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Transgenic crops producing Bacillus thuringiensis (Bt) toxins are commonly used for controlling insect pests. Nearby refuges of non-Bt host plants play a central role in delaying the evolution of resistance to Bt toxins by pests. Pervasive fitness costs associated with resistance, which entail lower fitness of resistant than susceptible individuals in refuges, can increase the ability of refuges to delay resistance. Moreover, these costs are affected by environmental factors such as host plant suitability, implying that manipulating refuge plant suitability could improve the success of the refuge strategy. Based on results from a previous study of Trichoplusia ni resistant to Bt sprays, it was proposed that low-suitability host plants could magnify costs. To test this hypothesis, we investigated the association between host plant suitability and fitness costs for 80 observations from 30 cases reported in 18 studies of 8 pest species from 5 countries. Consistent with the hypothesis, the association between plant suitability and fitness cost was negative. With plant suitability scaled to range from 0 (low) to 1 (high), the expected cost was 20.7% with a suitability of 1 and the fitness cost increased 2.5% for each 0.1 decrease in suitability. The most common type of resistance to Bt toxins involves mutations affecting a few types of midgut proteins to which Bt toxins bind to kill insects. A better understanding of how such mutations interact with host plant suitability to generate fitness costs could be useful for enhancing the refuge strategy and sustaining the efficacy of Bt crops. [ABSTRACT FROM AUTHOR]

Abstract Background Functional trade-offs through ecological specializations are hypothesized to become causes of adaptive phenotypic divergence under divergent natural selection, where intermediate phenotypes may have the lowest fitness. Evidence of phenotypic divergence in a trade-off between populations experiencing different environmental/ecological conditions is abundant. However, traits in divergent selection sometimes present non-discrete (unimodal) variability, including intermediate phenotypes, although the underlying mechanisms are poorly documented. A benthic cyprinid fish, Pseudogobio esocinus, in Lake Biwa, central Japan, exhibits a large non-discrete/continuous variation in mouthpart morphology (from wide to narrow) within a lake population. The variation is linked with individual diets (i.e., the compositions of two different types of prey) even at a single site, and thus the variability is hypothesized to persist under divergent selection for prey usage. As a first step toward understanding the persistence mechanisms, here I examined the presence of morphology-dependent feeding selectivity and a functional trade-off in a laboratory experiment. Results When each experimental fish was simultaneously provided the different types of prey (chironomid larvae and amphipods), the fish mostly utilized chironomid larvae as primary prey. However, compared with the wider-mouthed fish, the narrower-mouthed fish took a larger proportion of amphipods as secondary prey by changing feeding (attacking) behavior. The intermediate-mouthed fish had lower feeding efficiency than the extreme-mouthed fish, indicating potential disadvantage of the intermediate phenotype. Conclusions This experimental result supports the presence of morphology-dependent feeding performance and a functional trade-off with potential impacts on trait variability, which may favor specializations rather than generalizations. In the wild, however, there may be some situations for relaxing the trade-off, such as temporally fluctuating prey availability that could also favor generalizations depending on the conditions, and thus, both extreme and intermediate phenotypes may persist/coexist in a single habitat. Although further examinations, especially focusing on feeding efficiency for each prey type separated from the effects of prey selectivity, are needed, this case represents an opportunity to consider the possible mechanisms of the persistence of phenotypic variation that is maintained without divergence even in a trade-off.

To determine the optimal temperature in rearing of fry stream groupers, Acrossocheilus fasciatus, a total of 540 fry fish with an initial body weight of (0.57 ± 0.16) g, and body length of (4.08 ± 0.40) cm were randomly distributed to 18 15‐L tanks and reared at six different temperatures (12, 16, 20, 24, 26, and 28°C) for a period of 60 days. Fish were hand‐fed to satiation under all six different temperature treatments. At the end of the experiment, almost all the growth, feeding, and gonadal development parameters were higher in the 26°C group than in the rest of the groups. As temperature increased from 12 to 26°C, the specific growth rate and feeding efficiency of fry significantly increased (p < 0.05). When temperature reached 28°C, these parameters were significantly lower than in the 26°C group (p < 0.05). The histological structure of the gonads showed that in the 26°C group, a large number of sperm cells resided in the testis in a free condition, and many yolk granules aggregated together and formed plates in the ovary. This histological information indicated that the gonadal maturity of fish in the 26°C group was higher than that of the other groups. Thus showing a turning point of growth, feeding, and gonadal development in the 26°C group. In relation to the nutritive compositions of muscle tissue, fish reared at 16°C exhibited the highest content of amino acids and fatty acids. These parameters significantly (p < 0.05) decreased as the temperature increased from 16 to 28°C. The proportion of essential amino acids (EAA/NEAA) and unsaturation of fatty acids (∑UFA/FA) did not show significant temperature influence (p > 0.05). In conclusion, increases in temperature significantly improved the growth rate, feeding performance, and gonadal development rate of fry A. fasciatus. Regression analysis based on growth and feeding performance showed that the optimal temperature of rearing fry A. fasciatus was 23.81–26.57°C. [ABSTRACT FROM AUTHOR]

Background: Functional trade-offs through ecological specializations are hypothesized to become causes of adaptive phenotypic divergence under divergent natural selection, where intermediate phenotypes may have the lowest fitness. Evidence of phenotypic divergence in a trade-off between populations experiencing different environmental/ecological conditions is abundant. However, traits in divergent selection sometimes present non-discrete (unimodal) variability, including intermediate phenotypes, although the underlying mechanisms are poorly documented. A benthic cyprinid fish, Pseudogobio esocinus, in Lake Biwa, central Japan, exhibits a large non-discrete/continuous variation in mouthpart morphology (from wide to narrow) within a lake population. The variation is linked with individual diets (i.e., the compositions of two different types of prey) even at a single site, and thus the variability is hypothesized to persist under divergent selection for prey usage. As a first step toward understanding the persistence mechanisms, here I examined the presence of morphology-dependent feeding selectivity and a functional trade-off in a laboratory experiment. Results: When each experimental fish was simultaneously provided the different types of prey (chironomid larvae and amphipods), the fish mostly utilized chironomid larvae as primary prey. However, compared with the wider-mouthed fish, the narrower-mouthed fish took a larger proportion of amphipods as secondary prey by changing feeding (attacking) behavior. The intermediate-mouthed fish had lower feeding efficiency than the extreme-mouthed fish, indicating potential disadvantage of the intermediate phenotype. Conclusions: This experimental result supports the presence of morphology-dependent feeding performance and a functional trade-off with potential impacts on trait variability, which may favor specializations rather than generalizations. In the wild, however, there may be some situations for relaxing the trade-off, such as temporally fluctuating prey availability that could also favor generalizations depending on the conditions, and thus, both extreme and intermediate phenotypes may persist/coexist in a single habitat. Although further examinations, especially focusing on feeding efficiency for each prey type separated from the effects of prey selectivity, are needed, this case represents an opportunity to consider the possible mechanisms of the persistence of phenotypic variation that is maintained without divergence even in a trade-off. [ABSTRACT FROM AUTHOR]

Abstract To determine the optimal temperature in rearing of fry stream groupers, Acrossocheilus fasciatus, a total of 540 fry fish with an initial body weight of (0.57 ± 0.16) g, and body length of (4.08 ± 0.40) cm were randomly distributed to 18 15‐L tanks and reared at six different temperatures (12, 16, 20, 24, 26, and 28°C) for a period of 60 days. Fish were hand‐fed to satiation under all six different temperature treatments. At the end of the experiment, almost all the growth, feeding, and gonadal development parameters were higher in the 26°C group than in the rest of the groups. As temperature increased from 12 to 26°C, the specific growth rate and feeding efficiency of fry significantly increased (p 0.05). In conclusion, increases in temperature significantly improved the growth rate, feeding performance, and gonadal development rate of fry A. fasciatus. Regression analysis based on growth and feeding performance showed that the optimal temperature of rearing fry A. fasciatus was 23.81–26.57°C.

