Nitric oxide action in the digestive fluid of Nepenthes × ventrata is linked to the modulation of ROS level.

Nepenthes are carnivorous plants with photoactive leaves converted into jug-shaped containers filled with the digestive fluid. The digestion requires various enzymes and reactive oxygen species (ROS) that facilitate proteolysis. Reactive nitrogen species are present in the digestive fluid of Nepenthes × ventrata, and the increased nitric oxide (NO) formation is associated with protein degradation. The aim of the work was to verify the beneficial effect of NO application into the trap on the dynamics of protein digestion and ROS homeostasis. Measurements were done using the digestive fluid or the tissue collected from the mature pitcher plants (fed) grown in a greenhouse. Two independent methods confirmed NO formation in the digestive fluid of fed and non-fed traps. NO supplementation with food into the trap accelerated protein degradation in the digestive fluid by increasing the proteolytic activity. NO modulated free radical formation (as the result of direct impact on NADPH oxidase), stimulated ROS scavenging capacity, increased -SH groups and flavonoids content, particularly at the beginning of the digestion. In non-fed traps, the relatively high level of protein nitration in the digestive fluid may prevent self-protein proteolysis. Whereas, after initiation of the digestion decreasing level of nitrated proteins in the fluid may indicate their accelerated degradation. Therefore, it can be assumed that NO exhibits a protective effect on the fluid and the trap tissue before digestion, while during digestion, NO is an accelerator of protein decomposition and the ROS balance keeper.

Carnivorous Nepenthes pitcher plants combine common developmental processes to make a complex epidermal trapping surface.

BACKGROUND AND AIMS: A hierarchical micro-topography of ridges and steps renders the trap rim of carnivorous Nepenthes pitcher plants unusually wettable, and slippery for insects when wet. This complex three-dimensional epidermis structure forms, hidden from plain sight, inside the still-closed developing pitcher bud. Here, we reveal the sequence of epidermal patterning events that shape the trap rim. By linking this sequence to externally visible markers of bud development, we provide a framework for targeting individual stages of surface development in future studies. METHODS: We used cryo-scanning electron microscopy to investigate the detailed morphogenesis and epidermal patterning of the Nepenthes x hookeriana pitcher rim. In addition, we collected morphometric and qualitative data from developing pitcher traps including those sampled for microscopy. KEY RESULTS: We identified three consecutive patterning events. First, strictly oriented cell divisions resulted in radially aligned rows of cells and established a macroscopic ridge-and-groove pattern. Next, conical papillate cells formed, and papillae elongated towards the trap interior, increasingly overlapping adjacent cells and eventually forming continuous microscopic ridges. In between these ridges, the flattened papillae formed acutely angled arched steps. Finally, the cells elongated radially, thereby establishing the convex collar shape of the rim. This general sequence of surface development also showed a spatial progression from the outer to the inner trap rim edge, with several consecutive developmental stages co-occurring at any given time. CONCLUSIONS: We demonstrate that the complex surface microtopography of the Nepenthes pitcher rim develops by sequentially combining widespread, evolutionarily conserved epidermal patterning processes in a new way. This makes the Nepenthes trap rim an excellent model for studying epidermal patterning mechanisms in leaves.

Expert assessment of illegal collecting impacts on Venus flytraps and priorities for research on illegal trade.

