sublethal exposure to an insecticide may alter insect feeding, mating, oviposition, fecundity, development, and many other life history parameters. Such effects may have population-level consequences that are not apparent in traditional dose-mortality evaluations. Earlier, we found that a routinely used combination insecticide that includes a pyrethroid and a neonicotinoid (Temprid® SC) had deleterious effects on multiple bed bug (Cimex lectularius, L.) behaviors. Here, we demonstrate that sublethal exposure impacts physiology and reproduction as well. We report that sublethal exposure to Temprid SC has variable aberrant effects on bed bugs depending on the strain, including: a reduction in male mating success and delayed oviposition by females. However, after sublethal exposure, egg hatch rate consistently declined in every strain tested, anywhere from 34%-73%. Conversely, impact on fifth instar eclosion time was not significant. While the strains that we tested varied in their respective magnitude of sublethal effects, taken together, these effects could reduce bed bug population growth. These changes in bed bug behavior and fecundity could lead to improved efficacy of Temprid SC in the field, but recovery of impacted bugs must be considered in future studies. Sublethal effects should not be overlooked when evaluating insecticide efficacy, as it is likely that other products may also have indirect effects on population dynamics that could either aid or inhibit successful management of pest populations.

Animal movement is a key process that connects and maintains populations on the landscape, yet for most species, we do not understand how intrinsic and extrinsic factors interact to influence individual movement behavior. Land‐use/land‐cover changes highlight that connectivity among populations will depend upon an individual's ability to traverse habitats, which may vary as a result of habitat permeability, individual condition, or a combination of these factors. We examined the effects of intrinsic (body size) and extrinsic (habitat type) factors on desiccation tolerance, movement, and orientation in three anuran species (American toads, Anaxyrus americanus; northern leopard frogs, Lithobates pipiens; and Blanchard's cricket frogs, Acris blanchardi) using laboratory and field studies to connect the effects of susceptibility to desiccation, size, and movement behavior in single‐habitat types and at habitat edges. Smaller anurans were more vulnerable to desiccation, particularly for species that metamorphose at relatively small sizes. Habitat type had the strongest effect on movement, while body size had more situational and species‐specific effects on movement. We found that individuals moved the farthest in habitat types that, when given the choice, they oriented away from, suggesting that these habitats are less favorable and could represent barriers to movement. Overall, our work demonstrated that differences in habitat type had strong impacts on individual movement behavior and influenced choices at habitat edges. By integrating intrinsic and extrinsic factors into our study, we provided evidence that population connectivity may be influenced not only by the habitat matrix but also by the condition of the individuals leaving the habitat patch. We examined the effects of intrinsic (body size) and extrinsic (habitat type) factors on desiccation tolerance, movement, and orientation in three anuran species using a combination of laboratory desiccation trials and field studies to disentangle the individual and combined effects of these factors on movement. Habitat type had the strongest effect on movement, while body size had more situational and species‐specific effects on movement. We found that the habitats that most individuals oriented away from were the ones in which that same species moved the farthest, suggesting that this habitat is less favorable and could represent a barrier for movement.

Recently, mass mortality affected the cultured small abalone, Haliotis diversicolor diversicolor, which was the dominant cultured abalone species in southern China. Prior studies revealed that survivorship varied significantly between different stocks and crosses. However, the immunological basis for differences in susceptibility has not been well understood to date. Herein, low temperature, air exposure tolerance tests, and pull-off force measurement were assessed in the three groups (Japan, Taiwan, and their Hybrid stock). The results showed that the critical thermal minimum (CTMin) at 50% was 15.6 °C for the Taiwan stock, 12.1 °C for the Japan stock, and 13.2 °C for the Hybrid stock. Upon air exposure challenge, 100% abalones from the Taiwan group died after 8 h at 24 °C, while the survival rate in the Japan and Hybrid groups were 37.8% and 29.4%, respectively. The detachment stress for the Japan group was 42.3 kPa, which was 2.78-fold and 1.43-fold higher compared to the Taiwan and Hybrid groups, respectively. Variation in susceptibility to disease may be based on the effectiveness of the innate immune responses. Therefore, total hemocyte count, phagocytosis, respiratory burst, superoxide dismutase activity, acid phosphatase activity, alkaline phosphatase activity, and myeloperoxidase activity were determined for the healthy abalones in each group. Positive mid-parent heterosis on immunological parameters was consistent with the prior knowledge on the positive mid-parent heterosis for survival rate, which indicated the improvement on immune reaction and disease resistance through hybridization methods. The current study will be useful in efficient design of breeding programs for the development of sustainable abalone aquaculture.

