Broad Diet Research Articles

Transcriptomics and Metabolomics Explain the Crisping Mechanisms of Broad Bean-Based Crisping Diets on Nile Tilapia (Orechromis niloticus)

Background/Objectives: To investigate the crisping mechanism of broad bean-based crisping diets on Nile Tilapia. Methods: Four crisping diets were designed to feed 360 fish for 90 days, and multiomics analyses were employed. Results: Our results indicated that the designed crisping diets for Nile tilapia can effectively make tilapia muscle crispy. The ingestion of broad bean-based diets induced metabolic reprogramming dominated by glycolytic metabolism inhibition in fish, and metabolic reprogramming is the initiator of muscle structural remodeling. Among these, glucose is the main DAMP to be recognized by cellular PRRs, activating further immune response and oxidative stress and finally resulting in muscle change. Conclusions: Based on our results of multiomics, pck2, and ldh played main roles in crisping molecular mechanisms in driving the initial metabolic reprogram. Moreover, the addition of the crisping package further activated the ErbB signaling pathway and downstream MAPK signaling pathway to strengthen immune response, promoting muscle fiber development and growth. Our study delved into the effects of crisping formula diet on the liver of Nile tilapia at the molecular level, providing theoretical guidance for the nutritional regulation of crispy Nile tilapia.

The relationship between body size and diet breadth in non‐web building spiders

Abstract The handling hypothesis assumes that large animals have broader diets than small animals because small animals are restricted to small prey while large animals can handle both small and large prey. On the other hand, the optimal foraging hypothesis assumes no relationship between predator body size and diet breadth because large predators should shift from small prey to large prey to maximize the net energy intake. Using the diets and body sizes of 89 non‐web building spider species obtained from public databases (World Spider Trait database, Spiders of Europe and World Spider Catalogue), we investigated the relationship between body size and diet breadth in this group of terrestrial arthropod predators. We found that the taxonomic niche diet breadth measured by Hill numbers (i.e., prey richness, Shannon index of diversity and Simpson index of equitability) had no significant relationship with spider body size. The minimum prey size did not show any relationship with spider body size. On the other hand, mean, maximum, range and variability in prey size increased with spider body size. The results provide support for both hypotheses. The pattern in prey taxonomic dimension supports the optimal foraging hypothesis, while the pattern in prey size dimension supports the handling hypothesis. Overall, the observed distinct patterns between the taxonomic and prey size niche axes can be caused by the fact that the non‐web building spiders utilize similar prey types that are however highly size‐structured.

Prey availability and diet composition of the Grey plover (Pluvialis squatarola) during migration on the South-Western Black Sea coast, Bulgaria

Migratory waders use stopover sites to refuel for the next stages of their migration, relying on seasonally abundant prey. Migration success depends on food quality and availability at these key sites. We studied the diet composition and preferences of the Grey Plover (Pluvialis squatarola) at its migration stopover at Pomorie Lake on the South-Western Black Sea coast, Bulgaria through DNA metabarcoding of faeces collected in autumn 2020 and spring 2021. Prey availability samples were also collected from the surf zone and the supralittoral sandy shore habitats in the study area.Grey Plover had a broad diet spectrum, with 332 prey taxa in total identified by metabarcoding. Both terrestrial and marine taxa were found, suggesting that the birds use multiple coastal habitats for foraging. Terrestrial arthropods, particularly insects, predominated in the Grey Plover diet; mytilid bivalves were the most represented marine taxon. The birds had a generalist feeding strategy, with diverse prey items eaten in small quantities. Most Grey Plovers fed on insects (Diptera, Lepidoptera, Hymenoptera), but some individuals showed specialisation for other taxa (mussels, spiders, polychaetes). The most abundant potential prey in the environment were not the most frequently consumed, but it is possible the prey sampling failed to capture the whole spectrum of available prey due to methodological limitations.We found no significant seasonal variation in Grey Plover diet composition, but the proportions of some prey taxa in the diet changed slightly, probably reflecting seasonal differences in their abundance and activity in coastal habitats.Our results contribute to the knowledge of Grey Plover diet, prey choice and habitat use in a little-studied region, and could help design effective conservation measures to preserve habitat quality at stopover sites for this wader and others with similar ecology.