We explore the effect of complete oral motor intervention (OMI) and nonnutritive sucking (NNS) alone on oral feeding in preterm infants through a meta-analysis. We searched the Embased, Medline, Cochrane Library, and Web of Science databases for randomized controlled trials up to 8 August 2023, based on established selection criteria. Quality evaluations of the studies were carried out by applying both the Cochrane risk of bias assessment tool and the Jadad scale. The outcome measures of three clinical indicators included transition time to oral feeding, weight gain, and hospitalization duration. We conducted a meta-analysis using a random-effects model to determine the pooled effect sizes, expressed as standardized mean differences (SMDs) and their corresponding confidence intervals (CIs). Additionally, we undertook a subgroup analysis and meta-regression to investigate any potential moderating factors. Eight randomized controlled trials with 419 participants were selected. Meta-analysis revealed that receiving a complete OMI had significantly reduced transition time compared with those receiving NNS alone in preterm newborns (SMD, −1.186; 95% CI, −2.160 to −0.212, p = 0.017). However, complete OMI had no significant effect on shortened hospitalization duration (SMD, −0.394; 95% CI, −0.979 to 0.192, p = 0.188) and increased weight gain (SMD, 0.346; 95% CI, −0.147 to 0.838, p = 0.169) compared with NNS alone. In brief, a complete OMI should not be replaced by NNS alone. However, we were unable to draw decisive conclusions because of the limitations of our meta-analysis. Future well-designed randomized controlled trials are necessary to confirm our conclusion. [ABSTRACT FROM AUTHOR]

Ants are a dominant family of eusocial terrestrial insects with a diversity of ecologies, lifestyles and morphologies. Ant diet preferences range from strict carnivory through omnivory to almost complete herbivory in species feeding on seeds or exudates of plant-sucking insects. While several studies have investigated ant feeding performance on different substrates, comparatively little is known about the functional morphology of the structures involved in food uptake or their diversification across the ants. To take stock of our current knowledge, we give an overview of how adult ants ingest food, followed by a morphological description of the mouthparts, preoral space and cephalic sucking pump. The mandibles are the most prominent mouthparts and have received considerable attention in the literature, so we focus on the maxillae and labium here. We present current hypotheses for the movement patterns of these parts and discuss morphological differences among ants that may be related to their ecological diversity. Finally, we give short comparisons of the ant condition with some other insects and vertebrates, as well as an outlook summarizing gaps in our knowledge. This sets the stage for future studies elucidating the connections between ant feeding mechanisms and mouthpart evolution. This article is part of the theme issue 'Food processing and nutritional assimilation in animals'. [ABSTRACT FROM AUTHOR]

Anthropogenic noise in marine and freshwater environments has increased dramatically, with a range of negative impacts and detrimental consequences on many aquatic animals across taxa. Benthic organisms, including many invertebrates, can sense underwater sounds, yet the responses they trigger in these organisms have received little attention. We conducted two laboratory-based experiments to investigate the effect of underwater sound playback on the movement behavior and feeding performance of the red cherry shrimp Neocaridina davidi as a model of freshwater decapod. Movement speed decreased significantly upon opening the divider in both the sound and control treatments. However, there were no significant sound-dependent changes overall between the control and sound treatments. The spatial distribution of shrimp in response to the sound treatment showed significant changes; shrimp spent more time at the farthest one-third position from the sound source. Feeding latency (latency to find food) also increased in the sound treatment compared to the control. Moreover, in terms of the number of successes and failures in finding the food source in the control treatment, significantly more shrimp succeeded in finding the food source. The number of revisits to the food source decreased in the sound treatment compared to control and more shrimp were significantly distracted in the sound treatment. Our study highlights the potential for human-made sound to impact on crustacean activity. Thus, they are prone to the impacts of anthropogenic noise, causing negative impacts on their movement-swimming activities, and feeding behavior. Behavioral changes observed, namely altered feeding and locomotory behavior may have wider-reaching negative effects, including detrimental impacts on animal fitness.

In granivorous songbirds, feeding is a complex process as seeds need to be dehusked before they can be consumed, making the feeding act a biomechanically challenging endeavour. However, most previous research has focused on how beak morphology affects feeding performance, while the influences of beak kinematics remain largely unknown.In this study, we hence investigated at the individual level how feeding performance (i.e. seed processing time and success rate) relates to both beak kinematics (i.e. beak tip speed, acceleration, frequency) and skill (i.e. seed handling tactics and cracking techniques) in the Canary Serinus canaria. To do so, high‐speed videos during feeding were recorded and subjected to automated tracking of beak tip movements.Better skills, that is accurate positioning of the seed for being split in half, reduced total seed handling time compared to more random positioning and crushing the husk into multiple, scattering fragments. Surprisingly, individual variation in beak speed, acceleration or frequency generally did not relate to differences in performance.Thus, our data suggest that seed positioning precision, and hence the control of coordinated beak and tongue movement, is critical to minimize feeding durations in songbirds. Further studies are needed to explore whether this develops via a positive feedback between behaviour, learning and increased efficiency or if it relates to intrinsic differences. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

This study investigated the impact of Aphis gossypii watery saliva on the induction of tomato (Solanum lycopersicum) plant resistance. To examine the role of A. gossypii saliva, we collected watery saliva from A. gossypii after a 48 h feeding period on an artificial diet. SDS-PAGE resolving gel 12% was used to separate the salivary proteins. Relative expression of gene analysis revealed that the intrusion of A. gossypii saliva dripping onto S. lycopersicum leaves triggered robust defense responses mediated by a signaling molecule, i.e., salicylic acid, while the signaling molecule's jasmonic acid-dependent defense responses were moderately activated. Aphid saliva infiltrated S. lycopersicum leaves slowed the intrinsic rate of population growth of A. gossypii and significantly reduced the number of nymphs produced daily, compared to untreated leaves. During a choice test with untreated S. lycopersicum, aphids showed a repellent response towards saliva-infiltrated S. lycopersicum. Moreover, the (EPG) electrical penetration graph analysis demonstrated that the eating pattern of A. gossypii compared to untreated S. lycopersicum, that had been exposed to saliva was negatively impacted. These results provide compelling evidence for the involvement of salivary components of A. gossypii in inducing resistance against aphids in S. lycopersicum plants. Furthermore, the study underscores the crucial role of watery saliva in the intricate interactions between aphids and plants. The activation of pathways was also part of the defensive response (jasmonic acid (JA), salicylic acid (SA) signaling molecules). The findings of this research deliver valuable insights into the potential of watery aphid saliva as a natural defense mechanism against aphid infestations in S. lycopersicum crops. [ABSTRACT FROM AUTHOR]

Introduction: Predation is a complex process for which behavior, morphology, and size of both predator and prey can affect the success and effectiveness of the predator. For predators such as snakes that swallow prey whole, gape ultimately limits prey size, but the behaviors used to select, capture, and consume prey and attributes of the prey can also affect maximal prey size. For example, swallowing live, struggling prey is difficult, but using coiling or envenomation to restrain or kill prey has evolved repeatedly in snakes. Methods: To test the potential benefits of these behaviors, we manipulated the type and size of prey, and determined how stereotyped predatory behavior was in a snake species (Liodytes rigida) that uses both coiling and envenomation to restrain and immobilize its formidable prey of crayfish. We also studied a close relative (Liodytes pygaea) that eats fish and salamanders to gain insights into the evolution of these traits. Results: For L. rigida, envenomation of hard-shell crayfish via their soft underside was very stereotyped (100% of feedings). Envenomation of soft-shell crayfish was less frequent (59% of feedings) but became more likely both with increased relative prey size and increased time after molt (hardness). L. rigida coiled more for hard-shell than soft-shell crayfish (77% vs. 30%). The probability of coiling was unaffected by prey size, but it increased with increased time after molt for the soft-shell crayfish. Liodytes rigida waited to swallow crayfish until they were completely immobile in 75% and 37% of the feedings with hard- and softshelled crayfish, respectively. Even with large prey L. pygaea never used coiling or envenomation, whereas previous studies of L. alleni, the sister species of L. rigida, observed non-lethal coiling without envenomation when eating hard-shell crayfish. Discussion: Our findings for the Liodytes clade of three species suggest that coiling evolved ancestral to the crayfish specialists (L. alleni; L. rigida), and envenomation by L. rigida subsequently evolved as an additional means of subduing formidable prey. The proximate benefits observed for coiling and envenomation in L. rigida support the evolutionary scenario that both traits evolved to enhance the feeding performance for more formidable prey. [ABSTRACT FROM AUTHOR]

