Herbivores Research Articles

Within-region differences in growth responses of an herbivorous coral reef fish to local and regional climatic processes

Within-region differences in growth responses of an herbivorous coral reef fish to local and regional climatic processes

Smooth and Time-Optimal Trajectory Planning for Robots Using Improved Carnivorous Plant Algorithm

To improve the safety and reliability of robotic manipulators during high-speed precision movements, this paper proposes a method for smooth and time-optimal trajectory planning incorporating kinodynamic constraints. The primary objective is to use an evolutionary algorithm to determine a trajectory by considering time and jerk within the feasible path-pseudo-velocity phase plane region. Firstly, the path parameterization theory extracted the maximum pseudo-velocity projection curve from the kinodynamic constraints. Subsequently, the feasible region in the phase plane was defined through reachability analysis of discrete linear systems. Thereafter, we constructed the trajectory function using a cubic B-spline curve, optimizing its control points with an improved carnivorous plant optimization algorithm. Finally, the effectiveness and practicality of this method were verified through simulations on a 6-DOF manipulator.

A biomimetic approach towards a universal slippery liquid infused surface coating.

One biomimetic approach to surface passivation involves a series of surface coatings based on the slick surfaces of carnivorous pitcher plants (Nepenthes), termed slippery liquid-infused porous surfaces (SLIPS). This study introduces a simplified method to produce SLIPS using a polydopamine (PDA) anchor layer, inspired by mussel adhesion. SLIPS layers were formed on cyclic olefin copolymer, silicon, and stainless steel substrates, by first growing a PDA film on each substrate. This was followed by a hydrophobic liquid anchor layer created by functionalizing the PDA film with a fluorinated thiol. Finally, perfluorodecalin was applied to the surface immediately prior to use. These biomimetic surface functionalization steps were confirmed by several complimentary surface analysis techniques. The wettability of each surface was probed with water contact angle measurements, while the chemical composition of the layer was determined by X-ray photoelectron spectroscopy. Finally, ordering of specific chemical groups within our PDA SLIPS layer was determined via sum frequency generation spectroscopy. The hemocompatibility of our new PDA-based SLIPS coating was then evaluated by tracking FXII activation, fibrin generation time, clot morphology, and platelet adhesion to the surface. This hemocompatibility work suggests that PDA SLIPS coatings slow or prevent clotting, but the observation of both FXII activation and the presence of adherent and activated platelets at the PDA SLIPS samples imply that this formulation of a SLIPS coating is not completely omniphobic.

Interactive Kinetic Facade with Design for Disassembly (DfD) strategy: improving energy efficiency and circularity of building materials in tropical climate

ABSTRACT Building is a significant contributor to energy and material consumption. In tropical countries, the primary energy consumer in buildings is Air Conditioning (AC), driven by the cooling load from solar radiation. Interactive Kinetic Facade (IKF) can reduce building energy consumption by mitigating solar radiation. Furthermore, IKF has drawbacks in maintenance and disassembly. Therefore, this study proposed a Design for Disassembly (DfD) strategy that allows building components to easily disassemble for reuse. The objective of this study was to investigate the application of IKF with DfD strategy in the Engineering Center (EC) building facade. This study proposed a combination of on-site measurements, simulations, and calculations to comprehend the impact of IKF with DfD strategy implementation on energy consumption and material reusability. This research found that implementing IKF with the DfD strategy can significantly reduce solar radiation through building facade. The reduction can be indicated by a decrease of several parameters, Overall Thermal Transfer Value (OTTV) by 59%, annual operative temperature by 2.53°C and Energy Use Intensity (EUI) by 47.43%. In addition, the facade disassembly process is simpler with only 1 tool and 4 stages. This study could serve as a reference to improve energy efficiency and material reusability in building sector.