A glimpse into daily life in an Ottoman harbour: Evidence from a cesspit in Ainos (Türkiye)

The daily life of non-elite people from the past is usually hard to evaluate, since historical sources largely concentrate on the upper classes. This knowledge can be gained by archaeological excavations and use of geo- and bioarchaeological methods. In 2021, geophysical prospections in Enez (Türkiye) revealed a circular stone structure. The excavators identified a latrine probably used from 17th until the 19th century. Palynological, palaeoparasitological and archaeobotanical methods have been applied for understanding the diet, hygiene and diseases of the people using the latrine. The cesspit was a closed round structure with walls made of stones. It had no contamination from outside and was filled with liquid or semi-liquid content with dissolved salts and organic matter derived from urine, faeces, kitchen waste, dung and other rubbish. Results show a broad diet including wheat, chili peppers, olives, spices, a wide range of fruits, meat, fish and oysters. This sanitation did not protect the inhabitants of the house from intestinal parasites in the forms of helminths whipworm, roundworm and the protozoan Giardia duodenalis that causes diarrhoea. The data highlight the special role played by the harbour of Ainos in the establishment and possible expansion of new food products from the New World.

Quantifying the importance of ontogeny and prey type in modeling top-down and bottom-up effects of an ectothermic predator

Dietary decisions by predators can affect prey abundance and overall food web dynamics. Many predators do not forage on the same prey at the same frequency throughout their lives. Ontogenetic shifts in prey preference are not, however, often accounted for when modeling food web relationships, despite growing literature that suggests that stage specific dietary relationships may be an important consideration when modeling trophic interactions. We investigated the importance of considering size-structure of a predator population with ontogenetic diet shifts in evaluating relationships with prey response using a manipulative experiment with the brown treesnake (Boiga irregularis) in Guam. After removing ~ 40% of the snake population via toxic mammal carrion, we measured the strength of the relationship between snake density and the response of two types of prey (lizards and mammals). We evaluated these relationships based on total population size or division of the population into stage specific size categories based on diet preference predictions. We hypothesized that the density of juvenile snakes would correlate more strongly with lizard detections, while adult snakes would better correlate to rodent detections. We also measured reproductive output following changes in rates of prey detection. As expected by known ontogenetic shifts in dietary preference, explicit stage-based models better predicted shifts in rates of observed prey items than did total predator density for both lizards and mammals. Additionally, rodent detections were predictive of one reproductive pulse from snakes, while lizard detections were not predictive or correlated. Our findings support that consideration of predatory species stage-based dietary preference can be meaningful for understanding food web dynamics, particularly when a predator has a broad diet or one that changes through time.

The ecological roles of the European rabbit in the Magellanic/Fuegian ecosystem of southernmost Chile

The European rabbit has invaded numerous ecosystems worldwide, but rarely steppes. Since its various introduction attempts into the ecosystems of the Magallanes/Fuegian region, the rabbit has become a key player, interacting with species at different trophic levels and generating impacts on ecosystems. To better understand the role of the rabbit in steppe and scrub ecosystems, we characterised the food web in the Magallanes/Fuegian region to understand the identity of their interacting species, the mechanisms and complexities of their interactions to demonstrate that rabbit management may become more complex than just controlling a single species. Based on a bibliographic review and wildlife specialists’ opinions, we built the Magellanic/Fuegian food web, evaluated their topological properties and performed a rabbit extinction simulation to assess the possible short-term ecological mechanisms operating in the community. We found that the network had 206 nodes (64% native, 13% exotic, and 22% mixed) and 535 links among nodes. The European rabbit was the most connected node of the food web, had the second largest dietary breadth, and ranked as the seventh prey item with more predators. A rabbit extinction simulation shows a possible release of herbivory pressure on plants, including that on several native plants (e.g., Gunnera tinctoria, Pratia repens, Gavilea lutea, Tetroncium magellanicus), and a possible release of competition for some herbivores that share resources with the rabbit (e.g., Ovis aries, Lama guanicoe, Bos taurus). Although rabbit predators have a broad and generalist diet, some such as the native Galicitis cuja, could face a 20% reduction in their trophic width and could intensify predation on alternative prey. These results show that the European rabbit is strongly embedded in the Magellanic/Fuegian ecosystem and linked to several native species. Therefore, rabbit management should consider ecosystem approaches accompanied by monitoring programs on native fauna and experimental pilot studies on native flora to conserve the Chilean Patagonia community.

