Shrimp Eggs Research Articles

Developmental toxicity of the neonicotinoid pesticide clothianidin to the larvae of the crustacean Decapoda, Penaeus vannamei

The developmental toxicity effects of neonicotinoid pesticides such as clothianidin have not been fully explored in agricultural applications. This is particularly noteworthy because such pesticides significantly impact the survival rates of invertebrates, with arthropod larvae being particularly vulnerable. This study aimed to address this research gap by specifically investigating the toxicological effects of clothianidin on the developmental stages of the larvae of the economically important aquaculture species Penaeus vannamei. In these experiments, shrimp eggs were exposed to seawater containing different concentrations of clothianidin beginning at N1, and each phase was observed and analyzed to determine its toxic impact on larval development. These results revealed that clothianidin induces an increase in deformity rates and triggers abnormal cell apoptosis. It also significantly reduced survival rates and markedly decreased body length and heart rate in the later stages of larval development (P3). Transcriptomic analysis revealed disruptions in larval DNA integrity, protein synthesis, and signal transduction caused by clothianidin. To survive prolonged exposure, larvae may attempt to maintain their viability by repairing cell structures and enhancing signal transduction mechanisms. This study offers the first empirical evidence of the toxicity of clothianidin to arthropod larvae, underscoring the impact of environmental pollution on aquatic health.

Programmable spin and transport of a living shrimp egg through photoacoustic pressure.

In the fields of biomedicine and microfluidics, the non-contact capture, manipulation, and spin of micro-particles hold great importance. In this study, we propose a programmable non-contact manipulation technique that utilizes photoacoustic effect to spin and transport living shrimp eggs. By directing a modulated pulsed laser toward a liquid-covered stainless-steel membrane, we can excite patterned Lamb waves within the membrane. These Lamb waves occur at the interface between the membrane and the liquid, enabling the manipulation of nearby particles. Experimental results demonstrate the successful capture, spin, and transport of shrimp eggs in diameter of 220 µm over a distance of about 5 mm. Calculations indicate that the acoustic radiation force and torque generated by our photoacoustic manipulation system are more than 299.5 nN and 41.0 nN·mm, respectively. The system surpasses traditional optical tweezers in terms of force and traditional acoustic tweezers in terms of flexibility. Consequently, this non-contact manipulation system significantly expands the possibilities for applications in various fields, including embryo screening, cell manipulation, and microfluidics.

Evaluation of Black Soldier Fly Hermetia illucens as Food for Pink-Spotted Lady Beetle Coleomegilla maculata.

The discovery of new and improved factitious and artificial diets is necessary for cost-effective rearing of predatory arthropods. This study evaluated Hermetia illucens black soldier fly (BSF) as a suitable alternative food source for rearing the predatory coccinellid Coleomegilla maculata (Cmac). The hypothesis that BSF larval powder was suitable food to support the growth, development, and reproduction of Cmac was tested in the laboratory. When compared to a standard in-house diet containing brine shrimp egg powder plus Chlorella vulgaris green algae and myristic acid (BSE+CM), the BSF and BSF+CM diets reduced immature growth and development. Immatures successfully reared to teneral adults were smaller when fed BSF or BSF+CM rather than BSE+CM. Combining BSF with a powdered artificial diet (AD), i.e., BSF+AD, did not improve predator growth or development, compared to Cmac reared on BSE+CM. Cmac oviposition responses, i.e., egg clutch production, to BSF vs. BSE+CM or BSF+AD vs. BSE+CM did not differ significantly. In conclusion, BSF has the potential to be food that supports Cmac oviposition behavior. Future research is necessary to discover an ideal mixture of BSF, BSE+CM, or AD that supports Cmac growth, development, and reproduction over multiple generations.

Preparation of Ocimum Sanctum-Based Hydrogel and Evaluation of Its Cytotoxicity: An In Vitro Study.