Illegal collecting of wild Venus flytraps (Dionaea muscipula) for the horticultural trade represents a persistent threat to populations of the species across their endemic range in the coastal plain of North and South Carolina (United States). Although wild collecting of Venus flytraps is not a novel threat, there has been very little research on the impacts of collecting on the species' conservation to date or why an illegal trade persists alongside a legal one. We drew on qualitative expert stakeholder elicitation to contextualize the threat of illegal collecting to the long-term conservation of Venus flytraps in relation to other anthropogenic threats. Expert elicitation included botanical and conservation researchers, cognizant state and federal agency staff, land managers, and conservation nonprofit actors. The workshop included mapping of supply chain structures and prioritization of social and environmental harms. Expert consensus determined illegal collecting is an ongoing problem for Venus flytrap conservation, but habitat destruction, degradation, and fire suppression are the most significant threats to flytrap conservation. Supply chain analysis showed that observable social and environmental harms of the trade are focused at the supply stage and that less is known about transit and demand stages. Key research gaps identified include a lack of understanding of plant laundering practices relevant to a range of desirable plant taxa; the role of commercial nurseries in illicit horticultural supply chains; motivations for engaging in Venus flytrap collecting; and the persistent demand for illegally harvested plants when cultivated, legally obtainable plants are readily available. Our findings and methodology are relevant to a range of ornamental plants affected by illegal trade for which robust social data on illegal collecting drivers are lacking.

Evaluación experta del impacto de la colecta ilegal de venus atrapamoscas y las prioridades de investigación sobre el mercado ilegal Resumen La colecta ilegal de venus atrapamoscas (Dionaea muscipula) silvestres para el mercado de horticultura representa una amenaza constante para las poblaciones de la especie a lo largo de su distribución endémica en la planicie costera de Carolina del Norte y del Sur, Estados Unidos. Aunque esta colecta no es una amenaza novedosa, a la fecha se ha investigado muy poco sobre su impacto en la conservación de la especie o por qué el mercado ilegal persiste a la par del legal. Partimos del conocimiento cualitativo de los actores expertos para contextualizar la amenaza de la colecta ilegal para la conservación a largo plazo de la venus atrapamoscas en relación con otras amenazas antropogénicas. Este conocimiento involucró a investigadores de la conservación y la botánica, personal consciente de agencias federales y estatales y actores de la conservación sin fines de lucro. El taller incluyó el mapeo de las estructuras de las cadenas de suministro y la priorización de los daños sociales y ambientales. El consenso de los expertos determinó que la colecta ilegal es un problema continuo para la conservación de la venus atrapamoscas, pero la destrucción y degradación del hábitat, así como la contención de incendios son las amenazas más significativas. El análisis de las cadenas de suministro mostró que los daños ambientales y sociales observables en el mercado se enfocan en la fase de suministro y que se sabe poco sobre las fases de tránsito y demanda. Los vacíos de investigación más importantes incluyen la falta de entendimiento de las prácticas de lavado de plantas relevantes para un rango de taxones deseables de plantas; el papel de los viveros comerciales en las cadenas de suministro de la horticultura ilícita; los motivos para participar en la colecta de venus atrapamoscas; y la demanda continua de plantas cosechadas ilegalmente cuando ya hay disponibilidad de plantas cultivadas que se obtienen legalmente. Nuestros descubrimientos y metodología son relevantes para una gama de plantas ornamentales afectadas por el mercado ilegal para las cuales hay carencia de datos sociales sólidos sobre los factores de colecta ilegal.

To Eat or Not to Eat: Novel Stable Isotope Models Reveal a Shift in Carnivory with Nutrient Availability for Aquatic Utricularia spp.

BACKGROUND AND AIMS: Freshwater nitrogen inputs are increasing globally, altering the structure and function of wetland ecosystems adapted to low nutrient conditions. Carnivorous wetland plants, Utricularia spp., are hypothesised to reduce their reliance on carnivory and increase their assimilation of environmental nutrients when the supply of ambient nutrients increases. Despite success in using stable isotope approaches to quantify carnivory of terrestrial carnivorous plants, quantifying carnivory of aquatic Utricularia requires improvement. METHODS: We developed stable isotope mixing models to quantify aquatic plant carnivory and used these models to measure dietary changes of three Utricularia species: Utricularia australis, U. gibba, and U. uliginosa in 11 wetlands across a 794 km gradient in eastern Australia. Diet was assessed using multiple models that compared variations in the natural abundance nitrogen isotope composition (δ15N) of Utricularia spp. with that of non-carnivorous plants, and environmental and carnivorous nitrogen sources. KEY RESULTS: Carnivory supplied 40 - 100 % of plant nitrogen. The lowest carnivory rates coincided with the highest availability of ammonium and dissolved organic carbon. CONCLUSIONS: Our findings suggest that Utricularia populations may adapt to high nutrient environments by shifting away from energetically costly carnivory. This has implications for species conservation as anthropogenic impacts continue to affect global wetland ecosystems.