Influences on Consumer Behaviour Regarding the Purchase Intention of Poultry Products

Objective: The objective of this study is to identify factors influencing effective purchasing behaviours in the context of poultry products. Theoretical Framework: The investigation into agricultural product purchases remains a relatively under-researched area within academic literature, particularly concerning detailed analyses of consumer behaviour. This study responds to the theoretical need raised by Pang et al. (2021) to apply their research methodology to different contexts. Method: The methodology adopted for this research was an online survey with a sample of 358 individuals in Colombia. The data analysis was carried out using Structural Equations Modelling with structures in variance. Results and Discussion: The results obtained revealed that aspects such as Trust, Corporate ability, Brand positioning, Consumer cognition and Health consciousness are crucial for consumers of these products. Research Implications: The practical and theoretical implications of this research are discussed indicate that aspects such as Trust, Corporate ability, Brand positioning, Consumer cognition and Health consciousness are crucial for consumers of these products. These factors are considered critical for consumers engaged in purchasing these types of products and provide substantive insights for the broader market of primary consumer goods. Originality/Value: The findings contribute to the scarce literature on consumer behaviour in agricultural product purchasing, offering a nuanced understanding of the determinants that drive consumer choices in this sector.

Leaving the niche: Recommendations for mainstreaming Low Trophic Aquaculture in countries around the Atlantic basin

Low Trophic Aquaculture (LTA) is the farming of aquatic organisms such as primary producers (e.g., seaweeds) and primary consumers (e.g. bivalves). Despite recognition as a key pathway to the provision of sustainable food from the oceans, many forms of LTA around the Atlantic basin remain in the niche stage of socio-technical evolution. With governance regarded as a limiting factor to LTA development, aquaculture experts and stakeholders were surveyed to find, and interviewed to document, examples of implemented good practice in rules, regulations and processes that were seen as supportive of the sustainable development of LTA and related Integrated Multi-Trophic Aquaculture. A theoretical framework on socio-technical change under polycentric governance informed an analysis of the good practices, according to five core themes: regulation and legislation; resources and infrastructure; human and social capital; financial instruments and economic support; and, the overarching socio-economic environment. Recommendations for action were constructed both inductively (from interview evidence) and deductively (from the theory), and were organised in relation to the three spheres of governance: Government should: provide stable policy and legal frameworks within which developers can operate with commercial confidence; ensure public trust in LTA products; support LTA start-ups; ensure availability of researchers and public officials with LTA relevant skills and knowledge. Market organisations should: allow LTA to better access financial capital and insurance; develop consultancy services; inform the public about LTA. Civil Society organisations, including universities, producer organisations and NGOs, should: in some cases, lead development of LTA with arrangements for local control; help certify appropriate LTA as sustainable, healthy and socially equitable.

Unraveling Community Potential Interactions by Environmental DNA in the Hong Kong Coastal Waters

ABSTRACTTraditional approaches for studying potential interactions in marine ecosystems often struggle to fully capture all taxa in a community, especially rare species. This issue is particularly challenging in coastal waters with high biodiversity and spatiotemporal dynamics. In this study, we employed environmental DNA (eDNA) metabarcoding, utilizing multiple marker genes, to comprehensively investigate interspecific interactions across various domains in the subtropical coastal waters of Hong Kong. The southern and eastern regions of Hong Kong waters exhibit distinct environmental seasonality, and our investigation focused on comparing the potential interaction networks and the keystone taxa between these two regions. The putative species interaction networks across various groups (i.e., bacteria, protists, and metazoans) were revealed by using weighted correlation network analysis (WGCNA). Our results showed that primary consumers, mainly dinoflagellates and ciliates, were the dominant actors within the interaction networks, although their distributions varied between the two regions. Bacterial taxa from the Pseudomonadota groups primarily constituted saprobes in the southern region, while exhibiting an even distribution in the eastern region. The interaction network in the southern region was larger but less stable compared to the eastern region. This could be attributed to the stronger responses of keystone taxa to environmental variations and the relatively higher number of connectors (e.g., Akashiwo and Protoperidinium within Dinophyceae) in the eastern region. Our findings highlight the versatility of eDNA metabarcoding for studying potential species interactions, providing critical insights into ecosystem structure and stability, and offering suggestions for marine biodiversity conservation.