Functional Characterization of an Odorant Receptor Expressed in Newly Hatched Larvae of Fall Armyworm Spodoptera frugiperda.

In the past decade, Spodoptera frugiperda has emerged as a significant invasive pest globally, posing a serious threat to agriculture due to its broad diet, migratory behavior, and ability to cause extensive plant damage. While extensive research has focused on the olfactory capabilities of adult S. frugiperda, understanding of the olfactory process in larvae remains limited, despite larvae playing a crucial role in crop damage. To address this gap, we identified an odorant receptor (OR), SfruOR40, expressed in the first-instar larvae through phylogenetic analysis. Using quantitative real-time PCR, we compared SfruOR40 expression levels in larvae and adults. We then characterized the function of SfruOR40 against 67 compounds using the Xenopus oocyte expression system and found that SfruOR40 responded to three plant volatiles. Further, behavioral experiments revealed a larval attraction to (-)-trans-Caryophyllene oxide. This study elucidates SfruOR40's role in the olfactory recognition of newly hatched S. frugiperda larvae, expanding our knowledge of such mechanisms in Noctuid moths. Furthermore, it highlights the potential of plant-derived natural products for biological pest control from a behavioral ecology perspective.

Diet of moulting Swainson's Thrushes (Catharus ustulatus) and Tennessee Warblers (Leiothlypis peregrina) at a stopover site during fall migration measured with fecal DNA metabarcoding

Moult and migration are energetically demanding and require adequate nutrition. In some species, individuals may interrupt their fall migration to moult at discrete stopover locations outside of their breeding grounds (i.e., moult-migration) leading to competing nutritional demands for moult and migration. Here, we use DNA barcoding of fecal samples to compare the diet of moulting and actively migrating (post-moult) Swainson’s Thrushes (Catharus ustulatus) and Tennessee Warblers (Leiothlypis peregrina) during their fall migration stopover at a large urban greenspace in Montreal, Canada. Diet differed according to moult status, species, and seasonality. Swainson’s Thrushes had a broad diet with frequent detections of both insects and berry-producing shrubs; while detections in Tennessee Warblers’ diets were mainly arthropods. For both species, more actively migrating individuals consumed fleshy-fruiting plants than moulting individuals. A higher proportion of moulting birds consumed arthropods compared to active migrants, due to either arthropod availability or a dietary preference for proteinaceous foods to grow feathers. Both species and moult classes consumed more native plants than non-native plants later in the season. We show the importance of managing urban greenspaces with native plants and diverse food sources that can provide for the different dietary needs of migratory birds.

Is the diet cyclic phase-dependent in boreal vole populations?

Herbivorous rodents in boreal, alpine and arctic ecosystems are renowned for their multi-annual population cycles. Researchers have hypothesised that these cycles may result from herbivore-plant interactions in various ways. For instance, if the biomass of preferred food plants is reduced after a peak phase of a cycle, rodent diets can be expected to become dominated by less preferred food plants, leading the population to a crash. It could also be expected that the taxonomic diversity of rodent diets increases from the peak to the crash phase of a cycle. The present study is the first to use DNA metabarcoding to quantify the diets of two functionally important boreal rodent species (bank vole and tundra vole) to assess whether their diet changed systematically in the expected cyclic phase-dependent manner. We found the taxonomic diet spectrum broad in both vole species but with little interspecific overlap. There was no evidence of systematic shifts in diet diversity metrics between the phases of the population cycle in either species. While both species' diet composition changed moderately between cycle phases and seasons, these changes were small compared to other sources of diet variation-especially differences between individuals. Thus, the variation in diet that could be attributed to cyclic phases is marginal relative to the overall diet flexibility. Based on general consumer-resource theory, we suggest that the broad diets with little interspecific overlap render it unlikely that herbivore-plant interactions generate their synchronous population cycles. We propose that determining dietary niche width should be the first step in scientific inquiries about the role of herbivore-plant interactions in cyclic vole populations.