While traditional periodontal treatments like scaling and root planing, antibiotics, and surgical intervention remain the primary approaches, herbal medicine is continuously evolving as an alternative for the management of periodontal diseases. This study focused on the evaluation of the cytotoxicity of Ocimum sanctum (OS)-based hydrogel for its use in local drug deliveryin periodontitis. OS-based hydrogel was prepared using 50 g of OS powder and 200 ml of ethanol, along with carboxymethyl cellulose gel and sorbitol. The prepared formulation was evaluated for its cytotoxicity by using the MTT assay, cell viability, cell morphology, and brine shrimp egg assessment. Cell viability was assessed, and it was above 95% for the control and 85% for the OS hydrogel by the 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide assay. Brine shrimp egg assessment also showed a survival rate of 80% at low concentrations. The cell morphology test showed round and uniform cells growing in a monolayer shape. The findings of this study confirmed that OS-based hydrogel is cytocompatible and, hence, can be used as a local drug delivery agent for periodontitis management, especially in resource-constrained settings where affordable and natural treatment options are highly valued.

Biological investigation of sonochemically synthesized CZTS nanoparticles

Cu2ZnSnS4 (CZTS) nanoparticles (NPs) are synthesized by sonochemical technique. The composition analysis showed the synthesized NPs to be stoichiometric. The X-ray diffraction confirms the CZTS phase and tetragonal unit cell structure. Three peaks corresponding to CZTS have been observed in Raman spectroscopy positioned at 293.47 cm−1, 373.8 cm−1, and 336.67 cm−1. The electron diffraction in the selected area showed faded rings with spot patterns indicating crystalline nature. The CZTS NPs have a direct optical bandgap of 1.62 eV, being ascertained by optical absorbance spectroscopy. The CZTS NPs antibacterial activity is determined against pathogenic gram-negative (E. coli, P. aeruginosa, P. vulgaris, and E. aerogenes) and gram-positive (S. aureus) bacteria by measuring the inhibition zone. The 2, 2-diphenyl-1-picrylhydrazyl assay is employed in deciding the antioxidant efficacy of CZTS NPs. The cytotoxicity of CZTS NPs is evaluated in Brine shrimp (Artemia salina) eggs hatched in synthetic seawater made from 38 g/l commercial sea salt. The findings are discussed in detail.

Pacific white shrimp (Litopenaeus vannamei) vitelline membrane outer layer protein 1 (VMO1) is produced in the hepatopancreas and transported into ovarian oocytes during vitellogenesis

In birds, vitelline membrane outer layer protein 1 (VMO1) is an exogenous protein that can be absorbed by eggs as a barrier to prevent the mixing of yolk and egg white. However, researches on VMO1 are limited in birds but not other non-avian species until now. In this study, we first identified a novel Vmo1 cDNA (Lv-Vmo1) in Pacific white shrimp (Litopenaeus vannamei), the most important cultured shrimp in the world. We further analyzed its gene organization, phylogenetic relationship and protein structure. The Lv-Vmo1 transcript was specifically expressed in the hepatopancreas without sexual dimorphism. During ovarian development in female, the hepatopancreatic Lv-Vmo1 mRNA levels showed a significant increase. By in situ hybridization, Lv-Vmo1 mRNA was present in three cell types of the hepatopancreas but neither oocytes nor follicle cells of the ovary. In contrast, immunofluorescence revealed that Lv-VMO1 protein was distributed in the cytoplasms of both hepatopancreatic cells and ovarian oocytes. Western blot showed that Lv-VMO1 protein was produced in the hepatopancreas and transported to the ovary via hemolymph circulation. Identification of a species-specific egg-entry guide protein is the key to the receptor-mediated ovarian transduction of cargo, a novel gene editing approach in oviparous animals. This study lays the mechanism for exogenous transport into penaeid shrimp eggs by VMO1, as a foundation for achieving exogenous protein-mediated incorporation into oocytes.

Analyses of biosynthesized silver nanoparticles produced from strawberry fruit pomace extracts in terms of biocompatibility, cytotoxicity, antioxidant ability, photodegradation, and in-silico studies