Seagrass Tolerance to Simulated Herbivory Along a Latitudinal Gradient: Predicting the Potential Effects of Tropicalisation

ABSTRACTThe polewards range expansion of tropical herbivorous fish into temperate latitudes is leading to overgrazing of marine habitats and community phase shifts in some regions. Here, we test the potential effects of increased herbivory on the temperate habitat‐forming seagrass Posidonia australis. We used a series of simulated herbivory experiments to predict the potential impacts of climate‐mediated increases in seagrass consumption along P. australis entire latitudinal range (~9° latitude) in eastern Australia (1700 km of coastline). We subjected treatment plots to two levels of simulated herbivory (10% or 80% of leaves clipped) and compared them to unclipped controls. We measured seagrass leaf growth rates and tissue chemical traits: carbohydrates in rhizomes, leaf phenolics, and nutrients (carbon, nitrogen, and C:N ratio) in leaves and rhizomes. At the warmest range‐edge population, we also tested how responses to increased herbivory may vary between summer and winter, or with repeated clipping events. Clipped shoots maintained growth rates similar to unclipped controls despite losing up to 80% of leaf biomass. This was consistent along the full latitudinal range and after repeated simulated herbivory at the northernmost location. One‐off clipping events impacted plant architecture, increasing the number of subdividing shoots. At the species range edge, leaves grew more in winter than in summer, and clipping tended to lower seagrass growth only in winter; however, higher levels of shoot subdivision were produced over summer than in winter. Plant chemical traits could not explain consistently the growth patterns observed despite some traits varying with latitude (e.g., leaf nitrogen content decreased with latitude and C:N ratio increased) and/or simulated herbivory. Synthesis: P. australis growth is not affected by increases in simulated herbivory and may be relatively resilient to future increases in seagrass consumption, suggesting that this species could be a relative ‘winner’ under future climate change conditions that lead to enhanced herbivory.

Hormonal profiles in shoot apices in (sub)tropical populations of the aquatic carnivorous plant Aldrovanda vesiculosa in summer and winter

Hormonal profiles in shoot apices in (sub)tropical populations of the aquatic carnivorous plant Aldrovanda vesiculosa in summer and winter

Ethylhexyl triazone sunscreen and its disinfection byproducts obtained after chlorine treatment: Ecofriendliness or ecotoxicity?

In recent years, there has been a growing demand for high-quality sunscreens that combine high efficacy with ecological characteristics. This trend has led to an increased use of triazine compounds, which represent an emerging class of UV filters. While it is well-established that sunscreens can have significant environmental impacts, there is limited data on the degradation of triazine UV filters, despite available information on their environmental persistence, particularly in relation to disinfection processes. This study investigates the chemical fate of ethylhexyl triazone (EHT) under chlorination conditions, typical of swimming pools. Twelve disinfection byproducts (DBPs) were isolated and fully identified using nuclear magnetic resonance and mass spectrometry, with three of these byproducts being identified for the first time. DBP1–DBP12 were isolated at relative percentages of 1.26, 9.68, 1.05, 0.42, 0.84, 3.37, 3.58, 1.89, 0.84, 1.47, 0.42, and 0.63. Additionally, a mechanism for their formation was proposed. The ecotoxicological assessment of EHT and of byproducts (DBP1-DBP4) was conducted using acute, sub-chronic or chronic toxicity tests in producers and primary consumers of the freshwater trophic chain. The organisms included the alga Raphidocelis subcapitata, the rotifer Brachionus calyciflorus, the crustacean anostracan Thamnocephalus platyurus and the benthic ostracod Heterocypris incongruens. EHT caused a lethal median concentration in rotifers, with values in the range of tens of mg/L. EHT, DBP1, and DBP4 exhibited sub-chronic effects in ostracods at concentrations in the μg/L range, with EC50s of 210, 9, 20 μg/L, respectively. Rotifers were slightly affected by DBP3 with a chronic EC50 of 200 μg/L. Algae were not affected by either EHT or byproducts.