Study of Altenia wagneriella (rebel) as a predator associated with Forda marginata from Iran.

BACKGROUND: The larvae of Altenia spp. and gall aphids are known to feed on plants related to Anacardiaceae. This study documents the aphidophagous habit of Altenia wagneriella, which was verified by molecular techniques, subsequently by the gut dissection test, and direct observation. MATERIALS AND METHODS: To identify the moth larvae and adult aphids, two mitochondrial genes, cytochrome c oxidase I (COI) and cytochrome b (Cytb), were amplified by polymerase chain reaction (PCR). Nested PCR with the aphid-specific primer pairs AphidF and AphidR was used to detect aphids in the body of moth larvae. The specificity of the primers was verified by PCR analysis of DNA from moth larvae and adult aphids. RESULTS: The method detected aphids in moth larvae, and a band of approximately 200 bp was amplified from moth larvae feeding on aphids. No cross reactions with moth larvae were observed. In the laboratory, all moth larvae feeding on aphids (Forda marginata) were also PCR positive for aphids. CONCLUSIONS: Gall-inducing insects are microhabitat engineers that manipulate their host to obtain a better nutrient supply, as well as protection from natural enemies and abiotic factors. This is the first recorded instance worldwide of the carnivorous larva of the moth A. wagneriella acting as an aphid predator, as well as the first record of a host insect for this species. Additionally, it is the first effort to molecularly analyze the predator-prey relationship between the moth larvae and the aphids inside the wild pistachio gall.

Density of a cryptic Australian small mammal: The threatened Julia Creek dunnart (Sminthopsis douglasi).

Globally, hundreds of mammal species face the threat of extinction in the coming decades, and in many cases, their ecology remains poorly understood. Fundamental ecological knowledge is crucial for effective conservation management of these species, but it is particularly lacking for small, cryptic mammals. The Julia Creek dunnart (Sminthopsis douglasi), a threatened, cryptic carnivorous marsupial that occurs in scattered populations in the central west of Queensland, Australia, was once so poorly studied that it was believed extinct. Sporadic research since its rediscovery in the early 1990s has revealed that S. douglasi is distributed across land at risk from many threats. Fundamental knowledge of S. douglasi population density is urgently required to inform conservation management at key sites, yet the species has historically proven hard to detect. Indeed, the status of the largest known population of S. douglasi, in Bladensburg National Park, is unknown. Here, we conducted a population study on S. douglasi at two sites within Bladensburg National Park via live mark-recapture surveys during 2022 and 2023. From likelihood-based spatially explicit capture-recapture (SECR) modelling we provide the first estimates of density and population size for S. douglasi. Live trapping resulted in captures of 49 individual S. douglasi (with 83 captures total, including recaptures). We estimated S. douglasi to occur at a density of 0.38 individuals ha-1 (0.25-0.58) at one site and 0.16 individuals ha-1 (0.09-0.27) at another site, with an estimated mean population size in suitable habitat at Bladensburg National Park of 1211 individuals (776-1646). Our S. douglasi density estimates were similar to that reported for other threatened small mammals in Australia. We also found evidence of extreme S. douglasi population fluctuations over time at Bladensburg National Park, which is of concern for its future conservation. Our study has provided the first estimate of density for S. douglasi, a threatened dasyurid species from the Mitchell Grass Downs of central western Queensland, Australia. Our research provides crucial population data to assist the management of this poorly studied species. We demonstrate a method that can be applied to species with low detection probability to ultimately help address the mammal extinction crisis faced by Australia and the rest of the world.