Numerous disciplines, including biology and materials science, are using nanoparticle engineering. Silver nanoparticles (AgNPs) are produced from strawberry pomace extracts using cutting-edge technology. Biosynthesized nanoparticles were examined for their formation, shape, crystallinity, and size at the nanoscale using a variety of spectral techniques, such as UV-vis absorption spectra, X-raypowder diffraction (XRD), scanning, transmission electron microscopy (SEM/TEM), and their associated techniques like energy-dispersive X-ray (EDX or EDS), and selective area electron diffraction (SAED). AgNPs formation was observed by the surface plasmon resonance (SPR) observation at 431 nm, which was caused by the collective oscillation of the silver nanoparticles' free electrons. AgNPs were confirmed by EDX, showing a distribution of elements and having a distinct peak at 3.0 keV. Thermogravimetric analysis (TGA) was utilized to evaluate the thermal stability of NPs in a nitrogen atmosphere.Spectrophotometry was utilized to investigate the photocatalytic degradation of methyl orange employing biogenic NPs as nanocatalysts. The solution's decolonization revealed that the dye degrades gradually with longer exposure times. Antioxidant capability was evaluated using the stable free radical 2,2-Diphenyl-1-picrylhydrazyl (DPPH). Additionally, testing for biocompatibility and toxicity employing brine shrimps and red blood cells, respectively, revealed remarkable hemocompatibility with RBCs and no observable toxicity to brine shrimps at lower AgNPs concentrations. Additionally, the active amino acids involved in brine shrimp egg hatching were identified using molecular docking of silver nanoparticles against serine protease. Moreover, to look into non-bonding interactions with the amino acids of the enzyme that can inhibit cyst hatching and healthy growth of brine shrimp napuli.

The earliest known brood care in insects.

Brood care enhances offspring fitness and survival by providing protection or feeding through parents (commonly by females). It has evolved independently multiple times in animals, e.g. mammals, birds, dinosaurs and arthropods, especially various lineages of insects, and has significant implications for understanding the emergence of sociality of insects. However, few fossil insects document such an ephemeral behaviour directly. New exceptional fossils of the water boatman Karataviella popovi from the Middle-Late Jurassic Daohugou biota (ca 163.5 Ma, northeastern China), with adult females bearing clutches of eggs on their left mesotibia, provide a unique brooding strategy (asymmetric egg-carrying behaviour) unknown in all extinct and extant insects. Our discovery represents the earliest direct evidence of brood care among insects, pushing back by more than 38 million years, indicating that relevant adaptations associated with maternal investment of insects can be traced back to at least the Middle-Late Jurassic, and highlighting the existence of diverse brooding strategies in Mesozoic insects. In addition, our discovery reveals that a specialized trawl-like filter-capture apparatus of K. popovi probably represents pre-adaptions originally used for trapping coeval anostracan (fairy shrimp) eggs for food.

3D Acoustic Manipulation of Living Cells and Organisms Based On 2D Array.

Flexible manipulation techniques for living cells and organisms are extremely useful tools for fundamental biomedical and life science research. Acoustic tweezers, which permit non-contact, label-free manipulation, are particularly suited to micromanipulation tasks as they provide a large acoustic radiation force and can be applied in various media. Here, we describe the design and fabrication of a 3 MHz, 64-element (8 × 8), 2D planar ultrasound array that realizes the multidimensional translation, rotation, orientation, and levitation of living cells and organisms. The focusing vortex and twin fields are generated using the holographic acoustic elements framework method. We demonstrate that the eggs and larvae of brine shrimp can be translated along a preset trajectory by controlling the central position of the vortex. By multiplexing counterclockwise vortices, clockwise vortices, and twin trap fields in a time sequence, the rotation direction of the shrimp eggs can be switched in real time, while non-spherical larvae can be reoriented. Moreover, the reflection of the acoustic beam can lift eggs and larvae from the bottom of the culture dish and further manipulate them in the vertical and horizontal directions. Additionally, we present quantitative analyses of the shrimp-egg rotation frequency with respect to the focal depths, topological charges of the vortex, and excitation voltages. These results indicate that acoustic tweezers based on 2D matrix arrays can realize complex and selective manipulation of living cells and organisms, thereby demonstrating their value for advancing research in the fields of cell assembly, tissue engineering, and micro-robot driving.

Basic Studies Aiming at Orius minutus (Hemiptera: Anthocoridae) Mass-Rearing.