The study was to enrich high-quality forage varieties of grass in dry area of Longdong on loess plateau. A total of 14 soybean varieties of various types were introduced in study. On the basis of variance analysis, K-means algorithm was used for cluster analysis, TOPSIS method was used for comprehensive evaluation, and the forage productivity was discussed. The results showed that two forage varieties, Mulu No.9 and Mulu No.2, showed good adaptability to the climate in test area. The main stem was more than 2 m, with many branches and abundant leaves. The yield was 5 620.6, 4 586.7 kg/667 m2, the crude protein content was 17.30% and 17.90%, the neutral detergent fiber content was 44.17% and 45.32%, the acid detergent fiber content was 36.10% and 36.70%, the crude fat content was 4.68% and 4.70%, the calcium content was 1.97% and 1.93%, and the relative feed value was 143.50 and 135.75. Among seed soybeans, Guichun 1607 and Guixia No.7 can be used as forage, with yields of 3 710.7, 3 464.0 kg/667 m², crude protein content of 19.30% and 18.30%, neutral detergent fiber content of 41.32% and 42.74%, acid detergent fiber content of 32.80% and 34.45%, crude fat content of 4.00% and 4.35%, calcium content of 1.61% and 1.79%, and relative feed value of 151.00 and 143.50. The study indicates that Mulu No.9, Mulu No.2, Guichun 1607 and Guixia No.7 all have high feeding value. [ABSTRACT FROM AUTHOR]

IntroductionPredation is a complex process for which behavior, morphology, and size of both predator and prey can affect the success and effectiveness of the predator. For predators such as snakes that swallow prey whole, gape ultimately limits prey size, but the behaviors used to select, capture, and consume prey and attributes of the prey can also affect maximal prey size. For example, swallowing live, struggling prey is difficult, but using coiling or envenomation to restrain or kill prey has evolved repeatedly in snakes.MethodsTo test the potential benefits of these behaviors, we manipulated the type and size of prey, and determined how stereotyped predatory behavior was in a snake species (Liodytes rigida) that uses both coiling and envenomation to restrain and immobilize its formidable prey of crayfish. We also studied a close relative (Liodytes pygaea) that eats fish and salamanders to gain insights into the evolution of these traits.ResultsFor L. rigida, envenomation of hard-shell crayfish via their soft underside was very stereotyped (100% of feedings). Envenomation of soft-shell crayfish was less frequent (59% of feedings) but became more likely both with increased relative prey size and increased time after molt (hardness). L. rigida coiled more for hard-shell than soft-shell crayfish (77% vs. 30%). The probability of coiling was unaffected by prey size, but it increased with increased time after molt for the soft-shell crayfish. Liodytes rigida waited to swallow crayfish until they were completely immobile in 75% and 37% of the feedings with hard- and soft-shelled crayfish, respectively. Even with large prey L. pygaea never used coiling or envenomation, whereas previous studies of L. alleni, the sister species of L. rigida, observed non-lethal coiling without envenomation when eating hard-shell crayfish.DiscussionOur findings for the Liodytes clade of three species suggest that coiling evolved ancestral to the crayfish specialists (L. alleni; L. rigida), and envenomation by L. rigida subsequently evolved as an additional means of subduing formidable prey. The proximate benefits observed for coiling and envenomation in L. rigida support the evolutionary scenario that both traits evolved to enhance the feeding performance for more formidable prey.

Maize is an essential crop of China. The recent invasion of Spodoptera frugiperda, also known as fall armyworm (FAW), poses a danger to the country’s ability to maintain a sustainable level of productivity from this core crop. Entomopathogenic fungi (EPF) Metarhizium anisopliae MA, Penicillium citrinum CTD-28 and CTD-2, Cladosporium sp. BM-8, Aspergillus sp. SE-25 and SE-5, Metarhizium sp. CA-7, and Syncephalastrum racemosum SR-23 were tested to determine their effectiveness in causing mortality in second instars, eggs, and neonate larvae. Metarhizium anisopliae MA, P. citrinum CTD28, and Cladosporium sp. BM-8 caused the highest levels of egg mortality, with 86.0, 75.3, and 70.0%, respectively, followed by Penicillium sp. CTD-2 (60.0%). Additionally, M. anisopliae MA caused the highest neonatal mortality of 57.1%, followed by P. citrinum CTD-28 (40.7%). In addition, M. anisopliae MA, P. citrinum CTD-28, and Penicillium sp. CTD-2 decreased the feeding efficacy of second instar larvae of FAW by 77.8, 75.0, and 68.1%, respectively, followed by Cladosporium sp. BM-8 (59.7%). It is possible that EPF will play an important role as microbial agents against FAW after further research is conducted on the effectiveness of these EPF in the field. [ABSTRACT FROM AUTHOR]

We explore the effect of complete oral motor intervention (OMI) and nonnutritive sucking (NNS) alone on oral feeding in preterm infants through a meta-analysis. We searched the Embased, Medline, Cochrane Library, and Web of Science databases for randomized controlled trials up to 8 August 2023, based on established selection criteria. Quality evaluations of the studies were carried out by applying both the Cochrane risk of bias assessment tool and the Jadad scale. The outcome measures of three clinical indicators included transition time to oral feeding, weight gain, and hospitalization duration. We conducted a meta-analysis using a random-effects model to determine the pooled effect sizes, expressed as standardized mean differences (SMDs) and their corresponding confidence intervals (CIs). Additionally, we undertook a subgroup analysis and meta-regression to investigate any potential moderating factors. Eight randomized controlled trials with 419 participants were selected. Meta-analysis revealed that receiving a complete OMI had significantly reduced transition time compared with those receiving NNS alone in preterm newborns (SMD, −1.186; 95% CI, −2.160 to −0.212, p = 0.017). However, complete OMI had no significant effect on shortened hospitalization duration (SMD, −0.394; 95% CI, −0.979 to 0.192, p = 0.188) and increased weight gain (SMD, 0.346; 95% CI, −0.147 to 0.838, p = 0.169) compared with NNS alone. In brief, a complete OMI should not be replaced by NNS alone. However, we were unable to draw decisive conclusions because of the limitations of our meta-analysis. Future well-designed randomized controlled trials are necessary to confirm our conclusion.

Maize is an essential crop of China. The recent invasion of Spodoptera frugiperda, also known as fall armyworm (FAW), poses a danger to the country’s ability to maintain a sustainable level of productivity from this core crop. Entomopathogenic fungi (EPF) Metarhizium anisopliae MA, Penicillium citrinum CTD-28 and CTD-2, Cladosporium sp. BM-8, Aspergillus sp. SE-25 and SE-5, Metarhizium sp. CA-7, and Syncephalastrum racemosum SR-23 were tested to determine their effectiveness in causing mortality in second instars, eggs, and neonate larvae. Metarhizium anisopliae MA, P. citrinum CTD-28, and Cladosporium sp. BM-8 caused the highest levels of egg mortality, with 86.0, 75.3, and 70.0%, respectively, followed by Penicillium sp. CTD-2 (60.0%). Additionally, M. anisopliae MA caused the highest neonatal mortality of 57.1%, followed by P. citrinum CTD-28 (40.7%). In addition, M. anisopliae MA, P. citrinum CTD-28, and Penicillium sp. CTD-2 decreased the feeding efficacy of second instar larvae of FAW by 77.8, 75.0, and 68.1%, respectively, followed by Cladosporium sp. BM-8 (59.7%). It is possible that EPF will play an important role as microbial agents against FAW after further research is conducted on the effectiveness of these EPF in the field.