Population trends in the vulnerable Grey-headed flying-fox, Pteropus poliocephalus; results from a long-term, range-wide study.

Monitoring is necessary for the management of any threatened species if its predicament and status are to improve. Monitoring establishes baseline data for tracking trends in distribution and abundance and is a key tool for informing threatened species management. Across much of the Old World, bats in the genus Pteropus (Pteropodidae, Chiroptera) face significant threats from habitat loss, conflict with humans, and hunting. Despite conflict with humans and their threatened status, few Pteropus are being monitored. Often, this is because of difficulties associated with their high mobility, large and easily disturbed aggregations, and their use of unknown or remote habitat. Here we describe 10 years of results from the National Flying-fox Monitoring Program (NFFMP) for the grey-headed flying-fox, (Pteropus poliocephalus) in Australia. Range-wide quarterly surveys were conducted over a three-day period since November 2012 using standardized methods appropriate to conditions encountered at each roost. For our analysis of the population and its trend, we used a state-space model to account for the ecology of the grey-headed flying-fox and the errors associated with the surveying process. Despite the general perception that the species is in decline, our raw data and the modelled population trend suggest the grey-headed flying-fox population has remained stable during the NFFMP period, with the range also stable. These results indicate that the species' extreme mobility and broad diet bestow it with a high level of resilience to various disturbance events. Long-term, range-wide studies such as this one, are crucial for understanding relatively long-lived and highly nomadic species such as the grey-headed flying-fox. The outcomes of this study highlight the need for such systematic population monitoring of all threatened Pteropus species.

Warming changes the life history composition of marine fish communities at high latitudes

Across marine ecosystems, species are redistributing as a response to increased sea temperatures. In the Arctic, rapid warming causes poleward shifts of boreal species. Which species are redistributing and the drivers of their movements can be related to their life history traits. Here, we aimed to characterize and analyze the spatio-temporal changes in the life history strategy (LHS) composition of fish communities in the Barents Sea (2004-2017). We performed an archetype analysis to characterize species’ LHS based on their life history traits and related it to the equilibrium-periodic-opportunistic framework. Fish species in temperate ecosystems were documented to be largely distributed along the opportunistic-periodic continuum, whereas many fish species in the Barents Sea are distributed along the opportunistic-equilibrium continuum, illustrating the specificity of Arctic fish LHS. During the study period, boreal periodic species showed an increase in the central Barents Sea, a zoogeographic transition area. Simultaneously, Arctic opportunistic species retracted to cold waters, and the abundance of equilibrium strategists increased in the eastern Barents Sea. The expansion of periodic species may be explained by the configuration of their traits. This includes a high reproductive potential, broader diet, and migratory behavior. These traits might increase their tolerance and adaptive capacity to a changing environment. Fish LHS play a crucial role in fisheries management, particularly in promoting better fishing practices for vulnerable populations. By understanding the various LHS adopted by different fish species and their environmental preferences, fisheries managers can develop informed fishing strategies on a broader scale.

A global analysis of the introduction pathways and characteristics associated with non-native fish species introduction, establishment, and impacts

BackgroundThe invasion success of introduced freshwater fishes is influenced by many factors, including ecological, species, and socioeconomic characteristics. Most studies that document the importance of these characteristics are conducted at local scales and/or focus on a single step of the invasion process. In this study, we aim to determine the species characteristics, ecological characteristics, and socioeconomic characteristics of non-native freshwater fish invasions. Our assessment was done at the global scale and considers all three steps of the invasion (i.e., introduction, establishment, and impact). For this purpose, we applied generalized linear models to 20 variables collected for 307 non-native species and modeled them as a function of ecological characteristics (i.e., environmental features), species traits (i.e., functional and morphological), and socioeconomic characteristics (i.e., human use and introduction pathways). We considered the number of countries in which each species was introduced, established, or had ecological impacts as a proxy of invasion step success. We also explored the specifics of species introduced through the aquaculture and the ornamental fish trade pathways.ResultsWe found that non-native freshwater fishes with broad diets, high parental care, and multiple introduction pathways are the most widely introduced and established worldwide. The number of countries with impacts reported was best explained by the type of introduction pathway (i.e., aquaculture or fisheries). Moreover, among non-native species introduced through aquaculture, those belonging to Cypriniformes and having broad diets were the most widely introduced and established species. In contrast, the species introduced through the ornamental fish trade pathway belonged to various taxonomic orders but were mainly native to tropical regions.ConclusionsConsidering several types of factors is important when analyzing the invasion success of freshwater fish and disentangling the different invasion steps. These findings have strong implications for anticipating the profile of species with a high potential to invade many countries.