Cell Wall Microdomains in the External Glands of Utricularia dichotoma Traps.

The genus Utricularia (bladderworts) species are carnivorous plants that prey on invertebrates using traps with a high-speed suction mechanism. The outer trap surface is lined by dome-shaped glands responsible for secreting water in active traps. In terminal cells of these glands, the outer wall is differentiated into several layers, and even cell wall ingrowths are covered by new cell wall layers. Due to changes in the cell wall, these glands are excellent models for studying the specialization of cell walls (microdomains). The main aim of this study was to check if different cell wall layers have a different composition. Antibodies against arabinogalactan proteins (AGPs) were used, including JIM8, JIM13, JIM14, MAC207, and JIM4. The localization of the examined compounds was determined using immunohistochemistry techniques and immunogold labeling. Differences in composition were found between the primary cell wall and the cell secondary wall in terminal gland cells. The outermost layer of the cell wall of the terminal cell, which was cuticularized, was devoid of AGPs (JIM8, JIM14). In contrast, the secondary cell wall in terminal cells was rich in AGPs. AGPs localized with the JIM13, JIM8, and JIM14 epitopes occurred in wall ingrowths of pedestal cells. Our research supports the hypothesis of water secretion by the external glands.

In vitro evaluation of antiviral activity in carnivorous plant species.

Sarracenia purpurea is a carnivorous plant historically used to treat smallpox infections. Our previous data found S. purpurea had broad spectrum antiviral activity in vitro. S. purpurea is one of several hundred identified carnivorous species of plants. Carnivorous plants have evolved through convergent evolution in at least ten independent events, usually in response to harsh environments where nutrition from prey is required for growth. These prey are known vectors of plant viruses that might introduce novel biotic stressors and defense pathways in carnivorous plants. This study evaluated the antiviral activity of several non-carnivorous and carnivorous plants from four evolutionarily distinct clades. Results demonstrated that carnivorous plants have evolved antiviral activity, a trait that is not present in related species of non-carnivorous plants. The antiviral trait may be due to the plant-prey relationship with insect vectors and an evolutionary need for carnivorous plants to have more robust antiviral defense systems.

Do Arabinogalactan Proteins Occur in the Transfer Cells of Utricularia dichotoma?

Species in the genus Utricularia are carnivorous plants that prey on invertebrates using traps of leaf origin. The traps are equipped with numerous different glandular trichomes. Trichomes (quadrifids) produce digestive enzymes and absorb the products of prey digestion. The main aim of this study was to determine whether arabinogalactan proteins (AGPs) occur in the cell wall ingrowths in the quadrifid cells. Antibodies (JIM8, JIM13, JIM14, MAC207, and JIM4) that act against various groups of AGPs were used. AGP localization was determined using immunohistochemistry techniques and immunogold labeling. AGPs localized with the JIM13, JIM8, and JIM14 epitopes occurred in wall ingrowths of the pedestal cell, which may be related to the fact that AGPs regulate the formation of wall ingrowths but also, due to the patterning of the cell wall structure, affect symplastic transport. The presence of AGPs in the cell wall of terminal cells may be related to the presence of wall ingrowths, but processes also involve vesicle trafficking and membrane recycling, in which these proteins participate.

Respiratory paralysis in a patient with myasthenia gravis after ingestion of marine carnivorous gastropods: A case report.

The salivary glands of marine carnivorous gastropods contain tetramines, which usually cause mild symptoms of poisoning. However, these symptoms may be fatal in rare cases. A 58-year-old woman with a history of myasthenia gravis complained of dyspnea after consuming marine carnivorous gastropods with intact salivary glands. Upon arrival at the hospital, her blood gas analysis revealed type II respiratory failure with a pCO2 of 154 mmHg. Tracheal intubation was immediately performed. Her respiratory condition improved the following day, and she therefore could be weaned off the ventilator. Tetramine poisoning can be fatal for patients with certain underlying medical conditions.