A study was conducted to assess the effectiveness of oral stimulation on feeding performance among preterm babies in selected NICU. The study was conducted with the purpose of finding out whether the oral stimulation will help to improve the feeding performance and to assess the selected parameters like respiration, weight, and oxygen saturation. A quasi-experimental non-equivalent control group design was used to conduct the study. Total of 40 samples were selected by the non-probability purposive sampling technique. 20 samples were in the experimental group and 20 in the control group. Data was collected by using an observation checklist for assessing the feeding pattern and other parameters like spo2, respiration, and weight. Reliability of the tool was done by inter-rater method and calculated 'r' were o.89 and calibration of the weighing machine was done by the biomedical department. Babies who are shifted to breastfeeding were taken as samples. Oral stimulation was given for 5 minutes in the morning and evening followed by breastfeeding. Pre-assessment was done on the first day for both groups. The intervention was carried out for the experimental group for 5 days on the 5th day post assessment was done for both groups. The analysis of feeding performance were done by using frequency and percentage, comparison of the two groups was done by using an unpaired t-test. Result showed that on 5th day the mean value of feeding performance was 11.30 in the experimental group whereas in the control group it was 10.40 with a p-value of 0.031. This shows there is a significant difference in the feeding performance of pre-term babies after oral stimulation. There were no changes observed the parameters of spo2, respiratory rate and weight between both the groups. The research concluded that oral stimulation is effective in improving the feeding skills of preterm babies and it did not have any positive effect on the parameters like spo2 respiration rate and weight. [ABSTRACT FROM AUTHOR]

Juveniles within a species are often faced with similar ecological pressures on performance as adults, such as obtaining food and escaping predation, but with the potential limitation of being smaller. Previous results have suggested that juveniles may exhibit decreased performance because of their smaller size or may compensate due to increased selection pressure to have increased performance. Studies from vertebrates suggest that locomotion and escape performances should be higher in juveniles, while feeding should be lower. Furthermore, studies on vertebrate feeding have provided mixed support for two competing models of linear and angular kinematic scaling, with both predicting isometric relationships for either linear or angular kinematics. Few studies have examined the scaling, including ontogenetic, of feeding performance in an invertebrate system. Hemimetabolous arthropods, such as praying mantises, offer a unique opportunity to examine ontogenetic patterns of feeding performance as juveniles lack a defined larval stage and are scaled down versions of adults. Praying mantises use the coordinated movements of their raptorial forelegs to capture evasive prey throughout their lives (e.g., from hatching through adulthood), allowing for a direct comparison of individuals as they develop. The goal of this study was to examine the ontogenetic patterns of prey capture strikes using the ghost praying mantis (Phyllocrania paradoxa). I examined body size, foreleg size, and both behavioral and kinematic aspects of the prey capture strike across the same individuals through ontogeny. Results from mixed models suggest that juveniles are limited in aspects of their prey capture strikes, such as less linear displacement and slower linear velocity of their forelegs; but may be compensating through increased angles of joints and amount of their body used. These results may have implications for the optimal foraging of hemimetabolous insects at different life stages and the allometric relationships of feeding performance at static and evolutionary scales. [ABSTRACT FROM AUTHOR]

Many man-made chemicals that are released into water bodies in agricultural landscapes have been identified as endocrine disruptors and can cause serious impacts on the growth and survival of aquatic species living in these environments. However, very little attention has been paid to their toxicological effects in cultured non-fish species, such as aquatic turtles. We exposed hatchlings of the Chinese soft-shelled turtle (Pelodiscus sinensis) to different concentrations of vinclozolin (0, 5, 50 and 500 μg/L) for 60 days to assess physiological and metabolic impacts of this fungicide. Despite no death occurrence, hatchling turtles exposed to the highest concentration of vinclozolin consumed less food, grew more slowly (resulting in smaller body size after exposure) and performed more poorly in behavioral swimming tests than controls and turtles exposed to lower concentrations. Hepatic metabolite profiles acquired via liquid chromatography-mass spectrometry (LC-MS) revealed multiple metabolic perturbations related to amino acid, lipid, and fatty acid metabolism in animals exposed to environmentally relevant concentrations. Specifically, many critical metabolites involved in energy-related metabolic pathways (such as some intermediates in the tricarboxylic acid cycle, lactate, and some amino acids) were present in livers of hatchling turtles exposed vinclozolin, though at lower concentrations, reflecting energy metabolism dysregulation induced by exposure to this fungicide. Overall, our results suggest that the changes in growth and behavioral performances caused by chronic vinclozolin exposure may be associated with internal physiological and metabolic disorders mediated at the biochemical level.

Thermal stratification can significantly impact the distribution of species in aquatic systems. Organisms often travel between these thermoclines in order to locate prey and find optimal thermal condition. Since most aquatic animals are ectotherms, changes in ambient temperature can have immediate impacts on performance. We aimed to understand how prey capture kinematics change when bluegill sunfish (Lepomis macrochirus) are exposed to brief acute temperature changes that represent foraging bouts below the thermocline. To do this, we exposed bluegills to either 21°C (above thermocline) or 17°C (below thermocline) and fed them a cloud of defrosted brine shrimp. After digitizing high‐speed videography, we found that performance increased at the below thermocline temperature contrary to our prediction. During these feeding bouts, we noticed high variability in prey capture behaviors as the fish encountered the first prey item and subsequent prey items. In these successive feeding events, they demonstrated a remarkable amount of modulation in close succession. We conclude that acute exposure to the thermocline temperature tested here does not negatively impact prey capture. Furthermore, feeding in rapid succession could be a way to maximize prey captured while reducing energy for searching and capture. [ABSTRACT FROM AUTHOR]

Effects of different carbon to nitrogen ratios in the biofloc system with sugarcane molasses as organic carbon source on water quality, growth performance, and body composition of common carp (Cyprinus carpio L.) fingerlings were investigated in a 90-day trial. A total of 450 fish (14.17 ± 0.36 g) were fed twice daily with commercial diet at 5% of their body weight under a 12:12 light:dark regime and cultured in 1 control (without extra carbon source) and 4 experimental treatments (C/N: 11:1, 15:1, 19:1, and 23:1) with 3 replicates at a density of 1.06 kg m−3 per tank. Based on the results, the water electrical conductivity (EC) and total dissolved solids (TDS) (measured daily), flocs volume (FV), and total suspended solids (TSS) (measured once a week) were increased from C/N 11:1 to C/N 23:1. The variation patterns of the average levels of total ammonia nitrogen, nitrite, and nitrate (measured once a week) were similar and showed a decreasing trend with an increase in C/N ratio. Total heterotrophic bacteria was also positively affected by increasing C/N to 23:1. The highest fish final weight (59.36 ± 0.24 g), weight gain (45.21 ± 0.47 g), and protein efficiency ratio (PER, 1.77 ± 0.04) were recorded in C/N 19:1. The lowest (1.46 ± 0.03) and highest (1.51 ± 0.05) feed conversion ratio (FCR) and the highest (1.60 ± 0.03%/day) and lowest (1.49 ± 0.01%/day) specific growth rate (SGR) were observed in C/N 19:1 and the control group, respectively (P < 0.05). By increasing the C/N to 23:1, FCR increased and the feed intake, final weight, weight gain, PER, and SGR decreased. The highest crude protein content (77.31 ± 0.43 %DW) and the lowest crude lipid content (12.13 ± 0.32 %DW) of the fish carcass were observed in C/N 19:1 while these values for flocs were not significantly affected by C/N ratio. Overall, the biofloc system with C/N 19:1 improved the water quality and growth performance of common carp while not negatively affecting the carcass proximate analysis. [ABSTRACT FROM AUTHOR]

The carnivoran cranium undergoes tremendous growth in size and development of shape to process prey as adults and, importantly, these ontogenetic processes can also differ between the sexes. How these ontogenetic changes in morphology actually relate to the underlying jaw musculature and overall bite performance has rarely been investigated. In this study, I examined sex‐specific ontogenetic changes in cranial morphology, jaw adductor muscles, and theoretical bite force between subadults and adults in the fisher (Pekania pennanti) and American marten (Martes americana). I found evidence that cranial size alone does not completely explain ontogenetic increases in bite forces as found in other mammalian species. Instead, cranial shape development also drives ontogenetic increases in relative bite force by broadening the zygomatic arches and enlargement of the sagittal crest, both of which enable relatively larger jaw adductor muscles to attach. In contrast, examination of sexual dimorphism within each age‐class revealed that cranial shape dimorphism did not translate to dimorphism in either size‐corrected bite forces or size‐corrected physiological cross‐sectional area of the jaw adductor muscles. These results reveal that morphological size and shape variation can have different influences on bite performance depending on the level of intraspecific variation that is examined (i.e. ontogenetic versus sexual dimorphism). [ABSTRACT FROM AUTHOR]