Bat pollinators: a decade of monitoring reveals declining visitation rates for some species in Thailand

Bats are important pollinators, but they are difficult to study since they are volant and nocturnal. Thus, long-term studies of nectarivorous bats are scarce, despite their potential to help assess trends in bat populations and their pollination services. We used capture rates of nectarivorous bats at chiropterophilous flowers in order to examine temporal trends in bat visitation in an area that is undergoing extensive land use change. We mist-netted at five bat-pollinated plant taxa (Durio zibethinus, Musa acuminata, Oroxylum indicum, Parkia speciosa, and Sonneratia spp.) in southern Thailand over six years between 2011 and 2021. We found that the most common bat species, Eonycteris spelaea, was the main visitor at all five plant taxa and had consistent visitation rates across all study years. In contrast, two other important pollinators, Macroglossus minimus and M. sobrinus, showed 80% declines in the number of individuals netted at mangrove apple (Sonneratia spp.) and banana (Musa acuminata) flowers, respectively. These findings suggest that E. spelaea (a large, cave-roosting species with a broad diet) is more tolerant of anthropogenic change than are Macroglossus bats (small, foliage-roosting species with specialized diets), which may in turn affect the reproductive success of plants pollinated by these species. Our study demonstrates how decade-long monitoring can reveal species-specific temporal patterns in pollinator visitation, emphasizing the need for tailored conservation plans. While the conservation status of most nectarivorous bats in the area is Least Concern, our results indicate that population studies in Southeast Asia are urgently needed for updated bat species conservation assessments.

Bird population changes in urban green spaces explained by regional population trends

Urban bird species represent a subset of the regional species pool, consisting of species that have been able to survive in, or colonise, urban areas. Urban birds are typically resident non-forest species with a broad diet and nesting high in trees or in cavities, and some studies have also claimed that they are large-brained. However, little is known about how urban bird communities change over time. Does the urban environment impose specific selective pressures favouring particular species or ecological groups, or do birds in urban areas simply have population changes reflecting population trends at larger scales? We assessed population changes of 45 breeding land bird species in Oslo, the capital of Norway, based on surveys conducted ca. 15 years apart. Population changes within Oslo most closely matched changes occurring at the regional level (national population trends from Norway and Sweden). Thus, species increasing in Oslo were those that also increased at the regional level. We found no evidence that relative brain size, diet or habitat preferences influenced population trends. However, controlling for regional population trends, there were additional residual effects of nest site and migration: species nesting on the ground or low in bushes had more positive changes than species nesting high in trees or in cavities, and resident species did better than long- or short-distance migrants. These results indicate that urban environments are not isolated islands only influenced by own selection pressures, but are connected with regional population dynamics, most likely through immigration.

Investigating the diets and condition of Centrostephanus rodgersii (long-spined urchin) in barrens and macroalgae habitats in south-eastern Australia

Sea urchins are important herbivores that can graze macroalgae, creating ‘barren’ areas. These barrens are believed to offer little food for urchins due to the absence of attached macroalgae, leading to malnourishment as indicated by a low urchin gonad index. To investigate the diet and resultant gonad index of the long-spined sea urchin Centrostephanus rodgersii in New South Wales, Australia, we dissected 100 C. rodgersii individuals collected in macroalgae and barrens habitats along >470 km of SE NSW coastline. Diverse items were present in the digestive tracts of urchins from all habitats. These items included brown (42% barrens, 46% macroalgae), green (28% barrens, 42% macroalgae) and red algae (15% barrens, 12% macroalgae) and corallines (29% barrens, 37% macroalgae), molluscs (28% barrens, 29% macroalgae) and crustaceans (26% barrens, 22% macroalgae). There was no difference in urchin gut fullness between habitats (85% barrens, 90% macroalgae). Importantly, the gonad index only differed in macroalgae compared to barrens habitats at one location, with no differences detected at the other 4 locations. These results suggest that C. rodgersii has a diverse diet that is similar in both habitats, which could explain the similarities in gut fullness and gonad index. Our results suggest that C. rodgersii eat a broad diet including invertebrates and drift algae, and hence may not be malnourished in barrens. The finding of comparable gonad index between barrens and macroalgal areas further supports this conclusion. These findings challenge the prevailing perspective, indicating that sea urchins have sufficient food to survive and reproduce in different habitats.