Evaluating the carnivorous efficacy of Utricularia aurea (Lamiales: Lentibulariaceae) on the larval stages of Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti (Diptera: Culicidae).

The emergence of insecticide resistance in mosquitoes necessitates the exploration and validation of sustainable biological strategies for controlling mosquitoes in their natural habitats. We assessed the predatory effect of Utricularia aurea Lour (Lamiales: Lentibulariaceae), an aquatic carnivorous plant found in the Indian subcontinent, Japan, and Australia, on 4 instars of Anopheles stephensi Liston, Culex quinquefasciatus Say, and Aedes aegypti Linn (Diptera: Culicidae), in the laboratory and field settings. In the laboratory setting, predation of larvae by U. aurea was highest during the first hour when it predated 45%, 61%, and 58% of first instars of An. stephensi, Cx. quinquefasciatus, and, Ae. aegypti, respectively, and, within 12 h, U. aurea preyed upon ~95% of the first, second, and third instars of the 3 mosquito species, ~80% of the fourth instars of An. stephensi and Ae. aegypti, and ~60% of fourth instars of Cx. quinquefasciatus. The predatory effect of U. aurea varied with mosquito species and instar. Broadly, predation risk declined with the increase of the instar size. In the field setting, at the end of 16 days, U. aurea predated 76% and 71% of the immature An. stephensi and Ae. aegypti, respectively. Our findings suggest U. aurea can be utilized as a potential biocontrol agent for controlling mosquito larvae in natural habitats; however, the current claim warrants additional investigations in a variety of natural habitats.

An inquiline mosquito modulates microbial diversity and function in an aquatic microecosystem.

Understanding microbial roles in ecosystem function requires integrating microscopic processes into food webs. The carnivorous pitcher plant, Sarracenia purpurea, offers a tractable study system where diverse food webs of macroinvertebrates and microbes facilitate digestion of captured insect prey, releasing nutrients supporting the food web and host plant. However, how interactions between these macroinvertebrate and microbial communities contribute to ecosystem functions remains unclear. We examined the role of the pitcher plant mosquito, Wyeomyia smithii, in top-down control of the composition and function of pitcher plant microbial communities. Mosquito larval abundance was enriched or depleted across a natural population of S. purpurea pitchers over a 74-day field experiment. Bacterial community composition and microbial community function were characterized by 16S rRNA amplicon sequencing and profiling of carbon substrate use, bulk metabolic rate, hydrolytic enzyme activity, and macronutrient pools. Bacterial communities changed from pitcher opening to maturation, but larvae exerted minor effects on high-level taxonomic composition. Higher larval abundance was associated with lower diversity communities with distinct functions and elevated nitrogen availability. Treatment-independent clustering also supported roles for larvae in curating pitcher microbial communities through shifts in community diversity and function. These results demonstrate top-down control of microbial functions in an aquatic microecosystem.

Vulture poisoning in Sub-Saharan Africa and its implications for conservation planning: A systematic review.

The Old World Vultures (OWV), constituting 16 species primarily in Africa, Europe and Asia, are currently being driven to extinction mostly by anthropogenic activities, especially poisoning. The vulture losses from poisoning caused by human-related activities are en masse at a single mortality event-level and occur in complex social-ecological systems. There has been a growing body of knowledge on wildlife poisoning over the years. However, no review has been done to consolidate vulture poisoning studies in sub-Saharan Africa (SSA), with a social lens of conservation planning. Here we present a review of the vulture poisoning research by re-contextualizing the problem of vulture poisoning across SSA. We employed stepwise Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method to search for literature on vulture poisoning. The search yielded 211 studies which were trimmed to 55 after applying sets of eligibility criteria. Literature shows that efforts aimed at successful vulture conservation planning will require an understanding of the relational aspects of stakeholder social capital (assets) that are critical to the implementation of species recovery strategies. Strengthening relational social capital through multi-scale stakeholder evidence-based awareness creation and participation is necessary for addressing the African Vulture Crisis (AVC). Applying stakeholder social capital approaches to different vulture conservation scenarios at local, regional and international scales can enhance successful implementation of conservation strategies for the persistence of vultures in complex socio-ecological systems in African landscapes. Existing literature also showed the importance of stakeholder social capital as a countermeasure against vulture losses.