Nutritional indices of three geographic populations (Miandoab, Moghan and Kalposh) of the fifth instar of Spodoptera exigua (Lepidoptera: Noctuidae) on four sugar beet cultivars (Dorothea, Rozier, Persia and Perimer) were evaluated at 25 ± 1 °C, 65 ± 5 % RH and a 16:8 L:D photoperiod. The estimates of all the nutritional indices were affected by the interaction effect of the geographic population and the sugar beet cultivars. Miandoab population reared on Dorothea, and Moghan and Kalposh populations reared on Perimer had the highest approximate digestibility (AD). Miandoab and Kalposh populations reared on Rozier showed the highest efficiency of conversion of ingested food (ECI) and efficiency of conversion of digested food (ECD) values. Moghan population reared on Persia showed the lowest AD values and the highest ECI and ECD values. The present study showed that the nutritional indices of three populations, in most cases, were significantly different from with other, due to different environmental conditions that the pest collected from there. It is concluded that both geographic origins of the pest and host cultivar affected the nutritional indices of S. exigua larvae. Key Words: beet armyworm;

The yellow marmorated stink bug, Erthesina fullo (Thunberg, 1783), is a major pest of certain tree fruits in Northeast Asia. To better understand the feeding mechanism of E. fullo, the fine structure of the mouthparts, including the distribution and abundance of sensilla, are examined with scanning electron microscopy (SEM), and their functions are observed directly under laboratory conditions. The feeding performance is described in detail and illustrated for the first time. The adult feeding process involves several steps, including exploring and puncturing of the host plant epidermis, a probing phase, an engorgement phase, and removal of the mouthparts from the host tissue. Proceeding from labium towards the mandibular stylets, the movement pattern becomes increasingly stereotypical, including the sensilla on the tip of the labium probing, the labium making an elbow-like bend between the first and second segment, the base of the stylet fascicle housing in the groove of the labrum, the mandibular stylets penetrating the site and maxillary stylets feeding. In terms of morphology, the mouthparts are similar to those of other Heteroptera, consisting of a triangular pyramidal labrum, a tube-like and segmented labium with a deep groove on the anterior side, and a stylet fascicle consisting of two mandibular and two maxillary stylets. The four-segmented labium has five types of sensilla basiconica, three types of sensilla trichodea, two types of sensilla campaniformia and 1 type of sensilla coeloconica. Among them, sensilla trichodea one and sensilla basiconica one are most abundant. The tripartite apex of the labium is covered with abundant sensilla trichodea three and a few sensilla basiconica 5. The mandibular stylet tips have two nodules preapically on the dorsal margin of the convex external surface, which may help in penetrating plant tissue and anchoring the mouthparts. The externally smooth maxillary stylets interlock to form a larger food canal and a smaller salivary canal. The structure and function of the mouthparts are adapted for the phytophagous feeding habit in this species. Similarities and differences between the mouthparts of E. fullo and those of other Heteroptera are discussed.

Freshwater fish communities segregate along water temperature gradients attributed in part to temperature-mediated physiological processes that affect species fitness. In spring complexes of southwest USA, spring complexes with narrow range of water temperatures are dominated by a community of fishes (i.e., spring-associated fishes), whereas riverine habitats with wide-range of water temperatures are dominated by a different community of fishes (i.e., riverine-associated fishes). The purpose of this study was to test a prediction of the concept that temperature-mediated species performance is a mechanism in maintaining community segregation. We predicted that a spring-associated fish (Largespring Gambusia Gambusia geiseri) would feed first and more often in a pairing with a riverine-associated fish (Western Mosquitofish G. affinis) at an average spring temperature (23 °C) and that the riverine-associated fish would feed first and more often in a pairing with the spring-associated fish at a warm riverine temperature (30 °C). Among four trails consisting of 30 pairings, at the spring complex temperature (23 °C), Largespring Gambusia had a greater number of first feeds (mean ± 1 SD, 5.0 ± 0.82) than Western Mosquitofish (2.5 ± 1.73) and had greater mean number of total feeds (1.9 ± 0.31) than Western Mosquitofish (0.81 ± 0.70). At the riverine environment temperature (30 °C), Western Mosquitofish had a greater number of first feeds (5.25 ± 1.71) than Largespring Gambusia (2.5 ± 1.73) and had greater mean number of total feeds (2.78 ± 1.05) than Largespring Gambusia (0.94 ± 0.68). Our findings suggest that temperature-mediated species performance could be maintaining segregation between the two fish communities. This study benefits our understanding of distributional patterns and improves threat assessments of stenothermal aquatic organisms.

Nutritional indices of Helicoverpa armigera (Hübner) larvae, an economic insect pest of agricultural crops in the world, were studied on five corn hybrids (SC700, SC704, SC500, DC370 and SC260) when incorporated into artificial diets under laboratory conditions at 25 ± 1 °C, relative humidity of 65 ± 5% and a photoperiod of 16:8 (L: D) h. The highest values of consumption index (CI) and relative growth rate (RGR) for the fourth instars were on SC500 (37.21 ± 3.34 and 0.43 ± 0.07 mg/mg/day, respectively) and lowest values of these indices were on SC704 (21.44 ± 2.83 and 0.18 ± 0.04, respectively). Among the five corn hybrids tested, efficiency of conversion of ingested food (ECI) of fifth instars was the highest on SC260 (6.92 ± 0.5%) and the highest value of efficiency of conversion of digested food (ECD) was on SC704 (10.71 ± 3%) while the larvae fed on SC700 had the lowest values of ECI and ECD (3.57 ± 0.3 and 4.39 ± 0.4%, respectively). For the sixth instar larvae, although the lowest CI and approximate digestibility (AD) values were observed on SC260 (3.49 ± 0.17 and 53.89 ± 3.70%, respectively) the highest value of ECI and ECD was on SC260 (9.11 ± 0.6 and 16.54 ± 1.5%, respectively). For all instars (fourth to sixth instars), ECD value of H. armigera was the highest on SC260 (10.15 ± 1.08%) and lowest on SC700 (6.32 ± 0.47%). The result of this study pointed out higher nutritional performance of the larvae H. armigera reared on SC704 and SC260 and lower performance on SC700 and SC500.

Freshwater fish communities segregate along water temperature gradients attributed in part to temperature-mediated physiological processes that affect species fitness. In spring complexes of southwest USA, spring complexes with narrow range of water temperatures are dominated by a community of fishes (i.e., spring-associated fishes), whereas riverine habitats with wide-range of water temperatures are dominated by a different community of fishes (i.e., riverine-associated fishes). The purpose of this study was to test a prediction of the concept that temperature-mediated species performance is a mechanism in maintaining community segregation. We predicted that a spring-associated fish (Largespring Gambusia Gambusia geiseri) would feed first and more often in a pairing with a riverine-associated fish (Western Mosquitofish G. affinis) at an average spring temperature (23 °C) and that the riverine-associated fish would feed first and more often in a pairing with the spring-associated fish at a warm riverine temperature (30 °C). Among four trails consisting of 30 pairings, at the spring complex temperature (23 °C), Largespring Gambusia had a greater number of first feeds (mean ± 1 SD, 5.0 ± 0.82) than Western Mosquitofish (2.5 ± 1.73) and had greater mean number of total feeds (1.9 ± 0.31) than Western Mosquitofish (0.81 ± 0.70). At the riverine environment temperature (30 °C), Western Mosquitofish had a greater number of first feeds (5.25 ± 1.71) than Largespring Gambusia (2.5 ± 1.73) and had greater mean number of total feeds (2.78 ± 1.05) than Largespring Gambusia (0.94 ± 0.68). Our findings suggest that temperature-mediated species performance could be maintaining segregation between the two fish communities. This study benefits our understanding of distributional patterns and improves threat assessments of stenothermal aquatic organisms. [ABSTRACT FROM AUTHOR]