Simple SummaryThe rapid growth of the biocontrol market is increasing the research into the usefulness of native natural enemies. For the commercial use of native natural enemies, economical mass-rearing technology must be developed. This study was conducted to establish a mass-rearing technique for improving the usability of Orius minutus in Korea. This species uses plants for moisture intake, nutritional supplementation, and oviposition substrates. However, the use of plants in mass production systems significantly increases the cost of production. Eggs of stored grain insect pests used as food in rearing Orius spp., are the most nutritionally balanced food source, but their high market price necessitates the selection of an economical food source to replace them. In this study, Ephestia cautella eggs and iron-coated brine shrimp eggs were selected as diet, and cork sheets were selected as an artificial oviposition substrate to obtain basic data for establishing a plant-free rearing system. The plant-free model developed in our study can reduce rearing costs by 70.5% compared to the conventional mass-rearing model.This study presented biological and economic data for the mass-rearing of Orius minutus in Korea. Simplifying the mass-rearing process through an alternative diet and an artificial oviposition substrate is a prerequisite for enhancing the usability of this insect as a biological control agent. We compare the hatch rate of O. minutus eggs deposited on a plant substrate with that of eggs deposited on two artificial substrates, cork sheets and rubber. The results indicate that cork sheet is the most cost-effective artificial oviposition substrate for the mass-rearing of O. minutus. We also examine five feeding treatments that included two types of brine shrimp eggs and eggs of Ephestia cautella to compare the number of eggs laid in the fifth generation. We found no significant difference between the two treatment groups; 61.3 eggs were laid in the treatment group fed iron-coated brine shrimp and moth eggs, and 67.4 eggs were laid in the control group. The plant-free model developed in our study can reduce rearing costs by 70.5% compared to the conventional mass-rearing model.

Stevia and Peppermint Herbal Formulation Based Mouthwash and Its Efficacy in Antimicrobial and Cytotoxic Activities

Background: Dental caries is a condition induced by the microbial fermentation of dietary carbohydrates in the biofilm that is connected to the teeth, which results in the disintegration of local chemical surfaces of the teeth. The predominant microbial pathogen in the aetiology of caries is Streptococcus mutans. Caries can be avoided by brushing and flossing regularly, as well as using antimicrobial mouthwash.
 Aim: The aim of the study is to prepare the Stevia and Peppermint formulation mouthwash and evaluate the antimicrobial property and cytotoxic effect of the formulated mouthwash at varying concentrations.
 Materials and Methods: A herbal mouthwash consisting of Stevia and Peppermint as the chief ingredients was prepared in the laboratory and its antimicrobial activity of various concentrations (25 µL, 50 µL,100 µL) against S. mutans, S. aureus, E. faecalis, C. albicans were tested by the agar well diffusion method. The cytotoxic activity of the prepared herbal mouthwash was checked using lethality of the nauplii which hatched from brine shrimp eggs, which was inoculated for over 24 hours. The results obtained were statistically analysed using IBM SPSS software and the results interpreted in graphs and tables.
 Results: The antimicrobial activity of prepared mouthwash against different microorganisms at 25 µL was significantly lesser than the standard but there was a concentration dependent increase in the antimicrobial property. The cytotoxic effect of formulated mouthwash was found to be within limits at all concentrations. At low concentration the cytotoxic effect was found to be negligible and the cytotoxic effect also had a concentration dependent increase.
 Conclusion: The formulated Stevia and Peppermint mouthwash was ound to have effective antimicrobial properties and negligible cytotoxic effect. The antimicrobial property against different microorganisms at 25 µL is significantly less than the standard but the antimicrobial property increases as the concentration increases

Biocompatible CuInS2 Nanoparticles as Potential Antimicrobial, Antioxidant, and Cytotoxic Agents.