Investigating the effect of host plant identity on instar number in fall webworm, a common generalist herbivore.

For herbivorous insects with a broad diet breadth, host plant identity can influence larval development by either accelerating or delaying growth. For some species of Lepidoptera, the number of larval instars varies depending on the host plant's identity. Fall webworm (Hyphantria cunea, Drury) is a polyphagous herbivore that feeds on over 450 host plants worldwide. Of the 2 morphotypes (red- and black-head) of fall webworm, the number of instars for the red-head fall webworms has not been characterized. Given its broad diet breadth, fall webworm developmental stages may vary with plant identity. We investigated whether host plant identity affected the number of instars observed during red-head fall webworm development. We measured the head capsules of over 6,000 fall webworm larvae reared on 6 different plants commonly eaten by fall webworms in Colorado. We modeled head capsule widths as Gaussian mixture models, with a Gaussian distribution that corresponded to each instar. We show that our red-head fall webworms varied in number of instars depending on the identity of their host plant upon which they fed. We found that red-head fall webworm exhibited 7 instars on 5 of the host plants and 8 instars on 1 host plant that we studied. Our results for the number of instars for red-head fall webworm are consistent with reports of the number of instars for black-head fall webworm. Our research provides insight into the influence of host plant identity on fall webworm development, which can be used to advance lab and field research of this species.

A zooarchaeological perspective on late pleistocene/early holocene human behaviour in the Maloti-Drakensberg region, southern Africa: The view from Ha Makotoko and Ntloana Tšoana rock-shelters, Lesotho

Re-excavation of Ha Makotoko and Ntloana Tšoana rock-shelters in western Lesotho, produced abundant faunal remains (both macro and micro) from people using the Robberg technocomplex during the late Pleistocene (Ha Makotoko and Ntloana Tšoana (15.4–13.4 kcal. BP) and early Holocene (Ntloana Tšoana 11.1–10.2 kcal. BP). This faunal material allows us to identify the subsistence strategies they employed, using the unbiased Simpson's evenness index (1-D′), and Shannon's evenness index to track diet breadth. Detailed analyses of the sites' microfauna indicates that eagle owls and/or small carnivores — not humans — were responsible for introducing them into the deposits. A chi-squared test comparing diet breadth across the sites identifies hunting strategy, focused on size 2 and 3 migratory ungulates (equids, suids, and bovids), supplemented with size 1 and 4 bovids. Comparing the evenness values from Ha Makotoko and Ntloana Tšoana to published data from other Robberg-associated sites in the wider Maloti-Drakensberg region (Sehonghong, Rose Cottage Cave and Tloutle) allows variability in subsistence strategies to be addressed. A chi-squared test comparing ungulate size classes, small mammals and fish with the evenness index reveals two important statistical differences: the warm period occupation (16.5–14.3 kcal. BP) at Rose Cottage Cave presents a narrow diet heavily focused on size 3 ungulates (with a lack of fish). At the other end of the climate spectrum, cold conditions at Sehonghong immediately before the Last Glacial Maximum were associated with a narrow diet focused on intensive fishing, with lower-than-expected numbers of size 3 ungulates. The deposits at Ntloana Tšoana, Ha Makotoko, and Tloutle, along with the Younger Dryas-associated assemblage from Sehonghong, on the other hand, present broad diets. Fish and small mammals make more of a contribution to the expanding diet in the highlands. Our approach demonstrates the flexibility that makers of Robberg tools displayed in adapting to the changing climatic and ecological conditions of this high-elevation region in the interior of southern Africa during Marine Isotope Stage 2 and across the Pleistocene/Holocene transition.