Background: The efficient and safe oral feeding of preterm infants, an essential criterion for hospital discharge, is affected by neurodevelopmental maturation. However, the timing of initiating oral feeding and its relation to maturation, feeding performance, and physiological responses are unclear. Purpose: The aim of this study was to determine the effect of a 1-week delay in the initiation of oral feeding on feeding performance, transition time, weight gain, and cardiorespiratory responses in preterm infants. Methods: In this randomized controlled trial, 40 infants with a gestational age at birth of less than 32 weeks were recruited. The control group (n = 18) began oral feeding when the infants were physiologically stable, whereas the experimental group (n = 22) began oral feeding 1 week later. Infant feeding performance, heart rate, and oxygen saturation were measured before, during, and after feeding on the first day of oral feeding and 3 days later. Daily weight gain was calculated by measuring body weight every morning, and transition time was calculated by counting the number of days from the initiation of oral feeding to the termination of tube feeding. Results: There were no significant differences between the two groups in terms of feeding performance, weight gain, or postmenstrual age at the completion of full oral feeding. The transition time was significantly shorter in the experimental group than in the control group. More infants in the control group experienced episodes of oxygen desaturation during feeding than in the experimental group. Conclusions/Implications for Practice: For infants with a postmenstrual age of greater than 32 weeks who are ready to initiate oral feeding, postponing oral bottle feeding for 1 week may be considered as an intervention to reduce physiological distress. [ABSTRACT FROM AUTHOR]

As body size increases, some predators eliminate small prey from their diet exhibiting an ontogenetic shift toward larger prey. In contrast, some predators show a telescoping pattern of prey size in which both large and small prey are consumed with increasing predator size. To explore a functional explanation for the two feeding patterns, I examined feeding effort as both handling time and number of upper jaw movements during ingestion of fish of consistent size. I used a range of body sizes from two snake species that exhibit ontogenetic shifts in prey size ( Nerodia fasciata and N. rhombifer ) and a species that exhibits telescoping prey size with increased body size ( Thamnophis proximus ). For the two Nerodia species, individuals with small or large heads exhibited greater difficulty in feeding effort compared to snakes of intermediate size. However, for T. proximus measures of feeding effort were negatively correlated with head length and snout–vent length (SVL). These data indicate that ontogenetic shifters of prey size develop trophic morphology large enough that feeding effort increases for disproportionately small prey. I also compared changes in body size among the two diet strategies for active foraging snake species using data gleaned from the literature to determine if increased change in body size and thereby feeding morphology is observable in snakes regardless of prey type or foraging habitat. Of the 30 species sampled from literature, snakes that exhibit ontogenetic shifts in prey size have a greater magnitude of change in SVL than species that have telescoping prey size patterns. Based upon the results of the two data sets above, I conclude that ontogenetic shifts away from small prey occur in snakes due, in part, to growth of body size and feeding structures beyond what is efficient for handling small prey. [ABSTRACT FROM AUTHOR]

The eggs and larvae of the Indian meal moth, Plodia interpunctella (Hübner), are widely used in mass rearing of parasitoids and predators. Feeding indices and some biological parameters of P. interpunctella were studied on bran of different wheat cultivars ('Back-cross Roshan', 'Khooshe Pishgam', 'Khoshki line 9', 'Arg', 'Alvand', 'Pishtaz', 'WS-89-2', 'Sepahan' and 'Bam') when incorporated into artificial diets under laboratory conditions (25 ± 1 ºC, 65 ± 5% R.H., and a 16:8 h light-dark photoperiod). The efficiency of conversion of ingested food was highest on 'Back-cross Roshan' (98.79 ± 8.48%) and lowest on 'Pishtaz' (64.56 ± 9.66%). The highest and lowest percentage of mortality of P. interpunctella larvae were on 'Pishtaz' (56%) and 'Back cross Roshan' (12%). Our results showed that larval growth index was highest on 'Khoshki line 9' (5.81) and lowest on 'Pishtaz' (3.33). Moreover, the highest daily and total fecundity were detected in moths that were reared on 'Back-cross Roshan' (37.6 ± 0.93 and 177.3 ± 1.61 eggs, respectively). The results demonstrated that, among different wheat cultivars tested, 'Back-cross Roshan' was the most suitable cultivar for P. interpunctella rearing in order to optimize the mass production of natural enemies.

This work examined three different phenotypes of the yellow-eel stage of the European eel Anguilla anguilla, broad-heads, narrow-heads and eels with an intermediate head shape. The aim was to see whether broad-headed A. anguilla, which generally consume harder, larger prey, such as crustaceans and fish, exerted greater bite force than the narrow-headed variant, which mainly consume soft, small prey such as chironomid larvae. It was found that in 99 yellow A. anguilla, in vivo bite force of broad-heads are higher compared with narrow-heads and intermediates. [ABSTRACT FROM AUTHOR]

During aquatic feeding salamanders use the hyobranchial apparatus to capture prey. The hyobranchial apparatus depresses the floor of the mouth, effectively expanding the oropharyngeal cavity and generating suction. Within the family Salamandridae, there is a wide range of ecological diversity, with salamanders being terrestrial, semi-aquatic, or aquatic as adults. The purpose of this research was to quantify the diverse morphology and suction feeding performance of aquatically feeding salamandrids. We hypothesized that a more robust hyobranchial apparatus morphology would yield increased aquatic feeding performance. When compared to semi-aquatic newts, the fully aquatic species Paramesotriton labiatus had greater mineralization of the hyobranchial apparatus, as well as relatively more narrow basibranchial and wider ceratobranchial I + II complexes. These morphological differences coincide with greater aquatic feeding performance. Kinematics from high-speed videography revealed that maximum mouth opening velocity and acceleration were approximately two and five times greater, respectively, in Paramesotriton , and hyobranchial depression acceleration was found to be approximately three times greater than in the semi-aquatic species Pleurodeles waltl, Notophthalmus viridescens, Triturus dobrogicus, and Cynops cyanurus . Using digital particle image velocimetry, peak and average fluid velocity generated in Paramesotriton during suction feeding events were found to be 0.5 m s −1 and 0.2 m s −1 , respectively, doubling that of all semi-aquatic species. These findings reveal that specialized morphology increases aquatic feeding performance in a fully aquatic newt. [ABSTRACT FROM AUTHOR]

The objective of the present study was to determine the oral motor capacity and the feeding performance of preterm newborn infants when they were permitted to start oral feeding. This was an observational and prospective study conducted on 43 preterm newborns admitted to the Neonatal Intensive Care Unit of UFSM, RS, Brazil. Exclusion criteria were the presence of head and neck malformations, genetic disease, neonatal asphyxia, intracranial hemorrhage, and kernicterus. When the infants were permitted to start oral feeding, non-nutritive sucking was evaluated by a speech therapist regarding force (strong vs weak), rhythm (rapid vs slow), presence of adaptive oral reflexes (searching, sucking and swallowing) and coordination between sucking, swallowing and respiration. Feeding performance was evaluated on the basis of competence (defined by rate of milk intake, mL/min) and overall transfer (percent ingested volume/total volume ordered). The speech therapist's evaluation showed that 33% of the newborns presented weak sucking, 23% slow rhythm, 30% absence of at least one adaptive oral reflex, and 14% with no coordination between sucking, swallowing and respiration. Mean feeding competence was greater in infants with strong sucking fast rhythm. The presence of sucking-swallowing-respiration coordination decreased the days for an overall transfer of 100%. Evaluation by a speech therapist proved to be a useful tool for the safe indication of the beginning of oral feeding for premature infants.

Cyclical starvation and refeeding in order to induce compensatory growth were investigated in juvenile yellow mystus (Hemibagrus nemurus). The fish (7.12 ± 0.14 g initial body weight and 8.87 ± 0.04 cm initial length) were starved for one (1DPW), two (2DPW), three (3DPW) or four (4DPW) days per week and otherwise fed ad libitum, while the control group was fed every day (no starvation, 0DPW). The indoor experiments lasted six weeks and followed a completely randomized design (5 treatments ×3 replications ×10 fish per replication). Growth performance, feed utilization, specific activity of digestive enzymes, carcass composition and muscle quality were used to compare the treatment effects. The fish in the 3DPW group exhibited clear compensation for the reduced number of feeding days and had increased body weight towards the end of the experiment. However, this compensation was insufficient to match the specific growth rate in the control group that was fed to satiation daily. The 3DPW treatment also maintained feed utilization parameters, specific activities of protein-, carbohydrate- and lipiddigesting enzymes, carcass composition and muscle quality, relative to the 0DPW control group. The remaining treatments gave some inferior characteristics when compared to 3DPW and 0DPW; the ranking of these feeding treatments was unexpected within the studied period. These findings suggest that cyclical starvation for three days per week (3DPW treatment) and refeeding could be used for rearing juvenile yellow mystus. The intermittent feeding schedule scheme is useful for labor management in the aquaculture production of yellow mystus. However, since partial compensatory growth was observed in the 2DPW and 4DPW groups, as indicated by the compensation coefficient, prolonged experiments on the accelerated growth rate should be conducted in further studies. [ABSTRACT FROM AUTHOR]