Distribution of Acetogenic Naphthoquinones in Droseraceae and Their Chemotaxonomic Utility.

Chemotaxonomy is the link between the state of the art in analytical chemistry and the systematic classification and phylogenetic analysis of biota. Although the characteristic secondary metabolites from diverse biotic sources have been used in pharmacology and biological systematics since the dawn of mankind, only comparatively recently established reproducible methods have allowed the precise identification and distinction of structurally similar compounds. Reliable, rapid screening methods like TLC (Thin Layer Chromatography) can be used to investigate sufficiently large numbers of samples for chemotaxonomic purposes. Using distribution patterns of mutually exclusive naphthoquinones, it is demonstrated in this review how a simple set of chemical data from a representative sample of closely related species in the sundew family (Droseraceae, Nepenthales) provides taxonomically and phylogenetically informative signal within the investigated group and beyond.

Do Cuticular Gaps Make It Possible to Study the Composition of the Cell Walls in the Glands of Drosophyllum lusitanicum?

Carnivorous plants can survive in poor habitats because they have the ability to attract, capture, and digest prey and absorb animal nutrients using modified organs that are equipped with glands. These glands have terminal cells with permeable cuticles. Cuticular discontinuities allow both secretion and endocytosis. In Drosophyllum lusitanicum, these emergences have glandular cells with cuticular discontinuities in the form of cuticular gaps. In this study, we determined whether these specific cuticular discontinuities were permeable enough to antibodies to show the occurrence of the cell wall polymers in the glands. Scanning transmission electron microscopy was used to show the structure of the cuticle. Fluorescence microscopy revealed the localization of the carbohydrate epitopes that are associated with the major cell wall polysaccharides and glycoproteins. We showed that Drosophyllum leaf epidermal cells have a continuous and well-developed cuticle, which helps the plant inhibit water loss and live in a dry environment. The cuticular gaps only partially allow us to study the composition of cell walls in the glands of Drosophyllum. We recoded arabinogalactan proteins, some homogalacturonans, and hemicelluloses. However, antibody penetration was only limited to the cell wall surface. The localization of the wall components in the cell wall ingrowths was missing. The use of enzymatic digestion improves the labeling of hemicelluloses in Drosophyllum glands.

As prey and pollinators, insects increase reproduction and allow for outcrossing in the carnivorous plant Dionaea muscipula.

PREMISE: Understanding the factors that limit reproductive success is a key component of plant biology. Carnivorous plants rely on insects as both nutrient sources and pollinators, providing a unique system for studying the effects of both resource and pollen limitation on plant reproduction. METHODS: We conducted a field experiment using wild-growing Dionaea muscipula J. Ellis (Droseraceae) in which we manipulated prey and pollen in a factorial design and measured flower production, number of fruits, and number of seeds. Because understanding reproduction requires knowledge of a plant species' reproductive and pollination biology, we also examined the pollination system, per-visit pollinator effectiveness, and pollen-ovule (P/O) ratio of D. muscipula. RESULTS: Plants that received supplemental prey produced more flowers than control plants. They also had a higher overall fitness estimate (number of flowers × fruit set (total fruits/total flowers) × seeds per fruit), although this benefit was significant only when prey supplementation occurred in the previous growing season. Neither pollen supplementation nor the interaction between pollen and prey supplementation significantly affected overall plant fitness. CONCLUSIONS: This study reinforces the reliance of D. muscipula on adequate prey capture for flower, fruit, and seed production and a mobile pollen vector for reproduction, indicating the importance of considering insects as part of an effective conservation management plan for this species.

Multilocus Phylogeny and Characterization of Five Undescribed Aquatic Carnivorous Fungi (Orbiliomycetes).