Lake Restoration Improved Ecosystem Maturity Through Regime Shifts—A Case Study of Lake Baiyangdian, China

Lake ecosystems are impacted by anthropogenic disturbances and have become vulnerable worldwide. Highly disturbed lake ecosystems are not well understood due to the lack of data on changes in the structures and functions of ecosystems. In this paper, we focus on Lake Baiyangdian (BYDL), the largest shallow lake in North China. Following the establishment of the Xiong’an New Area (XNA) in 2017, concerted efforts to restore BYDL’s aquatic environment have been undertaken, which has led to significant changes in the structures and functions of the ecosystems. We evaluated the biomass dynamics of main biological communities and detected the regime shifts of environmental factors in BYDL from 2016 to 2023. Further, we constructed a food web model for the BYDL ecosystem in 2023 by using Ecopath with Ecosim (EwE) and made a comparison with the reported results in 2018. The results showed significant changes in the ecosystem structure of BYDL over the last 6 years. In 2023, the submerged macrophytes biomass in the system increased by 4.2 times compared to 2018, leading to an increase in total system throughput. We found that BYDL changed from an algal-type lake to a macrophyte-dominated lake. In addition, we found TN, NH4+-N, and CODMn were significantly decreased in BYDL during the restoration. TN and NH4+-N had a change point in approximately 2021, indicating that a regime shift had occurred during restoration. Overall, the BYDL ecosystem was in an immature but developing state, as indicated by ecological network analysis indicators. Nutrient-loading reduction, hydrological regulation, and rational biomanipulation may be the potential driving factors of change in the BYDL ecosystem. We strongly recommend the timely harvesting of submerged macrophytes, the proliferation and release of herbivorous fishes, and the assessment of the ecological capacity of carnivorous fishes in the future ecological restoration of BYDL.

Anthropogenic extinctions explain most size and trophic mismatches between large mammalian primary consumers from Amazonian and African rainforests

Anthropogenic extinctions explain most size and trophic mismatches between large mammalian primary consumers from Amazonian and African rainforests

Bioresources of lake Mostovoye and ways of their rational use

The ichthyofauna of most water bodies in the Altai Krai is represented by low-value and slow-growing fish. Fish productivity is largely determined by the degree of exploitation of the reservoir and the form of organization of the fishery. Rational fishery in natural reservoirs should ensure the exploitation of the ecosystem of the reservoir as a single whole. Mostovoe Lake is located in the Zavyalovsky and Baevsky districts of the Altai Krai, is one of the largest freshwater lakes in the Altai Territory, belonging to the floodplain of the Kulunda River. The water in the reservoir is of the sulfate-chloride class of the first type, fully meets all fish farming requirements. The collection of ichthyological material was carried out by the method of control catches. The species composition and spatial distribution of fish were studied by setting a set of fixed gill nets in the reservoirs. Information on the size and age structure of populations, catches of the main commercial fish and crayfish in Mostovoe Lake is provided. The magnitude of the fishing effort and the assessment of the state of aquatic bioresources (ichthyofauna) in the reservoir were carried out using one of the expert assessment options — the point systems method. The ichthyofauna of Mostovoe Lake includes six species that are subject to commercial fishing: common pike, roach, silver carp, river perch, common carp (carp), and common pike perch. Of the commercial invertebrates, crayfish is caught. The indicators of the commercial stock and the recommended catch of bioresources in the reservoir were calculated. Recommendations for regulating fisheries based on ichthyological monitoring are proposed. A certain effect for stabilizing the structure of the ichthyocenosis of the reservoir can be made by fishery melioration: the introduction of herbivorous fish — white amur (Ctenopharyngodon idella) and silver carp (Hypophthalmichthys molitrix) for a more complete use of the food base of the lake — phytoplankton and macrophytes. It is necessary to continue monitoring studies of the lake’s winter oxygen regime.