A simple hydrothermal route is employed to synthesize pure copper indium disulfide (CIS) and CIS nanoparticles (NPs) mediated by various natural plant extracts. The plant extracts used to mediate are Azadirachta indica (neem), Ocimum sanctum (basil), Cocos nucifera (coconut), Aloe vera (aloe), and Curcuma longa (turmeric). The tetragonal unit cell structure of as-synthesized NPs is confirmed by X-ray diffraction. The analysis by energy-dispersive X-rays shows that all the samples are near-stoichiometric. The morphologies of the NPs are confirmed by high-resolution scanning and transmission modes of electron microscopy. The thermal stability of the synthesized NPs is determined by thermogravimetric analysis. The optical energy band gap is determined from the absorption spectra using Tauc’s equation. The antimicrobial activity analysis and the estimation of the minimum inhibitory concentration (MIC) value of the samples are performed for Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Enterobacter aerogenes, and Staphylococcus aureus pathogens. It shows that the aloe-mediated CIS NPs possess a broad inhibitory spectrum. The best inhibitory effect is observed against S. aureus, whereas the least effect was exhibited against P. vulgaris. The least MIC value is found for aloe-mediated CIS NPs (0.300 mg/mL) against S. aureus, P. aeruginosa, and E. aerogenes, along with basil-mediated NPs against E. coli. The antioxidant activity study showed that the IC50 value to inhibit the scavenging activity is maximum for the control (vitamin C) and minimum for pure CIS NPs. The in vivo cytotoxicity study using brine shrimp eggs shows that the pure CIS NPs are more lethal to brine shrimp than the natural extract-mediated CIS NPs. The in vitro cytotoxicity study using the human lung carcinoma cell line (A549) shows that the IC50 value of turmeric extract-mediated CIS NPs is minimum (15.62 ± 1.58 μg/mL). This observation reveals that turmeric extract-mediated CIS NPs are the most potent in terms of cytotoxicity toward the A549 cell line.

Shrimp egg counting with fully convolutional regression network and generative adversarial network

Accurate egg counting is the basic demand in the hatcheries of the aquaculture. However, the time-consuming, fallible manual counting is now still adopted in most situations. Also, many traditional automatic egg counting methods cannot provide enough high efficiency and accuracy, especially in densely-distributed cases. In this paper, we propose a novel convolutional neural network (CNN) based method for shrimp egg counting. Compared to traditional methods mainly based on contour detection or image segmentation, the proposed method exploits the density map regression and is more efficient in densely-distributed case even with severe occlusion. Firstly, a new dataset of the redclaw crayfish Cherax quadricarinatus eggs is collected, which includes 450 images with about 272,000 eggs annotated accurately. Also, a synthetic dataset generation method based on generative adversarial network (GAN) is proposed to avoid the onerous manual labeling, and has potential applications in the supervised learning for the densely-distributed eggs or larvae counting. Then, considering the advantages of no manual preprocessing and fine-grained feature extraction in CNNs, a shrimp egg counting network (SECNet) based on fully convolutional regression network (FCRN) is proposed to realize the counting through regressing the input image into its density map. The test results show the average counting accuracy of the proposed SECNet can be up to 99.2 % when the SECNet is pre-trained on the synthetic dataset and finetuned on the collected dataset. Finally, a simple and cheap computer vision based counting setup is built by using three off-the-shelf devices and a convenient operation program integrated with the SECNet is developed for a person computer, which provides an accurate, real-time, and highly-efficient egg counting way.

Simplified insecticide toxicity determination method for Nesidiocoris tenuis using contaminated diet

Nesidiocoris tenuis is a zoophytophagous mirid bug widely studied for its role in preying on major greenhouse pests. Since N. tenuis has now been known for its vigorous predation potential on pests such as Bemisia tabaci, many applied entomologists are now recommending that N. tenuis be merged into the Integrated Pest management (IPM) systems. However, successful integration of N. tenuis into any IPM system depends on thorough evaluation with compatible pesticides, as incompatible pesticides can offset the whole idea of IPM. Here, we simulate the field situation where N. tenuis feeds directly on a contaminated B. tabaci nymph or leaves. However, instead of using live B. tabaci nymphs, we used brine shrimp eggs, Artemia salina (Linnaeus, 1758). Brine shrimp eggs have been reported to be an excellent factitious supplementary diet in augmenting N. tenuis populations. Thus, we use brine shrimp eggs to determine the toxicity of pesticides, to which the calculated mortality rates can be used to determine which pesticides can be used together with N. tenuis in an IPM system against any related pest.•We developed a customized containment system that promotes aeration and minimize contamination.•Pesticide contaminated hatched brine shrimp eggs is delivered to N. tenuis in the aerated containment system.•In addition to established methods such as leaf dipping or insect dipping, this method shows to mimic N. tenuis feeding on contaminated B. tabaci nymphs in field conditions thus, predicts how a pesticide may be of toxic or compatible with N. tenuis when both are integrated together.