Tolerance for acute ammonia exposure, defined to exist between NOEC (no observed effect concentration) and LOEC (lowest observed effect concentration), was validated in seven exposure experiments with Atlantic cod larvae from 15 to 63 days post-hatch, corresponding to larval sizes of 0.2 to 4.9 mg dry weight, respectively. LOEC was found in the range of 0.019–0.082 mg L−1 NH3-N, with corresponding NOECs of 0.013–0.045 mg L−1 NH3-N. Cod larvae of 1.0 and 1.7 mg dry weight (33 and 42 days after hatching) were found to be most sensitive and had the highest mortality to acute ammonia exposure, indicating ontogenetic changes in ammonia tolerance. The results suggest that specific care needs to be taken in designing and monitoring rearing systems, particularly recirculation systems, for toxic ammonia levels regarding larval rearing of Atlantic cod.

Temperature, salinity, and aerial exposure tolerances of the invasive green mussel, Perna viridis, were investigated under environmentally realistic conditions to address potential competition with native oysters, Crassostrea virginica. This study demonstrated that green mussels exhibit a temperature tolerance range similar to that of its native range (13–30 °C), thereby limiting northern spread of south Florida populations. Salinity tolerances as low as 6 were observed during gradual decreases; however, acute changes resulted in low survival at salinities of 15 and below. At low salinities, even when survival was high, reductions in normal behavior (byssal production and valve closure) were observed. Green mussel survival was significantly inhibited during aerial exposure across all temperatures, and mortality synergistically increased (60–80 %) with increasing temperatures and exposure time. In contrast, oysters demonstrated ≥97 % survival over the exposure period at similar internal temperatures observed in green mussels. Internal temperatures for both species frequently exceeded 33 °C, reaching temperatures as high as 41 °C, while air temperatures averaged only 26.4 ± 1.6 °C. Our results suggest that while Florida green mussel populations exhibit relatively broad temperature and salinity ranges, their spread is limited by the available subtidal habitat, potentially sparing intertidal oyster reefs from habitat and nutrient competition.

The exotic Chinese mystery snail ( Cipangopaludina chinensis malleata ) has invaded lakes and rivers across North America and is particularly widespread in northern Wisconsin. Although deliberate introductions and aquarium releases have likely been important, recreational boats may speed the spread of this snail into lakes. Prior research indicated boater access to be a significant predictor of invasion by C. chinensis and other invasive species in Wisconsin. To mimic the process of boater transport between lakes, I examined the tolerance of juvenile C.   chinensis to air exposure in a series of field and laboratory experiments. Field experiments under mesic conditions indicated that this snail can survive exposure to air for at least 4 weeks. Larger juveniles were more resistant than smaller juveniles, an effect that was also observed in the laboratory during short-term (3–14 days) experiments. Tolerance of small juveniles to air exposure appeared to be unaffected by temperature, but was affected by humidity, with higher survival at 64% than 34% relative humidity (RH). Results from the current study suggest that C.   chinensis is highly resistant to air exposure and could be readily transported by boats moving between lakes, particularly in cool mesic environments. Since juvenile C. chinensis are common around the roots of emergent macrophytes, hitchhiking with boats should be particularly common with boats or trailers infested with aquatic plants.