The diversity of nematode-trapping fungi (NTF) holds significant theoretical and practical implications in the study of adaptive evolution and the bio-control of harmful nematodes. However, compared to terrestrial ecosystems, research on aquatic NTF is still in its early stages. During a survey of NTF in six watersheds in Yunnan Province, China, we isolated 10 taxa from freshwater sediment. Subsequent identification based on morphological and multigene (ITS, TEF1-α, and RPB2) phylogenetic analyses inferred they belong to five new species within Arthrobotrys. This paper provides a detailed description of these five novel species (Arthrobotrys cibiensis, A. heihuiensis, A. jinshaensis, A. yangbiensis, and A. yangjiangensis), contributing novel insights for further research into the diversity of NTF and providing new material for the biological control of aquatic harmful nematodes. Additionally, future research directions concerning aquatic NTF are also discussed.

Ingestion of paralytic shellfish toxins in a carnivorous gastropod (Chorus giganteus): effects on their elemental composition and reproductive traits.

The producer of paralytic shellfish toxin (PST), Alexandrium catenella, is one of the main generators of HABs in the coasts of Chile. Its presence produces ecological and economic damage, directly affecting filter-feeding organisms, and indirectly to other organism through the trophic chain. The objective of this research was to identify the effect of a toxic diet on the energetic and reproductive parameters of the carnivorous snail Chorus giganteus. Two groups of snails were used, one fed with toxic prey (bivalves fed with A. catenella), and the other fed with non-toxic prey. Both treatments were maintained under these conditions for 63 days, then, elemental composition (C, N) and energy content were estimated, and fecundity parameters were analyzed. The results indicate that snails fed with toxic prey had a lower percentage of C and C/N ratio. The energy content was significantly lower in intoxicated snails. Regarding fecundity parameters, a higher number of egg-masses were produced by toxic snails, however, only 62% of these showed embryonic development, with 57% hatching success. A negative relationship was identified between the mean PST concentration, quantified in snails, and the number of egg-masses produced per aquarium. In the aquarium where the snails had highest average PST concentration (1200 ± 820 µg STX.2HCL eq. Kg-1) there was no oviposition, while egg-masses were only produced by snails in aquaria where the average concentration did not exceed 360 ± 160 µg STX.2HCL eq. Kg-1. It is likely that, with low levels of accumulated PST, C. giganteus activates its oviposition process as a response to toxin-induced stress, generating a higher energy expenditure supported by a redirection of its reserves. However, when the intoxication presents higher levels, the reproductive process could be inhibited, similar to what has been identified in other molluscs.

Is the co-option of jasmonate signalling for botanical carnivory a universal trait for all carnivorous plants?

The carnivorous plants in the order Caryophyllales co-opted jasmonate signalling from plant defence to botanical carnivory. However, carnivorous plants have at least 11 independent origins, and here we ask whether jasmonate signalling has been co-opted repeatedly in different evolutionary lineages. We experimentally wounded and fed the carnivorous plants Sarracenia purpurea (order Ericales), Cephalotus follicularis (order Oxalidales), Drosophyllum lusitanicum (order Caryophyllales), and measured electrical signals, phytohormone tissue level, and digestive enzymes activity. Coronatine was added exogenously to confirm the role of jasmonates in the induction of digestive process. Immunodetection of aspartic protease and proteomic analysis of digestive fluid was also performed. We found that prey capture induced accumulation of endogenous jasmonates only in D. lusitanicum, in accordance with increased enzyme activity after insect prey or coronatine application. In C. follicularis, the enzyme activity was constitutive while in S. purpurea was regulated by multiple factors. Several classes of digestive enzymes were identified in the digestive fluid of D. lusitanicum. Although carnivorous plants from different evolutionary lineages use the same digestive enzymes, the mechanism of their regulation differs. All investigated genera use jasmonates for their ancient role, defence, but jasmonate signalling has been co-opted for botanical carnivory only in some of them.