Experimental brine shrimp (Artemia Salina) lethality assay to evaluate the drug incompatibility on combined administration of Kakamachi (Solanum nigrum) and Madhu (honey)

Background: Drug incompatibility is one of the major causes of adverse drug reaction (ADR) or drug-induced toxicity in Ayurveda. In fact, this science has given special importance to such drug-induced issues and grouped them under the concept of Viruddha (drug incompatibility) and provided many measures to avoid them in clinical practice; one such example is a combination of fruits of Kakamachi (Solanum nigrum [SN]) and honey. The toxicity of this combination was not assessed; thus, the present study was planned to assess the toxic effect of the combined administration of fruits of Kakamachi and honey on brine shrimp lethality assay. Aims: To evaluate the brine shrimp lethality activity of the combined drug administration of fruits of Kakamachi and honey. Materials and Methods: Authentic brine shrimp eggs were laboratory cultured in artificially prepared saline sea water, and hatched brine shrimp nauplii were subjected to different concentrations of the combination to evaluate the LC50 and lethality assay. Results and conclusion: The study demonstrated that LC50 of fruit powder of SN and honey has shown potential cytotoxic effects at a dose of 0.57 mg on brine shrimp nauplii.

Possible climate-induced environmental impacts on parasite-infection rates of northern shrimp Pandalus borealis eggs in the Gulf of Maine.

The Gulf of Maine northern shrimp Pandalus borealis population once supported a significant commercial winter fishery for the New England states. However, the fishery has been on moratorium since 2014 due to consecutive recruitment failures. The issue of parasite-infected eggs, so-called 'white eggs,' has long been identified for the Gulf of Maine northern shrimp, which makes shrimp eggs nonviable and subsequently hampers the recruitment potential. Furthermore, the proportion of infected females was observed to increase with water temperature. As Gulf of Maine temperatures have been increasing for decades, it is important to re-visit issues related to white eggs to evaluate possible impacts of climate-induced environmental changes on the white egg infection rates. We used biological samples collected by the Northeast Fisheries Science Center in 2012-2016 to evaluate the probability that a female shrimp was infected (Pinf) and the proportion of white eggs in an infected female shrimp (pwe). Although Pinf was high, with an average of 73.81% over the Gulf of Maine, pwe was mostly <5%. The variation in both Pinf and pwe examined in this study was not well explained by environmental factors or female body size. However, the average rates of both Pinf and pwe observed in this study were higher than those observed in the 1960s when the bottom temperatures were cooler. The results can be used to account for egg mortality and provide information on potential impacts of possible climate-induced variability on shrimp population dynamics.

Composite of carbonyl iron particles and brine shrimp egg shell-derived porous carbon with excellent microwave absorption properties

Currently, the requirements of excellent comprehensive properties and high economic returns for microwave absorbers remain severe challenges for practical application of these materials. Herein, a composite of carbonyl iron particles (CIP) and bio-derived carbon was synthesized for microwave absorption for the first time. Brine shrimp egg shells (BSES) were chosen as the carbon precursor because the innate multilayer porous structure favours enhancing the microwave absorbing (MA) performance by inducing geometrical effect. Not only does the as-fabricated CIP/C composite exhibit outstanding MA properties, but the method is also facile and eco-friendly. Owing to the unique layered porous structure of BSES-derived carbon, well-matched complex permittivity and permeability together with the synergy of dielectric and magnetic loss, the composite displayed a remarkable reflection loss of − 55.4 dB at 13.0 GHz and a broad effective absorption bandwidth of 5.0 GHz with a thickness of only 1.5 mm, which is superior to those of most reported Fe/C composites, especially in thickness and effective absorption bandwidth. Hence, there are reasons to believe that the as-prepared CIP/C composite may have a bright prospect for practical application in civilian life and industry as an efficient MA material.