Insectivorous bats provide more pest suppression services than disservices - a case study in China

Many studies have investigated the role of insectivorous bats as natural enemies of agricultural pests. However, insectivorous bats have a broad diet, and whether their prey species are beneficial or harmful is unknown; thus, accurately assessing the services provided by bats is challenging. In China, most people, including farmers and plant protection workers, have an insufficient understanding of the ecological value of bats in biological control. Therefore, we collected the fecal samples of 10 bat species from three different sampling sites located in Guizhou Province, China, and conducted DNA metabarcoding to determine the diet composition of bats. We also categorized the prey species from the diet of bats as harmful or beneficial, based on previous studies, and recorded the industries they affect. Our results showed that the 10 bat species consumed prey from 19 orders and 96 families; most of them being lepidopterans. Among 564 total prey species recorded, 390 (69.15%) were pests and 28 (4.96%) were beneficial insects. Among them, 326 (57.80%) were agriculture or forestry pests, such as globally present Cotton bollworm (Helicoverpa armigera) and Beet armyworm (Spodoptera exigua). These results indicated that insectivorous bats have more beneficial effects than harmful effects, especially in the context of agriculture and forestry, as they suppressed very few beneficial arthropod mesopredators. By comparing the differences in the diet of I. io in different regions, we found that bats present in different regions can provide different predation services. Our study showed that insectivorous bats provide excellent pest suppression services in various industries and regions. It might be helpful for increasing awareness among people and bat conservation in China and other regions.

Effects of Broad Bean Diet on the Growth Performance, Muscle Characteristics, Antioxidant Capacity, and Intestinal Health of Nile Tilapia (Oreochromis niloticus)

Four crisping diets were designed to conduct a feeding experiment to investigate the use of broad bean in the formulated feed of Nile tilapia and optimize its use. The growth performance, muscle characteristics, antioxidant capacity, and intestinal health of Nile tilapia with an initial body weight of 617.32 ± 1.64 g were evaluated after being fed with different diets for 90 days. The results showed no adverse effect on the growth performance of Nile tilapia fed with broad bean diets. Contrastingly, some improvements were found in WGR and SGR, but a lower FCR was obtained. The supplementation of broad beans weakened the antioxidant capacity of fish but did not influence liver health and the immune system. Increasing the amount of broad bean addition can increase muscle quality values, and an embrittling functional package being added to the diet can also improve muscle hardness, adhesiveness, and chewiness of Nile tilapia muscle. In addition, the crisping functional package can be applied to tilapia crisping formulated feed, which helps to improve the integrity of the intestinal tissue structure and optimize the intestinal microbiota of Nile tilapia. The final achievement of this study is to provide a theoretical reference for optimizing the breeding technology of crispy Nile tilapia and developing a specialized crisping diet for the species.

Karoo dwarf tortoises (Chersobius boulengeri) prefer and disperse doll's roses (Hermannia spp.)

Tortoises inhabit arid regions where they may represent a significant herbivorous component, but are among the most threatened of tetrapod groups. Studying tortoise diets can help predict potential trophic disruptions following extinctions of tortoise populations, and inform conservation. We studied the diet of Karoo dwarf tortoises (Chersobius boulengeri), an endangered endemic of the arid Nama and Succulent Karoo biomes in South Africa, using vegetation analysis, DNA metabarcoding, morphological evaluation of faeces, a germination trial, and focal feeding observations. DNA metabarcoding was highly successful in the identification of dietary items. Karoo dwarf tortoises fed on a broad diet, including approximately 10 taxa eaten frequently. Specifically, doll's roses (five species in the genus Hermannia) were eaten more frequently than would be expected based on their availability, whereas grasses were rejected, for a dietary Proportional Similarity Index of 0.31–0.38. Dietary selection was likely related to water and nutrient contents of plant taxa. At least four plant species (including doll's roses) germinated from faecal samples, suggesting mutualistic relationships with Karoo dwarf tortoises. The habitat preference of Karoo dwarf tortoises (i.e., well-structured rocky terrain) may provide germination microsites with ample shade and run-off water to benefit seedling recruitment in an arid environment.