Sexual dimorphism attributed to niche divergence is often linked to differentiation between the sexes in both dietary resources and characters related to feeding and resource procurement. Although recent studies have indicated that southern sea otters (Enhydra lutris nereis) exhibit differences in dietary preferences as well as sexual dimorphism in skull size and shape, whether these intersexual differences translate to differentiation in feeding performances between the sexes remains to be investigated. To test the hypothesis that scaling patterns of bite force, a metric of feeding performance, differ between the sexes, we calculated theoretical bite forces for 55 naturally deceased male and female southern sea otters spanning the size ranges encountered over ontogeny. We then used standardized major axis regressions to simultaneously determine the scaling patterns of theoretical bite forces and skull components across ontogeny and assess whether these scaling patterns differed between the sexes. We found that positive allometric increases in theoretical bite force resulted from positive allometric increases in physiological cross-sectional area for the major jaw adductor muscle and mechanical advantage. Closer examination revealed that allometric increases in temporalis muscle mass and relative allometric decreases in out-lever lengths are driving these patterns. In our analysis of sexual dimorphism, we found that scaling patterns of theoretical bite force and morphological traits do not differ between the sexes. However, adult sea otters differed in their absolute bite forces, revealing that adult males exhibited greater bite forces as a result of their larger sizes. We found intersexual differences in biting ability that provide some support for the niche divergence hypothesis. Continued work in this field may link intersexual differences in feeding functional morphology with foraging ecology to show how niche divergence has the potential to reinforce sexual dimorphism in southern sea otters. [ABSTRACT FROM AUTHOR]

Insects infected with entomopathogenic fungi, experience physiological changes that influence their growth and immune defence. The potential of nine isolates of entomopathogenic fungi was evaluated after determining percent germination and relative conidial hydrophobicity. However, nutritional indices were evaluated after immersing eighth-instar Rhynchophorus ferrugineus larvae into each isolate suspension (1 × 107 conidia/mL). The results showed that isolates B6884 and M9374 had 44.51% and 39.02% higher conidial hydrophobicity compared with isolate I03011 (least virulent). The results of nutritional index assays revealed a significant reduction in growth indices after infection with different isolates. Compared with control, B6884 and M9374 greatly decreased larval growth by reducing the efficacy of conversion of ingested food (36%-47%) and Efficacy of conversion of digested food (50%-63%). Furthermore, only isolate B6884 induced 100% mortality within 12 days. Compared with control, isolate I03011, possessing the lowest conidial hydrophobicity, only reduced 0.29% of the efficacy of conversion of ingested food (ECI) and 0.48% of the efficacy of conversion of digested food (ECD). Similarly, transcriptomic analysis of genes related to the Red palm weevil (RPW) immune response, including pathogen recognition receptors (C-type lectin and endo-beta-1,4-glucanse), signal modulator (Serine protease-like protein), signal transductors (Calmodulin-like protein and EF-hand domain containing protein) and effectors (C-type lysozyme, Cathepsin L., Defensin-like protein, Serine carboxypeptidase, and Thaumatin-like protein), was significantly increased in larval samples infected with B6884 and M9374. These results suggest that for an isolate to be virulent, conidial hydrophobicity and germination should also be considered during pathogen selection, as these factors could significantly impact host growth and immune defence mechanisms. [ABSTRACT FROM AUTHOR]

In a fully randomized design, the effects of salinities at concentrations of 0 (control), 15, 35 and 50 ppt on feeding, growth performance, body composition, plasma glucose and cortisol levels in Asian sea bass (Lates calcarifer) of 34.36±0.41 gram initial weight were investigated in 300-liter pvc tanks. Feedinng was done to satiation twice a day for 30 days. At the end of the experiment, biometry was carried out and plasma and carcass samples were collected. The results showed significant difference in feeding and growth performance in 0 (control) with other treatments (p < 0.05). Carcass analyze also showed significantly higher moisture percentage compared to other treatments (p < 0.05). Glucose and cortisol values in 15 ppt treatment were significantly higher than at 35, 50 ppt treatment and 35 ppt and control treatments, respectively (p < 0.05). Overall, this study showed that this species was able to tolerate changes in salinity in the surrounding medium from seawater to brackish water through a period of 30 days and successfully adapt to freshwater without mortality. But, it could not be a good candidate for freshwater culture because of high energy expenditure for osmoregulation. [ABSTRACT FROM AUTHOR]

The eggs and larvae of the Mediterranean flour moth, Ephestia kuehniella Zeller are routinely utilized as a substitute host for the rearing of parasitoids and predators required for biological control. Nutritional performance, digestive enzymatic activities and growth indices of the fifth instar larvae of E. kuehniella were evaluated on flour of seven barley (Fajr 30, Reihan 03, 5 Shoor, Dasht, Sahra, Khorram and EH-83-7) and two wheat (Bam and Sepahan) cultivars at 25±1°C, 65±5% R.H., and a photoperiod of 16:8 (L: D) h. The results show that the highest larval growth index was observed when larvae were fed barley cultivar Reihan03. The highest and lowest values of larval weight gain were on barley cultivars EH-83-7 and Sahra, respectively. The highest value of efficiency of conversion of ingested food was in larvae reared on barley cultivar EH-83-7, whereas the lowest value was on barley cultivar Sahra. Moreover, the highest relative growth rate was detected on barley cultivar EH-83-7. The highest and lowest levels of amylolytic activity were on wheat cultivar Bam and barley cultivar Khorram, respectively. The highest proteolytic activity was observed in larvae reared on barley cultivar Fajr 30, whereas the lowest activity was on barley cultivars Dasht, Khorram and wheat cultivar Bam. Finally, barley cultivars EH-83-7 and Reihan 03 can be suggested as the most suitable cultivars for laboratory rearing of E. kuehniella. [ABSTRACT FROM AUTHOR]

The grape weevil, Naupactus xanthographus Germar (Coleoptera: Curculionidae), is a polyphagous insect which is a cause of important damage to several economically relevant crops, including grape ( Vitis vinifera) and avocado ( Persea americana), in several countries of Latin America. The larvae cause damage to the roots and rootlets of plants, and adults feed on leaves of their host plant. Despite its economic importance, there are few reports on the behavioral and nutritional ecology of this weevil. In this context, laboratory feeding and olfactometer bioassays with N. xanthographus were performed. The feeding performance was evaluated by measuring the weight variation of the insects after 1 and 6 h of feeding on grape or avocado leaves, respectively. After 1 h of feeding, insects showed no significant differences in weight increase. However, after a period of 6 h of feeding, males had continued feeding on grape leaves, but not on avocado leaves. Bioassays using a Y-tube olfactometer showed that males are attracted to volatiles of both host plants. Furthermore, starved males and females showed no preference to volatiles of grape or avocado. However, non-starved males and females preferred grape volatiles over avocado volatiles. Based on the combined results of the assays, we conclude that grape is preferred over avocado for N. xanthographus. Furthermore, this is the first report on the effect of starvation on the attraction to host plant volatiles in Curculionidae. [ABSTRACT FROM AUTHOR]

Nutritional indices of three geographic populations (Miandoab, Moghan and Kalposh) of the fifth instar of Spodoptera exigua (Lepidoptera: Noctuidae) on four sugar beet cultivars (Dorothea, Rozier, Persia and Perimer) were evaluated at 25 ± 1 °C, 65 ± 5 % RH and a 16:8 L:D photoperiod. The estimates of all the nutritional indices were affected by the interaction effect of the geographic population and the sugar beet cultivars. Miandoab population reared on Dorothea, and Moghan and Kalposh populations reared on Perimer had the highest approximate digestibility (AD). Miandoab and Kalposh populations reared on Rozier showed the highest efficiency of conversion of ingested food (ECI) and efficiency of conversion of digested food (ECD) values. Moghan population reared on Persia showed the lowest AD values and the highest ECI and ECD values. The present study showed that the nutritional indices of three populations, in most cases, were significantly different from with other, due to different environmental conditions that the pest collected from there. It is concluded that both geographic origins of the pest and host cultivar affected the nutritional indices of S. exigua larvae. [ABSTRACT FROM AUTHOR]