Acoustic tweezers and motor for living cells

Acoustic waves can act as tweezers to trap and rotate particles without contact, which have promising application in the manipulation of tissues and living cells. Here, we report a realization of acoustic tweezers and motor. The device is fabricated on a silicon chip scaled to manipulate living cells. The silicon chip transfers incident plane ultrasonic waves into a vortex beam, which traps particles in the center of the device and exerts torque on the particles simultaneously. As an illustration, we put living shrimp eggs inside the acoustic vortex and observe the acoustic driving rotation. The rotation frequency of the shrimp egg can be easily controlled, and its relationship between driving voltage and the egg size is established. We anticipate that the acoustic tweezers and motor can find widespread applications in cell manipulation, cell screening, and micro actuator in the future.

In search of floating algae and other organisms in global oceans and lakes

Surface floating macroalgae, microalgae, and other marine and freshwater organisms have been reported in many specific regions around the globe. However, it is technically challenging to identify similar occurrences, or other types of floating organisms or materials, within the vast global oceans and lakes. In this study, we address this challenge through combining global-scale, 375-m resolution false-colored Red-Green-Blue (FRGB) imagery from the Visible Infrared Imaging Radiometer Suite (VIIRS) in NOAA's online Ocean Color Viewer (OCView) for visual inspection and data from several other satellite sensors for spectral diagnostics. In the FRGB imagery, the near-infrared (NIR) band (862 nm) is used as the green channel, which is sensitive to floating algae and organisms/materials on the water surface. Visual inspection of the daily FRGB VIIRS imagery from January 2018 to October 2019 reveals the appearance of various slicks with different colors in many ocean regions and lakes. Combined with spectral diagnostics of the quasi-concurrent Sentinel-3A/3B Ocean and Land Colour Instrument (OLCI) and other higher spatial resolution satellite data as well as knowledge of local oceanography/limnology, most of these elongated or diffuse image features can be identified as Ulva, Sargassum, Noctiluca, Trichodesmium, Microcystis, oil slicks, or pumice rafts. Some of these identified features are found in regions where such occurrences have never been reported before. Some features are of unknown type as they have not been reported previously from remote sensing. In such cases, contemporaneous scientific literature and news reports as well as spectral diagnostics allow for educated inferences to be made. One example is from surface features in the northern Gulf of Maine, Bay of Fundy, and Southwest of Nova Scotia between early June and early July of 2019. Spectral shapes of the FRGB image features indicate transparent materials lacking pigments. Knowledge of local fisheries oceanography and frequent news reports all suggest that these unknown image features may be aggregations or blooms of sea jellies and, to a lesser extent, salps. Another example is from the Great Salt Lake, where image features in the south arm of the lake are speculated to be caused by aggregations of brine shrimp eggs. Once confirmed from field sightings, these findings may represent a milestone in satellite remote sensing because previously remote sensing could only be used to infer oceanographic environments conducive to sea jellies or shrimps. In addition to the findings presented here, the approach in this study may serve as a template to discover various known and unknown types of floating algae and organisms/materials as well as to routinely monitor and track their distributions and movements.

Productivity of Neoseiulus bicaudus (Acari: Phytoseiidae) Reared on Natural Prey, Alternative Prey, and Artificial Diet.

The predatory mite, Neoseiulus bicaudus (Wainstein), is a potential biological control agent against spider mites and thrips. The objective of this experiment was to compare the effects of three diets on the life table of N. bicaudus. The three diets were 1) Tetranychus turkestani (Ugarov & Nikolskii) (Acari: Tetranychidae), the natural prey of N. bicaudus; 2) Tyrophagus putrescentiae (Schrank) (Acari: Acaridae), an alternative prey; and 3) artificial diet primarily consisting of decapsulated shrimp cysts, egg yolk, and honey. The computer simulation was used to project the population growth of N. bicaudus fed on different diets. The preadult developmental time (3.83 d) of N. bicaudus was shortest, and the intrinsic rate of increase (r = 0.2782 d-1) and the net reproductive rate (R0 = 18.98 offspring) were highest when reared on the alternative prey Ty. putrescentiae. The total development time (7.37 d) was longest, and the population parameters were the lowest (r = -0.0081 d-1, R0 = 0.85 offspring) when N. bicaudus was reared on artificial diet. The population projection showed that the population of N. bicaudus reared on Ty. putrescentiae could increase fast. Our results showed that the Ty. putrescentiae was the most suitable prey for mass rearing of N. bicaudus. The artificial diet could not support the N. bicaudus population and needs to be improved.