Aligning Advances in Biodiesel Technology with the Needs of the Defense Community

The global transportation sector is transitioning towards renewable energy to combat climate change, with biodiesel playing a critical role. Significant research over the past decades has focused on enhancing biodiesel through novel feedstocks and production methods. The defense community, a major diesel consumer, is particularly interested in biodiesel to support national sustainability goals while also leveraging the benefits of the new technology, including the ability to produce biodiesel locally at the point of need. This paper sets out to review recent advances in biodiesel technology and aligning them with the needs of the defense communities. By doing so, this paper provides insight into the challenges, benefits, and technical feasibility for the two primary consumers of military diesel fuel—naval ships and ground vehicles. For naval applications, algae-based biodiesel shows promise due to its potential for local production near ports. Advances in genetic engineering and cultivation are crucial for increasing lipid content and reducing costs. Innovative methods such as microwave-assisted transesterification and artificial neural networks for optimization could further enhance economic viability. In military ground vehicles, locally produced biodiesel could sustain operations by minimizing supply chain dependencies. Efforts are ongoing to develop mobile production facilities and improve feedstock diversity and methanol-independent transesterification processes. Overall, advancements in biodiesel production from various feedstocks and innovative techniques are poised to significantly benefit the military sector, promoting sustainability and operational efficiency.

Exploring marine zooplankton dynamics through carbon stable isotope signatures in a recently marine submarine volcano

Submarine emissions of gases from hydrothermal vents alter the surrounding chemical environment, influencing species responses to the resulting environmental gradients. The 2011 underwater eruption of the Tagoro volcano off the coast of El Hierro in the Atlantic Ocean changed the physical and chemical conditions, impacting the distribution of pelagic fauna. Post-eruptive stages from 2013 to 2018 revealed changes in both benthic and pelagic communities, with continuous eruptions further affecting local carbon cycle through shifts in nutrient concentrations and isotopic composition. The lowest δ13C values in zooplanktonic primary consumers were found in areas directly influenced by the Tagoro submarine volcano. Although the mixing model results show that phytoplankton is the primary carbon source for copepods, contributing an average of 28.3% of their carbon, magmatic CO2 and seawater dissolved inorganic carbon each account for approximately 17–18%. The isotopic signatures reveal a gradient of enrichment in copepods, reflecting the influence of inorganic nutrient and gas emissions from the volcano's centre to its periphery within the marine ecosystem. This data is useful for understanding the worldwide significance of environmental stressors such as volcanic eruptions on marine organisms.

Characterizing the evolution of defense in a tripartite marine symbiosis using adaptive dynamics

Abstract The evolution and maintenance of symbiotic systems remains a fascinating puzzle. While the coevolutionary dynamics of bipartite (host–symbiont) systems are well-studied, the dynamics of more complex systems have only recently garnered attention with increasing technological advances. We model a tripartite system inspired by the marine symbiotic relationship between the alga Bryopsis sp., its intracellular defensive bacterial symbiont “Candidatus Endobryopsis kahalalidifaciens,” which produces a toxin that protects the alga against fish herbivores, and the sea-slug Elysia rufescens (Zan et al., 2019), which is not deterred by the toxin. We disentangle the role of selection on different actors within this system by investigating evolutionary scenarios where defense evolves as (i) a host-controlled trait that reduces algal reproductive ability; (ii) a symbiont-controlled trait that impacts symbiont transmission; and (iii) a trait jointly controlled by both host and symbiont. Optimal investment in defensive toxins varies based on the characteristics of the host, symbiont, and sea slug; and evolutionary trajectories are modulated by trade-off shape, i.e., a strongly decelerating trade-off between defense and symbiont transmission can drive symbiont diversification via evolutionary branching. Increasing slug herbivory reduces host investment in defense to favor reproduction, while symbiont investment in defense first declines and then increases as host density declines to the degree that horizontal symbiont transmission is no longer beneficial. Increasing vertical transmission selects for reduced defense by the host when it evolves as a jointly controlled trait, as a result of investment by the symbiont. Our theoretical exploration of the evolution of defensive symbiosis in scenarios involving interactions with multiple herbivores provides a first window into the origin and maintenance of the Bryopsis sp. system, and adds another piece to the puzzle of the evolution of symbiotic systems.