To evaluate how the Cry1Ac Bacillus thuringiensis (Bt) toxin and the ratio of dietary protein to carbohydrate (P:C) independently and jointly affect Helicoverpa zea (Boddie) larval feeding performance and behavior, we conducted no-choice and binary choice experiments using chemically defined diets. We tested two related strains of this polyphagous pest: a strain selected for resistance to Cry1Ac in the laboratory (GA-R), and its field-derived parent strain (GA). In no-choice tests, feeding performance in GA and GA-R was superior on a non-Cry1Ac 80P:20C diet compared to a non-Cry1Ac 35P:65C diet or an 80P:20C diet containing Cry1Ac. Based on consumption and position measurements in binary choice tests, larvae preferred the non-Cry1Ac 80P:20C diet over the other two diets mentioned above. However, the association between preference and performance was weaker when comparing the Cry1Ac 80P:20C diet versus a Cry1Ac 35P:65C diet, and when comparing the Cry1Ac 80P:20C diet versus the non-Cry1Ac 35P:65C diet. In all choice situations, consumption preference occurred mainly by the percentage of larvae that fed almost entirely from one or the other diet, rather than from variation in the extent of diet mixing by individuals. Resistance to Cry1Ac affected the balance between toxin avoidance and nutrient intake: larvae from the more resistant GA-R strain consumed significantly more of the Cry1Ac 80P:20C diet when paired with non-Cry1Ac 35P:65C diet, while GA larvae consumed more of the latter, though not significantly. The results show that dietary P:C ratio, Cry1Ac, and resistance to Cry1Ac affected feeding behavior and performance of H. zea larvae. [ABSTRACT FROM AUTHOR]

Being part of the elopomorph group of fishes, Anguillidae species show a leptocephalus larval stage. However, due to largely unknown spawning locations and habitats of their earliest life stages, as well as their transparency, these Anguilla larvae are rarely encountered in nature. Therefore, information regarding the early life history of these larvae, including their exogenous feeding strategy and feeding performance, is rather scarce. To better understand the structural basis and functional performance of larval feeding in captivity, the functional morphology of the cranial musculoskeletal system in pre- and first-feeding engyodontic leptocephali of the European eel ( Anguilla anguilla) was studied. A 3D reconstruction of the feeding apparatus (head of the leptocephali < 1 mm) was used to visualize and describe the musculoskeletal changes throughout these stages. To analyze the ontogenetic changes in the functionality of the feeding apparatus towards the active feeding phase, 3D data of joints, levers and muscles derived from the reconstructions were used to estimate bite and joint reaction forces (JRFs). Observing a maximum estimated bite force of about 65 μN (and corresponding JRFs of 260 μN), it can be hypothesized that leptocephalus larvae are functionally constrained to feed only on soft food particles. Additionally, potential prey items are size delimited, based on the theoretically estimated average gape of these larvae of about 100 μm. This hypothesis appears to be in line with recent observations of a diet consisting of small and/or gelatinous prey items (Hydrozoa, Thaliacea, Ctenophora, Polycystenia) found in the guts of euryodontic leptocephalus larvae. [ABSTRACT FROM AUTHOR]

Sediment resuspension during and after mechanical excavation of macrophytes may have a significant impact on resident fish populations. Unfortunately, little is known about the influence of this sediment on the respiratory performance and feeding abilities of fishes in New Zealand waterways. We examined the effects of suspended sediment (SS) concentrations previously observed after a large-scale macrophyte removal operation on oxygen consumption (MO2) and feeding rates of brown trout (Salmo trutta). MO2at 0 mg L−1, 150 mg L−1, 300 mg L−1, 450 mg L−1and 600 mg L−1of SS was measured using semi-closed respirometry. Feeding rates at the same SS concentrations were also measured using laboratory tank experiments. Results suggest that SS concentrations up to 600 mg L−1have no effect on MO2. Conversely, feeding rates were significantly reduced at 450 mg L−1(22% reduction) and 600 mg L−1(31% reduction), indicating that sediment concentrations above 450 mg L−1may negatively affect brown trout populations. [ABSTRACT FROM PUBLISHER]

Environmental variation drives ecological and phenotypic change. How predictable is differentiation in response to environmental change? Answering this question requires the development and testing of multifarious a priori predictions in natural systems. We employ this approach using Gobiomorus dormitor populations that have colonized inland blue holes differing in the availability of fish prey. We evaluated predictions of differences in demographics, habitat use, diet, locomotor and trophic morphology, and feeding kinematics and performance between G. dormitor populations inhabiting blue holes with and without fish prey. Populations of G. dormitor independently diverged between prey regimes, with broad agreement between observed differences and a priori predictions. For example, in populations lacking fish prey, we observed male-biased sex ratios, a greater use of shallow-water habitat, and larger population diet breadths as a result of greater individual diet specialization. Furthermore, we found predictable differences in body shape, mouth morphology, suction generation capacity, strike kinematics, and feeding performance on different prey types, consistent with the adaptation of G. dormitor to piscivory when coexisting with fish prey and to feeding on small invertebrates in their absence. The results of the present study suggest great potential in our ability to predict population responses to changing environments, which is an increasingly important capability in a human-dominated, ever-changing world. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114, 588-607. [ABSTRACT FROM AUTHOR]

Adult green turtles (Chelonia mydas) are unusual relative to other sea turtles in that they are predominately herbivorous. This herbivorous diet is reflected in the serrated morphology of their beak, bite performance and the relative morphometrics of their heads. Recent bite performance data in loggerhead turtles (Caretta caretta), which are known for their durophagous capability, have demonstrated that bite force is correlated with head morphometrics. The objective of this study was to characterize bite force in green turtles and correlate bite performance with head and carapace morphometrics. We predicted that maximum bite force in green turtles would be less in magnitude relative to loggerheads, but would be positively correlated with head morphometrics. Therefore, mass, straight carapace length, straight carapace width, greatest head width, height, and length were collected with bite force from free-ranging green turtles from Punta Abreojos, Baja California Sur, Mexico and Otsuchi, Japan. Subjects ranged from 10.9 to 48kg, with straight carapace length and width ranged from 40.6cm to 71.9cm (mean=56.3±8.5cm) and from 33.5cm to 55.9cm (mean=44.8±5.7cm), respectively. A bite force apparatus was used to collect bite performance from subjects. The maximum bite force was 303N. Mean head width, head height, and head length were 8.7±1.2, 8.2±1.1, and 11.5±1.5cm, respectively. Bite force was lower in magnitude than reported for loggerhead turtles as predicted but still strong enough to process algal and plant matter, as well as crush many hard prey items. Simultaneous measurements of body and head size, and the use of non-linear reduced major axis regression, show that bite force scaled isometrically relative to body size and head size. Simple correlation showed that all logged transformed morphometrics were good predictors of logged bite performance, but an AICc-based weighted regression showed that body mass, followed by head width and head height, were better predictors of bite force than carapace size. [ABSTRACT FROM AUTHOR]

Aim To evaluate the feeding behaviour and performance of preterm neonates receiving feeds by paladai (a small beaked receptacle). Methods We enrolled stable neonates - 10 each in 28-30 weeks [group I] and 31-32 weeks gestation [group II], and offered them paladai feeds. We recorded the feeding sessions on alternate days until they were on full enteral feeds. The outcome variables were (1) feeding behaviour, as assessed by changes in states of wakefulness, oromotor functions and coordination between breathing and swallowing; (2) feeding performance, as assessed by proficiency and efficiency. Results A total of 47 and 27 sessions were studied in groups I and II, respectively. The median postconceptional age ( PCA) at start of paladai feeding was 30 (range, 29-32) and 32 (31-32) weeks in the two groups. The infants accepted paladai feedings in all behavioural states. Incoordination between feeding and breathing was observed in about 25% of the sessions in both the groups. We observed a rapid improvement in feeding performance with experience - the median proficiency improved from 5.5 to 10.1 mL/min and 6.2-11.5 mL/min in groups I and II, respectively. The proficiency of group I infants at a median PCA of 30.9 weeks was higher than that of group II infants at median PCA 31.7 weeks. Conclusion Stable preterm neonates can be fed with paladai from 30 weeks PCA. The oropharyngeal ability is possibly influenced more by the postnatal experience than by maturity at birth. [ABSTRACT FROM AUTHOR]