Nutritional thermal ecology: investigating the combined influence of temperature and nutrient availability on plant‐ectotherm trophic interactions

Many primary consumers in freshwater, marine and terrestrial systems are ectotherms (e.g. zooplankton and insects), whose metabolisms, and therefore nutritional demands, are modulated by temperature. Further, nutrient availability largely influences the quality of resources consumed by these organisms, and hence affects whether nutritional demands of consumers are fulfilled. From these considerations, a crucial question arises: how do temperature and nutrient availability together modulate trophodynamics at the basis of food webs? Addressing this question for zooplankton and insects is essential since these consumers are the most abundant metazoans on Earth, and they link primary production to higher trophic levels. Here, we synthesize the existing literature and offer avenues to guide future scientific endeavours. We highlight that the vast majority of studies on the combined influence of temperature and nutrient availability published to date focus on at least one of the following research topics: 1) metabolic requirements of ectotherms; 2) feeding behaviour; 3) eco‐evolutionary processes; and 4) trophodynamics. We pose that further advances in this field of research may provide a robust understanding of how modulations of consumer metabolic requirements and resource quality define consumer–producer interactions across marine, freshwater and terrestrial ecosystems. This research effort would enable to combine the fields of Ecological stoichiometry and of Metabolic theory of ecology, and create an integrated approach, which we propose to call Nutritional thermal ecology.

Компоненты сыворотки крови как индикатор состояния растительноядных рыб

The results of studies of total protein and its fractions, as well as aminotransferases of blood serum of pond herbivorous fish are presented. Studies allow us to assess the activity of aminotransferases (alanine and aspartate aminotransferases), the activity of which in the blood serum somehow characterizes the condition and /or degree of damage to some organs of fish. Seasonal and age dynamics, as well as sex differences of the studied parameters in fish, have been established. Sex differences in these indicators are most noticeable in fish aged 0+ to 2 years. The data obtained allow us to judge the specific protein status, which differs in species characteristics and variability depending on the habitat conditions of fish, which gives an idea of the level of the physiological state of fish when grown in modern fish farms, and also allows us to assess the quality of the environment surrounding fish.

Segmenting the Chinese New Energy Compact SUV Market: A Latent Class Analysis of Consumer Preferences

The burgeoning new energy vehicle (NEV) sector in China, particularly the compact SUV market, presents a dynamic landscape for consumer preferences and behaviors. This study employs a latent class analysis (LCA) to segment the Chinese new energy compact SUV market, aiming to identify distinct consumer groups with homogeneous preferences and behaviors. Utilizing a comprehensive dataset of 6,720 consumer samples sourced from a reliable automotive statistics website, the study delineates two primary consumer segments: "Luxury Brand Preference Buyers" and "Normal Brand Rejection Buyers." The findings reveal that the former segment exhibits a marked preference for luxury brands, and tends to make fewer purchases, predominantly in the last quarter of the year 2023. In contrast, the latter segment shows a strong preference for another luxury brand and a balanced distribution of purchase quantities throughout the year, with a clear rejection of normal brands. These insights are instrumental for NEV enterprises to develop targeted marketing strategies that cater to the specific needs and preferences of these consumer segments, thereby enhancing market share, consumer satisfaction, and loyalty.

Ups and downs: copepods reverse the near-body flow to cruise in the water column

Copepods are negatively buoyant organisms actively participating in large-scale vertical migrations as primary consumers in marine ecosystems. As such, these organisms need to overcome their own weight to swim upwards, incurring extra energy costs that are not offset by any mechanism intrinsic to drag-based propulsion. While copepod vertical migrations are well documented, it is still unclear how they achieve extensive upward cruising despite this limitation. In this study, we found suction to be a compensatory mechanism enhancing thrust in upward-swimming copepods. Using experimentally derived velocity and pressure fields, we observed that copepods pull water in front of them to generate sub-ambient pressure gradients when cruising upward, thereby inducing an upstream suction force to complement the thrust produced by the legs. Contrary to expectations that drag always dominates the leg recovery phase, we found that the upstream suction generates net thrust for about a third of the recovery stroke. In contrast, downward-swimming copepods push rather than pull on water and do not benefit from thrust-enhancing suction effects during the recovery stroke. Differences in the induced flows are associated with contrasting leg kinematics, indicating a response to the body orientation rather than a fixed effect. These results offer insights into an important swimming mechanism that can inform the role mesozooplankton play in biogenic hydrodynamic transport and its impact on marine biogeochemistry.